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  • Revisiting the Generations

    - by Row Henson
    I was asked earlier this year to contribute an article to the IHRIM publication – Workforce Solutions Review.  My topic focused on the reality of the Gen Y population 10 years after their entry into the workforce.  Below is an excerpt from that article: It seems like yesterday that we were all talking about the entry of the Gen Y'ers into the workforce and what a radical change that would have on how we attract, retain, motivate, reward, and engage this new, younger segment of the workforce.  We all heard and read that these youngsters would be more entrepreneurial than their predecessors – the Gen X'ers – who were said to be more loyal to their profession than their employer. And, we heard that these “youngsters” would certainly be far less loyal to their employers than the Baby Boomers or even earlier Traditionalists. It was also predicted that – at least for the developed parts of the world – they would be more interested in work/life balance than financial reward; they would need constant and immediate reinforcement and recognition and we would be lucky to have them in our employment for two to three years. And, to keep them longer than that we would need to promote them often so they would be continuously learning since their long-term (10-year) goal would be to own their own business or be an independent consultant.  Well, it occurred to me recently that the first of the Gen Y'ers are now in their early 30s and it is time to look back on some of these predictions. Many really believed the Gen Y'ers would enter the workforce with an attitude – expect everything to be easy for them – have their employers meet their demands or move to the next employer, and I believe that we can now say that, generally, has not been the case. Speaking from personal experience, I have mentored a number of Gen Y'ers and initially felt that with a 40-year career in Human Resources and Human Resources Technology – I could share a lot with them. I found out very quickly that I was learning at least as much from them! Some of the amazing attributes I found from these under-30s was their fearlessness, ease of which they were able to multi-task, amazing energy and great technical savvy. They were very comfortable with collaborating with colleagues from both inside the company and peers outside their organization to problem-solve quickly. Most were eager to learn and willing to work hard.  This brings me to the generation that will follow the Gen Y'ers – the Generation Z'ers – those born after 1998. We have come full circle. If we look at the Silent Generation or Traditionalists, we find a workforce that preceded the television and even very early telephones. We Baby Boomers (as I fall right squarely in this category) remembered the invention of the television and telephone – but laptop computers and personal digital assistants (PDAs) were a thing of “StarTrek” and other science fiction movies and publications. Certainly, the Gen X'ers and Gen Y'ers grew up with the comfort of these devices just as we did with calculators. But, what of those under the age of 10 – how will the workplace look in 15 more years and what type of workforce will be required to operate in the mobile, global, virtual world. I spoke to a friend recently who had her four-year-old granddaughter for a visit. She said she found her in the den in front of the TV trying to use her hand to get the screen to move! So, you see – we have come full circle. The under-70 Traditionalist grew up in a world without TV and the Generation Z'er may never remember the TV we knew just a few years ago. As with every generation – we spend much time generalizing on their characteristics. The most important thing to remember is every generation – just like every individual – is different. The important thing for those of us in Human Resources to remember is that one size doesn’t fit all. What motivates one employee to come to work for you and stay there and be productive is very different than what the next employee is looking for and the organization that can provide this fluidity and flexibility will be the survivor for generations to come. And, finally, just when we think we have it figured out, a multitude of external factors such as the economy, world politics, industries, and technologies we haven’t even thought about will come along and change those predictions. As I reach retirement age – I do so believing that our organizations are in good hands with the generations to follow – energetic, collaborative and capable of working hard while still understanding the need for balance at work, at home and in the community! 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  • LINQ and ArcObjects

    - by Marko Apfel
    Motivation LINQ (language integrated query) is a component of the Microsoft. NET Framework since version 3.5. It allows a SQL-like query to various data sources such as SQL, XML etc. Like SQL also LINQ to SQL provides a declarative notation of problem solving – i.e. you don’t need describe in detail how a task could be solved, you describe what to be solved at all. This frees the developer from error-prone iterator constructs. Ideally, of course, would be to access features with this way. Then this construct is conceivable: var largeFeatures = from feature in features where (feature.GetValue("SHAPE_Area").ToDouble() > 3000) select feature; or its equivalent as a lambda expression: var largeFeatures = features.Where(feature => (feature.GetValue("SHAPE_Area").ToDouble() > 3000)); This requires an appropriate provider, which manages the corresponding iterator logic. This is easier than you might think at first sight - you have to deliver only the desired entities as IEnumerable<IFeature>. LINQ automatically establishes a state machine in the background, whose execution is delayed (deferred execution) - when you are really request entities (foreach, Count (), ToList (), ..) an instantiation processing takes place, although it was already created at a completely different place. Especially in multiple iteration through entities in the first debuggings you are rubbing your eyes when the execution pointer jumps magically back in the iterator logic. Realization A very concise logic for constructing IEnumerable<IFeature> can be achieved by running through a IFeatureCursor. You return each feature via yield. For an easier usage I have put the logic in an extension method Getfeatures() for IFeatureClass: public static IEnumerable<IFeature> GetFeatures(this IFeatureClass featureClass, IQueryFilter queryFilter, RecyclingPolicy policy) { IFeatureCursor featureCursor = featureClass.Search(queryFilter, RecyclingPolicy.Recycle == policy); IFeature feature; while (null != (feature = featureCursor.NextFeature())) { yield return feature; } //this is skipped in unit tests with cursor-mock if (Marshal.IsComObject(featureCursor)) { Marshal.ReleaseComObject(featureCursor); } } So you can now easily generate the IEnumerable<IFeature>: IEnumerable<IFeature> features = _featureClass.GetFeatures(RecyclingPolicy.DoNotRecycle); You have to be careful with the recycling cursor. After a delayed execution in the same context it is not a good idea to re-iterated on the features. In this case only the content of the last (recycled) features is provided and all the features are the same in the second set. Therefore, this expression would be critical: largeFeatures.ToList(). ForEach(feature => Debug.WriteLine(feature.OID)); because ToList() iterates once through the list and so the the cursor was once moved through the features. So the extension method ForEach() always delivers the same feature. In such situations, you must not use a recycling cursor. Repeated executions of ForEach() is not a problem, because for every time the state machine is re-instantiated and thus the cursor runs again - that's the magic already mentioned above. Perspective Now you can also go one step further and realize your own implementation for the interface IEnumerable<IFeature>. This requires that only the method and property to access the enumerator have to be programmed. In the enumerator himself in the Reset() method you organize the re-executing of the search. This could be archived with an appropriate delegate in the constructor: new FeatureEnumerator<IFeatureclass>(_featureClass, featureClass => featureClass.Search(_filter, isRecyclingCursor)); which is called in Reset(): public void Reset() { _featureCursor = _resetCursor(_t); } In this manner, enumerators for completely different scenarios could be implemented, which are used on the client side completely identical like described above. Thus cursors, selection sets, etc. merge into a single matter and the reusability of code is increasing immensely. On top of that in automated unit tests an IEnumerable could be mocked very easily - a major step towards better software quality. Conclusion Nevertheless, caution should be exercised with these constructs in performance-relevant queries. Because of managing a state machine in the background, a lot of overhead is created. The processing costs additional time - about 20 to 100 percent. In addition, working without a recycling cursor is fast a performance gap. However declarative LINQ code is much more elegant, flawless and easy to maintain than manually iterating, compare and establish a list of results. The code size is reduced according to experience an average of 75 to 90 percent! So I like to wait a few milliseconds longer. As so often it has to be balanced between maintainability and performance - which for me is gaining in priority maintainability. In times of multi-core processors, the processing time of most business processes is anyway not dominated by code execution but by waiting for user input. Demo source code The source code for this prototype with several unit tests, you can download here: https://github.com/esride-apf/Linq2ArcObjects. .

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  • Why won't USB 3.0 external hard drive run at USB 3.0 speeds?

    - by jgottula
    I recently purchased a PCI Express x1 USB 3.0 controller card (containing the NEC USB 3.0 controller) with the intent of using a USB 3.0 external hard drive with my Linux box. I installed the card in an empty PCIe slot on my motherboard, connected the card to a power cable, strung a USB 3.0 cable between one of the new ports and my external HDD, and connected the HDD to a wall socket for power. Booting the system, the drive works 100% as intended, with the one exception of throughput: rather than using SuperSpeed 4.8 Gbps connectivity, it seems to be falling back to High Speed 480 Mbps USB 2.0-style throughput. Disk Utility shows it as a 480 Mbps device, and running a couple Disk Utility and dd benchmarks confirms that the drive fails to exceed ~40 MB/s (the approximate limit of USB 2.0), despite it being an SSD capable of far more than that. When I connect my USB 3.0 HDD, dmesg shows this: [ 3923.280018] usb 3-2: new high speed USB device using ehci_hcd and address 6 where I would expect to find this: [ 3923.280018] usb 3-2: new SuperSpeed USB device using xhci_hcd and address 6 My system was running on kernel 2.6.35-25-generic at the time. Then, I stumbled upon this forum thread by an individual who found that a bug, which was present in kernels prior to 2.6.37-rc5, could be the culprit for this type of problem. Consequently, I installed the 2.6.37-generic mainline Ubuntu kernel to determine if the problem would go away. It didn't, so I tried 2.6.38-rc3-generic, and even the 2.6.38 nightly from 2010.02.01, to no avail. In short, I'm trying to determine why, with USB 3.0 support in the kernel, my USB 3.0 drive fails to run at full SuperSpeed throughput. See the comments under this question for additional details. Output that might be relevant to the problem (when booting from 2.6.38-rc3): Relevant lines from dmesg: [ 19.589491] xhci_hcd 0000:03:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17 [ 19.589512] xhci_hcd 0000:03:00.0: setting latency timer to 64 [ 19.589516] xhci_hcd 0000:03:00.0: xHCI Host Controller [ 19.589623] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 12 [ 19.650492] xhci_hcd 0000:03:00.0: irq 17, io mem 0xf8100000 [ 19.650556] xhci_hcd 0000:03:00.0: irq 47 for MSI/MSI-X [ 19.650560] xhci_hcd 0000:03:00.0: irq 48 for MSI/MSI-X [ 19.650563] xhci_hcd 0000:03:00.0: irq 49 for MSI/MSI-X [ 19.653946] xHCI xhci_add_endpoint called for root hub [ 19.653948] xHCI xhci_check_bandwidth called for root hub Relevant section of sudo lspci -v: 03:00.0 USB Controller: NEC Corporation uPD720200 USB 3.0 Host Controller (rev 03) (prog-if 30) Flags: bus master, fast devsel, latency 0, IRQ 17 Memory at f8100000 (64-bit, non-prefetchable) [size=8K] Capabilities: [50] Power Management version 3 Capabilities: [70] MSI: Enable- Count=1/8 Maskable- 64bit+ Capabilities: [90] MSI-X: Enable+ Count=8 Masked- Capabilities: [a0] Express Endpoint, MSI 00 Capabilities: [100] Advanced Error Reporting Capabilities: [140] Device Serial Number ff-ff-ff-ff-ff-ff-ff-ff Capabilities: [150] #18 Kernel driver in use: xhci_hcd Kernel modules: xhci-hcd Relevant section of sudo lsusb -v: Bus 012 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 3.00 bDeviceClass 9 Hub bDeviceSubClass 0 Unused bDeviceProtocol 3 bMaxPacketSize0 9 idVendor 0x1d6b Linux Foundation idProduct 0x0003 3.0 root hub bcdDevice 2.06 iManufacturer 3 Linux 2.6.38-020638rc3-generic xhci_hcd iProduct 2 xHCI Host Controller iSerial 1 0000:03:00.0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 25 bNumInterfaces 1 bConfigurationValue 1 iConfiguration 0 bmAttributes 0xe0 Self Powered Remote Wakeup MaxPower 0mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 9 Hub bInterfaceSubClass 0 Unused bInterfaceProtocol 0 Full speed (or root) hub iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0004 1x 4 bytes bInterval 12 Hub Descriptor: bLength 9 bDescriptorType 41 nNbrPorts 4 wHubCharacteristic 0x0009 Per-port power switching Per-port overcurrent protection TT think time 8 FS bits bPwrOn2PwrGood 10 * 2 milli seconds bHubContrCurrent 0 milli Ampere DeviceRemovable 0x00 PortPwrCtrlMask 0xff Hub Port Status: Port 1: 0000.0100 power Port 2: 0000.0100 power Port 3: 0000.0100 power Port 4: 0000.0100 power Device Status: 0x0003 Self Powered Remote Wakeup Enabled Full, non-verbose lsusb: Bus 012 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 011 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 010 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 009 Device 003: ID 04d9:0702 Holtek Semiconductor, Inc. Bus 009 Device 002: ID 046d:c068 Logitech, Inc. G500 Laser Mouse Bus 009 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 006: ID 174c:5106 ASMedia Technology Inc. Bus 003 Device 004: ID 0bda:0151 Realtek Semiconductor Corp. Mass Storage Device (Multicard Reader) Bus 003 Device 002: ID 058f:6366 Alcor Micro Corp. Multi Flash Reader Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 006: ID 1687:0163 Kingmax Digital Inc. Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 002: ID 046d:081b Logitech, Inc. Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Full output: full dmesg full lspci full lsusb

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  • Oracle Cloud Applications: The Right Ingredients Baked In

