Search Results

Search found 26695 results on 1068 pages for 'domain driven design'.

Page 181/1068 | < Previous Page | 177 178 179 180 181 182 183 184 185 186 187 188  | Next Page >

• How would you gather client's data on Google App Engine without using Datastore/Backend Instances too much?

  - by ruslan

  I'm relatively new to StackExchange and not sure if it's appropriate place to ask design question. Site gives me a hint "The question you're asking appears subjective and is likely to be closed". Please let me know. Anyway.. One of the projects I'm working on is online survey engine. It's my first big commercial project on Google App Engine. I need your advice on how to collect stats and efficiently record them in DataStore without bankrupting me. Initial requirements are: After user finishes survey client sends list of pairs [ID (int) + PercentHit (double)]. This list shows how close answers of this user match predefined answers of reference answerers (which identified by IDs). I call them "target IDs". Creator of the survey wants to see aggregated % for given IDs for last hour, particular timeframe or from the beginning of the survey. Some surveys may have thousands of target/reference answerers. So I created entity public class HitsStatsDO implements Serializable { @Id transient private Long id; transient private Long version = (long) 0; transient private Long startDate; @Parent transient private Key parent; // fake parent which contains target id @Transient int targetId; private double avgPercent; private long hitCount; } But writing HitsStatsDO for each target from each user would give a lot of data. For instance I had a survey with 3000 targets which was answered by ~4 million people within one week with 300K people taking survey in first day. Even if we assume they were answering it evenly for 24 hours it would give us ~1040 writes/second. Obviously it hits concurrent writes limit of Datastore. I decided I'll collect data for one hour and save that, that's why there are avgPercent and hitCount in HitsStatsDO. GAE instances are stateless so I had to use dynamic backend instance. There I have something like this: // Contains stats for one hour private class Shard { ReadWriteLock lock = new ReentrantReadWriteLock(); Map<Integer, HitsStatsDO> map = new HashMap<Integer, HitsStatsDO>(); // Key is target ID public void saveToDatastore(); public void updateStats(Long startDate, Map<Integer, Double> hits); } and map with shard for current hour and previous hour (which doesn't stay here for long) private HashMap<Long, Shard> shards = new HashMap<Long, Shard>(); // Key is HitsStatsDO.startDate So once per hour I dump Shard for previous hour to Datastore. Plus I have class LifetimeStats which keeps Map<Integer, HitsStatsDO> in memcached where map-key is target ID. Also in my backend shutdown hook method I dump stats for unfinished hour to Datastore. There is only one major issue here - I have only ONE backend instance :) It raises following questions on which I'd like to hear your opinion: Can I do this without using backend instance ? What if one instance is not enough ? How can I split data between multiple dynamic backend instances? It hard because I don't know how many I have because Google creates new one as load increases. I know I can launch exact number of resident backend instances. But how many ? 2, 5, 10 ? What if I have no load at all for a week. Constantly running 10 backend instances is too expensive. What do I do with data from clients while backend instance is dead/restarting? Thank you very much in advance for your thoughts.

  Read the article

• Method flags as arguments or as member variables?

  - by Martin

  I think the title "Method flags as arguments or as member variables?" may be suboptimal, but as I'm missing any better terminology atm., here goes: I'm currently trying to get my head around the problem of whether flags for a given class (private) method should be passed as function arguments or via member variable and/or whether there is some pattern or name that covers this aspect and/or whether this hints at some other design problems. By example (language could be C++, Java, C#, doesn't really matter IMHO): class Thingamajig { private ResultType DoInternalStuff(FlagType calcSelect) { ResultType res; for (... some loop condition ...) { ... if (calcSelect == typeA) { ... } else if (calcSelect == typeX) { ... } else if ... } ... return res; } private void InteralStuffInvoker(FlagType calcSelect) { ... DoInternalStuff(calcSelect); ... } public void DoThisStuff() { ... some code ... InternalStuffInvoker(typeA); ... some more code ... } public ResultType DoThatStuff() { ... some code ... ResultType x = DoInternalStuff(typeX); ... some more code ... further process x ... return x; } } What we see above is that the method InternalStuffInvoker takes an argument that is not used inside this function at all but is only forwarded to the other private method DoInternalStuff. (Where DoInternalStuffwill be used privately at other places in this class, e.g. in the DoThatStuff (public) method.) An alternative solution would be to add a member variable that carries this information: class Thingamajig { private ResultType DoInternalStuff() { ResultType res; for (... some loop condition ...) { ... if (m_calcSelect == typeA) { ... } ... } ... return res; } private void InteralStuffInvoker() { ... DoInternalStuff(); ... } public void DoThisStuff() { ... some code ... m_calcSelect = typeA; InternalStuffInvoker(); ... some more code ... } public ResultType DoThatStuff() { ... some code ... m_calcSelect = typeX; ResultType x = DoInternalStuff(); ... some more code ... further process x ... return x; } } Especially for deep call chains where the selector-flag for the inner method is selected outside, using a member variable can make the intermediate functions cleaner, as they don't need to carry a pass-through parameter. On the other hand, this member variable isn't really representing any object state (as it's neither set nor available outside), but is really a hidden additional argument for the "inner" private method. What are the pros and cons of each approach?

  Read the article

• How should I plan the inheritance structure for my game?

  - by Eric Thoma

  I am trying to write a platform shooter in C++ with a really good class structure for robustness. The game itself is secondary; it is the learning process of writing it that is primary. I am implementing an inheritance tree for all of the objects in my game, but I find myself unsure on some decisions. One specific issue that it bugging me is this: I have an Actor that is simply defined as anything in the game world. Under Actor is Character. Both of these classes are abstract. Under Character is the Philosopher, who is the main character that the user commands. Also under Character is NPC, which uses an AI module with stock routines for friendly, enemy and (maybe) neutral alignments. So under NPC I want to have three subclasses: FriendlyNPC, EnemyNPC and NeutralNPC. These classes are not abstract, and will often be subclassed in order to make different types of NPC's, like Engineer, Scientist and the most evil Programmer. Still, if I want to implement a generic NPC named Kevin, it would nice to be able to put him in without making a new class for him. I could just instantiate a FriendlyNPC and pass some values for the AI machine and for the dialogue; that would be ideal. But what if Kevin is the one benevolent Programmer in the whole world? Now we must make a class for him (but what should it be called?). Now we have a character that should inherit from Programmer (as Kevin has all the same abilities but just uses the friendly AI functions) but also should inherit from FriendlyNPC. Programmer and FriendlyNPC branched away from each other on the inheritance tree, so inheriting from both of them would have conflicts, because some of the same functions have been implemented in different ways on the two of them. 1) Is there a better way to order these classes to avoid these conflicts? Having three subclasses; Friendly, Enemy and Neutral; from each type of NPC; Engineer, Scientist, and Programmer; would amount to a huge number of classes. I would share specific implementation details, but I am writing the game slowly, piece by piece, and so I haven't implemented past Character yet. 2) Is there a place where I can learn these programming paradigms? I am already trying to take advantage of some good design patterns, like MVC architecture and Mediator objects. The whole point of this project is to write something in good style. It is difficult to tell what should become a subclass and what should become a state (i.e. Friendly boolean v. Friendly class). Having many states slows down code with if statements and makes classes long and unwieldy. On the other hand, having a class for everything isn't practical. 3) Are there good rules of thumb or resources to learn more about this? 4) Finally, where does templating come in to this? How should I coordinate templates into my class structure? I have never actually taken advantage of templating honestly, but I hear that it increases modularity, which means good code.

