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  • JavaOne Kicks Off with Sunday Keynotes

    - by Yolande Poirier
    The Java Strategy, Partner, and Technical keynotes will be held on Sunday, September 22, beginning at 4:00 p.m. like last year, to free up time for session slots on Monday and Tuesday. The keynotes will again take place at the historic Masonic Auditorium on Nob Hill. That same evening at 7:00 p.m., attendees are invited to the official JavaOne Welcome Reception at the Taylor Street Café @ the Zone. Sunday will also feature User Group meetings (at Moscone West) and Java University courses (Hilton San Francisco Union Square). On Thursday, the Java Community keynote will start the wrap up of the conference. Register before July 19, 2013 and save US$400. Click here for information on registration packages, including the low-cost Discover pass alternative.

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  • Feynman's inbox

    - by user12607414
    Here is Richard Feynman writing on the ease of criticizing theories, and the difficulty of forming them: The problem is not just to say something might be wrong, but to replace it by something — and that is not so easy. As soon as any really definite idea is substituted it becomes almost immediately apparent that it does not work. The second difficulty is that there is an infinite number of possibilities of these simple types. It is something like this. You are sitting working very hard, you have worked for a long time trying to open a safe. Then some Joe comes along who knows nothing about what you are doing, except that you are trying to open the safe. He says ‘Why don’t you try the combination 10:20:30?’ Because you are busy, you have tried a lot of things, maybe you have already tried 10:20:30. Maybe you know already that the middle number is 32 not 20. Maybe you know as a matter of fact that it is a five digit combination… So please do not send me any letters trying to tell me how the thing is going to work. I read them — I always read them to make sure that I have not already thought of what is suggested — but it takes too long to answer them, because they are usually in the class ‘try 10:20:30’. (“Seeking New Laws”, page 161 in The Character of Physical Law.) As a sometime designer (and longtime critic) of widely used computer systems, I have seen similar difficulties appear when anyone undertakes to publicly design a piece of software that may be used by many thousands of customers. (I have been on both sides of the fence, of course.) The design possibilities are endless, but the deep design problems are usually hidden beneath a mass of superfluous detail. The sheer numbers can be daunting. Even if only one customer out of a thousand feels a need to express a passionately held idea, it can take a long time to read all the mail. And it is a fact of life that many of those strong suggestions are only weakly supported by reason or evidence. Opinions are plentiful, but substantive research is time-consuming, and hence rare. A related phenomenon commonly seen with software is bike-shedding, where interlocutors focus on surface details like naming and syntax… or (come to think of it) like lock combinations. On the other hand, software is easier than quantum physics, and the population of people able to make substantial suggestions about software systems is several orders of magnitude bigger than Feynman’s circle of colleagues. My own work would be poorer without contributions — sometimes unsolicited, sometimes passionately urged on me — from the open source community. If a Nobel prize winner thought it was worthwhile to read his mail on the faint chance of learning a good idea, I am certainly not going to throw mine away. (In case anyone is still reading this, and is wondering what provoked a meditation on the quality of one’s inbox contents, I’ll simply point out that the volume has been very high, for many months, on the Lambda-Dev mailing list, where the next version of the Java language is being discussed. Bravo to those of my colleagues who are surfing that wave.) I started this note thinking there was an odd parallel between the life of the physicist and that of a software designer. On second thought, I’ll bet that is the story for anybody who works in public on something requiring special training. (And that would be pretty much anything worth doing.) In any case, Feynman saw it clearly and said it well.

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  • Online ALTER TABLE in MySQL 5.6