    - by yaldahhakim
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Oracle Cloud Applications: The Right Ingredients Baked In Eggs, flour, milk, and sugar. The magic happens when you mix these ingredients together. The same goes for the hottest technologies fast changing how IT impacts our organizations today: cloud, social, mobile, and big data. By themselves they’re pretty good; combining them with a great recipe is what unlocks real transformation power. Choosing the right cloud can be very similar to choosing the right cake. First consider comparing the core ingredients that go into baking a cake and the core design principles in building a cloud-based application. For instance, if flour is the base ingredient of a cake, then rich functionality that spans complete business processes is the base of an enterprise-grade cloud. Cloud computing is more than just consuming an "application as service", and having someone else manage it for you. Rather, the value of cloud is about making your business more agile in the marketplace, and shortening the time it takes to deliver and adopt new innovation. It’s also about improving not only the efficiency at which we communicate but the actual quality of the information shared as well. Data from different systems, like ingredients in a cake, must also be blended together effectively and evaluated through a consolidated lens. When this doesn’t happen, for instance when data in your sales cloud doesn't seamlessly connect with your order management and other “back office” applications, the speed and quality of information can decrease drastically. It’s like mixing ingredients in a strainer with a straw – you just can’t bring it all together without losing something. Mixing ingredients is similar to bringing clouds together, and co-existing cloud applications with traditional on premise applications. This is where a shared services  platform built on open standards and Service Oriented Architecture (SOA) is critical. It’s essentially a cloud recipe that calls for not only great ingredients, but also ingredients you can get locally or most likely already have in your kitchen (or IT shop.) Open standards is the best way to deliver a cost effective, durable application integration strategy – regardless of where your apps are deployed. It’s also the best way to build your own cloud applications, or extend the ones you consume from a third party. Just like using standard ingredients and tools you already have in your kitchen, a standards based cloud enables your IT resources to ensure a cloud works easily with other systems. Your IT staff can also make changes using tools they are already familiar with. Or even more ideal, enable business users to actually tailor their experience without having to call upon IT for help at all. This frees IT resources to focus more on developing new innovative services for the organization vs. run and maintain. Carrying the cake analogy forward, you need to add all the ingredients in before you bake it. The same is true with a modern cloud. To harness the full power of cloud, you can’t leave out some of the most important ingredients and just layer them on top later. This is what a lot of our niche competitors have done when it comes to social, mobile, big data and analytics, and other key technologies impacting the way we do business. The transformational power of these technology trends comes from having a strategy from the get-go that combines them into a winning recipe, and delivers them in a unified way. In looking at ways Oracle’s cloud is different from other clouds – not only is breadth of functionality rich across functional pillars like CRM, HCM, ERP, etc. but it embeds social, mobile, and rich intelligence capabilities where they make the most sense across business processes. This strategy enables the Oracle Cloud to uniquely deliver on all three of these dimensions to help our customers unlock the full power of these transformational technologies.

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  • Building a Repository Pattern against an EF 5 EDMX Model - Part 1

    - by Juan
    I am part of a year long plus project that is re-writing an existing application for a client.  We have decided to develop the project using Visual Studio 2012 and .NET 4.5.  The project will be using a number of technologies and patterns to include Entity Framework 5, WCF Services, and WPF for the client UI.This is my attempt at documenting some of the successes and failures that I will be coming across in the development of the application.In building the data access layer we have to access a database that has already been designed by a dedicated dba. The dba insists on using Stored Procedures which has made the use of EF a little more difficult.  He will not allow direct table access but we did manage to get him to allow us to use Views.  Since EF 5 does not have good support to do Code First with Stored Procedures, my option was to create a model (EDMX) against the existing database views.   I then had to go select each entity and map the Insert/Update/Delete functions to their respective stored procedure. The next step after I had completed mapping the stored procedures to the entities in the EDMX model was to figure out how to build a generic repository that would work well with Entity Framework 5.  After reading the blog posts below, I adopted much of their code with some changes to allow for the use of Ninject for dependency injection.http://www.tcscblog.com/2012/06/22/entity-framework-generic-repository/ http://www.tugberkugurlu.com/archive/generic-repository-pattern-entity-framework-asp-net-mvc-and-unit-testing-triangle IRepository.cs public interface IRepository : IDisposable where T : class { void Add(T entity); void Update(T entity, int id); T GetById(object key); IQueryable Query(Expression> predicate); IQueryable GetAll(); int SaveChanges(); int SaveChanges(bool validateEntities); } GenericRepository.cs public abstract class GenericRepository : IRepository where T : class { public abstract void Add(T entity); public abstract void Update(T entity, int id); public abstract T GetById(object key); public abstract IQueryable Query(Expression> predicate); public abstract IQueryable GetAll(); public int SaveChanges() { return SaveChanges(true); } public abstract int SaveChanges(bool validateEntities); public abstract void Dispose(); } One of the issues I ran into was trying to do an update. I kept receiving errors so I posted a question on Stack Overflow http://stackoverflow.com/questions/12585664/an-object-with-the-same-key-already-exists-in-the-objectstatemanager-the-object and came up with the following hack. If someone has a better way, please let me know. DbContextRepository.cs public class DbContextRepository : GenericRepository where T : class { protected DbContext Context; protected DbSet DbSet; public DbContextRepository(DbContext context) { if (context == null) throw new ArgumentException("context"); Context = context; DbSet = Context.Set(); } public override void Add(T entity) { if (entity == null) throw new ArgumentException("Cannot add a null entity."); DbSet.Add(entity); } public override void Update(T entity, int id) { if (entity == null) throw new ArgumentException("Cannot update a null entity."); var entry = Context.Entry(entity); if (entry.State == EntityState.Detached) { var attachedEntity = DbSet.Find(id); // Need to have access to key if (attachedEntity != null) { var attachedEntry = Context.Entry(attachedEntity); attachedEntry.CurrentValues.SetValues(entity); } else { entry.State = EntityState.Modified; // This should attach entity } } } public override T GetById(object key) { return DbSet.Find(key); } public override IQueryable Query(Expression> predicate) { return DbSet.Where(predicate); } public override IQueryable GetAll() { return Context.Set(); } public override int SaveChanges(bool validateEntities) { Context.Configuration.ValidateOnSaveEnabled = validateEntities; return Context.SaveChanges(); } #region IDisposable implementation public override void Dispose() { if (Context != null) { Context.Dispose(); GC.SuppressFinalize(this); } } #endregion IDisposable implementation } At this point I am able to start creating individual repositories that are needed and add a Unit of Work.  Stay tuned for the next installment in my path to creating a Repository Pattern against EF5.

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  • Is software support an option for your career?

    - by Maria Sandu
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 If you have a technical background, why should you choose a career in support? We have invited Serban to answer these questions and to give us an overview of one of the biggest technical teams in Oracle Romania. He’s been with Oracle for 7 years leading the local PeopleSoft Financials & Supply Chain Support team. Back in 2013 Serban started building a new support team in Romania – Fusion HCM. His current focus is building a strong support team for Fusion HCM, latest solution for Business HR Professionals from Oracle. The solution is offered both on Premise (customer site installation) but more important as a Cloud offering – SaaS.  So, why should a technical person choose Software Support over other technical areas?  “I think it is mainly because of the high level of technical skills required to provide the best technical solutions to our customers. Oracle Software Support covers complex solutions going from Database or Middleware to a vast area of business applications (basically covering any needs that a large enterprise may have). Working with such software requires very strong skills both technical and functional for the different areas, going from Finance, Supply Chain Management, Manufacturing, Sales to other very specific business processes. Our customers are large enterprises that already have a support layer inside their organization and therefore the Oracle Technical Support Engineers are working with highly specialized staff (DBA’s, System/Application Admins, Implementation Consultants). This is a very important aspect for our engineers because they need to be highly skilled to match our customer’s specialist’s expectations”.  What’s the career path in your team? “Technical Analysts joining our teams have a clear growth path. The main focus is to become a master of the product they will support. I think one need 1 or 2 years to reach a good level of understanding the product and delivering optimal solutions because of the complexity of our products. At a later stage, engineers can choose their professional development areas based on the business needs and preferences and then further grow towards as technical expert or a management role. We have analysts that have more than 15 years of technical expertise and they still learn and grow in technical area. Important fact is, due to the expansion of the Romanian Software support center, there are various management opportunities. So, if you want to leverage your experience and if you want to have people management responsibilities Oracle Software Support is the place to be!”  Our last question to Serban was about the benefits of being part of Oracle Software Support. Here is what he said: “We believe that Oracle delivers “State of the art” Support level to our customers. This is not possible without high investment in our staff. We commit from the start to support any technical analyst that joins us (being junior or very senior) with any training needs they have for their job. We have various technical trainings as well as soft-skills trainings required for a customer facing professional to be successful in his role. Last but not least, we’re aiming to make Oracle Romania SW Support a global center of excellence which means we’re investing a lot in our employees.”  If you’re looking for a job where you can combine your strong technical skills with customer interaction Oracle Software Support is the place to be! Send us your CV at [email protected]. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Database Partitioning and Multiple Data Source Considerations

    - by Jeffrey McDaniel
    With the release of P6 Reporting Database 3.0 partitioning was added as a feature to help with performance and data management.  Careful investigation of requirements should be conducting prior to installation to help improve overall performance throughout the lifecycle of the data warehouse, preventing future maintenance that would result in data loss. Before installation try to determine how many data sources and partitions will be required along with the ranges.  In P6 Reporting Database 3.0 any adjustments outside of defaults must be made in the scripts and changes will require new ETL runs for each data source.  Considerations: 1. Standard Edition or Enterprise Edition of Oracle Database.   If you aren't using Oracle Enterprise Edition Database; the partitioning feature is not available. Multiple Data sources are only supported on Enterprise Edition of Oracle   Database. 2. Number of Data source Ids for partitioning during configuration.   This setting will specify how many partitions will be allocated for tables containing data source information.  This setting requires some evaluation prior to installation as       there are repercussions if you don't estimate correctly.   For example, if you configured the software for only 2 data sources and the partition setting was set to 2, however along came a 3rd data source.  The necessary steps to  accommodate this change are as follows: a) By default, 3 partitions are configured in the Reporting Database scripts. Edit the create_star_tables_part.sql script located in <installation directory>\star\scripts   and search for partition.  You’ll see P1, P2, P3.  Add additional partitions and sub-partitions for P4 and so on. These will appear in several areas.  (See P6 Reporting Database 3.0 Installation and Configuration guide for more information on this and how to adjust partition ranges). b) Run starETL -r.  This will recreate each table with the new partition key.  The effect of this step is that all tables data will be lost except for history related tables.   c) Run starETL for each of the 3 data sources (with the data source # (starETL.bat "-s2" -as defined in P6 Reporting Database 3.0 Installation and Configuration guide) The best strategy for this setting is to overestimate based on possible growth.  If during implementation it is deemed that there are atleast 2 data sources with possibility for growth, it is a better idea to set this setting to 4 or 5, allowing room for the future and preventing a ‘start over’ scenario. 3. The Number of Partitions and the Number of Months per Partitions are not specific to multi-data source.  These settings work in accordance to a sub partition of larger tables with regard to time related data.  These settings are dataset specific for optimization.  The number of months per partition is self explanatory, optimally the smaller the partition, the better query performance so if the dataset has an extremely large number of spread/history records, a lower number of months is optimal.  Working in accordance with this setting is the number of partitions, this will determine how many "buckets" will be created per the number of months setting.  For example, if you kept the default for # of partitions of 3, and select 2 months for each partitions you would end up with: -1st partition, 2 months -2nd partition, 2 months -3rd partition, all the remaining records Therefore with records to this setting, it is important to analyze your source db spread ranges and history settings when determining the proper number of months per partition and number of partitions to optimize performance.  Also be aware the DBA will need to monitor when these partition ranges will fill up and when additional partitions will need to be added.  If you get to the final range partition and there are no additional range partitions all data will be included into the last partition. 

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  • How can I implement a database TableView like thing in C++?

