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Committed JDO writes do not apply on local GAE HRD, or possibly reused transaction

- by eeeeaaii

I'm using JDO 2.3 on app engine. I was using the Master/Slave datastore for local testing and recently switched over to using the HRD datastore for local testing, and parts of my app are breaking (which is to be expected). One part of the app that's breaking is where it sends a lot of writes quickly - that is because of the 1-second limit thing, it's failing with a concurrent modification exception. Okay, so that's also to be expected, so I have the browser retry the writes again later when they fail (maybe not the best hack but I'm just trying to get it working quickly). But a weird thing is happening. Some of the writes which should be succeeding (the ones that DON'T get the concurrent modification exception) are also failing, even though the commit phase completes and the request returns my success code. I can see from the log that the retried requests are working okay, but these other requests that seem to have committed on the first try are, I guess, never "applied." But from what I read about the Apply phase, writing again to that same entity should force the apply... but it doesn't. Code follows. Some things to note: I am attempting to use automatic JDO caching. So this is where JDO uses memcache under the covers. This doesn't actually work unless you wrap everything in a transaction. all the requests are doing is reading a string out of an entity, modifying part of the string, and saving that string back to the entity. If these requests weren't in transactions, you'd of course have the "dirty read" problem. But with transactions, isolation is supposed to be at the level of "serializable" so I don't see what's happening here. the entity being modified is a root entity (not in a group) I have cross-group transactions enabled Another weird thing is happening. If the concurrent modification thing happens, and I subsequently edit more than 5 more entities (this is the max for cross-group transactions), then nothing happens right away, but when I stop and restart the server I get "IllegalArgumentException: operating on too many entity groups in a single transaction". Could it be possible that the PMF is returning the same PersistenceManager every time, or the PM is reusing the same transaction every time? I don't see how I could possibly get the above error otherwise. The code inside the transaction just edits one root entity. I can't think of any other way that GAE would give me the "too many entity groups" error. The relevant code (this is a simplified version) PersistenceManager pm = PMF.getManager(); Transaction tx = pm.currentTransaction(); String responsetext = ""; try { tx.begin(); // I have extra calls to "makePersistent" because I found that relying // on pm.close didn't always write the objects to cache, maybe that // was only a DataNucleus 1.x issue though Key userkey = obtainUserKeyFromCookie(); User u = pm.getObjectById(User.class, userkey); pm.makePersistent(u); // to make sure it gets cached for next time Key mapkey = obtainMapKeyFromQueryString(); // this is NOT a java.util.Map, just FYI Map currentmap = pm.getObjectById(Map.class, mapkey); Text mapData = currentmap.getMapData(); // mapData is JSON stored in the entity Text newMapData = parseModifyAndReturn(mapData); // transform the map currentmap.setMapData(newMapData); // mutate the Map object pm.makePersistent(currentmap); // make sure to persist so there is a cache hit tx.commit(); responsetext = "OK"; } catch (JDOCanRetryException jdoe) { // log jdoe responsetext = "RETRY"; } catch (Exception e) { // log e responsetext = "ERROR"; } finally { if (tx.isActive()) { tx.rollback(); } pm.close(); } resp.getWriter().println(responsetext); EDIT: so I have verified that it fails after exactly 5 transactions. Here's what I do: I create a Foo (root entity), do a bunch of concurrent operations on that Foo, and some fail and get retried, and some commit but don't apply (as described above). Then, I start creating more Foos, and do a few operations on those new Foos. If I only create four Foos, stopping and restarting app engine does NOT give me the IllegalArgumentException. However if I create five Foos (which is the limit for cross-group transactions), then when I stop and restart app engine, I do get the exception. So it seems that somehow these new Foos I am creating are counting toward the limit of 5 max entities per transaction, even though they are supposed to be handled by separate transactions. It's as if a transaction is still open and is being reused by the servlet when it handles the new requests for the 2nd through 5th Foos. EDIT2: it looks like the IllegalArgument thing is independent of the other bug. In other words, it always happens when I create five Foos, even if I don't get the concurrent modification exception. I don't know if it's a symptom of the same problem or if it's unrelated. EDIT3: I found out what was causing the (unrelated) IllegalArgumentException, it was a dumb mistake on my part. But the other issue is still happening. EDIT4: added pseudocode for the datastore access EDIT5: I am pretty sure I know why this is happening, but I will still award the bounty to anyone who can confirm it. Basically, I think the problem is that transactions are not really implemented in the local version of the datastore. References: https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/gVMS1dFSpcU https://groups.google.com/forum/?fromgroups=#!topic/google-appengine-java/deGasFdIO-M https://groups.google.com/forum/?hl=en&fromgroups=#!msg/google-appengine-java/4YuNb6TVD6I/gSttMmHYwo0J Because transactions are not implemented, rollback is essentially a no-op. Therefore, I get a dirty read when two transactions try to modify the record at the same time. In other words, A reads the data and B reads the data at the same time. A attempts to modify the data, and B attempts to modify a different part of the data. A writes to the datastore, then B writes, obliterating A's changes. Then B is "rolled back" by app engine, but since rollbacks are a no-op when running on the local datastore, B's changes stay, and A's do not. Meanwhile, since B is the thread that threw the exception, the client retries B, but does not retry A (since A was supposedly the transaction that succeeded).