    - by Marko Mäkelä
    This is the low-level view of data dictionary language (DDL) operations in the InnoDB storage engine in MySQL 5.6. John Russell gave a more high-level view in his blog post April 2012 Labs Release – Online DDL Improvements. MySQL before the InnoDB Plugin Traditionally, the MySQL storage engine interface has taken a minimalistic approach to data definition language. The only natively supported operations were CREATE TABLE, DROP TABLE and RENAME TABLE. Consider the following example: CREATE TABLE t(a INT); INSERT INTO t VALUES (1),(2),(3); CREATE INDEX a ON t(a); DROP TABLE t; The CREATE INDEX statement would be executed roughly as follows: CREATE TABLE temp(a INT, INDEX(a)); INSERT INTO temp SELECT * FROM t; RENAME TABLE t TO temp2; RENAME TABLE temp TO t; DROP TABLE temp2; You could imagine that the database could crash when copying all rows from the original table to the new one. For example, it could run out of file space. Then, on restart, InnoDB would roll back the huge INSERT transaction. To fix things a little, a hack was added to ha_innobase::write_row for committing the transaction every 10,000 rows. Still, it was frustrating that even a simple DROP INDEX would make the table unavailable for modifications for a long time. Fast Index Creation in the InnoDB Plugin of MySQL 5.1 MySQL 5.1 introduced a new interface for CREATE INDEX and DROP INDEX. The old table-copying approach can still be forced by SET old_alter_table=0. This interface is used in MySQL 5.5 and in the InnoDB Plugin for MySQL 5.1. Apart from the ability to do a quick DROP INDEX, the main advantage is that InnoDB will execute a merge-sort algorithm before inserting the index records into each index that is being created. This should speed up the insert into the secondary index B-trees and potentially result in a better B-tree fill factor. The 5.1 ALTER TABLE interface was not perfect. For example, DROP FOREIGN KEY still invoked the table copy. Renaming columns could conflict with InnoDB foreign key constraints. Combining ADD KEY and DROP KEY in ALTER TABLE was problematic and not atomic inside the storage engine. The ALTER TABLE interface in MySQL 5.6 The ALTER TABLE storage engine interface was completely rewritten in MySQL 5.6. Instead of introducing a method call for every conceivable operation, MySQL 5.6 introduced a handful of methods, and data structures that keep track of the requested changes. In MySQL 5.6, online ALTER TABLE operation can be requested by specifying LOCK=NONE. Also LOCK=SHARED and LOCK=EXCLUSIVE are available. The old-style table copying can be requested by ALGORITHM=COPY. That one will require at least LOCK=SHARED. From the InnoDB point of view, anything that is possible with LOCK=EXCLUSIVE is also possible with LOCK=SHARED. Most ALGORITHM=INPLACE operations inside InnoDB can be executed online (LOCK=NONE). InnoDB will always require an exclusive table lock in two phases of the operation. The execution phases are tied to a number of methods: handler::check_if_supported_inplace_alter Checks if the storage engine can perform all requested operations, and if so, what kind of locking is needed. handler::prepare_inplace_alter_table InnoDB uses this method to set up the data dictionary cache for upcoming CREATE INDEX operation. We need stubs for the new indexes, so that we can keep track of changes to the table during online index creation. Also, crash recovery would drop any indexes that were incomplete at the time of the crash. handler::inplace_alter_table In InnoDB, this method is used for creating secondary indexes or for rebuilding the table. This is the ‘main’ phase that can be executed online (with concurrent writes to the table). handler::commit_inplace_alter_table This is where the operation is committed or rolled back. Here, InnoDB would drop any indexes, rename any columns, drop or add foreign keys, and finalize a table rebuild or index creation. It would also discard any logs that were set up for online index creation or table rebuild. The prepare and commit phases require an exclusive lock, blocking all access to the table. If MySQL times out while upgrading the table meta-data lock for the commit phase, it will roll back the ALTER TABLE operation. In MySQL 5.6, data definition language operations are still not fully atomic, because the data dictionary is split. Part of it is inside InnoDB data dictionary tables. Part of the information is only available in the *.frm file, which is not covered by any crash recovery log. But, there is a single commit phase inside the storage engine. Online Secondary Index Creation It may occur that an index needs to be created on a new column to speed up queries. But, it may be unacceptable to block modifications on the table while creating the index. It turns out that it is conceptually not so hard to support online index creation. All we need is some more execution phases: Set up a stub for the index, for logging changes. Scan the table for index records. Sort the index records. Bulk load the index records. Apply the logged changes. Replace the stub with the actual index. Threads that modify the table will log the operations to the logs of each index that is being created. Errors, such as log overflow or uniqueness violations, will only be flagged by the ALTER TABLE thread. The log is conceptually similar to the InnoDB change buffer. The bulk load of index records will bypass record locking. We still generate redo log for writing the index pages. It would suffice to log page allocations only, and to flush the index pages from the buffer pool to the file system upon completion. Native ALTER TABLE Starting with MySQL 5.6, InnoDB supports most ALTER TABLE operations natively. The notable exceptions are changes to the column type, ADD FOREIGN KEY except when foreign_key_checks=0, and changes to tables that contain FULLTEXT indexes. The keyword ALGORITHM=INPLACE is somewhat misleading, because certain operations cannot be performed in-place. For example, changing the ROW_FORMAT of a table requires a rebuild. Online operation (LOCK=NONE) is not allowed in the following cases: when adding an AUTO_INCREMENT column, when the table contains FULLTEXT indexes or a hidden FTS_DOC_ID column, or when there are FOREIGN KEY constraints referring to the table, with ON…CASCADE or ON…SET NULL option. The FOREIGN KEY limitations are needed, because MySQL does not acquire meta-data locks on the child or parent tables when executing SQL statements. Theoretically, InnoDB could support operations like ADD COLUMN and DROP COLUMN in-place, by lazily converting the table to a newer format. This would require that the data dictionary keep multiple versions of the table definition. For simplicity, we will copy the entire table, even for DROP COLUMN. The bulk copying of the table will bypass record locking and undo logging. For facilitating online operation, a temporary log will be associated with the clustered index of table. Threads that modify the table will also write the changes to the log. When altering the table, we skip all records that have been marked for deletion. In this way, we can simply discard any undo log records that were not yet purged from the original table. Off-page columns, or BLOBs, are an important consideration. We suspend the purge of delete-marked records if it would free any off-page columns from the old table. This is because the BLOBs can be needed when applying changes from the log. We have special logging for handling the ROLLBACK of an INSERT that inserted new off-page columns. This is because the columns will be freed at rollback.