    - by Industrial-antidepressant
    How can I implement a TableView like thing in C++? I want to emulating a tiny relation database like thing in C++. I have data tables, and I want to transform it somehow, so I need a TableView like class. I want filtering, sorting, freely add and remove items and transforming (ex. view as UPPERCASE and so on). The whole thing is inside a GUI application, so datatables and views are attached to a GUI (or HTML or something). So how can I identify an item in the view? How can I signal it when the table is changed? Is there some design pattern for this? Here is a simple table, and a simple data item: #include <string> #include <boost/multi_index_container.hpp> #include <boost/multi_index/member.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/random_access_index.hpp> using boost::multi_index_container; using namespace boost::multi_index; struct Data { Data() {} int id; std::string name; }; struct row{}; struct id{}; struct name{}; typedef boost::multi_index_container< Data, indexed_by< random_access<tag<row> >, ordered_unique<tag<id>, member<Data, int, &Data::id> >, ordered_unique<tag<name>, member<Data, std::string, &Data::name> > > > TDataTable; class DataTable { public: typedef Data item_type; typedef TDataTable::value_type value_type; typedef TDataTable::const_reference const_reference; typedef TDataTable::index<row>::type TRowIndex; typedef TDataTable::index<id>::type TIdIndex; typedef TDataTable::index<name>::type TNameIndex; typedef TRowIndex::iterator iterator; DataTable() : row_index(rule_table.get<row>()), id_index(rule_table.get<id>()), name_index(rule_table.get<name>()), row_index_writeable(rule_table.get<row>()) { } TDataTable::const_reference operator[](TDataTable::size_type n) const { return rule_table[n]; } std::pair<iterator,bool> push_back(const value_type& x) { return row_index_writeable.push_back(x); } iterator erase(iterator position) { return row_index_writeable.erase(position); } bool replace(iterator position,const value_type& x) { return row_index_writeable.replace(position, x); } template<typename InputIterator> void rearrange(InputIterator first) { return row_index_writeable.rearrange(first); } void print_table() const; unsigned size() const { return row_index.size(); } TDataTable rule_table; const TRowIndex& row_index; const TIdIndex& id_index; const TNameIndex& name_index; private: TRowIndex& row_index_writeable; }; class DataTableView { DataTableView(const DataTable& source_table) {} // How can I implement this? // I want filtering, sorting, signaling upper GUI layer, and sorting, and ... }; int main() { Data data1; data1.id = 1; data1.name = "name1"; Data data2; data2.id = 2; data2.name = "name2"; DataTable table; table.push_back(data1); DataTable::iterator it1 = table.row_index.iterator_to(table[0]); table.erase(it1); table.push_back(data1); Data new_data(table[0]); new_data.name = "new_name"; table.replace(table.row_index.iterator_to(table[0]), new_data); for (unsigned i = 0; i < table.size(); ++i) std::cout << table[i].name << std::endl; #if 0 // using scenarios: DataTableView table_view(table); table_view.fill_from_source(); // synchronization with source table_view.remove(data_item1); // remove item from view table_view.add(data_item2); // add item from source table table_view.filter(filterfunc); // filtering table_view.sort(sortfunc); // sorting // modifying from source_able, hot to signal the table_view? // FYI: Table view is atteched to a GUI item table.erase(data); table.replace(data); #endif return 0; }

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  • Deep Cloning C++ class that inherits CCNode in Cocos2dx

    - by A Devanney
    I stuck with something in Cocos2dx ... I'm trying to deep clone one of my classes that inherits CCNode. Basically i have.... GameItem* pTemp = new GameItem(*_actualItem); // loops through all the blocks in gameitem and updates their position pTemp->moveDown(); // if in boundary or collision etc... if (_gameBoard->isValidMove(pTemp)) { _actualItem = pTemp; // display the position CCLog("pos (1) --- (X : %d,Y : %d)", _actualItem->getGridX(),_actualItem->getGridY()); } Then doesn't work, because the gameitem inherits CCNode and has the collection of another class that also inherits CCNode. its just creating a shallow copy and when you look at children of the gameitem node in the copy, just point to the original? class GameItem : public CCNode { // maps to the actual grid position of the shape CCPoint* _rawPosition; // tracks the current grid position int _gridX, _gridY; // tracks the change if the item has moved CCPoint _offset; public: //constructors GameItem& operator=(const GameItem& item); GameItem(Shape shape); ... } then in the implementation.... GameItem& GameItem::operator=(const GameItem& item) { _gridX = item.getGridX(); _gridY = item.getGridY(); _offset = item.getOffSet(); _rawPosition = item.getRawPosition(); // how do i copy the node? return *this; } // shape contains an array of position for the game character GameItem::GameItem(Shape shape) { _rawPosition = shape.getShapePositions(); //loop through all blocks in position for (int i = 0; i < 7; i++) { // get the position of the first block in the shape and add to the position of the first block int x = (int) (getRawPosition()[i].x + getGridX()); int y = (int) (getRawPosition()[i].y + getGridY()); //instantiate a block with the position and type Block* block = Block::blockWithFile(x,y,(i+1), shape); // add the block to the this node this->addChild(block); } } And for clarity here is the block class class Block : public CCNode{ private: // using composition over inheritance CCSprite* _sprite; // tracks the current grid position int _gridX, _gridY; // used to store actual image number int _blockNo; public: Block(void); Block(int gridX, int gridY, int blockNo); Block& operator=(const Block& block); // static constructor for the creation of a block static Block* blockWithFile(int gridX, int gridY,int blockNo, Shape shape); ... } The blocks implementation..... Block& Block::operator=(const Block& block) { _sprite = new CCSprite(*block._sprite); _gridX = block._gridX; _gridY = block._gridY; _blockNo = block._blockNo; //again how to clone CCNode? return *this; } Block* Block::blockWithFile(int gridX, int gridY,int blockNo, Shape shape) { Block* block = new Block(); if (block && block->initBlockWithFile(gridX, gridY,blockNo, shape)) { block->autorelease(); return block; } CC_SAFE_DELETE(block); return NULL; } bool Block::initBlockWithFile(int gridX, int gridY,int blockNo, Shape shape) { setGridX(gridX); setGridY(gridY); setBlockNo(blockNo); const char* characterImg = helperFunctions::Format(shape.getFileName(),blockNo); // add to the spritesheet CCTexture2D* gameArtTexture = CCTextureCache::sharedTextureCache()->addImage("Character.pvr.ccz"); CCSpriteBatchNode::createWithTexture(gameArtTexture); // block settings _sprite = CCSprite::createWithSpriteFrameName(characterImg); // set the position of the block and add it to the layer this->setPosition(CONVERTGRIDTOACTUALPOS_X_Y(gridX,gridY)); this->addChild(_sprite); return true; } Any ideas are welcome at this point!! thanks

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  • Data Source Security Part 2

    - by Steve Felts
    In Part 1, I introduced the default security behavior and listed the various options available to change that behavior.  One of the key topics to understand is the difference between directly using database user and password values versus mapping from WLS user and password to the associated database values.   The direct use of database credentials is relatively new to WLS, based on customer feedback.  Some of the trade-offs are covered in this article. Credential Mapping vs. Database Credentials Each WLS data source has a credential map that is a mechanism used to map a key, in this case a WLS user, to security credentials (user and password).  By default, when a user and password are specified when getting a connection, they are treated as credentials for a WLS user, validated, and are converted to a database user and password using a credential map associated with the data source.  If a matching entry is not found in the credential map for the data source, then the user and password associated with the data source definition are used.  Because of this defaulting mechanism, you should be careful what permissions are granted to the default user.  Alternatively, you can define an invalid default user to ensure that no one can accidentally get through (in this case, you would need to set the initial capacity for the pool to zero so that the pool is populated only by valid users). To create an entry in the credential map: 1) First create a WLS user.  In the administration console, go to Security realms, select your realm (e.g., myrealm), select Users, and select New.  2) Second, create the mapping.  In the administration console, go to Services, select Data sources, select your data source name, select Security, select Credentials, and select New.  See http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/jdbc/jdbc_datasources/ConfigureCredentialMappingForADataSource.html for more information. The advantages of using the credential mapping are that: 1) You don’t hard-code the database user/password into a program or need to prompt for it in addition to the WLS user/password and 2) It provides a layer of abstraction between WLS security and database settings such that many WLS identities can be mapped to a smaller set of DB identities, thereby only requiring middle-tier configuration updates when WLS users are added/removed. You can cut down the number of users that have access to a data source to reduce the user maintenance overhead.  For example, suppose that a servlet has the one pre-defined, special WLS user/password for data source access, hard-wired in its code in a getConnection(user, password) call.  Every WebLogic user can reap the specific DBMS access coded into the servlet, but none has to have general access to the data source.  For instance, there may be a ‘Sales’ DBMS which needs to be protected from unauthorized eyes, but it contains some day-to-day data that everyone needs. The Sales data source is configured with restricted access and a servlet is built that hard-wires the specific data source access credentials in its connection request.  It uses that connection to deliver only the generally needed day-to-day information to any caller. The servlet cannot reveal any other data, and no WebLogic user can get any other access to the data source.  This is the approach that many large applications take and is the reasoning behind the default mapping behavior in WLS. The disadvantages of using the credential map are that: 1) It is difficult to manage (create, update, delete) with a large number of users; it is possible to use WLST scripts or a custom JMX client utility to manage credential map entries. 2) You can’t share a credential map between data sources so they must be duplicated. Some applications prefer not to use the credential map.  Instead, the credentials passed to getConnection(user, password) should be treated as database credentials and used to authenticate with the database for the connection, avoiding going through the credential map.  This is enabled by setting the “use-database-credentials” to true.  See http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/jdbc/jdbc_datasources/ConfigureOracleParameters.html "Configure Oracle parameters" in Oracle WebLogic Server Administration Console Help. Use Database Credentials is not currently supported for Multi Data Source configurations.  When enabled, it turns off credential mapping on Generic and Active GridLink data sources for the following attributes: 1. identity-based-connection-pooling-enabled (this interaction is available by patch in 10.3.6.0). 2. oracle-proxy-session (this interaction is first available in 10.3.6.0). 3. set client identifier (this interaction is available by patch in 10.3.6.0).  Note that in the data source schema, the set client identifier feature is poorly named “credential-mapping-enabled”.  The documentation and the console refer to it as Set Client Identifier. To review the behavior of credential mapping and using database credentials: - If using the credential map, there needs to be a mapping for each WLS user to database user for those users that will have access to the database; otherwise the default user for the data source will be used.  If you always specify a user/password when getting a connection, you only need credential map entries for those specific users. - If using database credentials without specifying a user/password, the default user and password in the data source descriptor are always used.  If you specify a user/password when getting a connection, that user will be used for the credentials.  WLS users are not involved at all in the data source connection process.

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  • Getting Started with ADF Mobile Sample Apps

    - by Denis T
    Getting Started with ADF Mobile Sample Apps   Installation Steps Install JDeveloper 11.1.2.3.0 from Oracle Technology Network After installing JDeveloper, go to Help menu and select "Check For Updates" and find the ADF Mobile extension and install this. It will require you restart JDeveloper For iOS development, be on a Mac and have Xcode installed. (Currently only Xcode 4.4 is officially supported. Xcode 4.5 support is coming soon) For Android development, have the Android SDK installed. In the JDeveloper Tools menu, select "Preferences". In the Preferences dialog, select ADF Mobile. You can expand it to select configure your Platform preferences for things like the location of Xcode and the Android SDK. In your /jdeveloper/jdev/extensions/oracle.adf.mobile/Samples folder you will find a PublicSamples.zip. Unzip this into the Samples folder so you have all the projects ready to go. Open each of the sample application's .JWS file to open the corresponding workspace. Then from the "Application" menu, select "Deploy" and then select the deployment profile for the platform you wish to deploy to. Try deploying to the simulator/emulator on each platform first because it won't require signing. Note: If you wish to deploy to the Android emulator, it must be running before you start the deployment.   Sample Application Details   Recommended Order of Use Application Name Description 1 HelloWorld The "hello world" application for ADF Mobile, which demonstrates the basic structure of the framework. This basic application has a single application feature that is implemented with a local HTML file. Use this application to ascertain that the development environment is set up correctly to compile and deploy an application. See also Section 4.2.2, "What Happens When You Create an ADF Mobile Application." 2 CompGallery This application is meant to be a runtime application and not necessarily to review the code, though that is available. It serves as an introduction to the ADF Mobile AMX UI components by demonstrating all of these components. Using this application, you can change the attributes of these components at runtime and see the effects of those changes in real time without recompiling and redeploying the application after each change. See generally Chapter 8, "Creating ADF Mobile AMX User Interface." 3 LayoutDemo This application demonstrates the user interface layout and shows how to create the various list and button styles that are commonly used in mobile applications. It also demonstrates how to create the action sheet style of a popup component and how to use various chart and gauge components. See Section 8.3, "Creating and Using UI Components" and Section 8.5, "Providing Data Visualization." Note: This application must be opened from the Samples directory or the Default springboard option must be cleared in the Applications page of the adfmf-application.xml overview editor, then selected again. 4 JavaDemo This application demonstrates how to bind the user interface to Java beans. It also demonstrates how to invoke EL bindings from the Java layer using the supplied utility classes. See also Section 8.10, "Using Event Listeners" and Section 9.2, "Understanding EL Support." 5 Navigation This application demonstrates the various navigation techniques in ADF Mobile, including bounded task flows and routers. It also demonstrates the various page transitions. See also Section 7.2, "Creating Task Flows." Note: This application must be opened from the Samples directory or the Default springboard option must be cleared in the Applications page of the adfmf-application.xml overview editor, then selected again. 6 LifecycleEvents This application implements lifecycle event handlers on the ADF Mobile application itself and its embedded application features. This application shows you where to insert code to enable the applications to perform their own logic at certain points in the lifecycle. See also Section 5.6, "About Lifecycle Event Listeners." Note: iOS, the LifecycleEvents sample application logs data to the Console application, located at Applications-Utilities-Console application. 7 DeviceDemo This application shows you how to use the DeviceFeatures data control to expose such device features as geolocation, e-mail, SMS, and contacts, as well as how to query the device for its properties. See also Section 9.5, "Using the DeviceFeatures Data Control." Note: You must also run this application on an actual device because SMS and some of the device properties do not function on an iOS simulator or Android emulator. 8 GestureDemo This application demonstrates how gestures can be implemented and used in ADF Mobile applications. See also Section 8.4, "Enabling Gestures." 9 StockTracker This application demonstrates how data change events use Java to enable data changes to be reflected in the user interface. It also has a variety of layout use cases, gestures and basic mobile patterns. See also Section 9.7, "Data Change Events."

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  • How to make this design closer to proper DDD?