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WebLogic Server Performance and Tuning: Part I - Tuning JVM

- by Gokhan Gungor

Each WebLogic Server instance runs in its own dedicated Java Virtual Machine (JVM) which is their runtime environment. Every Admin Server in any domain executes within a JVM. The same also applies for Managed Servers. WebLogic Server can be used for a wide variety of applications and services which uses the same runtime environment and resources. Oracle WebLogic ships with 2 different JVM, HotSpot and JRocket but you can choose which JVM you want to use. JVM is designed to optimize itself however it also provides some startup options to make small changes. There are default values for its memory and garbage collection. In real world, you will not want to stick with the default values provided by the JVM rather want to customize these values based on your applications which can produce large gains in performance by making small changes with the JVM parameters. We can tell the garbage collector how to delete garbage and we can also tell JVM how much space to allocate for each generation (of java Objects) or for heap. Remember during the garbage collection no other process is executed within the JVM or runtime, which is called STOP THE WORLD which can affect the overall throughput. Each JVM has its own memory segment called Heap Memory which is the storage for java Objects. These objects can be grouped based on their age like young generation (recently created objects) or old generation (surviving objects that have lived to some extent), etc. A java object is considered garbage when it can no longer be reached from anywhere in the running program. Each generation has its own memory segment within the heap. When this segment gets full, garbage collector deletes all the objects that are marked as garbage to create space. When the old generation space gets full, the JVM performs a major collection to remove the unused objects and reclaim their space. A major garbage collect takes a significant amount of time and can affect system performance. When we create a managed server either on the same machine or on remote machine it gets its initial startup parameters from $DOMAIN_HOME/bin/setDomainEnv.sh/cmd file. By default two parameters are set: Xms: The initial heapsize Xmx: The max heapsize Try to set equal initial and max heapsize. The startup time can be a little longer but for long running applications it will provide a better performance. When we set -Xms512m -Xmx1024m, the physical heap size will be 512m. This means that there are pages of memory (in the state of the 512m) that the JVM does not explicitly control. It will be controlled by OS which could be reserve for the other tasks. In this case, it is an advantage if the JVM claims the entire memory at once and try not to spend time to extend when more memory is needed. Also you can use -XX:MaxPermSize (Maximum size of the permanent generation) option for Sun JVM. You should adjust the size accordingly if your application dynamically load and unload a lot of classes in order to optimize the performance. You can set the JVM options/heap size from the following places: Through the Admin console, in the Server start tab In the startManagedWeblogic script for the managed servers $DOMAIN_HOME/bin/startManagedWebLogic.sh/cmd JAVA_OPTIONS="-Xms1024m -Xmx1024m" ${JAVA_OPTIONS} In the setDomainEnv script for the managed servers and admin server (domain wide) USER_MEM_ARGS="-Xms1024m -Xmx1024m" When there is free memory available in the heap but it is too fragmented and not contiguously located to store the object or when there is actually insufficient memory we can get java.lang.OutOfMemoryError. We should create Thread Dump and analyze if that is possible in case of such error. The second option we can use to produce higher throughput is to garbage collection. We can roughly divide GC algorithms into 2 categories: parallel and concurrent. Parallel GC stops the execution of all the application and performs the full GC, this generally provides better throughput but also high latency using all the CPU resources during GC. Concurrent GC on the other hand, produces low latency but also low throughput since it performs GC while application executes. The JRockit JVM provides some useful command-line parameters that to control of its GC scheme like -XgcPrio command-line parameter which takes the following options; XgcPrio:pausetime (To minimize latency, parallel GC) XgcPrio:throughput (To minimize throughput, concurrent GC ) XgcPrio:deterministic (To guarantee maximum pause time, for real time systems) Sun JVM has similar parameters (like -XX:UseParallelGC or -XX:+UseConcMarkSweepGC) to control its GC scheme. We can add -verbosegc -XX:+PrintGCDetails to monitor indications of a problem with garbage collection. Try configuring JVM’s of all managed servers to execute in -server mode to ensure that it is optimized for a server-side production environment.