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  • Exalogic 2.0.1 Tea Break Snippets - Creating and using Distribution Groups

    - by The Old Toxophilist
    By default running your Exalogic in a Virtual provides you with, what to Cloud Users, is a single large resource and they can just create vServers and not care about how they are laid down on the the underlying infrastructure. All the Cloud Users will know is that they can create vServers. For example if we have a Quarter Rack (8 Nodes) and our Cloud User creates 8 vServers those 8 vServers may run on 8 distinct nodes or may all run on the same node. Although in many cases we, as Cloud Users, may not be to worried how the Virtualisation Algorithm decides where to place our vServers there are cases where it is extremely important that vServers run on distinct physical compute nodes. For example if we have a Weblogic Cluster we will want the Servers with in the cluster to run on distinct physical node to cover for the situation where one physical node is lost. To achieve this the Exalogic Virtualised implementation provides Distribution Groups that define and anti-aliasing policy that the underlying Virtualisation Algorithm will take into account when placing vServers. It should be noted that Distribution Groups must be created before you create vServers because a vServer can only be added to a Distribution Group at creation time. Creating A Distribution Group To create a Distribution Groups we will first need to select the Account in which we want the Distribution Group to be created. Once we have selected the account we will see the Interface update and Account specific Actions will be displayed within the Action Panes. From the Action pane (or Right-Click on the Account) select the "Create Distribution Group" action. This will initiate the create wizard as follows. Distribution Group Details Within the first Step of the Wizard we can specify the name of the distribution group and this should be unique. In addition we can provide a detailed description of the group. Distribution Group Configuration The second step of the configuration wizard allows you to specify the number of elements that are required within this group and will specify a maximum of the number of nodes within you Exalogic. At this point it is always better to specify a group with spare capacity allowing for future expansion. As vServers are added to group the available slots decrease. Summary Finally the last step of the wizard display a summary of the information entered.

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  • Implicit and Explicit implementations for Multiple Interface inheritance

    Following C#.NET demo explains you all the scenarios for implementation of Interface methods to classes. There are two ways you can implement a interface method to a class. 1. Implicit Implementation 2. Explicit Implementation. Please go though the sample. using System; namespace ImpExpTest {     class Program     {         static void Main(string[] args)         {             C o3 = new C();             Console.WriteLine(o3.fu());             I1 o1 = new C();             Console.WriteLine(o1.fu());             I2 o2 = new C();             Console.WriteLine(o2.fu());             var o4 = new C();       //var is considered as C             Console.WriteLine(o4.fu());             var o5 = (I1)new C();   //var is considered as I1             Console.WriteLine(o5.fu());             var o6 = (I2)new C();   //var is considered as I2             Console.WriteLine(o6.fu());             D o7 = new D();             Console.WriteLine(o7.fu());             I1 o8 = new D();             Console.WriteLine(o8.fu());             I2 o9 = new D();             Console.WriteLine(o9.fu());         }     }     interface I1     {         string fu();     }     interface I2     {         string fu();     }     class C : I1, I2     {         #region Imicitly Defined I1 Members         public string fu()         {             return "Hello C"         }         #endregion Imicitly Defined I1 Members         #region Explicitly Defined I1 Members         string I1.fu()         {             return "Hello from I1";         }         #endregion Explicitly Defined I1 Members         #region Explicitly Defined I2 Members         string I2.fu()         {             return "Hello from I2";         }         #endregion Explicitly Defined I2 Members     }     class D : C     {         #region Imicitly Defined I1 Members         public string fu()         {             return "Hello from D";         }         #endregion Imicitly Defined I1 Members     } } Output:- Hello C Hello from I1 Hello from I2 Hello C Hello from I1 Hello from I2 Hello from D Hello from I1 Hello from I2 span.fullpost {display:none;}

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  • sqlplus: Running "set lines" and "set pagesize" automatially

    - by katsumii
    This is a followup to my previous entry. Using the full tty real estate with sqlplus (INOUE Katsumi @ Tokyo) 'rlwrap' is widely used for adding 'sqlplus' the history function and command line editing. Here's another but again kludgy implementation. First this is the alias. alias sqlplus="rlwrap -z ~/sqlplus.filter sqlplus" And this is the file content. #!/usr/bin/env perl use lib ($ENV{RLWRAP_FILTERDIR} or "."); use RlwrapFilter; use POSIX qw(:signal_h); use strict; my $filter = new RlwrapFilter; $filter -> prompt_handler(\&prompt); sigprocmask(SIG_UNBLOCK, POSIX::SigSet->new(28)); $SIG{WINCH} = 'winchHandler'; $filter -> run; sub winchHandler { $filter -> input_handler(\&input); sigprocmask(SIG_UNBLOCK, POSIX::SigSet->new(28)); $SIG{WINCH} = 'winchHandler'; $filter -> run; } sub input { $filter -> input_handler(undef); return `resize |sed -n "1s/COLUMNS=/set linesize /p;2s/LINES=/set pagesize /p"` . $_; } sub prompt { if ($_ =~ "SQL> ") { $filter -> input_handler(\&input); $filter -> prompt_handler(undef); } return $_; } I hope I can compare these 2 implementations after testing more and getting some feedbacks.