    - by Seralize
    I've read about DDD for days now and need help with this sample design. All the rules of DDD make me very confused to how I'm supposed to build anything at all when domain objects are not allowed to show methods to the application layer; where else to orchestrate behaviour? Repositories are not allowed to be injected into entities and entities themselves must thus work on state. Then an entity needs to know something else from the domain, but other entity objects are not allowed to be injected either? Some of these things makes sense to me but some don't. I've yet to find good examples of how to build a whole feature as every example is about Orders and Products, repeating the other examples over and over. I learn best by reading examples and have tried to build a feature using the information I've gained about DDD this far. I need your help to point out what I do wrong and how to fix it, most preferably with code as "I would not recomment doing X and Y" is very hard to understand in a context where everything is just vaguely defined already. If I can't inject an entity into another it would be easier to see how to do it properly. In my example there are users and moderators. A moderator can ban users, but with a business rule: only 3 per day. I did an attempt at setting up a class diagram to show the relationships (code below): interface iUser { public function getUserId(); public function getUsername(); } class User implements iUser { protected $_id; protected $_username; public function __construct(UserId $user_id, Username $username) { $this->_id = $user_id; $this->_username = $username; } public function getUserId() { return $this->_id; } public function getUsername() { return $this->_username; } } class Moderator extends User { protected $_ban_count; protected $_last_ban_date; public function __construct(UserBanCount $ban_count, SimpleDate $last_ban_date) { $this->_ban_count = $ban_count; $this->_last_ban_date = $last_ban_date; } public function banUser(iUser &$user, iBannedUser &$banned_user) { if (! $this->_isAllowedToBan()) { throw new DomainException('You are not allowed to ban more users today.'); } if (date('d.m.Y') != $this->_last_ban_date->getValue()) { $this->_ban_count = 0; } $this->_ban_count++; $date_banned = date('d.m.Y'); $expiration_date = date('d.m.Y', strtotime('+1 week')); $banned_user->add($user->getUserId(), new SimpleDate($date_banned), new SimpleDate($expiration_date)); } protected function _isAllowedToBan() { if ($this->_ban_count >= 3 AND date('d.m.Y') == $this->_last_ban_date->getValue()) { return false; } return true; } } interface iBannedUser { public function add(UserId $user_id, SimpleDate $date_banned, SimpleDate $expiration_date); public function remove(); } class BannedUser implements iBannedUser { protected $_user_id; protected $_date_banned; protected $_expiration_date; public function __construct(UserId $user_id, SimpleDate $date_banned, SimpleDate $expiration_date) { $this->_user_id = $user_id; $this->_date_banned = $date_banned; $this->_expiration_date = $expiration_date; } public function add(UserId $user_id, SimpleDate $date_banned, SimpleDate $expiration_date) { $this->_user_id = $user_id; $this->_date_banned = $date_banned; $this->_expiration_date = $expiration_date; } public function remove() { $this->_user_id = ''; $this->_date_banned = ''; $this->_expiration_date = ''; } } // Gathers objects $user_repo = new UserRepository(); $evil_user = $user_repo->findById(123); $moderator_repo = new ModeratorRepository(); $moderator = $moderator_repo->findById(1337); $banned_user_factory = new BannedUserFactory(); $banned_user = $banned_user_factory->build(); // Performs ban $moderator->banUser($evil_user, $banned_user); // Saves objects to database $user_repo->store($evil_user); $moderator_repo->store($moderator); $banned_user_repo = new BannedUserRepository(); $banned_user_repo->store($banned_user); Should the User entitity have a 'is_banned' field which can be checked with $user->isBanned();? How to remove a ban? I have no idea.

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  • Plagued by multithreaded bugs

    - by koncurrency
    On my new team that I manage, the majority of our code is platform, TCP socket, and http networking code. All C++. Most of it originated from other developers that have left the team. The current developers on the team are very smart, but mostly junior in terms of experience. Our biggest problem: multi-threaded concurrency bugs. Most of our class libraries are written to be asynchronous by use of some thread pool classes. Methods on the class libraries often enqueue long running taks onto the thread pool from one thread and then the callback methods of that class get invoked on a different thread. As a result, we have a lot of edge case bugs involving incorrect threading assumptions. This results in subtle bugs that go beyond just having critical sections and locks to guard against concurrency issues. What makes these problems even harder is that the attempts to fix are often incorrect. Some mistakes I've observed the team attempting (or within the legacy code itself) includes something like the following: Common mistake #1 - Fixing concurrency issue by just put a lock around the shared data, but forgetting about what happens when methods don't get called in an expected order. Here's a very simple example: void Foo::OnHttpRequestComplete(statuscode status) { m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } So now we have a bug in which Shutdown could get called while OnHttpNetworkRequestComplete is occuring on. A tester finds the bug, captures the crash dump, and assigns the bug to a developer. He in turn fixes the bug like this. void Foo::OnHttpRequestComplete(statuscode status) { AutoLock lock(m_cs); m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { AutoLock lock(m_cs); m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } The above fix looks good until you realize there's an even more subtle edge case. What happens if Shutdown gets called before OnHttpRequestComplete gets called back? The real world examples my team has are even more complex, and the edge cases are even harder to spot during the code review process. Common Mistake #2 - fixing deadlock issues by blindly exiting the lock, wait for the other thread to finish, then re-enter the lock - but without handling the case that the object just got updated by the other thread! Common Mistake #3 - Even though the objects are reference counted, the shutdown sequence "releases" it's pointer. But forgets to wait for the thread that is still running to release it's instance. As such, components are shutdown cleanly, then spurious or late callbacks are invoked on an object in an state not expecting any more calls. There are other edge cases, but the bottom line is this: Multithreaded programming is just plain hard, even for smart people. As I catch these mistakes, I spend time discussing the errors with each developer on developing a more appropriate fix. But I suspect they are often confused on how to solve each issue because of the enormous amount of legacy code that the "right" fix will involve touching. We're going to be shipping soon, and I'm sure the patches we're applying will hold for the upcoming release. Afterwards, we're going to have some time to improve the code base and refactor where needed. We won't have time to just re-write everything. And the majority of the code isn't all that bad. But I'm looking to refactor code such that threading issues can be avoided altogether. One approach I am considering is this. For each significant platform feature, have a dedicated single thread where all events and network callbacks get marshalled onto. Similar to COM apartment threading in Windows with use of a message loop. Long blocking operations could still get dispatched to a work pool thread, but the completion callback is invoked on on the component's thread. Components could possibly even share the same thread. Then all the class libraries running inside the thread can be written under the assumption of a single threaded world. Before I go down that path, I am also very interested if there are other standard techniques or design patterns for dealing with multithreaded issues. And I have to emphasize - something beyond a book that describes the basics of mutexes and semaphores. What do you think? I am also interested in any other approaches to take towards a refactoring process. Including any of the following: Literature or papers on design patterns around threads. Something beyond an introduction to mutexes and semaphores. We don't need massive parallelism either, just ways to design an object model so as to handle asynchronous events from other threads correctly. Ways to diagram the threading of various components, so that it will be easy to study and evolve solutions for. (That is, a UML equivalent for discussing threads across objects and classes) Educating your development team on the issues with multithreaded code. What would you do?

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  • Scripting with the Sun ZFS Storage 7000 Appliance