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OWB 11gR2 - Find and Search Metadata in Designer

- by David Allan

Here are some tools and techniques for finding objects, specifically in the design repository. There are ways of navigating and collating objects that are useful for day to day development and build-time usage - this includes features out of the box and utilities constructed on top. There are a variety of techniques to navigate and find objects in the repository, the first 3 are out of the box, the 4th is an expert utility. Navigating by the tree, grouping by project and module - ok if you are aware of the exact module/folder that objects reside in. The structure panel is a useful way of finding parts of an object, especially when large rather than using the canvas. In large scale projects it helps to have accelerators (either find or collections below). Advanced find to search by name - 11gR2 included a find capability specifically for large scale projects. There were improvements in both the tree search and the object editors (including highlighting in mapping for example). So you can now do regular expression based search and quickly navigate to objects within a repository. Collections - logically organize your objects into virtual folders by shortcutting the actual objects. This is useful for a range of things since all the OWB services operate on collections too (export/import, validation, deployment). See the post here for new collection functionality in 11gR2. Reports for searching by type, updated on, updated by etc. Useful for activities such as periodic incremental actions (deploy all mappings changed in the past week). The report style view is useful since I can quickly see who changed what and when. You can see all the audit details for objects within each objects property inspector, but its useful to just get all objects changed today or example, all objects changed since my last build etc. This utility combines both UI extensions via experts and the public views on the repository. In the figure to the right you see the contextual option 'Object Search' which invokes the utility, you can see I have quite a number of modules within my project. Figure out all the potential objects which have been changed is not simple. The utility is an expert which provides this kind of search capability. The utility provides a report of the objects in the design repository which satisfy some filter criteria. The type of criteria includes; objects updated in the last n days optionally filter the objects updated by user filter the user by project and by type (table/mappings etc.) The search dialog appears with these options, you can multi-select the object types, so for example you can select TABLE and MAPPING. Its also possible to search across projects if need be. If you have multiple users using the repository you can define the OWB user name in the 'Updated by' property to restrict the report to just that user also. Finally there is a search name that will be used for some of the options such as building a collection - this name is used for the collection to be built. In the example I have done, I've just searched my project for all process flows and mappings that users have updated in the last 7 days. The results of the query are returned in a table containing the object names, types, full path and audit details. The columns are sort-able, you can sort the results by name, type, path etc. One of the cool things here, is that you can then perform operations on these objects - such as edit them, export single selection or entire results to MDL, create a collection from the results (now you have a saved set of references in the repository, you could do deploy/export etc.), create a deployment script from the results...or even add in your own ideas! You see from this that you can do bulk operations on sets of objects based on search results. So for example selecting the 'Build Collection' option creates a collection with all of the objects from my search, you can subsequently deploy/generate/maintain this collection of objects. Under the hood of the expert if just basic OMB commands from the product and the use of the public views on the design repository. You can see how easy it is to build up macro-like capabilities that will help you do day-to-day as well as build like tasks on sets of objects.

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Tuple in C# 4.0

- by Jalpesh P. Vadgama

C# 4.0 language includes a new feature called Tuple. Tuple provides us a way of grouping elements of different data type. That enables us to use it a lots places at practical world like we can store a coordinates of graphs etc. In C# 4.0 we can create Tuple with Create method. This Create method offer 8 overload like following. So you can group maximum 8 data types with a Tuple. Followings are overloads of a data type. Create(T1)- Which represents a tuple of size 1 Create(T1,T2)- Which represents a tuple of size 2 Create(T1,T2,T3) – Which represents a tuple of size 3 Create(T1,T2,T3,T4) – Which represents a tuple of size 4 Create(T1,T2,T3,T4,T5) – Which represents a tuple of size 5 Create(T1,T2,T3,T4,T5,T6) – Which represents a tuple of size 6 Create(T1,T2,T3,T4,T5,T6,T7) – Which represents a tuple of size 7 Create(T1,T2,T3,T4,T5,T6,T7,T8) – Which represents a tuple of size 8 Following are some example code for tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple); var t = System.Tuple.Create<int, string>(1, "Jalpesh"); Console.WriteLine(t); } } } Following is a output of above as expected. You can also access values insides Tuple with ItemN property. Where N represents particular number of item in tuple. Following is an example of it. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create<string, string, string>("Jalpesh", "P", "Vadgama"); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Here you can see I have printed items with Item1,Item2 and Item3 . Following is the output of above code. Even we can create a nested tuple also following is code for nested tuple. using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace TupleExample { class Program { static void Main(string[] args) { var tuple = System.Tuple.Create(1,"Jalpesh",new Tuple<string,string>("P","Vadgama")); Console.WriteLine(tuple.Item1); Console.WriteLine(tuple.Item2); Console.WriteLine(tuple.Item3); } } } Following is a output above code as expected. As you can see there are unlimited possibilities we can do lots of things with Tuple. Hope you liked it. Stay tuned for more. Till then Happy Programming!!