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  • New Procurement Report for Transportation Sourcing

    - by John Murphy
    Welcome to our fourth annual transportation procurement benchmark report. American Shipper, in partnership with the Council of Supply Chain Management Professionals (CSCMP) and the Retail Industry Leaders Association (RILA), surveyed roughly 275 transportation buyers and sellers on procurement practices, processes, technologies and results. Some key findings: • Manual, spreadsheet-based procurement processes remain the most prevalent among transportation buyers, with 42 percent of the total • Another 25 percent of respondents use a hybrid platform, which presumably means these buyers are using spreadsheets for at least one mode and/or geography • Only 23 percent of buyers are using a completely systems-based approach of some kind • Shippers were in a holding pattern with regards to investment in procurement systems the past year • Roughly three-quarters of survey respondents report that transportation spend has increased in 2012, although the pace has declined slightly from last year’s increases • Nearly every survey respondent purchases multiple modes of transportation • The number of respondents with plans to address technology to support the procurement process has increased in 2012. About one quarter of respondents who do not have a system report they have a budget for this investment in the next two years.

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  • JCP 2.9 & Transparency Spec Lead Call material is available

    - by Heather VanCura
    The JCP 2.9 & Transparency Spec Lead Call materials and recording from 9 November are now available on the JCP.org multimedia page.  Learn about changes introduced with JCP 2.9, effective Tuesday, 13 November, and a review of the JCP.Next reform efforts. Plus, a progress report on JCP 2.8, specifically around the areas of transparency, participation and agility, as well as suggestions for how you can get more involved in supporting these efforts with the current JCP program JSRs. 

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  • Integrating a Progress Bar into a Wizard

    - by Geertjan
    Normally, when you create a wizard, as described here, and you have your own iterator, you'll have a class signature like this: public final class MyWizardWizardIterator implements WizardDescriptor.InstantiatingIterator<WizardDescriptor> { Let's now imagine that you've got some kind of long running process your wizard needs to perform. Maybe the wizard needs to connect to something, which could take some time. Start by adding a new dependency on the Progress API, which gives you the classes that access the NetBeans Platform's progress functionality. Now all we need to do is change the class signature very slightly: public final class MyWizardWizardIterator implements WizardDescriptor.ProgressInstantiatingIterator<WizardDescriptor> { Take a look at the part of the signature above that is highlighted. I.e., use WizardDescriptor.ProgressInstantiatingIterator instead of WizardDescriptor.InstantiatingIterator. Now you will need to implement a new instantiate method, one that receives a ProgressHandle. The other instantiate method, i.e., the one that already existed, should never be accessed anymore, and so you can add an assert to that effect: @Override public Set<?> instantiate() throws IOException {     throw new AssertionError("instantiate(ProgressHandle) " //NOI18N             + "should have been called"); //NOI18N } @Override public Set instantiate(ProgressHandle ph) throws IOException {     return Collections.emptySet(); } OK. Let's now add some code to make our progress bar work: @Override public Set instantiate(ProgressHandle ph) throws IOException {     ph.start();     ph.progress("Processing...");     try {         //Simulate some long process:         Thread.sleep(2500);     } catch (InterruptedException ex) {         Exceptions.printStackTrace(ex);     }     ph.finish();     return Collections.emptySet(); } And, maybe even more impressive, you can also do this: @Override public Set instantiate(ProgressHandle ph) throws IOException {     ph.start(1000);     ph.progress("Processing...");     try {         //Simulate some long process:         ph.progress("1/4 complete...", 250);         Thread.sleep(2500);         ph.progress("1/2 complete...", 500);         Thread.sleep(5000);         ph.progress("3/4 complete...", 750);         Thread.sleep(7500);         ph.progress("Complete...", 1000);         Thread.sleep(1000);     } catch (InterruptedException ex) {         Exceptions.printStackTrace(ex);     }     ph.finish();     return Collections.emptySet(); } The screenshots above show you what you should see when the Finish button is clicked in each case.