    - by Geoff Ongley
    The Sun ZFS Storage 7000 appliance has a user friendly and easy to understand graphical web based interface we call the "BUI" or "Browser User Interface".This interface is very useful for many tasks, but in some cases a script (or workflow) may be more appropriate, such as:Repetitive tasksTasks which work on (or obtain information about) a large number of shares or usersTasks which are triggered by an alert threshold (workflows)Tasks where you want a only very basic input, but a consistent output (workflows)The appliance scripting language is based on ECMAscript 3 (close to javascript). I'm not going to cover ECMAscript 3 in great depth (I'm far from an expert here), but I would like to show you some neat things you can do with the appliance, to get you started based on what I have found from my own playing around.I'm making the assumption you have some sort of programming background, and understand variables, arrays, functions to some extent - but of course if something is not clear, please let me know so I can fix it up or clarify it.Variable Declarations and ArraysVariablesECMAScript is a dynamically and weakly typed language. If you don't know what that means, google is your friend - but at a high level it means we can just declare variables with no specific type and on the fly.For example, I can declare a variable and use it straight away in the middle of my code, for example:projects=list();Which makes projects an array of values that are returned from the list(); function (which is usable in most contexts). With this kind of variable, I can do things like:projects.length (this property on array tells you how many objects are in it, good for for loops etc). Alternatively, I could say:projects=3;and now projects is just a simple number.Should we declare variables like this so loosely? In my opinion, the answer is no - I feel it is a better practice to declare variables you are going to use, before you use them - and given them an initial value. You can do so as follows:var myVariable=0;To demonstrate the ability to just randomly assign and change the type of variables, you can create a simple script at the cli as follows (bold for input):fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("Number of projects is: %d\n",projects.length);("." to run)> projects=152;("." to run)> printf("Value of the projects variable as an integer is now: %d\n",projects);("." to run)> .Number of projects is: 7Value of the projects variable as an integer is now: 152You can also confirm this behaviour by checking the typeof variable we are dealing with:fishy10:> script("." to run)> run("cd /");("." to run)> run ("shares");("." to run)> var projects;("." to run)> projects=list();("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> projects=152;("." to run)> printf("var projects is of type %s\n",typeof(projects));("." to run)> .var projects is of type objectvar projects is of type numberArraysSo you likely noticed that we have already touched on arrays, as the list(); (in the shares context) stored an array into the 'projects' variable.But what if you want to declare your own array? Easy! This is very similar to Java and other languages, we just instantiate a brand new "Array" object using the keyword new:var myArray = new Array();will create an array called "myArray".A quick example:fishy10:> script("." to run)> testArray = new Array();("." to run)> testArray[0]="This";("." to run)> testArray[1]="is";("." to run)> testArray[2]="just";("." to run)> testArray[3]="a";("." to run)> testArray[4]="test";("." to run)> for (i=0; i < testArray.length; i++)("." to run)> {("." to run)>    printf("Array element %d is %s\n",i,testArray[i]);("." to run)> }("." to run)> .Array element 0 is ThisArray element 1 is isArray element 2 is justArray element 3 is aArray element 4 is testWorking With LoopsFor LoopFor loops are very similar to those you will see in C, java and several other languages. One of the key differences here is, as you were made aware earlier, we can be a bit more sloppy with our variable declarations.The general way you would likely use a for loop is as follows:for (variable; test-case; modifier for variable){}For example, you may wish to declare a variable i as 0; and a MAX_ITERATIONS variable to determine how many times this loop should repeat:var i=0;var MAX_ITERATIONS=10;And then, use this variable to be tested against some case existing (has i reached MAX_ITERATIONS? - if not, increment i using i++);for (i=0; i < MAX_ITERATIONS; i++){ // some work to do}So lets run something like this on the appliance:fishy10:> script("." to run)> var i=0;("." to run)> var MAX_ITERATIONS=10;("." to run)> for (i=0; i < MAX_ITERATIONS; i++)("." to run)> {("." to run)>    printf("The number is %d\n",i);("." to run)> }("." to run)> .The number is 0The number is 1The number is 2The number is 3The number is 4The number is 5The number is 6The number is 7The number is 8The number is 9While LoopWhile loops again are very similar to other languages, we loop "while" a condition is met. For example:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n",counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Counter is 10Loop has ended and Counter is 11So what do we notice here? Something has actually gone wrong - counter will technically be 11 once the loop completes... Why is this?Well, if we have a loop like this, where the 'while' condition that will end the loop may be set based on some other condition(s) existing (such as the counter has reached 10) - we must ensure that we  terminate this iteration of the loop when the condition is met - otherwise the rest of the code will be followed which may not be desirable. In other words, like in other languages, we will only ever check the loop condition once we are ready to perform the next iteration, so any other code after we set "isTen" to be true, will still be executed as we can see it was above.We can avoid this by adding a break into our loop once we know we have set the condition - this will stop the rest of the logic being processed in this iteration (and as such, counter will not be incremented). So lets try that again:fishy10:> script("." to run)> var isTen=false;("." to run)> var counter=0;("." to run)> while(isTen==false)("." to run)> {("." to run)>    if (counter==10) ("." to run)>    { ("." to run)>            isTen=true;   ("." to run)>            break;("." to run)>    } ("." to run)>    printf("Counter is %d\n",counter);("." to run)>    counter++;    ("." to run)> }("." to run)> printf("Loop has ended and Counter is %d\n", counter);("." to run)> .Counter is 0Counter is 1Counter is 2Counter is 3Counter is 4Counter is 5Counter is 6Counter is 7Counter is 8Counter is 9Loop has ended and Counter is 10Much better!Methods to Obtain and Manipulate DataGet MethodThe get method allows you to get simple properties from an object, for example a quota from a user. The syntax is fairly simple:var myVariable=get('property');An example of where you may wish to use this, is when you are getting a bunch of information about a user (such as quota information when in a shares context):var users=list();for(k=0; k < users.length; k++){     user=users[k];     run('select ' + user);     var username=get('name');     var usage=get('usage');     var quota=get('quota');...Which you can then use to your advantage - to print or manipulate infomation (you could change a user's information with a set method, based on the information returned from the get method). The set method is explained next.Set MethodThe set method can be used in a simple manner, similar to get. The syntax for set is:set('property','value'); // where value is a string, if it was a number, you don't need quotesFor example, we could set the quota on a share as follows (first observing the initial value):fishy10:shares default/test-geoff> script("." to run)> var currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> set('quota','30G');("." to run)> run('commit');("." to run)> currentQuota=get('quota');("." to run)> printf("Current Quota is: %s\n",currentQuota);("." to run)> .Current Quota is: 0Current Quota is: 32212254720This shows us using both the get and set methods as can be used in scripts, of course when only setting an individual share, the above is overkill - it would be much easier to set it manually at the cli using 'set quota=3G' and then 'commit'.List MethodThe list method can be very powerful, especially in more complex scripts which iterate over large amounts of data and manipulate it if so desired. The general way you will use list is as follows:var myVar=list();Which will make "myVar" an array, containing all the objects in the relevant context (this could be a list of users, shares, projects, etc). You can then gather or manipulate data very easily.We could list all the shares and mountpoints in a given project for example:fishy10:shares another-project> script("." to run)> var shares=list();("." to run)> for (i=0; i < shares.length; i++)("." to run)> {("." to run)>    run('select ' + shares[i]);("." to run)>    var mountpoint=get('mountpoint');("." to run)>    printf("Share %s discovered, has mountpoint %s\n",shares[i],mountpoint);("." to run)>    run('done');("." to run)> }("." to run)> .Share and-another discovered, has mountpoint /export/another-project/and-anotherShare another-share discovered, has mountpoint /export/another-project/another-shareShare bob discovered, has mountpoint /export/another-projectShare more-shares-for-all discovered, has mountpoint /export/another-project/more-shares-for-allShare yep discovered, has mountpoint /export/another-project/yepWriting More Complex and Re-Usable CodeFunctionsThe best way to be able to write more complex code is to use functions to split up repeatable or reusable sections of your code. This also makes your more complex code easier to read and understand for other programmers.We write functions as follows:function functionName(variable1,variable2,...,variableN){}For example, we could have a function that takes a project name as input, and lists shares for that project (assuming we're already in the 'project' context - context is important!):function getShares(proj){        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                printf("Discovered share: %s\n",shares[i]);        }        run('done'); // exit selected project}Commenting your CodeLike any other language, a large part of making it readable and understandable is to comment it. You can use the same comment style as in C and Java amongst other languages.In other words, sngle line comments use://at the beginning of the comment.Multi line comments use:/*at the beginning, and:*/ at the end.For example, here we will use both:fishy10:> script("." to run)> // This is a test comment("." to run)> printf("doing some work...\n");("." to run)> /* This is a multi-line("." to run)> comment which I will span across("." to run)> three lines in total */("." to run)> printf("doing some more work...\n");("." to run)> .doing some work...doing some more work...Your comments do not have to be on their own, they can begin (particularly with single line comments this is handy) at the end of a statement, for examplevar projects=list(); // The variable projects is an array containing all projects on the system.Try and Catch StatementsYou may be used to using try and catch statements in other languages, and they can (and should) be utilised in your code to catch expected or unexpected error conditions, that you do NOT wish to stop your code from executing (if you do not catch these errors, your script will exit!):try{  // do some work}catch(err) // Catch any error that could occur{ // do something here under the error condition}For example, you may wish to only execute some code if a context can be reached. If you can't perform certain actions under certain circumstances, that may be perfectly acceptable.For example if you want to test a condition that only makes sense when looking at a SMB/NFS share, but does not make sense when you hit an iscsi or FC LUN, you don't want to stop all processing of other shares you may not have covered yet.For example we may wish to obtain quota information on all shares for all users on a share (but this makes no sense for a LUN):function getShareQuota(shar) // Get quota for each user of this share{        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","----");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}Running Scripts Remotely over SSHAs you have likely noticed, writing and running scripts for all but the simplest jobs directly on the appliance is not going to be a lot of fun.There's a couple of choices on what you can do here:Create scripts on a remote system and run them over sshCreate scripts, wrapping them in workflow code, so they are stored on the appliance and can be triggered under certain circumstances (like a threshold being reached)We'll cover the first one here, and then cover workflows later on (as these are for the most part just scripts with some wrapper information around them).Creating a SSH Public/Private SSH Key PairLog on to your handy Solaris box (You wouldn't be using any other OS, right? :P) and use ssh-keygen to create a pair of ssh keys. I'm storing this separate to my normal key:[geoff@lightning ~] ssh-keygen -t rsa -b 1024Generating public/private rsa key pair.Enter file in which to save the key (/export/home/geoff/.ssh/id_rsa): /export/home/geoff/.ssh/nas_key_rsaEnter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /export/home/geoff/.ssh/nas_key_rsa.Your public key has been saved in /export/home/geoff/.ssh/nas_key_rsa.pub.The key fingerprint is:7f:3d:53:f0:2a:5e:8b:2d:94:2a:55:77:66:5c:9b:14 geoff@lightningInstalling the Public Key on the ApplianceOn your Solaris host, observe the public key:[geoff@lightning ~] cat .ssh/nas_key_rsa.pub ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc= geoff@lightningNow, copy and paste everything after "ssh-rsa" and before "user@hostname" - in this case, geoff@lightning. That is, this bit:AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc=Logon to your appliance and get into the preferences -> keys area for this user (root):[geoff@lightning ~] ssh [email protected]: Last login: Mon Dec  6 17:13:28 2010 from 192.168.0.2fishy10:> configuration usersfishy10:configuration users> select rootfishy10:configuration users root> preferences fishy10:configuration users root preferences> keysOR do it all in one hit:fishy10:> configuration users select root preferences keysNow, we create a new public key that will be accepted for this user and set the type to RSA:fishy10:configuration users root preferences keys> createfishy10:configuration users root preferences key (uncommitted)> set type=RSASet the key itself using the string copied previously (between ssh-rsa and user@host), and set the key ensuring you put double quotes around it (eg. set key="<key>"):fishy10:configuration users root preferences key (uncommitted)> set key="AAAAB3NzaC1yc2EAAAABIwAAAIEAvYfK3RIaAYmMHBOvyhKM41NaSmcgUMC3igPN5gUKJQvSnYmjuWG6CBr1CkF5UcDji7v19jG3qAD5lAMFn+L0CxgRr8TNaAU+hA4/tpAGkjm+dKYSyJgEdMIURweyyfUFXoerweR8AWW5xlovGKEWZTAfvJX9Zqvh8oMQ5UJLUUc="Now set the comment for this key (do not use spaces):fishy10:configuration users root preferences key (uncommitted)> set comment="LightningRSAKey" Commit the new key:fishy10:configuration users root preferences key (uncommitted)> commitVerify the key is there:fishy10:configuration users root preferences keys> lsKeys:NAME     MODIFIED              TYPE   COMMENT                                  key-000  2010-10-25 20:56:42   RSA    cycloneRSAKey                           key-001  2010-12-6 17:44:53    RSA    LightningRSAKey                         As you can see, we now have my new key, and a previous key I have created on this appliance.Running your Script over SSH from a Remote SystemHere I have created a basic test script, and saved it as test.ecma3:[geoff@lightning ~] cat test.ecma3 script// This is a test script, By Geoff Ongley 2010.printf("Testing script remotely over ssh\n");.Now, we can run this script remotely with our keyless login:[geoff@lightning ~] ssh -i .ssh/nas_key_rsa root@fishy10 < test.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Testing script remotely over sshPutting it Together - An Example Completed Quota Gathering ScriptSo now we have a lot of the basics to creating a script, let us do something useful, like, find out how much every user is using, on every share on the system (you will recognise some of the code from my previous examples): script/************************************** Quick and Dirty Quota Check script ** Written By Geoff Ongley            ** 25 October 2010                    **************************************/function getUserQuota(usr){        run('select ' + usr);        var username=get('name');        var usage=get('usage');        var quota=get('quota');        var usage_g=usage / 1073741824; // convert bytes to gigabytes        var quota_g=quota / 1073741824; // as above        var quota_percent=0        if (quota > 0)        {                quota_percent=(usage / quota)*(100/1);        }        printf("    %20s        %8.2f           %8.2f           %d%%\n",username,usage_g,quota_g,quota_percent);        run('done'); // done with this selected user}function getShareQuota(shar){        //printf("DEBUG: selecting share %s\n", shar);        run('select ' + shar);        printf("  SHARE: %s\n", shar);        try        {                run('users');                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","--------");                                users=list();                for(k=0; k < users.length; k++)                {                        user=users[k];                        getUserQuota(user);                }                run('done'); // exit user context        }        catch(err)        {                printf("    SKIPPING %s - This is NOT a NFS or CIFs share, not looking for users\n", shar);        }        run('done'); // done with this share}function getShares(proj){        //printf("DEBUG: selecting project %s\n",proj);        run('select ' + proj);        shares=list();        printf("Project: %s\n", proj);        for(j=0; j < shares.length; j++)        {                share=shares[j];                getShareQuota(share);        }        run('done'); // exit selected project}function getProjects(){        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                var project=projects[i];                getShares(project);        }        run('done'); // exit context for all projects}getProjects();.Which can be run as follows, and will print information like this:[geoff@lightning ~/FISHWORKS_SCRIPTS] ssh -i ~/.ssh/nas_key_rsa root@fishy10 < get_quota_utilisation.ecma3Pseudo-terminal will not be allocated because stdin is not a terminal.Project: another-project  SHARE: and-another                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                 geoffro            0.05            0.00        0%                   Billy            0.10            0.00        0%                    root            0.00            0.00        0%            testing-user            0.05            0.00        0%  SHARE: another-share                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                 geoffro            0.05            0.49        9%            testing-user            0.05            0.02        249%                   Billy            0.10            0.29        33%  SHARE: bob                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%  SHARE: more-shares-for-all                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                   Billy            0.10            0.00        0%            testing-user            0.05            0.00        0%                  nobody            0.00            0.00        0%                    root            0.00            0.00        0%                 geoffro            0.05            0.00        0%  SHARE: yep                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                    root            0.00            0.00        0%                  nobody            0.00            0.00        0%                   Billy            0.10            0.01        999%            testing-user            0.05            0.49        9%                 geoffro            0.05            0.00        0%Project: default  SHARE: Test-LUN    SKIPPING Test-LUN - This is NOT a NFS or CIFs share, not looking for users  SHARE: test-geoff                Username           Usage(G)       Quota(G)    Quota(%)                --------           --------       --------    --------                 geoffro            0.05            0.00        0%                    root            3.18           10.00        31%                    uucp            0.00            0.00        0%                  nobody            0.59            0.49        119%^CKilled by signal 2.Creating a WorkflowWorkflows are scripts that we store on the appliance, and can have the script execute either on request (even from the BUI), or on an event such as a threshold being met.Workflow BasicsA workflow allows you to create a simple process that can be executed either via the BUI interface interactively, or by an alert being raised (for some threshold being reached, for example).The basics parameters you will have to set for your "workflow object" (notice you're creating a variable, that embodies ECMAScript) are as follows (parameters is optional):name: A name for this workflowdescription: A Description for the workflowparameters: A set of input parameters (useful when you need user input to execute the workflow)execute: The code, the script itself to execute, which will be function (parameters)With parameters, you can specify things like this (slightly modified sample taken from the System Administration Guide):          ...parameters:        variableParam1:         {                             label: 'Name of Share',                             type: 'String'                  },                  variableParam2                  {                             label: 'Share Size',                             type: 'size'                  },execute: ....};  Note the commas separating the sections of name, parameters, execute, and so on. This is important!Also - there is plenty of properties you can set on the parameters for your workflow, these are described in the Sun ZFS Storage System Administration Guide.Creating a Basic Workflow from a Basic ScriptTo make a basic script into a basic workflow, you need to wrap the following around your script to create a 'workflow' object:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function() {// (basic script goes here, minus the "script" at the beginning, and "." at the end)}};However, it appears (at least in my experience to date) that the workflow object may only be happy with one function in the execute parameter - either that or I'm doing something wrong. As far as I can tell, after execute: you should only have a basic one function context like so:execute: function(){}To deal with this, and to give an example similar to our script earlier, I have created another simple quota check, to show the same basic functionality, but in a workflow format:var workflow = {name: 'Get User Quotas',description: 'Displays Quota Utilisation for each user on each share',execute: function () {        run('cd /');        run('shares');        projects=list();                for (i=0; i < projects.length; i++)        {                run('select ' + projects[i]);                shares=list('filesystem');                printf("Project: %s\n", projects[i]);                for(j=0; j < shares.length; j++)                {                        run('select ' +shares[j]);                        try                        {                                run('users');                                printf("  SHARE: %s\n", shares[j]);                                printf("    %20s        %11s    %11s    %3s\n","Username","Usage(G)","Quota(G)","Quota(%)");                                printf("    %20s        %11s    %11s    %4s\n","--------","--------","--------","-------");                                users=list();                                for(k=0; k < users.length; k++)                                {                                        run('select ' + users[k]);                                        username=get('name');                                        usage=get('usage');                                        quota=get('quota');                                        usage_g=usage / 1073741824; // convert bytes to gigabytes                                        quota_g=quota / 1073741824; // as above                                        quota_percent=0                                        if (quota > 0)                                        {                                                quota_percent=(usage / quota)*(100/1);                                        }                                        printf("    %20s        %8.2f   %8.2f   %d%%\n",username,usage_g,quota_g,quota_percent);                                        run('done');                                }                                run('done'); // exit user context                        }                        catch(err)                        {                        //      printf("    %s is a LUN, Not looking for users\n", shares[j]);                        }                        run('done'); // exit selected share context                }                run('done'); // exit project context        }        }};SummaryThe Sun ZFS Storage 7000 Appliance offers lots of different and interesting features to Sun/Oracle customers, including the world renowned Analytics. Hopefully the above will help you to think of new creative things you could be doing by taking advantage of one of the other neat features, the internal scripting engine!Some references are below to help you continue learning more, I'll update this post as I do the same! Enjoy...More information on ECMAScript 3A complete reference to ECMAScript 3 which will help you learn more of the details you may be interested in, can be found here:http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262,%203rd%20edition,%20December%201999.pdfMore Information on Administering the Sun ZFS Storage 7000The Sun ZFS Storage 7000 System Administration guide can be a useful reference point, and can be found here:http://wikis.sun.com/download/attachments/186238602/2010_Q3_2_ADMIN.pdf