  Read the article

• Would this be a good web application architecture?

  - by Gustav Bertram

  My problem Our MVC based framework does not allow us to cache only part of our output. Ideally we want to cahce static and semi-static bits, and run dynamic bits. In addition, we need to consider data caching that reacts to database changes. My idea The concept I came up with was to represent a page as a tree of XML fragment objects. (I say XML, but I mean XHTML). Some of the fragments are dynamic, and can pull their data directly from models or other sources, but most of the fragments are static scaffolding. If a subtree of fragments is completely static, then I imagine that they could unfold into pure XML that would then be cached as the text representation of their parent element. This process would ideally continue until we are left with a root element that contains all of the static XML, and has a couple of dynamic XML fragments that are resolved and attached to the relevant nodes of the XML tree just before the page is displayed. In addition to separating content into dynamic and static fragments, some fragments could be dynamic and cached. A simple expiry time which propagates up through the XML fragment tree would indicate that a specific fragment should periodically be refreshed. A newspaper section or front page does not need to be updated each second. Minutes or sometimes even longer is sufficient. Other fragments would be dynamic and uncached. Typically too many articles are viewed for them to be cached - the cache would overflow. Some individual articles may be cached if they are extremely popular. Functional notes The folding mechanism could be to be smart enough to judge when it would be more profitable to fold a dynamic cached fragment and propagate the expiry date to the parent fragment, or to keep it separate and simple attach to the XML tree when resolving the page. If some dynamic cached fragments are associated to database objects through mechanisms like a globally unique content id, then changes to the database could trigger changes to the output cache. If fragments store the identifiers of parent fragments, then they could trigger a refolding process that would then include the updated data. A set of pure XML with an ordered array of fragment objects (that each store the identifying information of the node to which they should be attached), can be resolved in a fairly simple way by walking the XML tree, and merging the data from the fragments. Because it is not necessary to parse and construct the entire tree in memory before attaching nodes, processing should be fairly fast. The identifiers of each fragment would be a combination of relevant identity data and the type of fragment object. Cached parent fragments would contain references to these identifiers, in order to then either pull them from the fragment cache, or to run their code. The controller's responsibility is reduced to making changes to the database, and telling the root XML fragment object to render itself. The Question My question has two parts: Is this a good design? Are there any obvious flaws I'm missing? Has somebody else thought of this before? References? Is there an existing alternative that I should consider? A cool templating engine maybe?

  Read the article

• Writing a method to 'transform' an immutable object: how should I approach this?

  - by Prog

  (While this question has to do with a concrete coding dilemma, it's mostly about what's the best way to design a function.) I'm writing a method that should take two Color objects, and gradually transform the first Color into the second one, creating an animation. The method will be in a utility class. My problem is that Color is an immutable object. That means that I can't do color.setRGB or color.setBlue inside a loop in the method. What I can do, is instantiate a new Color and return it from the method. But then I won't be able to gradually change the color. So I thought of three possible solutions: 1- The client code includes the method call inside a loop. For example: int duration = 1500; // duration of the animation in milliseconds int steps = 20; // how many 'cycles' the animation will take for(int i=0; i<steps; i++) color = transformColor(color, targetColor, duration, steps); And the method would look like this: Color transformColor(Color original, Color target, int duration, int steps){ int redDiff = target.getRed() - original.getRed(); int redAddition = redDiff / steps; int newRed = original.getRed() + redAddition; // same for green and blue .. Thread.sleep(duration / STEPS); // exception handling omitted return new Color(newRed, newGreen, newBlue); } The disadvantage of this approach is that the client code has to "do part of the method's job" and include a for loop. The method doesn't do it's work entirely on it's own, which I don't like. 2- Make a mutable Color subclass with methods such as setRed, and pass objects of this class into transformColor. Then it could look something like this: void transformColor(MutableColor original, Color target, int duration){ final int STEPS = 20; int redDiff = target.getRed() - original.getRed(); int redAddition = redDiff / steps; int newRed = original.getRed() + redAddition; // same for green and blue .. for(int i=0; i<STEPS; i++){ original.setRed(original.getRed() + redAddition); // same for green and blue .. Thread.sleep(duration / STEPS); // exception handling omitted } } Then the calling code would usually look something like this: // The method will usually transform colors of JComponents JComponent someComponent = ... ; // setting the Color in JComponent to be a MutableColor Color mutableColor = new MutableColor(someComponent.getForeground()); someComponent.setForeground(mutableColor); // later, transforming the Color in the JComponent transformColor((MutableColor)someComponent.getForeground(), new Color(200,100,150), 2000); The disadvantage is - the need to create a new class MutableColor, and also the need to do casting. 3- Pass into the method the actual mutable object that holds the color. Then the method could do object.setColor or similar every iteration of the loop. Two disadvantages: A- Not so elegant. Passing in the object that holds the color just to transform the color feels unnatural. B- While most of the time this method will be used to transform colors inside JComponent objects, other kinds of objects may have colors too. So the method would need to be overloaded to receive other types, or receive Objects and have instanceof checks inside.. Not optimal. Right now I think I like solution #2 the most, than solution #1 and solution #3 the least. However I'd like to hear your opinions and suggestions regarding this.

  Read the article

• Is my class structure good enough?

  - by Rivten

  So I wanted to try out this challenge on reddit which is mostly about how you structure your data the best you can. I decided to challenge my C++ skills. Here's how I planned this. First, there's the Game class. It deals with time and is the only class main has access to. A game has a Forest. For now, this class does not have a lot of things, only a size and a Factory. Will be put in better use when it will come to SDL-stuff I guess A Factory is the thing that deals with the Game Objects (a.k.a. Trees, Lumberjack and Bears). It has a vector of all GameObjects and a queue of Events which will be managed at the end of one month. A GameObject is an abstract class which can be updated and which can notify the Event Listener The EventListener is a class which handles all the Events of a simulation. It can recieve events from a Game Object and notify the Factory if needed, the latter will manage correctly the event. So, the Tree, Lumberjack and Bear classes all inherits from GameObject. And Sapling and Elder Tree inherits from Tree. Finally, an Event is defined by an event_type enumeration (LUMBERJACK_MAWED, SAPPLING_EVOLUTION, ...) and an event_protagonists union (a GameObject or a pair of GameObject (who killed who ?)). I was quite happy at first with this because it seems quite logic and flexible. But I ended up questionning this structure. Here's why : I dislike the fact that a GameObject need to know about the Factory. Indeed, when a Bear moves somewhere, it needs to know if there's a Lumberjack ! Or it is the Factory which handles places and objects. It would be great if a GameObject could only interact with the EventListener... or maybe it's not that much of a big deal. Wouldn't it be better if I separate the Factory in three vectors ? One for each kind of GameObject. The idea would be to optimize research. If I'm looking do delete a dead lumberjack, I would only have to look in one shorter vector rather than a very long vector. Another problem arises when I want to know if there is any particular object in a given case because I have to look for all the gameObjects and see if they are at the given case. I would tend to think that the other idea would be to use a matrix but then the issue would be that I would have empty cases (and therefore unused space). I don't really know if Sapling and Elder Tree should inherit from Tree. Indeed, a Sapling is a Tree but what about its evolution ? Should I just delete the sapling and say to the factory to create a new Tree at the exact same place ? It doesn't seem natural to me to do so. How could I improve this ? Is the design of an Event quite good ? I've never used unions before in C++ but I didn't have any other ideas about what to use. Well, I hope I have been clear enough. Thank you for taking the time to help me !