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  • SOA Suite 11g: Unable to start domain (Error occurred during initialization of VM)

    - by Chris Tomkins
    If you have recently installed SOA Suite, created a domain and then tried to start it only to find it fails with the error: Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. the solution is to edit the file <domain home>\bin\setSOADomainEnv.cmd/sh (depending on your platform) and modify the line: set DEFAULT_MEM_ARGS=-Xms512m -Xmx1024m to something like: set DEFAULT_MEM_ARGS=-Xms512m -Xmx768m Save the file and then try to start your domain again. Everything should now work at least it does on the Dell Latitude 630 laptop with 4Gb RAM that I have. Technorati Tags: soa suite,11g,java,troubleshooting,problems,domain

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  • Reading a ZFS USB drive with Mac OS X Mountain Lion

    - by Karim Berrah
    The problem: I'm using a MacBook, mainly with Solaris 11, but something with Mac OS X (ML). The only missing thing is that Mac OS X can't read my external ZFS based USB drive, where I store all my data. So, I decided to look for a solution. Possible solution: I decided to use VirtualBox with a Solaris 11 VM as a passthrough to my data. Here are the required steps: Installing a Solaris 11 VM Install VirtualBox on your Mac OS X, add the extension pack (needed for USB) Plug your ZFS based USB drive on your Mac, ignore it when asked to initialize it. Create a VM for Solaris (bridged network), and before installing it, create a USB filter (in the settings of your Vbox VM, go to Ports, then USB, then add a new USB filter from the attached device "grey usb-connector logo with green plus sign")  Install a Solaris 11 VM, boot it, and install the Guest addition check with "ifconfg -a" the IP address of your Solaris VM Creating a path to your ZFS USB drive In MacOS X, use the "Disk Utility" to unmount the USB attached drive, and unplug the USB device. Switch back to VirtualBox, select the top of the window where your Solaris 11 is running plug your ZFS USB drive, select "ignore" if Mac OS invite you to initialize the disk In the VirtualBox VM menu, go to "Devices" then "USB Devices" and select from the dropping menu your "USB device" Connection your Solaris VM to the USB drive Inside Solaris, you might now check that your device is accessible by using the "format" cli command If not, repeat previous steps Now, with root privilege, force a zpool import -f myusbdevicepoolname because this pool was created on another system check that you see your new pool with "zpool status" share your pool with NFS: share -F NFS /myusbdevicepoolname Accessing the USB ZFS drive from Mac OS X This is the easiest step: access an NFS share from mac OS Create a "ZFSdrive" folder on your MacOS desktop from a terminal under mac OS: mount -t nfs IPadressofMySoalrisVM:/myusbdevicepoolname  /Users/yourusername/Desktop/ZFSdrive et voila ! you might access your data, on a ZFS USB drive, directly from your Mountain Lion Desktop. You might play with the share rights in order to alter any read/write rights as needed. You might activate compression, encryption inside the Solaris 11 VM ...

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  • A Patent for Workload Management Based on Service Level Objectives

    - by jsavit
    I'm very pleased to announce that after a tiny :-) wait of about 5 years, my patent application for a workload manager was finally approved. Background Many operating systems have a resource manager which lets you control machine resources. For example, Solaris provides controls for CPU with several options: shares for proportional CPU allocation. If you have twice as many shares as me, and we are competing for CPU, you'll get about twice as many CPU cycles), dedicated CPU allocation in which a number of CPUs are exclusively dedicated to an application's use. You can say that a zone or project "owns" 8 CPUs on a 32 CPU machine, for example. And, capped CPU in which you specify the upper bound, or cap, of how much CPU an application gets. For example, you can throttle an application to 0.125 of a CPU. (This isn't meant to be an exhaustive list of Solaris RM controls.) Workload management Useful as that is (and tragic that some other operating systems have little resource management and isolation, and frighten people into running only 1 app per OS instance - and wastefully size every server for the peak workload it might experience) that's not really workload management. With resource management one controls the resources, and hope that's enough to meet application service objectives. In fact, we hold resource distribution constant, see if that was good enough, and adjust resource distribution if that didn't meet service level objectives. Here's an example of what happens today: Let's try 30% dedicated CPU. Not enough? Let's try 80% Oh, that's too much, and we're achieving much better response time than the objective, but other workloads are starving. Let's back that off and try again. It's not the process I object to - it's that we to often do this manually. Worse, we sometimes identify and adjust the wrong resource and fiddle with that to no useful result. Back in my days as a customer managing large systems, one of my users would call me up to beg for a "CPU boost": Me: "it won't make any difference - there's plenty of spare CPU to be had, and your application is completely I/O bound." User: "Please do it anyway." Me: "oh, all right, but it won't do you any good." (I did, because he was a friend, but it didn't help.) Prior art There are some operating environments that take a stab about workload management (rather than resource management) but I find them lacking. I know of one that uses synthetic "service units" composed of the sum of CPU, I/O and memory allocations multiplied by weighting factors. A workload is set to make a target rate of service units consumed per second. But this seems to be missing a key point: what is the relationship between artificial 'service units' and actually meeting a throughput or response time objective? What if I get plenty of one of the components (so am getting enough service units), but not enough of the resource whose needed to remove the bottleneck? Actual workload management That's not really the answer either. What is needed is to specify a workload's service levels in terms of externally visible metrics that are meaningful to a business, such as response times or transactions per second, and have the workload manager figure out which resources are not being adequately provided, and then adjust it as needed. If an application is not meeting its service level objectives and the reason is that it's not getting enough CPU cycles, adjust its CPU resource accordingly. If the reason is that the application isn't getting enough RAM to keep its working set in memory, then adjust its RAM assignment appropriately so it stops swapping. Simple idea, but that's a task we keep dumping on system administrators. In other words - don't hold the number of CPU shares constant and watch the achievement of service level vary. Instead, hold the service level constant, and dynamically adjust the number of CPU shares (or amount of other resources like RAM or I/O bandwidth) in order to meet the objective. Instrumenting non-instrumented applications There's one little problem here: how do I measure application performance in a way relating to a service level. I don't want to do it based on internal resources like number of CPU seconds it received per minute - We need to make resource decisions based on externally visible and meaningful measures of performance, not synthetic items or internal resource counters. If I have a way of marking the beginning and end of a transaction, I can then measure whether or not the application is meeting an objective based on it. If I can observe the delay factors for an application, I can see which resource shortages are slowing an application enough to keep it from meeting its objectives. I can then adjust resource allocations to relieve those shortages. Fortunately, Solaris provides facilities for both marking application progress and determining what factors cause application latency. The Solaris DTrace facility let's me introspect on application behavior: in particular I can see events like "receive a web hit" and "respond to that web hit" so I can get transaction rate and response time. DTrace (and tools like prstat) let me see where latency is being added to an application, so I know which resource to adjust. Summary After a delay of a mere few years, I am the proud creator of a patent (advice to anyone interested in going through the process: don't hold your breath!). The fundamental idea is fairly simple: instead of holding resource constant and suffering variable levels of success meeting service level objectives, properly characterise the service level objective in meaningful terms, instrument the application to see if it's meeting the objective, and then have a workload manager change resource allocations to remove delays preventing service level attainment. I've done it by hand for a long time - I think that's what a computer should do for me.