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  • Ubuntu 10.10 Ad-Hoc Setup (from Wireless Router, to Ubuntu Server/Desktop to Wireless Router)

    - by user60375
    Okay, so I know there are different approaches for this, but I will explain my story briefly before getting to the technical stuff. My fiancée and I are going through some financial issues (as I assume a lot of us are). We ended up having to move from our house and stay with some friends/family for 6 months, just to get ourselves caught up. (Medical bills, among other issues,etc). So this is where it gets fun. At our friends house, we are staying in the loft setup which is not near the cable modem and wireless router. I have a "hand-crafted" media center running XBMC, an Ubuntu 10.10 Server/Desktop (multi-purpose, very powerful and tons drive space), two working laptops, a between the two of us we have multiple wireless devices/phones. Now our friends Wireless router doesn't have any options for assigning IP addresses, but my router does. My current setup is: Friends Cable Modem -- Friend's Wireless Router -- Ubuntu 10.10 Server -- My Wireless Router (local-link from Friend's wireless (incoming) to sharing connection on ETH0 (outgoing)) -- to all devices. (Wireless Modem, Ubuntu Server that share's it's wireless incoming connection to the ethernet port my Wireless router share's with the rest of the devices). I setup my router to use default settings from my friend's router, using Google's DNS on my router (disabled DNS setup on Ubuntu Server), everything is assigned nicely and runs smooth. My Ubuntu server was given the address 10.42.43.1 (assuming standard from Network-Manager). (On the Ubuntu machine that shares to my wireless router; I have some server apps installed, but mainly just use Samba/NFS/Tangerine action. My problem/goal is that every device has no problem of accessing the internet from my router, the media-center has an assigned ip address, all services from all devices (ZeroConf, Avanhi, Bonjour, GIT, SSH, FTP, Apache2, etc) all work correctly except from my Ubuntu Server (which serves the wireless connection to ETH0 to another Wireless Router). The Ubuntu 10.10 Server/Desktop is not broadcasting anything (the Zeroconf Service Discovery 0.4 Gnome Applet shows the services from the Ubuntu server but no other computers can see them). I can access it from my Media-Center (Running Xbuntu 10.04) if I direct it to 10.42.43.1, no problem. But I cannot access Tangerine (Daapd) and the Samba shares do not show up on any computers for 10.42.43.1 (not in the WORKGROUP which Samba is setup simple and default but I can direct computers to that address and the shares will add except on a damn Windows 7 parition). Is this an issue with how I have my router setup and possible the gateway? An issue with Network-Manager? And issue with my Ubuntu Server/Desktop? I know there is a lot to that, but it's simpler than I probably have explained? Any help would be appreciated. If you need more details, I can provide them. If there is a better way of my attempting this home-network, please let me know. Thanks in advance for the help.

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  • Apache 2.2 and FastCGI stops responding, warnings, crashes

    - by Brett
    I've seen this question posted a few times using a Google search, with no real answers. I have a multi-threaded FastCGI application running with Apache 2.2 on FreeBSD 7.2. There are a few issues with it, and I am unable to really figure out the source of the problem even after poking through a bunch of the mod_fastcgi source code. My FastCGI application gets anywhere from 2 to 15 or so hits per second, and mostly services a back-end API (the majority of web server usage is for this, and not actually serving content). Everything seems to work ok under normal conditions, but recently this problem has been becoming worse. It starts out with the FastCGI process manager apparently trying to close unneeded processes, sending them a SIGTERM signal. I catch the signal, clean up some stuff, and exit (by calling exit()) with status code 0. This process seems to result in three log messages in my httpd error log: [Tue Jun 01 14:03:31 2010] [warn] FastCGI: (dynamic) server "/home/program/wwwroot/domains/www.mydomain.com/cgi-bin/program.cgi" (pid 98182) termination signaled [Tue Jun 01 14:03:31 2010] [warn] FastCGI: (dynamic) server "/home/program/wwwroot/domains/www.mydomain.com/cgi-bin/program.cgi" (pid 98182) terminated by calling exit with status '0' [Tue Jun 01 14:03:31 2010] [warn] FastCGI: (dynamic) server "/home/program/wwwroot/domains/www.mydomain.com/cgi-bin/program.cgi" restarted (pid 98294) I am not sure why it says it is restarting the process, but in any case no core dump is ever generated so I do believe it is the FastCGI process manager doing it's thing. This makes sense because it begins to happen after the initial load increase from restarting Apache. Since it's down for a few seconds, it gets hit with a couple of hundred requests over the first few seconds it's running again (sometimes even hitting the upper limit of MAXCLIENTS in Apache), and this seems to be the process manager doing the work of spawning more processes to handle the increased load. So this all seems fine, but here is where things get weird. There are really two problems that I see. First, my multithreaded FastCGI process spawns 25 worker threads, and all seem to be used according to my internal log files (multiple processes are clearly using multiple threads to do work). However it seems that 3 or 4 FastCGI processes is not enough to handle the 5 to 15 hit per second load, even though the requests take about .02s or so to process internally. In order to be at all responsive, it seems I need 50 or more FastCGI processes, leading me to believe that FastCGI does not realize that my program is multithreaded. I've read the documentation at http://www.fastcgi.com/mod_fastcgi/docs/mod_fastcgi.html and do not see any option pertaining to multithreaded-ness, and my internal code is more or less set up just like the examples provided by the FastCGI library. The second problem I am having is that once process termination has happened a bunch of times as above (and seemingly at random), I begin getting a lot of these messages in my error log: [Tue Jun 01 14:06:22 2010] [warn] (32)Broken pipe: FastCGI: write() to PM failed (ignore if a restart or shutdown is pending) The messages occur for about half the hits I get to the server, and it completely kills the responsiveness of my application - it seems FastCGI will look for a working "pipe" until it finds one, and fail to realize that whatever application it is trying to contact is dead. It does still work though, it's just incredibly unresponsive - sometimes taking up to 40 or so seconds to process a request. I recompiled mod_fastcgi with some extra debugging around the point of the error message, and it appears that the error happens when it tries to write() to the application. The call to write() fails with a -1 return code, and sets errno to EPIPE. I am noticing that the issue happens mostly when either a crash occurs in one of the FastCGI processes, or a bunch of them are seemingly terminated by the process manager. I haven't had any core dumps though, except for one, where the backtrace outputted by gdb is just a single call to free() at address 0x0000000000000000 with nothing else in the stack trace, so I don't really know what to make of that. I'm thinking it happens sometime after the SIGTERM signal is caught, maybe some global variable not being cleaned up properly or something.

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  • Capistrano asks for SSH password when deploying from local machine to server

    - by GhostRider
    When I try to ssh to a server, I'm able to do it as my id_rsa.pub key is added to the authorized keys in the server. Now when I try to deploy my code via Capistrano to the server from my local project folder, the server asks for a password. I'm unable to understand what could be the issue if I'm able to ssh and unable to deploy to the same server. $ cap deploy:setup "no seed data" triggering start callbacks for `deploy:setup' * 13:42:18 == Currently executing `multistage:ensure' *** Defaulting to `development' * 13:42:18 == Currently executing `development' * 13:42:18 == Currently executing `deploy:setup' triggering before callbacks for `deploy:setup' * 13:42:18 == Currently executing `db:configure_mongoid' * executing "mkdir -p /home/deploy/apps/development/flyingbird/shared/config" servers: ["dev1.noob.com", "176.9.24.217"] Password: Cap script: # gem install capistrano capistrano-ext capistrano_colors begin; require 'capistrano_colors'; rescue LoadError; end require "bundler/capistrano" # RVM bootstrap # $:.unshift(File.expand_path('./lib', ENV['rvm_path'])) require 'rvm/capistrano' set :rvm_ruby_string, 'ruby-1.9.2-p290' set :rvm_type, :user # or :user # Application setup default_run_options[:pty] = true # allow pseudo-terminals ssh_options[:forward_agent] = true # forward SSH keys (this will use your SSH key to get the code from git repository) ssh_options[:port] = 22 set :ip, "dev1.noob.com" set :application, "flyingbird" set :repository, "repo-path" set :scm, :git set :branch, fetch(:branch, "master") set :deploy_via, :remote_cache set :rails_env, "production" set :use_sudo, false set :scm_username, "user" set :user, "user1" set(:database_username) { application } set(:production_database) { application + "_production" } set(:staging_database) { application + "_staging" } set(:development_database) { application + "_development" } role :web, ip # Your HTTP server, Apache/etc role :app, ip # This may be the same as your `Web` server role :db, ip, :primary => true # This is where Rails migrations will run # Use multi-staging require "capistrano/ext/multistage" set :stages, ["development", "staging", "production"] set :default_stage, rails_env before "deploy:setup", "db:configure_mongoid" # Uncomment if you use any of these databases after "deploy:update_code", "db:symlink_mongoid" after "deploy:update_code", "uploads:configure_shared" after "uploads:configure_shared", "uploads:symlink" after 'deploy:update_code', 'bundler:symlink_bundled_gems' after 'deploy:update_code', 'bundler:install' after "deploy:update_code", "rvm:trust_rvmrc" # Use this to update crontab if you use 'whenever' gem # after "deploy:symlink", "deploy:update_crontab" if ARGV.include?("seed_data") after "deploy", "db:seed" else p "no seed data" end #Custom tasks to handle resque and redis restart before "deploy", "deploy:stop_workers" after "deploy", "deploy:restart_redis" after "deploy", "deploy:start_workers" after "deploy", "deploy:cleanup" 'Create symlink for public uploads' namespace :uploads do task :symlink do run <<-CMD rm -rf #{release_path}/public/uploads && mkdir -p #{release_path}/public && ln -nfs #{shared_path}/public/uploads #{release_path}/public/uploads CMD end task :configure_shared do run "mkdir -p #{shared_path}/public" run "mkdir -p #{shared_path}/public/uploads" end end namespace :rvm do desc 'Trust rvmrc file' task :trust_rvmrc do run "rvm rvmrc trust #{current_release}" end end namespace :db do desc "Create mongoid.yml in shared path" task :configure_mongoid do db_config = <<-EOF defaults: &defaults host: localhost production: <<: *defaults database: #{production_database} staging: <<: *defaults database: #{staging_database} EOF run "mkdir -p #{shared_path}/config" put db_config, "#{shared_path}/config/mongoid.yml" end desc "Make symlink for mongoid.yml" task :symlink_mongoid do run "ln -nfs #{shared_path}/config/mongoid.yml #{release_path}/config/mongoid.yml" end desc "Fill the database with seed data" task :seed do run "cd #{current_path}; RAILS_ENV=#{default_stage} bundle exec rake db:seed" end end namespace :bundler do desc "Symlink bundled gems on each release" task :symlink_bundled_gems, :roles => :app do run "mkdir -p #{shared_path}/bundled_gems" run "ln -nfs #{shared_path}/bundled_gems #{release_path}/vendor/bundle" end desc "Install bundled gems " task :install, :roles => :app do run "cd #{release_path} && bundle install --deployment" end end namespace :deploy do task :start, :roles => :app do run "touch #{current_path}/tmp/restart.txt" end desc "Restart the app" task :restart, :roles => :app do run "touch #{current_path}/tmp/restart.txt" end desc "Start the workers" task :stop_workers do run "cd #{current_path}; RAILS_ENV=#{default_stage} bundle exec rake resque:stop_workers" end desc "Restart Redis server" task :restart_redis do "/etc/init.d/redis-server restart" end desc "Start the workers" task :start_workers do run "cd #{current_path}; RAILS_ENV=#{default_stage} bundle exec rake resque:start_workers" end end

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  • iproute2 not functioning ("RTNETLINK answers: Operation not supported")