  Read the article

• Why is 0 false?

  - by Morwenn

  This question may sound dumb, but why does 0 evaluates to false and any other [integer] value to true is most of programming languages? String comparison Since the question seems a little bit too simple, I will explain myself a little bit more: first of all, it may seem evident to any programmer, but why wouldn't there be a programming language - there may actually be, but not any I used - where 0 evaluates to true and all the other [integer] values to false? That one remark may seem random, but I have a few examples where it may have been a good idea. First of all, let's take the example of strings three-way comparison, I will take C's strcmp as example: any programmer trying C as his first language may be tempted to write the following code: if (strcmp(str1, str2)) { // Do something... } Since strcmp returns 0 which evaluates to false when the strings are equal, what the beginning programmer tried to do fails miserably and he generally does not understand why at first. Had 0 evaluated to true instead, this function could have been used in its most simple expression - the one above - when comparing for equality, and the proper checks for -1 and 1 would have been done only when needed. We would have considered the return type as bool (in our minds I mean) most of the time. Moreover, let's introduce a new type, sign, that just takes values -1, 0 and 1. That can be pretty handy. Imagine there is a spaceship operator in C++ and we want it for std::string (well, there already is the compare function, but spaceship operator is more fun). The declaration would currently be the following one: sign operator<=>(const std::string& lhs, const std::string& rhs); Had 0 been evaluated to true, the spaceship operator wouldn't even exist, and we could have declared operator== that way: sign operator==(const std::string& lhs, const std::string& rhs); This operator== would have handled three-way comparison at once, and could still be used to perform the following check while still being able to check which string is lexicographically superior to the other when needed: if (str1 == str2) { // Do something... } Old errors handling We now have exceptions, so this part only applies to the old languages where no such thing exist (C for example). If we look at C's standard library (and POSIX one too), we can see for sure that maaaaany functions return 0 when successful and any integer otherwise. I have sadly seen some people do this kind of things: #define TRUE 0 // ... if (some_function() == TRUE) { // Here, TRUE would mean success... // Do something } If we think about how we think in programming, we often have the following reasoning pattern: Do something Did it work? Yes -> That's ok, one case to handle No -> Why? Many cases to handle If we think about it again, it would have made sense to put the only neutral value, 0, to yes (and that's how C's functions work), while all the other values can be there to solve the many cases of the no. However, in all the programming languages I know (except maybe some experimental esotheric languages), that yes evaluates to false in an if condition, while all the no cases evaluate to true. There are many situations when "it works" represents one case while "it does not work" represents many probable causes. If we think about it that way, having 0 evaluate to true and the rest to false would have made much more sense. Conclusion My conclusion is essentially my original question: why did we design languages where 0 is false and the other values are true, taking in account my few examples above and maybe some more I did not think of? Follow-up: It's nice to see there are many answers with many ideas and as many possible reasons for it to be like that. I love how passionate you seem to be about it. I originaly asked this question out of boredom, but since you seem so passionate, I decided to go a little further and ask about the rationale behind the Boolean choice for 0 and 1 on Math.SE :)

  Read the article

• Best Method For Evaluating Existing Software or New Software

  How many of us have been faced with having to decide on an off-the-self or a custom built component, application, or solution to integrate in to an existing system or to be the core foundation of a new system? What is the best method for evaluating existing software or new software still in the design phase? One of the industry preferred methodologies to use is the Active Reviews for Intermediate Designs (ARID) evaluation process.  ARID is a hybrid mixture of the Active Design Review (ADR) methodology and the Architectural Tradeoff Analysis Method (ATAM). So what is ARID? ARD’s main goal is to ensure quality, detailed designs in software. One way in which it does this is by empowering reviewers by assigning generic open ended survey questions. This approach attempts to remove the possibility for allowing the standard answers such as “Yes” or “No”. The ADR process ignores the “Yes”/”No” questions due to the fact that they can be leading based on how the question is asked. Additionally these questions tend to receive less thought in comparison to more open ended questions. Common Active Design Review Questions What possible exceptions can occur in this component, application, or solution? How should exceptions be handled in this component, application, or solution? Where should exceptions be handled in this component, application, or solution? How should the component, application, or solution flow based on the design? What is the maximum execution time for every component, application, or solution? What environments can this component, application, or solution? What data dependencies does this component, application, or solution have? What kind of data does this component, application, or solution require? Ok, now I know what ARID is, how can I apply? Let’s imagine that your organization is going to purchase an off-the-shelf (OTS) solution for its customer-relationship management software. What process would we use to ensure that the correct purchase is made? If we use ARID, then we will have a series of 9 steps broken up by 2 phases in order to ensure that the correct OTS solution is purchases. Phase 1 Identify the Reviewers Prepare the Design Briefing Prepare the Seed Scenarios Prepare the Materials When identifying reviewers for a design it is preferred that they be pulled from a candidate pool comprised of developers that are going to implement the design. The believe is that developers actually implementing the design will have more a vested interest in ensuring that the design is correct prior to the start of code. Design debriefing consist of a summary of the design, examples of the design solving real world examples put in to use and should be no longer than two hours typically. The primary goal of this briefing is to adequately summarize the design so that the review members could actually implement the design. In the example of purchasing an OTS product I would attempt to review my briefing prior to its distribution with the review facilitator to ensure that nothing was excluded that should have not been. This practice will also allow me to test the length of the briefing to ensure that can be delivered in an appropriate about of time. Seed Scenarios are designed to illustrate conceptualized scenarios when applied with a set of sample data. These scenarios can then be used by the reviewers in the actual evaluation of the software, All materials needed for the evaluation should be prepared ahead of time so that they can be reviewed prior to and during the meeting. Materials Included: Presentation Seed Scenarios Review Agenda Phase 2 Present ARID Present Design Brainstorm and prioritize scenarios Apply scenarios Summarize Prior to the start of any ARID review meeting the Facilitator should define the remaining steps of ARID so that all the participants know exactly what they are doing prior to the start of the review process. Once the ARID rules have been laid out, then the lead designer presents an overview of the design which typically takes about two hours. During this time no questions about the design or rational are allowed to be asked by the review panel as a standard, but they are written down for use latter in the process. After the presentation the list of compiled questions is then summarized and sent back to the lead designer as areas that need to be addressed further. In the example of purchasing an OTS product issues could arise regarding security, the implementation needed or even if this is this the correct product to solve the needed solution. After the Design presentation a brainstorming and prioritize scenarios process begins by reducing the seed scenarios down to just the highest priority scenarios.  These will then be used to test the design for suitability. Once the selected scenarios have been defined the reviewers apply the examples provided in the presentation to the scenarios. The intended output of this process is to provide code or pseudo code that makes use of the examples provided while solving the selected seed scenarios. As a standard rule, the designers of the systems are not allowed to help the review board unless they all become stuck. When this occurs it is documented and along with the reason why the designer needed to help the review panel back on track. Once all of the scenarios have been completed the review facilitator reviews with the group issues that arise during the process. Then the reviewers will be polled as to efficacy of the review experience. References: Clements, Paul., Kazman, Rick., Klien, Mark. (2002). Evaluating Software Architectures: Methods and Case Studies Indianapolis, IN: Addison-Wesley