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  • Enterprise Architecture - Wikipedia

    - by pat.shepherd
    I was looking at the Wikipedia entry for EA and found this chart which does a great job showing the differences of ENTERPRISE Architecture vs. SOLUTION Architecture across several categories.  This really gets at the heart of a misconception many people have about what EA is and where it sits in the grand business –> technical detail continuum. The following image from the 2006 FEA Practice Guidance of US OMB sheds light on the relationship between enterprise architecture and segment(BPR) or Solution architectures. (From this figure and a bit of thinking[which?] one can see that software architecture is truly a solution architecture discipline, for example.) Enterprise architecture - Wikipedia, the free encyclopedia

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  • Schema Based Code Completion for NetBeans Platform Applications

    - by Geertjan
    Toni's recent blog entry provides, among several other interesting things, instructions for something I've been wanting to cover for a long time, which is schema based code completion: The above is a sample I created via Toni's tutorial, using the schema described here: http://www.w3schools.com/schema/schema_example.asp The support for the Navigator ain't bad either, especially considering I didn't do any coding at all to get all this: And here's where you can find the whole sample: http://java.net/projects/nb-api-samples/sources/api-samples/show/versions/7.2/misc/ShipOrder

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  • State Design Pattern .NET Code Sample

    using System;using System.Collections.Generic;using System.Linq;using System.Text;class Program{ static void Main(string[] args) { Person p1 = new Person("P1"); Person p2 = new Person("P2"); p1.EatFood(); p2.EatFood(); p1.Vomit(); p2.Vomit(); }}interface StomachState{ void Eat(Person p); void Vomit(Person p);}class StomachFull : StomachState{ public void Eat(Person p) { Console.WriteLine("Can't eat more."); } public void Vomit(Person p) { Console.WriteLine("I've just Vomited."); p.StomachState = new StomachEmpty(); }}class StomachEmpty : StomachState{ public void Eat(Person p) { Console.WriteLine("I've just had food."); p.StomachState = new StomachFull(); } public void Vomit(Person p) { Console.WriteLine("Nothing to Vomit."); }}class Person{ private StomachState stomachState; private String personName; public Person(String personName) { this.personName = personName; StomachState = new StomachEmpty(); } public StomachState StomachState { get { return stomachState; } set { stomachState = value; Console.WriteLine(personName + " Stomach State Changed to " + StomachState.GetType().Name); Console.WriteLine("***********************************************\n"); } } public Person(StomachState StomachState) { this.StomachState = StomachState; } public void EatFood() { StomachState.Eat(this); } public void Vomit() { StomachState.Vomit(this); }} span.fullpost {display:none;}

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  • UNESCO, J-ISIS, and the JavaFX 2.2 WebView