    - by James Watt
    The command and error message: gtwy ~ # ip rule add from 64.251.23.186 table t1 RTNETLINK answers: Operation not supported Older article of the same problem, but it did not help me: http://forums.gentoo.org/viewtopic-t-696982-start-0-postdays-0-postorder-asc-highlight-.html I have looked on google at great lengths to try to find a solution. It seems that my kernel configuration is missing something? Any help or ideas would be appreciated. My system/kernel is: 2.6.36-gentoo-r5 #3 SMP Thu Jan 13 10:49:06 EST 2011 x86_64 Intel(R) Xeon(R) CPU X3220 @ 2.40GHz GenuineIntel GNU/Linux. I am posting this on SuperUser since this system is used as a workstation and this problem is unrelated to specific tasks that are handled exclusively by servers. iproute2 is installed: gtwy etc # emerge --search iproute2 Searching... [ Results for search key : iproute2 ] [ Applications found : 1 ] * sys-apps/iproute2 Latest version available: 2.6.35-r2 Latest version installed: 2.6.35-r2 Size of files: 378 kB Homepage: http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 Description: kernel routing and traffic control utilities License: GPL-2 A small snippet of my kernel .config (view entire .config): gtwy linux # cat .config | grep NETLINK CONFIG_NETFILTER_NETLINK=y CONFIG_NETFILTER_NETLINK_QUEUE=y CONFIG_NETFILTER_NETLINK_LOG=y CONFIG_NF_CT_NETLINK=y CONFIG_SCSI_NETLINK=y gtwy linux # cat .config | grep IP_ADVANCED_ROUTER CONFIG_IP_ADVANCED_ROUTER=y gtwy linux # cat .config | grep INGRESS CONFIG_NET_SCH_INGRESS=y gtwy linux # cat .config | grep NET_SCHED CONFIG_NET_SCHED=y emerge --info Portage 2.1.9.25 (default/linux/amd64/10.0, gcc-4.1.2, glibc-2.10.1-r1, 2.6.36-gentoo-r5 x86_64) ================================================================= System uname: Linux-2.6.36-gentoo-r5-x86_64-Intel-R-_Xeon-R-_CPU_X3220_@_2.40GHz-with-gentoo-1.12.13 Timestamp of tree: Thu, 13 Jan 2011 01:15:01 +0000 app-shells/bash: 4.0_p37 dev-java/java-config: 1.3.7-r1, 2.1.10 dev-lang/python: 2.4.6, 2.5.4-r4, 2.6.5-r2, 3.1.2-r3 sys-apps/baselayout: 1.12.13 sys-apps/sandbox: 1.6-r2 sys-devel/autoconf: 2.13, 2.65 sys-devel/automake: 1.9.6-r2::<unknown repository>, 1.10.2, 1.11.1 sys-devel/binutils: 2.20.1-r1 sys-devel/gcc: 4.1.2, 4.3.4, 4.4.3-r2 sys-devel/gcc-config: 1.4.1 sys-devel/libtool: 2.2.6b sys-devel/make: 3.81 virtual/os-headers: 2.6.30-r1 (sys-kernel/linux-headers) ACCEPT_KEYWORDS="amd64" ACCEPT_LICENSE="*" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=nocona -O2 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /var/bind" CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/php/apache2-php5/ext-active/ /etc/php/cgi-php5/ext-active/ /etc/php/cli-php5/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo" CXXFLAGS="-march=nocona -O2 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="assume-digests binpkg-logs distlocks fixlafiles fixpackages news parallel-fetch protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch" GENTOO_MIRRORS="http://gentoo.chem.wisc.edu/gentoo" LC_ALL="en_US.UTF-8" LDFLAGS="-Wl,-O1 -Wl,--as-needed" LINGUAS="en" MAKEOPTS="-j5" PKGDIR="/usr/portage/packages" PORTAGE_CONFIGROOT="/" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://rsync.namerica.gentoo.org/gentoo-portage" USE="acl amd64 apache2 berkdb bzip2 cli cracklib crypt ctype cups curl cxx dri fortran gdbm gpm iconv jpeg jpeg2k libwww mmx modules mudflap multilib mysql ncurses nls nptl nptlonly openmp pam pcre perl php png pppd python readline session sockets sse sse2 ssl symlink sysfs tcpd threads unicode vhosts xml xorg xsl zlib" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" ELIBC="glibc" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ubx" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="en" PHP_TARGETS="php5-3" RUBY_TARGETS="ruby18" USERLAND="GNU" VIDEO_CARDS="fbdev glint intel mach64 mga neomagic nouveau nv r128 radeon savage sis tdfx trident vesa via vmware dummy v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account" Unset: CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, FFLAGS, INSTALL_MASK, LANG, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

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  • disk-to-disk backup without costly backup redundancy?

    - by AaronLS
    A good backup strategy involves a combination of 1) disconnected backups/snapshots that will not be affected by bugs, viruses, and/or security breaches 2) geographically distributed backups to protect against local disasters 3) testing backups to ensure that they can be restored as needed Generally I take an onsite backup daily, and an offsite backup weekly, and do test restores periodically. In the rare circumstance that I need to restore files, I do some from the local backup. Should a catastrophic event destroy the servers and local backups, then the offsite weekly tape backup would be used to restore the files. I don't need multiple offsite backups with redundancy. I ALREADY HAVE REDUNDANCY THROUGH THE USE OF BOTH LOCAL AND REMOTE BACKUPS. I have recovery blocks and par files with the backups, so I already have protection against a small percentage of corrupt bits. I perform test restores to ensure the backups function properly. Should the remote backups experience a dataloss, I can replace them with one of the local backups. There are historical offsite backups as well, so if a dataloss was not noticed for a few weeks(such as a bug/security breach/virus), the data could be restored from an older backup. By doing this, the only scenario that poses a risk to complete data loss would be one where both the local, remote, and servers all experienced a data loss in the same time period. I'm willing to risk that happening since the odds of that trifecta negligibly small, and the data isn't THAT valuable to me. So I hope I have emphasized that I don't need redundancy in my offsite backups because I have covered all the bases. I know this exact technique is employed by numerous businesses. Of course there are some that take multiple offsite backups, because the data is so incredibly valuable that they don't even want to risk that trifecta disaster, but in the majority of cases the trifecta disaster is an accepted risk. I HAD TO COVER ALL THIS BECAUSE SOME PEOPLE DON'T READ!!! I think I have justified my backup strategy and the majority of businesses who use offsite tape backups do not have any additional redundancy beyond what is mentioned above(recovery blocks, par files, historical snapshots). Now I would like to eliminate the use of tapes for offsite backups, and instead use a backup service. Most however are extremely costly for $/gb/month storage. I don't mind paying for transfer bandwidth, but the cost of storage is way to high. All of them advertise that they maintain backups of the data, and I imagine they use RAID as well. Obviously if you were using them to host servers this would all be necessary, but for my scenario, I am simply replacing my offsite backups with such a service. So there is no need for RAID, and absolutely no value in another layer of backups of backups. My one and only question: "Are there online data-storage/backup services that do not use redundancy or offer backups(backups of my backups) as part of their packages, and thus are more reasonably priced?" NOT my question: "Is this a flawed strategy?" I don't care if you think this is a good strategy or not. I know it pretty standard. Very few people make an extra copy of their offsite backups. They already have local backups that they can use to replace the remote backups if something catastrophic happens at the remote site. Please limit your responses to the question posed. Sorry if I seem a little abrasive, but I had some trolls in my last post who didn't read my requirements nor my question, and were trying to go off answering a totally different question. I made it pretty clear, but didn't try to justify my strategy, because I didn't ask about whether my strategy was justifyable. So I apologize if this was lengthy, as it really didn't need to be, but since there are so many trolls here who try to sidetrack questions by responding without addressing the question at hand.

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  • Why do we get a sudden spike in response times?

    - by Christian Hagelid
    We have an API that is implemented using ServiceStack which is hosted in IIS. While performing load testing of the API we discovered that the response times are good but that they deteriorate rapidly as soon as we hit about 3,500 concurrent users per server. We have two servers and when hitting them with 7,000 users the average response times sit below 500ms for all endpoints. The boxes are behind a load balancer so we get 3,500 concurrents per server. However as soon as we increase the number of total concurrent users we see a significant increase in response times. Increasing the concurrent users to 5,000 per server gives us an average response time per endpoint of around 7 seconds. The memory and CPU on the servers are quite low, both while the response times are good and when after they deteriorate. At peak with 10,000 concurrent users the CPU averages just below 50% and the RAM sits around 3-4 GB out of 16. This leaves us thinking that we are hitting some kind of limit somewhere. The below screenshot shows some key counters in perfmon during a load test with a total of 10,000 concurrent users. The highlighted counter is requests/second. To the right of the screenshot you can see the requests per second graph becoming really erratic. This is the main indicator for slow response times. As soon as we see this pattern we notice slow response times in the load test. How do we go about troubleshooting this performance issue? We are trying to identify if this is a coding issue or a configuration issue. Are there any settings in web.config or IIS that could explain this behaviour? The application pool is running .NET v4.0 and the IIS version is 7.5. The only change we have made from the default settings is to update the application pool Queue Length value from 1,000 to 5,000. We have also added the following config settings to the Aspnet.config file: <system.web> <applicationPool maxConcurrentRequestsPerCPU="5000" maxConcurrentThreadsPerCPU="0" requestQueueLimit="5000" /> </system.web> More details: The purpose of the API is to combine data from various external sources and return as JSON. It is currently using an InMemory cache implementation to cache individual external calls at the data layer. The first request to a resource will fetch all data required and any subsequent requests for the same resource will get results from the cache. We have a 'cache runner' that is implemented as a background process that updates the information in the cache at certain set intervals. We have added locking around the code that fetches data from the external resources. We have also implemented the services to fetch the data from the external sources in an asynchronous fashion so that the endpoint should only be as slow as the slowest external call (unless we have data in the cache of course). This is done using the System.Threading.Tasks.Task class. Could we be hitting a limitation in terms of number of threads available to the process?

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  • Determining cause of high NFS/IO utilization without iotop

    - by Matt
    I have a server that is doing an NFSv4 export for user's home directories. There are roughly 25 users (mostly developers/analysts) and about 40 servers mounting the home directory export. Performance is miserable, with users often seeing multi-second lags for simple commands (like ls, or writing a small text file). Sometimes the home directory mount completely hangs for minutes, with users getting "permission denied" errors. The hardware is a Dell R510 with dual E5620 CPUs and 8 GB RAM. There are eight 15k 2.5” 600 GB drives (Seagate ST3600057SS) configured in hardware RAID-6 with a single hot spare. RAID controller is a Dell PERC H700 w/512MB cache (Linux sees this as a LSI MegaSAS 9260). OS is CentOS 5.6, home directory partition is ext3, with options “rw,data=journal,usrquota”. I have the HW RAID configured to present two virtual disks to the OS: /dev/sda for the OS (boot, root and swap partitions), and /dev/sdb for the home directories. What I find curious, and suspicious, is that the sda device often has very high utilization, even though it only contains the OS. I would expect this virtual drive to be idle almost all the time. The system is not swapping, according to "free" and "vmstat". Why would there be major load on this device? Here is a 30-second snapshot from iostat: Time: 09:37:28 AM Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0.00 44.09 0.03 107.76 0.13 607.40 11.27 0.89 8.27 7.27 78.35 sda1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sda2 0.00 44.09 0.03 107.76 0.13 607.40 11.27 0.89 8.27 7.27 78.35 sdb 0.00 2616.53 0.67 157.88 2.80 11098.83 140.04 8.57 54.08 4.21 66.68 sdb1 0.00 2616.53 0.67 157.88 2.80 11098.83 140.04 8.57 54.08 4.21 66.68 dm-0 0.00 0.00 0.03 151.82 0.13 607.26 8.00 1.25 8.23 5.16 78.35 dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-2 0.00 0.00 0.67 2774.84 2.80 11099.37 8.00 474.30 170.89 0.24 66.84 dm-3 0.00 0.00 0.67 2774.84 2.80 11099.37 8.00 474.30 170.89 0.24 66.84 Looks like iotop is the ideal tool to use to sniff out these kinds of issues. But I'm on CentOS 5.6, which doesn't have a new enough kernel to support that program. I looked at Determining which process is causing heavy disk I/O?, and besides iotop, one of the suggestions said to do a "echo 1 /proc/sys/vm/block_dump". I did that (after directing kernel messages to tempfs). In about 13 minutes I had about 700k reads or writes, roughly half from kjournald and the other half from nfsd: # egrep " kernel: .*(READ|WRITE)" messages | wc -l 768439 # egrep " kernel: kjournald.*(READ|WRITE)" messages | wc -l 403615 # egrep " kernel: nfsd.*(READ|WRITE)" messages | wc -l 314028 For what it's worth, for the last hour, utilization has constantly been over 90% for the home directory drive. My 30-second iostat keeps showing output like this: Time: 09:36:30 PM Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sda 0.00 6.46 0.20 11.33 0.80 71.71 12.58 0.24 20.53 14.37 16.56 sda1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sda2 0.00 6.46 0.20 11.33 0.80 71.71 12.58 0.24 20.53 14.37 16.56 sdb 137.29 7.00 549.92 3.80 22817.19 43.19 82.57 3.02 5.45 1.74 96.32 sdb1 137.29 7.00 549.92 3.80 22817.19 43.19 82.57 3.02 5.45 1.74 96.32 dm-0 0.00 0.00 0.20 17.76 0.80 71.04 8.00 0.38 21.21 9.22 16.57 dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 dm-2 0.00 0.00 687.47 10.80 22817.19 43.19 65.48 4.62 6.61 1.43 99.81 dm-3 0.00 0.00 687.47 10.80 22817.19 43.19 65.48 4.62 6.61 1.43 99.82

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  • Network authentication + roaming home directory - which technology should I look into using?