  Read the article

• High Availability for IaaS, PaaS and SaaS in the Cloud

  - by BuckWoody

  Outages, natural disasters and unforeseen events have proved that even in a distributed architecture, you need to plan for High Availability (HA). In this entry I'll explain a few considerations for HA within Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) and Software-as-a-Service (SaaS). In a separate post I'll talk more about Disaster Recovery (DR), since each paradigm has a different way to handle that. Planning for HA in IaaS IaaS involves Virtual Machines - so in effect, an HA strategy here takes on many of the same characteristics as it would on-premises. The primary difference is that the vendor controls the hardware, so you need to verify what they do for things like local redundancy and so on from the hardware perspective. As far as what you can control and plan for, the primary factors fall into three areas: multiple instances, geographical dispersion and task-switching. In almost every cloud vendor I've studied, to ensure your application will be protected by any level of HA, you need to have at least two of the Instances (VM's) running. This makes sense, but you might assume that the vendor just takes care of that for you - they don't. If a single VM goes down (for whatever reason) then the access to it is lost. Depending on multiple factors, you might be able to recover the data, but you should assume that you can't. You should keep a sync to another location (perhaps the vendor's storage system in another geographic datacenter or to a local location) to ensure you can continue to serve your clients. You'll also need to host the same VM's in another geographical location. Everything from a vendor outage to a network path problem could prevent your users from reaching the system, so you need to have multiple locations to handle this. This means that you'll have to figure out how to manage state between the geo's. If the system goes down in the middle of a transaction, you need to figure out what part of the process the system was in, and then re-create or transfer that state to the second set of systems. If you didn't write the software yourself, this is non-trivial. You'll also need a manual or automatic process to detect the failure and re-route the traffic to your secondary location. You could flip a DNS entry (if your application can tolerate that) or invoke another process to alias the first system to the second, such as load-balancing and so on. There are many options, but all of them involve coding the state into the application layer. If you've simply moved a state-ful application to VM's, you may not be able to easily implement an HA solution. Planning for HA in PaaS Implementing HA in PaaS is a bit simpler, since it's built on the concept of stateless applications deployment. Once again, you need at least two copies of each element in the solution (web roles, worker roles, etc.) to remain available in a single datacenter. Also, you need to deploy the application again in a separate geo, but the advantage here is that you could work out a "shared storage" model such that state is auto-balanced across the world. In fact, you don't have to maintain a "DR" site, the alternate location can be live and serving clients, and only take on extra load if the other site is not available. In Windows Azure, you can use the Traffic Manager service top route the requests as a type of auto balancer. Even with these benefits, I recommend a second backup of storage in another geographic location. Storage is inexpensive; and that second copy can be used for not only HA but DR. Planning for HA in SaaS In Software-as-a-Service (such as Office 365, or Hadoop in Windows Azure) You have far less control over the HA solution, although you still maintain the responsibility to ensure you have it. Since each SaaS is different, check with the vendor on the solution for HA - and make sure you understand what they do and what you are responsible for. They may have no HA for that solution, or pin it to a particular geo, or perhaps they have a massive HA built in with automatic load balancing (which is often the case).   All of these options (with the exception of SaaS) involve higher costs for the design. Do not sacrifice reliability for cost - that will always cost you more in the end. Build in the redundancy and HA at the very outset of the project - if you try to tack it on later in the process the business will push back and potentially not implement HA. References: http://www.bing.com/search?q=windows+azure+High+Availability  (each type of implementation is different, so I'm routing you to a search on the topic - look for the "Patterns and Practices" results for the area in Azure you're interested in)