    - by Geertjan
    J-ISIS, which is the newly developed Java version of the UNESCO generalized information storage and retrieval system for bibliographic information, continues to be under heavy development and code refactoring in its open source repository. Read more about J-ISIS and its NetBeans Platform basis here. Soon a new version will be available for testing and it would be cool to see the application in action at that time. Currently, it looks as follows, though note that the menu bar is under development and many menus you see there will be replaced or removed soon: About one aspect of the application, the browser, which you can see above, Jean-Claude Dauphin, its project lead, wrote me the following: The DJ-Native Swing JWebBrowser has been a nice solution for getting a Java Web Browser for most popular platforms. But the Java integration has always produced from time to time some strange behavior (like losing the focus on the other components after clicking on the Browser window, overlapping of windows, etc.), most probably because of mixing heavyweight and lightweight components and also because of our incompetency in solving the issues. Thus, recently we changed for the JavaFX 2.2 WebWiew. The integration with Java is fine and we have got rid of all the DJ-Native Swing problems. However, we have lost some features which were given for free with the native browsers such as downloading resources in different formats and opening them in the right application. This is a pretty cool step forward, i.e., the JavaFX integration. It also confirms for me something I've heard other people saying too: the JavaFX WebView component is a perfect low threshold entry point for Swing developers feeling their way into the world of JavaFX.

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  • How can I convince management to deal with technical debt?

    - by Desolate Planet
    This is a question that I often ask myself when working with developers. I've worked at four companies so far and I've become aware of a lack of attention to keeping code clean and dealing with technical debt that hinders future progress in a software app. For example, the first company I worked for had written a database from scratch rather than use something like MySQL and that created hell for the team when refactoring or extending the application. I've always tried to be honest and clear with my manager when he discusses projections, but management doesn't seem interested in fixing what's already there and it's horrible to see the impact it has on team morale. What are your thoughts on the best way to tackle this problem? What I've seen is people packing up and leaving. The company then becomes a revolving door with developers coming in and out and making the code worse. How do you communicate this to management to get them interested in sorting out technical debt?

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  • Enter comments on queries in TraceTune

    - by Bill Graziano
    I’m trying to make TraceTune (and eventually ClearTrace) work the way I do.  My typical query tuning session goes like this: Run a trace and upload to TraceTune/ClearTrace Tune the slowest queries Goto 1 I might do this two or three times in one day and then not come back to it again for weeks or even months.  This is especially true for those clients that I only visit a few times per month.  In many cases I’ll look at a query, decide I can’t do much with it and move on.  I needed a way to capture that information. TraceTune now lets you enter a comment for a query.  It can be as simple or as complex as you like.  The comment will be shown inline with the execution history of that query. This should let you walk back through your history with a query and decide whether you should spend more time tuning it.

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  • Inline template efficiency

    - by Darryl Gove
    I like inline templates, and use them quite extensively. Whenever I write code with them I'm always careful to check the disassembly to see that the resulting output is efficient. Here's a potential cause of inefficiency. Suppose we want to use the mis-named Leading Zero Detect (LZD) instruction on T4 (this instruction does a count of the number of leading zero bits in an integer register - so it should really be called leading zero count). So we put together an inline template called lzd.il looking like: .inline lzd lzd %o0,%o0 .end And we throw together some code that uses it: int lzd(int); int a; int c=0; int main() { for(a=0; a<1000; a++) { c=lzd(c); } return 0; } We compile the code with some amount of optimisation, and look at the resulting code: $ cc -O -xtarget=T4 -S lzd.c lzd.il $ more lzd.s .L77000018: /* 0x001c 11 */ lzd %o0,%o0 /* 0x0020 9 */ ld [%i1],%i3 /* 0x0024 11 */ st %o0,[%i2] /* 0x0028 9 */ add %i3,1,%i0 /* 0x002c */ cmp %i0,999 /* 0x0030 */ ble,pt %icc,.L77000018 /* 0x0034 */ st %i0,[%i1] What is surprising is that we're seeing a number of loads and stores in the code. Everything could be held in registers, so why is this happening? The problem is that the code is only inlined at the code generation stage - when the actual instructions are generated. Earlier compiler phases see a function call. The called functions can do all kinds of nastiness to global variables (like 'a' in this code) so we need to load them from memory after the function call, and store them to memory before the function call. Fortunately we can use a #pragma directive to tell the compiler that the routine lzd() has no side effects - meaning that it does not read or write to memory. The directive to do that is #pragma no_side_effect(<routine name), and it needs to be placed after the declaration of the function. The new code looks like: int lzd(int); #pragma no_side_effect(lzd) int a; int c=0; int main() { for(a=0; a<1000; a++) { c=lzd(c); } return 0; } Now the loop looks much neater: /* 0x0014 10 */ add %i1,1,%i1 ! 11 ! { ! 12 ! c=lzd(c); /* 0x0018 12 */ lzd %o0,%o0 /* 0x001c 10 */ cmp %i1,999 /* 0x0020 */ ble,pt %icc,.L77000018 /* 0x0024 */ nop