    - by Brian
    I'm looking into software which provides a user with a single identity across multiple computers. That is, a user should have the same permissions on each computer, and the user should have access to all of his or her files (roaming home directory) on each computer. There seem to be many solutions for this general idea, but I'm trying to determine the best one for me. Here are some details along with requirements: The network of machines are Amazon EC2 instances running Ubuntu. We access the machines with SSH. Some machines on this LAN may have different uses, but I am only discussing machines for a certain use (running a multi-tenancy platform). The system will not necessarily have a constant amount of machines. We may have to permanently or temporarily alter the amount of machines running. This is the the reason why I'm looking into centralized authentication/storage. The implementation of this effect should be a secure one. We're unsure if users will have direct shell access, but their software will potentially be running (under restricted Linux user names, of course) on our systems, which is as good as direct shell access. Let's assume that their software could potentially be malicious for the sake of security. I have heard of several technologies/combinations to achieve my goal, but I'm unsure of the ramifications of each. An older ServerFault post recommended NFS & NIS, though the combination has security problems according to this old article by Symantec. The article suggests moving to NIS+, but, as it is old, this Wikipedia article has cited statements suggesting a trending away from NIS+ by Sun. The recommended replacement is another thing I have heard of... LDAP. It looks like LDAP can be used to save user information in a centralized location on a network. NFS would still need to be used to cover the 'roaming home folder' requirement, but I see references of them being used together. Since the Symantec article pointed out security problems in both NIS and NFS, is there software to replace NFS, or should I heed that article's suggestions for locking it down? I'm tending toward LDAP because another fundamental piece of our architecture, RabbitMQ, has a authentication/authorization plugin for LDAP. RabbitMQ will be accessible in a restricted manner to users on the system, so I would like to tie the security systems together if possible. Kerberos is another secure authentication protocol that I have heard of. I learned a bit about it some years ago in a cryptography class but don't remember much about it. I have seen suggestions online that it can be combined with LDAP in several ways. Is this necessary? What are the security risks of LDAP without Kerberos? I also remember Kerberos being used in another piece of software developed by Carnegie Mellon University... Andrew File System, or AFS. OpenAFS is available for use, though its setup seems a bit complicated. At my university, AFS provides both requirements... I can log in to any machine, and my "AFS folder" is always available (at least when I acquire an AFS token). Along with suggestions for which path I should look into, does anybody have any guides which were particularly helpful? As the bold text pointed out, LDAP looks to be the best choice, but I'm particularly interested in the implementation details (Keberos? NFS?) with respect to security.

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  • DHCP and DNS services configuration for VOIP system, windows domain, etc

    - by Stemen
    My company has numerous physical offices (for purposes of this discussion, 15 buildings). Some of them are well-connected to our primary data center via fiber. Others will be connected to the data center by P2P T1. We are in the beginning stages of implementing an Avaya VOIP telephone system, and we will be replacing a significant portion of our network infrastructure in the process. In tandem with the phone system implementation, we are going to be re-addressing some of our networks, and consolidating most of our Windows domains into one (not all domains, just most). We currently have quite a few Windows domains, and they of course each have their own DNS zones. A few of those networks currently use DHCP, but the majority use static IP assignments for every device. I'm tired of managing static assignments -- I want to use DHCP configuration on everything except servers. Printers and etc will have DHCP reservations. The new IP phones will need to get IP addresses from DHCP, though they need to be in a separate VLAN from the computers/printers/etc. The computers and printers need to be registered in DNS. That's currently handled by the Windows DHCP servers on each of the respective domains. We need to place a priority on DHCP and DNS being available on a per-site basis (in case something were to interrupt the WAN connection) for computers and (primarily) phones. Smaller locations (which will have IP phones but not be a member of any Windows domain) will not have any Windows DNS/DHCP server(s) available. We also are looking for the easiest way to replace a part if it were to fail. That is to say, if a server/appliance/router hosting DHCP were to crash hard, and we couldn't extremely quickly recover the DHCP reservations and leases (and subsequently restore them onto a cold spare), we anticipate that bad things could happen. What is the best idea for how to re-implement DNS and DHCP keeping all of the above in mind? Some thoughts that have been raised (by myself or my coworkers): Use Windows DNS and DHCP servers, where they exist, and use IP helpers to route DHCP requests to some other Windows server if necessary. May not be acceptable if the WAN goes down and clients don't get a DHCP response. Use Windows DNS (everywhere, over WAN in some cases) and a mix of Windows DHCP and DHCP provided by Cisco routers. Every site would be covered for DHCP, but from what I've read, Cisco routers can't handle dynamic registration of DHCP clients to Windows DNS servers, which might create a problem where Cisco routers are used for DHCP. Use Windows DNS (everywhere, over WAN in some cases) and a mix of Windows DHCP and DHCP provided by some service running on an extremely low-price linux server. Is there any such software that would allow DHCP leases granted by these linux boxes to be dynamically registered on the Windows DNS servers? Come up with a Linux solution for both DNS and DHCP, and deploy low-price linux servers to every site. Requirements would be that the DNS zone be multi-master (like Windows DNS integrated with Active Directory), that DHCP be able to make dynamic DNS registrations in that zone, for every lease (where a hostname is provided and is thus possible), and that multiple servers be either authoritative for the same DHCP scope or at least receiving a real-time copy / replication / sync of the leases table so that if one server dies, we still know which MAC has what address. Purchase dedicated DNS/DHCP appliances, deploying to all sites. From what I read/see, this solves all of our technical problems. Then come the financial problems... I don't have a ton of money to spend on this. Or, some other solution that we've thus far overlooked and will consider upon recommendation. Can Cisco routers or Windows servers sync DHCP lease tables so that multiple servers can be authoritative (or active/passive for all I care) for the same scope, in case one of the partners were to fail? I've read online (repeatedly) that ISC's DHCP is able to maintain the same lease table across multiple servers, in order to solve this problem. Does anyone have any experience or advice to regarding that?

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  • Lag spikes at full CPU usage, lagy mouse, maybe video card

    - by Roberts
    My PC specs: Motherboard Name - Gigabyte GA-945PL-S3 CPU Type - DualCore Intel Core 2 Duo E4300, 1800 MHz (9 x 200) OS - Microsoft Windows 7 Ultimate OS Kernel Type - 32-bit OS Version - 6.1.7601 I bougth a new video card one month ago. GeForce 210. I didn't have any problems. I wanted to overclock it, in other words: "Play with it". So I installed Gigabyte EasyBoost from CD and overclocked the GPU 590 + 110 mhz, memory to max to 960mhz from 800mhz. Benchmarks showed a little bit bigger score. Then I overclocked shader clock from 1405 to [..] (don't remeber really). So I was playing Modern Warfare 2 when off sudden computer froze when I wanted to select team, I was afk before that. I had to reset CMOS. After that I had problems with Skype: unread messages and no sound. Then I figured it out that when ever I open EasyBoost - Skype starts to glitch again. Now I use EVGA Precission X. Now after a month, I cleaned computer and closed the case, it was open all the time. I started to overclock GPU clock only (just a bit) because there was no problems that would stop me. So sometimes on heavy CPU load graphics starts to lag. Dragging a window is painful to watch too. Sometimes the screen freezes for 5 to 10 seconds (I can see that hard disk activity is maximal). You may say that CPU fault it is, isn't it? But sometimes lag spikes starts randomly when CPU load is at maximum. All 3 benchmark softwares (PerformanceTest, NovaBench and MSI Kombustor) shows that performance of my video card has dropped about 25%. BUT! CPU score is lower too. I ignored these problems but when I refreshed Windows Experience Index I was shocked. Month before (in latvian language but not so hard to understand): Now 01.04.2012 (upgraded RAM): This happened when I tried to capture Minecraft with Fraps on underclocked GPU to 580mhz (def: 590mhz): All drivers are up to date. Average CPU temperature from 55°C to 75°C (at 70°C sometimes starts these lag spikes). Video card's tempratures are from 45°C to 60°C (very hard to reach 60°C). So my hope is that the video card is fine, cause this card is very new and I want to upgrade CPU anyways. Aplogies for my mistakes in vocabulary (I am trying to type this as fast I can). Update 02.04.2012 - 7:21 Forgot one thing, my hard disk is extrimly slow and I will upgrade it this week or next week so I will be installing same OS again. I am multi-tasker but I can't do much because of 1.8 GHz CPU and slow hard drive (Model ID - WDC WD800JD-60JRC0). The Windows Experience Index is back to normal. Actually "Spelu grafika" (Gaming graphics) are higher than month ago. During this test mouse was very lagy, but month ago there weren't any problems. WHY!?

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  • xen debian: domU can't get out side

    - by iftol
    hi every body. i'm a trainee as a sysAdmin, it is my first expérience with virtualization. i have a server setup debian xen 3 with 2 physical interfaces. eth 0 for local network 10.0.0.1 and eth1 for internet (194.X.X.4). i created 3 VMs (web server, mail server and dabase server) with local ip addresses 172.10.0.x/24. the problem i had first is that domU can't ping dom0. i asked the sysAdmin of our ISP and he sais that he fogot to setup the bridginb. so he ceated a bridge with 172.10.0.1/24 after that i was able to ping the real server (194.X.X.4). but i can't go out side from my VMs, how can i fixe this issue? real or physical server ifconfig eth0 Link encap:Ethernet HWaddr 23:26:34:84:ce:xe inet adr:10.1.3.12 Bcast:10.1.3.255 Masque:255.255.255.0 adr inet6: fe80::226:b9ff:fe84:ceb4/64 Scope:Lien UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:412006 errors:0 dropped:0 overruns:0 frame:0 TX packets:411296 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 lg file transmission:1000 RX bytes:31410957 (29.9 MiB) TX bytes:31178370 (29.7 MiB) Interruption:36 Mémoire:d6000000-d6012100 eth1 Link encap:Ethernet HWaddr 23:26:34:84:ce:xe inet adr:194.x.x.4 Bcast:194.254.167.255 Masque:255.255.255.0 adr inet6: fe80::226:b9ff:fe84:ceb6/64 Scope:Lien UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:25872332 errors:0 dropped:0 overruns:0 frame:0 TX packets:414578 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 lg file transmission:0 RX bytes:2642278343 (2.4 GiB) TX bytes:35436775 (33.7 MiB) lo Link encap:Boucle locale inet adr:127.0.0.1 Masque:255.0.0.0 adr inet6: ::1/128 Scope:Hôte UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:1308073 errors:0 dropped:0 overruns:0 frame:0 TX packets:1308073 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 lg file transmission:0 RX bytes:109871395 (104.7 MiB) TX bytes:109871395 (104.7 MiB) peth1 Link encap:Ethernet HWaddr 23:26:34:84:ce:xe UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:31818694 errors:0 dropped:0 overruns:0 frame:0 TX packets:414818 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 lg file transmission:1000 RX bytes:5197318822 (4.8 GiB) TX bytes:37904897 (36.1 MiB) Interruption:48 Mémoire:d8000000-d8012100 vif281.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff adr inet6: fe80::fcff:ffff:feff:ffff/64 Scope:Lien UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:207 errors:0 dropped:0 overruns:0 frame:0 TX packets:298 errors:0 dropped:2 overruns:0 carrier:0 collisions:0 lg file transmission:32 RX bytes:24629 (24.0 KiB) TX bytes:28404 (27.7 KiB) vif281.1 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff adr inet6: fe80::fcff:ffff:feff:ffff/64 Scope:Lien UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:45 errors:0 dropped:47063 overruns:0 carrier:0 collisions:0 lg file transmission:32 RX bytes:0 (0.0 B) TX bytes:4449 (4.3 KiB) vif282.0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff adr inet6: fe80::fcff:ffff:feff:ffff/64 Scope:Lien UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:78 errors:0 dropped:0 overruns:0 frame:0 TX packets:13 errors:0 dropped:1 overruns:0 carrier:0 collisions:0 lg file transmission:32 RX bytes:5041 (4.9 KiB) TX bytes:714 (714.0 B) xenbr0 Link encap:Ethernet HWaddr fe:ff:ff:ff:ff:ff inet adr:172.10.0.1 Bcast:172.10.0.255 Masque:255.255.255.0 adr inet6: fe80::5c72:c6ff:fe49:7fe/64 Scope:Lien UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7180 errors:0 dropped:0 overruns:0 frame:0 TX packets:8615 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 lg file transmission:0 RX bytes:756804 (739.0 KiB) TX bytes:791206 (772.6 KiB) brtcl show bridge name bridge id STP enabled interfaces eth1 8000.0026b984ceb6 no peth1 vif281.1 xenbr0 8000.feffffffffff no vif281.0 vif282.0 network-multi-bridge /etc/xen/scripts/network-virtual start vifnum="0" bridgeip="172.10.0.1/24" brnet="172.10.0.0/24" VM webserver eth0 Link encap:Ethernet HWaddr 00:16:3E:42:33:70 inet addr:172.10.0.2 Bcast:172.10.0.255 Mask:255.255.255.0 inet6 addr: fe80::216:3eff:fe42:3370/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:3 errors:0 dropped:0 overruns:0 frame:0 TX packets:27 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:126 (126.0 b) TX bytes:2036 (1.9 KiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) Thank you for your help.

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