  Read the article

• 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; }

  Read the article

• BIND returns serverfail when querying for its authoriative domain

  - by estol

  Hi there Serverfault folks! First of all: sorry about the title, I had some problem coming up with the proper title. I have a little home server set up, for internet sharing, samba, basic http, dlna mediaserver and what not, and I happend to have a domain at hand, so I thought why not direct it to this computer? I have a BIND 9.8.0 installed, and - afaik - configured it properly. For a few days, the public view did not worked, and I really did not cared, since the local view worked. But now suddenly, even the local view fails. If I try to query the nameserver for anything in my domain, it returns the following error: $ nslookup andromeda.dafaces.com ;; Got SERVFAIL reply from ::1, trying next server ;; Got SERVFAIL reply from ::1, trying next server Server: 127.0.0.1 Address: 127.0.0.1#53 ** server can't find andromeda.dafaces.com.dafaces.com: SERVFAIL Also, the public view points to the old ip address of the domain, probably because of the same error. Some information about the system: $ uname -a Linux tressis 2.6.37-ARCH #1 SMP PREEMPT Tue Mar 15 09:21:17 CET 2011 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 5000+ AuthenticAMD GNU/Linux $ named -v BIND 9.8.0 And the named.conf file: # cat /etc/named.conf // // /etc/named.conf // include "/etc/rndc.key"; #controls { # inet 127.0.0.1 allow {localhost; } keys { "dnskulcs"; }; #}; options { directory "/var/named"; pid-file "/var/run/named/named.pid"; auth-nxdomain yes; datasize default; // Uncomment these to enable IPv6 connections support // IPv4 will still work: listen-on-v6 { any; }; listen-on { any; }; // Add this for no IPv4: // listen-on { none; }; // Default security settings. // allow-recursion { 127.0.0.1; ::1; 192.168.1.0/24; }; // allow-recursion { any; }; allow-query { any; }; allow-transfer { 127.0.0.1; ::1; 92.243.14.172; 87.98.164.164; 88.191.64.64; }; allow-update { key "dnskulcs"; }; version none; hostname none; server-id none; zone-statistics yes; forwarders { 213.46.246.53; 213.26.246.54; 8.8.8.8; 8.8.4.4; 192.188.242.65; 193.227.196.3; 2001:470:20::2; }; }; view "local" { match-clients { 192.168.1.0/24; 127.0.0.1; ::1; fec0:0:0:ffff::/64; }; recursion yes; zone "localhost" IN { type master; file "localhost.zone"; allow-transfer { any; }; }; zone "0.0.127.in-addr.arpa" IN { type master; file "127.0.0.zone"; allow-transfer { any; }; }; zone "." IN { type hint; file "root.hint"; }; zone "dafaces.com" IN { type master; file "internal/dafaces.com.fw"; allow-update { key "dnskulcs"; }; }; zone "1.168.192.in-addr.arpa" IN { type master; file "internal/dafaces.com.rev"; allow-update { key "dnskulcs"; }; }; }; view "public" { match-clients { any;}; recursion no; zone "dafaces.com" IN { type master; file "external/dafaces.com.fw"; allow-transfer { 87.98.164.164; 195.234.42.1; 88.191.64.64; }; }; }; //zone "example.org" IN { // type slave; // file "example.zone"; // masters { // 192.168.1.100; // }; // allow-query { any; }; // allow-transfer { any; }; //}; logging { channel xfer-log { file "/var/log/named.log"; print-category yes; print-severity yes; print-time yes; severity info; }; category xfer-in { xfer-log; }; category xfer-out { xfer-log; }; category notify { xfer-log; }; }; All help would be highly appreciated! EDIT: Zone files: # cat /var/named/internal/dafaces.com.fw $ORIGIN . $TTL 3600 ; 1 hour dafaces.com IN SOA tressis.dafaces.com. postmaster.dafaces.com. ( 2011032201 ; serial 28800 ; refresh (8 hours) 7200 ; retry (2 hours) 2419200 ; expire (4 weeks) 3600 ; minimum (1 hour) ) NS tressis.dafaces.com. A 192.168.1.1 MX 10 mail.dafaces.com. $ORIGIN _tcp.dafaces.com. _http SRV 0 5 80 www.dafaces.com. _ssh SRV 0 5 22 tressis.dafaces.com. $ORIGIN dafaces.com. acrisius A 192.168.1.230 andromeda A 192.168.1.7 andromeda-win7 CNAME andromeda aspasia A 192.168.1.233 athena A 192.168.1.232 callisto A 192.168.1.102 db A 192.168.1.1 management A 192.168.1.1 ; web management for the router functions haley A 192.168.1.5 hoth A 192.168.1.101 mail A 192.168.1.1 satelite A 192.168.1.20 sony-player A 192.168.1.103 TXT "310f16de2d2712dfc4ae6e5c54f60f828e" torrent A 192.168.1.1 tracker A 192.168.1.1 tressis A 192.168.1.1 www A 192.168.1.1 zeus A 192.168.1.231 and # cat /var/named/external/dafaces.com.fw $ORIGIN . $TTL 3600 dafaces.com IN SOA ns.dafaces.com. postmaster.dafaces.com. ( 2011032405; serial 28800; refresh 7200; retry 2419200; expire 3600; minimum ) NS ns.dafaces.com. NS ns0.xname.org. NS ns1.xname.org. NS ns2.xname.org. A 89.135.129.37 MX 10 mail.dafaces.com. $ORIGIN dafaces.com. ;Szolgaltatasok _ssh._tcp SRV 0 5 22 tressis _http._tcp SRV 0 5 80 www ns A 89.135.129.37 hoth A 89.135.129.37 www A 89.135.129.37 mail A 89.135.129.37 db A 89.135.129.37 torrent A 89.135.129.37 tracker A 89.135.129.37 Edit: Ohh, hell I almost forgot. Since the node is connected to the internet via a residential connection, there is a possibility, that the public ipv4 address will change(but thank god, it is a very rare case), so I daily update the external IP address in the zone file with a shellscript: # cat /etc/cron.daily/dnsupdate #!/bin/sh FILE="/var/named/external/dafaces.com.fw" SERIAL=$(date +%Y%m%d05) PUBLIC_IP=$(ifconfig internet |sed -n "/inet addr:.*255.255.255.255/{s/.*inet addr://; s/ .*//; p}") cat $FILE | sed --posix 's/^.* serial$/\t\t\t\t\t'$SERIAL'; serial/' | sed --posix 's/[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*/'$PUBLIC_IP'/' > /tmp/ujzona mv /tmp/ujzona $FILE /etc/rc.d/named reload

  Read the article

• Wednesday at Oracle OpenWorld 2012 - Must See Session: “Event-Driven Patterns and Best Practices: Even More Important with Big Data”

  - by Lionel Dubreuil

  Don’t miss this “CON8636 - Event-Driven Patterns and Best Practices: Even More Important with Big Data“ session: Speakers: Faisal Nazir - Senior Solutions Architect, Motorola Shinichiro Takahashi - Senior Manager, Service Platform Department, NTT DOCOMO, INC. Robin Smith - Product Management/Strategy Director - Oracle Event Processing, Oracle Date: Wednesday, Oct 3 Time: 10:15 AM - 11:15 AM Location: Moscone South - 310 As the demand for big data analytics and integration grows across all industries, this session focuses on the role of the Oracle event-driven solution platform in delivering vital real-time integrated analysis intelligence to the data streams consumed and emitted from these large distributed data stores. Objectives for this session are to: Increase awareness of Oracle Event Processing, showcasing tight alignment with big data solutions Highlight emerging usage patterns in relation to streaming event data and distributed data stores Show a significant Oracle competitive advantage over IBM solutions advertised in this domain Normal 0 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:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}

  Read the article

• Reading php generated XML in flash?