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  • APEX-Berichte automatisch aktualisieren

    - by carstenczarski
    Einen Bericht auf einer Anwendungsseite in regelmäßigen Abständen zu aktualisieren, ist recht einfach: Seit APEX 4.0 muss man noch nicht einmal JavaScript-Code dafür programmieren; mit einem einfach zu nutzenden Plugin des APEX-Entwicklerteams setzt man das in kürzester Zeit um. In diesem Tipp gehen wir noch etwas weiter: Für eine Tabelle, die eine Spalte mit dem Zeitpunkt der letzten Änderung enthält, wollen wir die zuletzt geänderten Werte hervorheben, so dass man sie leichter erkennen kann.

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  • Parleys Testimonial at GlassFish Community Event, JavaOne 2012

    - by arungupta
    Parleys.com is an e-learning platform that provide a unique experience of online and offline viewing presentations, with integrated movies and chaptering, from the top notch developer conferences and about 40 JUGs all around the world. Stephan Janssen (the Devoxx man and Parleys webmaster) presented at the GlassFish Community Event at JavaOne 2012 and shared why they moved from Tomcat to GlassFish. The move paid off as GlassFish was able to handle 2000 concurrent users very easily. Now they are also running Devoxx CFP and registration on this updated infrastructure. The GlassFish clustering, the asadmin CLI, application versioning, and JMS implementation are some of the features that made them a happy user. Recently they migrated their application from Spring to Java EE 6. This allows them to get locked into proprietary frameworks and also avoid 40MB WAR file deployments. Stateless application, JAX-RS, MongoDB, and Elastic Search is their magical forumla for success there. Watch the video below showing him in full action: More details about their infrastructure is available here.

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  • Mobile or the Science of Programming Languages

    - by user12652314
    Just two things to share today. First is some news in the mobile computing space and a pretty cool new relationship developing with DubLabs and AT&T to enable a student-centric mobile experience for our Campus Solution customers. And second, is an interesting article shared by a friend on Research in Programming Languages related to STEM education, a key story element to my project with Americas Cup and iED, but also to our national interest

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  • Library order is important

    - by Darryl Gove
    I've written quite extensively about link ordering issues, but I've not discussed the interaction between archive libraries and shared libraries. So let's take a simple program that calls a maths library function: #include <math.h int main() { for (int i=0; i<10000000; i++) { sin(i); } } We compile and run it to get the following performance: bash-3.2$ cc -g -O fp.c -lm bash-3.2$ timex ./a.out real 6.06 user 6.04 sys 0.01 Now most people will have heard of the optimised maths library which is added by the flag -xlibmopt. This contains optimised versions of key mathematical functions, in this instance, using the library doubles performance: bash-3.2$ cc -g -O -xlibmopt fp.c -lm bash-3.2$ timex ./a.out real 2.70 user 2.69 sys 0.00 The optimised maths library is provided as an archive library (libmopt.a), and the driver adds it to the link line just before the maths library - this causes the linker to pick the definitions provided by the static library in preference to those provided by libm. We can see the processing by asking the compiler to print out the link line: bash-3.2$ cc -### -g -O -xlibmopt fp.c -lm /usr/ccs/bin/ld ... fp.o -lmopt -lm -o a.out... The flag to the linker is -lmopt, and this is placed before the -lm flag. So what happens when the -lm flag is in the wrong place on the command line: bash-3.2$ cc -g -O -xlibmopt -lm fp.c bash-3.2$ timex ./a.out real 6.02 user 6.01 sys 0.01 If the -lm flag is before the source file (or object file for that matter), we get the slower performance from the system maths library. Why's that? If we look at the link line we can see the following ordering: /usr/ccs/bin/ld ... -lmopt -lm fp.o -o a.out So the optimised maths library is still placed before the system maths library, but the object file is placed afterwards. This would be ok if the optimised maths library were a shared library, but it is not - instead it's an archive library, and archive library processing is different - as described in the linker and library guide: "The link-editor searches an archive only to resolve undefined or tentative external references that have previously been encountered." An archive library can only be used resolve symbols that are outstanding at that point in the link processing. When fp.o is placed before the libmopt.a archive library, then the linker has an unresolved symbol defined in fp.o, and it will search the archive library to resolve that symbol. If the archive library is placed before fp.o then there are no unresolved symbols at that point, and so the linker doesn't need to use the archive library. This is why libmopt needs to be placed after the object files on the link line. On the other hand if the linker has observed any shared libraries, then at any point these are checked for any unresolved symbols. The consequence of this is that once the linker "sees" libm it will resolve any symbols it can to that library, and it will not check the archive library to resolve them. This is why libmopt needs to be placed before libm on the link line. This leads to the following order for placing files on the link line: Object files Archive libraries Shared libraries If you use this order, then things will consistently get resolved to the archive libraries rather than to the shared libaries.

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