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World Record Batch Rate on Oracle JD Edwards Consolidated Workload with SPARC T4-2

- by Brian

Oracle produced a World Record batch throughput for single system results on Oracle's JD Edwards EnterpriseOne Day-in-the-Life benchmark using Oracle's SPARC T4-2 server running Oracle Solaris Containers and consolidating JD Edwards EnterpriseOne, Oracle WebLogic servers and the Oracle Database 11g Release 2. The workload includes both online and batch workload. The SPARC T4-2 server delivered a result of 8,000 online users while concurrently executing a mix of JD Edwards EnterpriseOne Long and Short batch processes at 95.5 UBEs/min (Universal Batch Engines per minute). In order to obtain this record benchmark result, the JD Edwards EnterpriseOne, Oracle WebLogic and Oracle Database 11g Release 2 servers were executed each in separate Oracle Solaris Containers which enabled optimal system resources distribution and performance together with scalable and manageable virtualization. One SPARC T4-2 server running Oracle Solaris Containers and consolidating JD Edwards EnterpriseOne, Oracle WebLogic servers and the Oracle Database 11g Release 2 utilized only 55% of the available CPU power. The Oracle DB server in a Shared Server configuration allows for optimized CPU resource utilization and significant memory savings on the SPARC T4-2 server without sacrificing performance. This configuration with SPARC T4-2 server has achieved 33% more Users/core, 47% more UBEs/min and 78% more Users/rack unit than the IBM Power 770 server. The SPARC T4-2 server with 2 processors ran the JD Edwards "Day-in-the-Life" benchmark and supported 8,000 concurrent online users while concurrently executing mixed batch workloads at 95.5 UBEs per minute. The IBM Power 770 server with twice as many processors supported only 12,000 concurrent online users while concurrently executing mixed batch workloads at only 65 UBEs per minute. This benchmark demonstrates more than 2x cost savings by consolidating the complete solution in a single SPARC T4-2 server compared to earlier published results of 10,000 users and 67 UBEs per minute on two SPARC T4-2 and SPARC T4-1. The Oracle DB server used mirrored (RAID 1) volumes for the database providing high availability for the data without impacting performance. Performance Landscape JD Edwards EnterpriseOne Day in the Life (DIL) Benchmark Consolidated Online with Batch Workload System Rack Units BatchRate(UBEs/m) Online Users Users /Units Users /Core Version SPARC T4-2 (2 x SPARC T4, 2.85 GHz) 3 95.5 8,000 2,667 500 9.0.2 IBM Power 770 (4 x POWER7, 3.3 GHz, 32 cores) 8 65 12,000 1,500 375 9.0.2 Batch Rate (UBEs/m) — Batch transaction rate in UBEs per minute Configuration Summary Hardware Configuration: 1 x SPARC T4-2 server with 2 x SPARC T4 processors, 2.85 GHz 256 GB memory 4 x 300 GB 10K RPM SAS internal disk 2 x 300 GB internal SSD 2 x Sun Storage F5100 Flash Arrays Software Configuration: Oracle Solaris 10 Oracle Solaris Containers JD Edwards EnterpriseOne 9.0.2 JD Edwards EnterpriseOne Tools (8.98.4.2) Oracle WebLogic Server 11g (10.3.4) Oracle HTTP Server 11g Oracle Database 11g Release 2 (11.2.0.1) Benchmark Description JD Edwards EnterpriseOne is an integrated applications suite of Enterprise Resource Planning (ERP) software. Oracle offers 70 JD Edwards EnterpriseOne application modules to support a diverse set of business operations. Oracle's Day in the Life (DIL) kit is a suite of scripts that exercises most common transactions of JD Edwards EnterpriseOne applications, including business processes such as payroll, sales order, purchase order, work order, and manufacturing processes, such as ship confirmation. These are labeled by industry acronyms such as SCM, CRM, HCM, SRM and FMS. The kit's scripts execute transactions typical of a mid-sized manufacturing company. The workload consists of online transactions and the UBE – Universal Business Engine workload of 61 short and 4 long UBEs. LoadRunner runs the DIL workload, collects the user’s transactions response times and reports the key metric of Combined Weighted Average Transaction Response time. The UBE processes workload runs from the JD Enterprise Application server. Oracle's UBE processes come as three flavors: Short UBEs < 1 minute engage in Business Report and Summary Analysis, Mid UBEs > 1 minute create a large report of Account, Balance, and Full Address, Long UBEs > 2 minutes simulate Payroll, Sales Order, night only jobs. The UBE workload generates large numbers of PDF files reports and log files. The UBE Queues are categorized as the QBATCHD, a single threaded queue for large and medium UBEs, and the QPROCESS queue for short UBEs run concurrently. Oracle's UBE process performance metric is Number of Maximum Concurrent UBE processes at transaction rate, UBEs/minute. Key Points and Best Practices Two JD Edwards EnterpriseOne Application Servers, two Oracle WebLogic Servers 11g Release 1 coupled with two Oracle Web Tier HTTP server instances and one Oracle Database 11g Release 2 database on a single SPARC T4-2 server were hosted in separate Oracle Solaris Containers bound to four processor sets to demonstrate consolidation of multiple applications, web servers and the database with best resource utilizations. Interrupt fencing was configured on all Oracle Solaris Containers to channel the interrupts to processors other than the processor sets used for the JD Edwards Application server, Oracle WebLogic servers and the database server. A Oracle WebLogic vertical cluster was configured on each WebServer Container with twelve managed instances each to load balance users' requests and to provide the infrastructure that enables scaling to high number of users with ease of deployment and high availability. The database log writer was run in the real time RT class and bound to a processor set. The database redo logs were configured on the raw disk partitions. The Oracle Solaris Container running the Enterprise Application server completed 61 Short UBEs, 4 Long UBEs concurrently as the mixed size batch workload. The mixed size UBEs ran concurrently from the Enterprise Application server with the 8,000 online users driven by the LoadRunner. See Also SPARC T4-2 Server oracle.com OTN JD Edwards EnterpriseOne oracle.com OTN Oracle Solaris oracle.com OTN Oracle Database 11g Release 2 Enterprise Edition oracle.com OTN Oracle Fusion Middleware oracle.com OTN Disclosure Statement Copyright 2012, Oracle and/or its affiliates. All rights reserved. Oracle and Java are registered trademarks of Oracle and/or its affiliates. Other names may be trademarks of their respective owners. Results as of 09/30/2012.