  - by AdonisSMU

  Here is part 1 of our problem (Loading a dynamically generated XML file as PHP in Flash). Now we were able to get Flash to read the XML file, but we can only see the Flash render correctly when tested(test movie) from the actual Flash program. However, when we upload our files online to preview the Flash does not render correctly, missing some vital information(thumbnails, titles, video etc..). Here is a link to the Flash file using a manually created XML file (The Flash renders correctly): http://www.gaban.com/stackoverflow/TEN_xml.html Here is the path to the manually created XML file: http://dev.touchstorm.com/ten_hpn_admin2/client_user2.xml Now here is the link to the Flash file using the PHP generated XML file (Renders incomplete): http://www.gaban.com/stackoverflow/TEN_php.html Path to the PHP generated file (exactly the same as the manually created one): http://dev.touchstorm.com/ten_hpn_admin2/client_user.php?id=2 Additional information: The SWF file exists on Domain 1 The XML & PHP file both exists on Domain 2 And the HTML file with the embed code lies on Domain 3 Wondering if this could be a crossdomain issue? We have one of those files in place on Domain 1 & 2 where we have access too, however for Domain 3 we can't have a crossdomain.xml file there. Here is the PHP code: $xml = new XMLWriter(); $xml->openMemory(); $xml->setIndent(true); $xml->setIndentString("\t"); $xml->startDocument(); $xml->startElement('data'); $xml->startElement('config'); $xml->startElement('hex'); $xml->writeCData('0x' . $widget_profile['background_color']); $xml->endElement(); $xml->startElement('width'); $xml->writeCData($widget_profile['width']); $xml->endElement(); $xml->startElement('height'); $xml->writeCData($widget_profile['height']); $xml->endElement(); $xml->startElement('fullscreen'); $xml->writeCData('false'); $xml->endElement(); $xml->startElement('special'); $xml->writeCData('false'); $xml->endElement(); $xml->startElement('specialName'); $xml->writeCData('Tools & Offers'); $xml->endElement(); $xml->startElement('specialLink'); $xml->writeCData('http://bettycrocker.com'); $xml->endElement(); $xml->startElement('client'); $xml->writeCData($widget_profile['site_url']); $xml->endElement(); $xml->endElement(); if (count($widget_content) > 0) { foreach ($widget_content as $tab) { $xml->startElement('tab'); $xml->writeAttribute('id', $tab['tabname']); if (count($tab['video']) > 0) { foreach ($tab['video'] as $video) { $video_sql = "select VID, flvdoname, title from video where VID='" . $video . "'"; $video_result = $howdini->query($video_sql); if ($video_result->rowCount() > 0) { foreach ($video_result as $video_row) { $video_row['flvdoname'] = substr($video_row['flvdoname'], 35, -4); $xml->startElement('vid'); $xml->writeAttribute('flv', $video_row['flvdoname']); $xml->writeAttribute('thumb', 'http://www.howdini.com/thumb/' . $video_row['VID'] . '.jpg'); $xml->writeAttribute('title', $video_row['title']); $xml->endElement(); } } } } $xml->endElement(); } } $xml->endElement(); $xml->endDocument(); header('Content-Type: text/xml; charset=UTF-8'); echo $xml->flush(); Thanks in advance for any answers! EDIT: I have included the change and now Firebug sees the XML. Now it's just not seeing the swf file but I can see the swf file in other parts of the page.

  Read the article

• Suggestions on how to map from Domain (ORM) objects to Data Transfer Objects (DTO)

  - by FryHard

  The current system that I am working on makes use of Castle Activerecord to provide ORM (Object Relational Mapping) between the Domain objects and the database. This is all well and good and at most times actually works well! The problem comes about with Castle Activerecords support for asynchronous execution, well, more specifically the SessionScope that manages the session that objects belong to. Long story short, bad stuff happens! We are therefore looking for a way to easily convert (think automagically) from the Domain objects (who know that a DB exists and care) to the DTO object (who know nothing about the DB and care not for sessions, mapping attributes or all thing ORM). Does anyone have suggestions on doing this. For the start I am looking for a basic One to One mapping of object. Domain object Person will be mapped to say PersonDTO. I do not want to do this manually since it is a waste. Obviously reflection comes to mind, but I am hoping with some of the better IT knowledge floating around this site that "cooler" will be suggested. Oh, I am working in C#, the ORM objects as said before a mapped with Castle ActiveRecord. Example code: By @ajmastrean's request I have linked to an example that I have (badly) mocked together. The example has a capture form, capture form controller, domain objects, activerecord repository and an async helper. It is slightly big (3MB) because I included the ActiveRecored dll's needed to get it running. You will need to create a database called ActiveRecordAsync on your local machine or just change the .config file. Basic details of example: The Capture Form The capture form has a reference to the contoller private CompanyCaptureController MyController { get; set; } On initialise of the form it calls MyController.Load() private void InitForm () { MyController = new CompanyCaptureController(this); MyController.Load(); } This will return back to a method called LoadComplete() public void LoadCompleted (Company loadCompany) { _context.Post(delegate { CurrentItem = loadCompany; bindingSource.DataSource = CurrentItem; bindingSource.ResetCurrentItem(); //TOTO: This line will thow the exception since the session scope used to fetch loadCompany is now gone. grdEmployees.DataSource = loadCompany.Employees; }, null); } } this is where the "bad stuff" occurs, since we are using the child list of Company that is set as Lazy load. The Controller The controller has a Load method that was called from the form, it then calls the Asyc helper to asynchronously call the LoadCompany method and then return to the Capture form's LoadComplete method. public void Load () { new AsyncListLoad<Company>().BeginLoad(LoadCompany, Form.LoadCompleted); } The LoadCompany() method simply makes use of the Repository to find a know company. public Company LoadCompany() { return ActiveRecordRepository<Company>.Find(Setup.company.Identifier); } The rest of the example is rather generic, it has two domain classes which inherit from a base class, a setup file to instert some data and the repository to provide the ActiveRecordMediator abilities.

  Read the article

• C#. Struct design. Why 16 byte is recommended size?

  - by maxima120

  I read Cwalina book (recommendations on development and design of .NET apps). He says that good designed struct has to be less than 16 bytes in size (for performance purpose). My questions is - why exactly is this? And (more important) can I have larger struct with same efficiency if I run my .NET 3.5 (soon to be .NET 4.0) 64-bit application on i7 under Win7 x64 (is this limitation CPU / OS based)? Just to stress again - I need as efficient struct as it is possible. I try to keep it in stack all the time, the application is heavily multi-threaded and runs on sub-millisecond intervals, the current size of the struct is 64 byte.

  Read the article

• best practice to removing DC from Site that no longer connects via vpn in another city

  - by dasko

  hi i am looking for a recap of what i have done already to see if i missed anything. i had two cities connected by wan using a ipsec persistent tunnel between gateways. i had one DC (DOMAIN CONTROLLER) in each city that was a global catalog server (GC) they were set up to replicate and i had them configured under Sites and Servers with their own subnet etc... about 6 months ago the one city was removed and i was not able to gracefully remove, through dcpromo, the server that was there. it is no longer used and cannot be brought back. the company went from two sites down to single site. Problem is i had a whole bunch of kcc errors and replication bugs in the event viewer. i wanted to clean up my active directory and decided to use the ntdsutil metadata cleanup commands. i removed the server from the specifed site based on a procedure from petri website. I then removed the instances of the old DC and site from Sites and Servers. Then i went and cleaned up the DNS by removing Host A records, NS server name from both the local DNS forward lookup zone and the _msdcs i also removed the reverse lookup zone for the subnet that no longer exists. is there anything i missed? thanks in advance for any help. gd

  Read the article

• Website does not resolve in browser but traceroute is successful

  - by Colum

  I am trying to figure out an issue. My internet is working fine, but this one website is not resolving. It works via a proxy, traceroute works: 1 192.168.1.1 (192.168.1.1) 4.205 ms 0.568 ms 0.510 ms 2 * * * 3 67.59.255.13 (67.59.255.13) 10.583 ms 7.949 ms 7.557 ms 4 67.59.255.61 (67.59.255.61) 10.256 ms 9.576 ms 13.083 ms 5 64.15.8.126 (64.15.8.126) 9.943 ms 11.929 ms 11.452 ms 6 64.15.0.217 (64.15.0.217) 14.655 ms 14.092 ms 13.771 ms 7 64.15.0.118 (64.15.0.118) 33.201 ms 34.875 ms 36.544 ms 8 xe-6-0-3.ar1.ord1.us.nlayer.net (69.31.111.169) 34.027 ms 34.957 ms 34.231 ms 9 ae1-30g.cr1.ord1.us.nlayer.net (69.31.111.133) 82.683 ms 35.138 ms 37.592 ms 10 xe-3-0-0.cr2.iad1.us.nlayer.net (69.22.142.26) 41.657 ms 34.063 ms 34.519 ms 11 ae2-30g.ar2.iad1.us.nlayer.net (69.31.31.186) 35.780 ms 36.361 ms 33.968 ms 12 as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.230) 35.086 ms as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.234) 38.031 ms as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.230) 36.833 ms 13 cr1.iad2.inforelay.net (66.231.176.246) 32.595 ms cr2.iad1.inforelay.net (66.231.176.10) 31.771 ms cr1.iad2.inforelay.net (66.231.176.246) 32.622 ms 14 cr1.iad2.inforelay.net (66.231.176.246) 32.956 ms 33.625 ms !X 41.058 ms 15 * cr1.iad2.inforelay.net (66.231.176.246) 35.312 ms !X * 16 * cr1.iad2.inforelay.net (66.231.176.246) 32.814 ms !X * 17 cr1.iad2.inforelay.net (66.231.176.246) 35.459 ms !X * 53.137 ms !X Ping returns this: Request timeout for icmp_seq 0 Request timeout for icmp_seq 1 Request timeout for icmp_seq 2 Request timeout for icmp_seq 3 Request timeout for icmp_seq 4 Request timeout for icmp_seq 5 Request timeout for icmp_seq 6 But what I can not figure out is why my browsers (Firefox, Safari, Opera) can not resolve the domain. I am on a Wifi connection. What could be the problem? BTW I am on a Mac (10.6.5)

  Read the article

• Website does not resolve in browser but traceroute is successful

  - by Colum

  I am trying to figure out an issue. My internet is working fine, but this one website is not resolving. It works via a proxy, traceroute works: 1 192.168.1.1 (192.168.1.1) 4.205 ms 0.568 ms 0.510 ms 2 * * * 3 67.59.255.13 (67.59.255.13) 10.583 ms 7.949 ms 7.557 ms 4 67.59.255.61 (67.59.255.61) 10.256 ms 9.576 ms 13.083 ms 5 64.15.8.126 (64.15.8.126) 9.943 ms 11.929 ms 11.452 ms 6 64.15.0.217 (64.15.0.217) 14.655 ms 14.092 ms 13.771 ms 7 64.15.0.118 (64.15.0.118) 33.201 ms 34.875 ms 36.544 ms 8 xe-6-0-3.ar1.ord1.us.nlayer.net (69.31.111.169) 34.027 ms 34.957 ms 34.231 ms 9 ae1-30g.cr1.ord1.us.nlayer.net (69.31.111.133) 82.683 ms 35.138 ms 37.592 ms 10 xe-3-0-0.cr2.iad1.us.nlayer.net (69.22.142.26) 41.657 ms 34.063 ms 34.519 ms 11 ae2-30g.ar2.iad1.us.nlayer.net (69.31.31.186) 35.780 ms 36.361 ms 33.968 ms 12 as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.230) 35.086 ms as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.234) 38.031 ms as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.230) 36.833 ms 13 cr1.iad2.inforelay.net (66.231.176.246) 32.595 ms cr2.iad1.inforelay.net (66.231.176.10) 31.771 ms cr1.iad2.inforelay.net (66.231.176.246) 32.622 ms 14 cr1.iad2.inforelay.net (66.231.176.246) 32.956 ms 33.625 ms !X 41.058 ms 15 * cr1.iad2.inforelay.net (66.231.176.246) 35.312 ms !X * 16 * cr1.iad2.inforelay.net (66.231.176.246) 32.814 ms !X * 17 cr1.iad2.inforelay.net (66.231.176.246) 35.459 ms !X * 53.137 ms !X Ping returns this: Request timeout for icmp_seq 0 Request timeout for icmp_seq 1 Request timeout for icmp_seq 2 Request timeout for icmp_seq 3 Request timeout for icmp_seq 4 Request timeout for icmp_seq 5 Request timeout for icmp_seq 6 But what I can not figure out is why my browsers (Firefox, Safari, Opera) can not resolve the domain. I am on a Wifi connection. What could be the problem? BTW I am on a Mac (10.6.5)

  Read the article

• Restoring snapshot for Microsoft Exchange server

  - by Mugen

  Hi, The background: I need to do some testing with Microsoft exchange server. Specifically, I'll be installing some software on the Microsoft exchange server machine and uninstalling that same software again. The problem I face: While I repeatedly do this with different versions of my software there is a chance that sometime later the Exchange server installation might get corrupted. When that happens I would need to reinstall Exchange server which I feel is somewhat of a chore. So what I am planning to do is to install the Ms Exchange server on a virtual machine in VMware ESX server and take a snapshot so that during my work whenever the installation is corrupted I can restore the snapshot. So here's my question: Would restoring the snapshot for the Microsoft Exchange server virtual machine work correctly? I'm not familiar with the intricacies of exchange server and any changes (if any) that happen with the Domain controller when we use or install an exchange server (Personally I don't think that should happen but just making sure). I have a shortage of time and hence decided to post this question here. Could someone please tell me whether restoring a snapshot for Exchange server would work fine? Thanks a load, Mugen

  Read the article

• How to fix subfolders IIS7 functionality?

  - by Amr ElGarhy

  I have a problem in my sharing hosting that all websites in subfolders, their URL appear like this: http://amrelgarhy.com/amrelgarhy/ I sent to godaddy, and they sent me that its because of IIS7 and they can't solve, any one can tell me how to fix that? Here what i sent to godaddy and their reply: "as i saw before on this page http://www.godaddy.com/gdshop/hosting/shared.asp?ci=9009 compare windows plans, "Multiple Web sites: unlimited" so i have the right to run more than one website inside my hosting. But what i am facing now that i can't make more than website as a primary website. I have igurr.com as a primary website, i want to make others as primary because: I am facing a problem that all home pages for the other websites "which physically in sub folders" are like that "http://amrelgarhy.com/amrelgarhy/" the URL + the folder name and that what i don't want." GODADDY "Thank you for contacting Hosting Support. The behavior you are describing is standard for IIS 7.0 accounts. All alias domains in this environment will append the foldername their located in. I.E. a an alias domain www.coolexample.com pointed to the '/example' directory will display in a browser as "www.coolexample.com/example". This is due to the way IIS 7.0 handles virtual directories. Unfortunately we do not have any direct work around for this. We apologize for any inconvenience this may cause. "

  Read the article

• Servers in DMZ will not communicate with each other

  - by Tukaro

  (Full disclosure: I rate barely above "noob" when it comes to networking.) My workplace recent got a new web server. Since we're nearing the end of an overhaul of our website, we're doing a slooooow migration between the old web server and the new one. The old webserver (we'll call it SERVOLD) is Windows Server 2008 with IIS 7. It does not have SQL Server installed. The new server (SERVNEW) is Windows Server 2008 R2, IIS 7.5, with the same version of SQL Server installed. Both are located in the DMZ for our network, and both have their own outward-facing IP address (.3 and .4, respectively). Each server can communicate fine with computers within the domain (not in the DMZ), and those same computers have no trouble communicating with either server. Both servers are also accessible from the internet just fine. However, no matter what, these two servers just refuse to recognize each other. They have the same Workgroup name listed (WORKGROUP), and I thought that would be enough for them to recognize each other. What needs to happen such that I can get these two servers to communicate with each other? We want to do a gradual roll-over to the new website (new one uses ASP.NET, old one uses CFMX), so being able to use one database between both servers is a necessity. Thanks!

  Read the article

• New AD-DC in a new Site is refusing cross-site IPv4 connections

  - by sysadmin1138

  We just added a new Server 2008 (sp2) Domain Controller in a new Site, our first such config. It's over a VPN gateway WAN (10Mbit). Unfortunately it is displaying a strange network symptom. Connections to the SMB ports (TCP/139 and TCP/445) are being actively refused... if the connection is coming in on pure IPv4. If the incoming connection is coming by way of the 6to4 tunnel those connections establish and work just fine. It isn't the Firewall, since this behavior can be replicated with the firewall turned off. Also, it's actually issuing RST packets to connection attempts; something that only happens with a Windows Firewall if there is a service behind a port and the service itself denies access. I doubt it's some firewall device on the wire, since the server this one replaced was running Samba and access to it from our main network functioned just fine. I'm thinking it might have something to do with the Subnet lists in AD Sites & Services, but I'm not sure. We haven't put any IPv6 addresses in there, just v4, and it's the v4 connections that are being denied. Unfortunately, I can't figure this out. We need to be able to talk to this DC from the main campus. Is there some kind of site-based SMB-level filtering going on? I can talk to the DC's on campus just fine, but that's over that v6 tunnel. I don't have access to a regular machine on that remote subnet, which limits my ability to test.

  Read the article

• VMWare Newbie - looking for hardware recommendations and help :) [closed]

  - by Dan

  I am looking for some hardware recommendations on an upcoming virtualization project. We are a small company (80 users - 25 in site 1, 55 in site 2) currently using Windows Server 2003 - no VM servers yet. Our AD is setup where site 1 is the root domain and site 2 is a subdomain/subnet - connected by T1 and VPN for failover. The current DC's also server as file servers, print servers, AntiVirus servers. Email is in the cloud. Additionally then in site 1 we have 3 additional member servers - one running IBM Websphere for a customer specific app, one running Infor PowerLink (no real heavy load) and another that we use for Virtual Studio apps and also runs DirSync for Exchange Online. No heavy workloads on any of these machines really. We also have an AS400 box that we run ERP/CRM software on that site 2 connects to over the WAN link. In site 2 we also have a SQL machine that runs on Win2K server. Database files are not large less than 5 GB. Light to Medium workload on this machine. File servers in each site store less than 500 GB data and probably won't grow to more than 1TB in the next 5 years. I am looking to go to VMWare in both sites and virtualize all servers. What recommendations do you have for server, storage hardware? Is it safe to virtualize all of your DC's? Any help or advice would be greatly appreciated. Thanks.

  Read the article

• Using Round Robin DNS on simple VPN setup

  - by dannymcc

  We have two internet connections which are load balanced to share the load between the two. We set this up after one of the internet provider proved to be less than reliable but great speed and latency wise when it is working. We'd rather utilise both connections as much as possible rather than leave one idle until the other drops out. We have a number of remote workers who occasionally need to connect via VPN from their laptops or iPads, we also have a small number of permanent LAN to LAN tunnels running from smaller branches. Originally we only had one internet connection and used one of our static IP addresses for all VPN users. Now that we have two internet connections running all of the time I am trying to make sure that the VPN is available to our team regardless of which connection drops. So my solution is to create two A records for our domain name with a value of vpn. and the two static IP addresses from each peer. Is this a sensible way of achieving this? Should I expect higher latency due to packets being lost if one peer fails and some packets still get routed to it anyway? A brief mockup of the setup I have:

  Read the article

• Website does not resolve in browser but traceroute is successful

  - by Colum

  I am trying to figure out an issue. My internet is working fine, but this one website is not resolving. It works via a proxy, traceroute works: 1 192.168.1.1 (192.168.1.1) 4.205 ms 0.568 ms 0.510 ms 2 * * * 3 67.59.255.13 (67.59.255.13) 10.583 ms 7.949 ms 7.557 ms 4 67.59.255.61 (67.59.255.61) 10.256 ms 9.576 ms 13.083 ms 5 64.15.8.126 (64.15.8.126) 9.943 ms 11.929 ms 11.452 ms 6 64.15.0.217 (64.15.0.217) 14.655 ms 14.092 ms 13.771 ms 7 64.15.0.118 (64.15.0.118) 33.201 ms 34.875 ms 36.544 ms 8 xe-6-0-3.ar1.ord1.us.nlayer.net (69.31.111.169) 34.027 ms 34.957 ms 34.231 ms 9 ae1-30g.cr1.ord1.us.nlayer.net (69.31.111.133) 82.683 ms 35.138 ms 37.592 ms 10 xe-3-0-0.cr2.iad1.us.nlayer.net (69.22.142.26) 41.657 ms 34.063 ms 34.519 ms 11 ae2-30g.ar2.iad1.us.nlayer.net (69.31.31.186) 35.780 ms 36.361 ms 33.968 ms 12 as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.230) 35.086 ms as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.234) 38.031 ms as33597.xe-3-0-7.ar2.iad1.us.nlayer.net (69.31.30.230) 36.833 ms 13 cr1.iad2.inforelay.net (66.231.176.246) 32.595 ms cr2.iad1.inforelay.net (66.231.176.10) 31.771 ms cr1.iad2.inforelay.net (66.231.176.246) 32.622 ms 14 cr1.iad2.inforelay.net (66.231.176.246) 32.956 ms 33.625 ms !X 41.058 ms 15 * cr1.iad2.inforelay.net (66.231.176.246) 35.312 ms !X * 16 * cr1.iad2.inforelay.net (66.231.176.246) 32.814 ms !X * 17 cr1.iad2.inforelay.net (66.231.176.246) 35.459 ms !X * 53.137 ms !X Ping returns this: Request timeout for icmp_seq 0 Request timeout for icmp_seq 1 Request timeout for icmp_seq 2 Request timeout for icmp_seq 3 Request timeout for icmp_seq 4 Request timeout for icmp_seq 5 Request timeout for icmp_seq 6 But what I can not figure out is why my browsers (Firefox, Safari, Opera) can not resolve the domain. I am on a Wifi connection. What could be the problem? BTW I am on a Mac (10.6.5)

  Read the article

< Previous Page | 177 178 179 180 181 182 183 184 185 186 187 188  | Next Page >