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Part 8: How to name EBS Customizations

- by volker.eckardt(at)oracle.com

You might wonder why I am discussing this here. The reason is simple: nearly every project has a bit different naming conventions, which makes a the life always a bit complicated (for developers, but also setup responsible, and also for consultants). Although we always create a document to describe the technical object naming conventions, I have rarely seen a dedicated document with functional naming conventions. To be precisely, from my stand point, there should always be one global naming definition for an implementation! Let me discuss some related questions: What is the best convention for the customization reference? How to name database objects (tables, packages etc.)? How to name functional objects like Value Sets, Concurrent Programs, etc. How to separate customizations from standard objects best? What is the best convention for the customization reference? The customization reference is the key you use to reference your customization from other lists, from the project plan etc. Usually it is something like XXHU_CONV_22 (HU=customer abbreviation, CONV=Conversion object #22) or XXFA_DEPRN_RPT_02 (FA=Fixed Assets, DEPRN=Short object group, here depreciation, RPT=Report, 02=2nd report in this area) As this is just a reference (not an object name yet), I would prefer the second option. XX=Customization, FA=Main EBS Module linked (you may have sometimes more, but FA is the main) DEPRN_RPT=Short name to specify the customization 02=a unique number Important here is that the HU isn’t used, because XX is enough to mark a custom object, and the 3rd+4th char can be used by the EBS module short name. How to name database objects (tables, packages etc.)? I was leading different developer teams, and I know that one common way is it to take the Customization reference and add more chars behind to classify the object (like _V for view and _T1 for triggers etc.). The only concern I have with this approach is the reusability. If you name your view XXFA_DEPRN_RPT_02_V, no one will by choice reuse this nice view, as it seams to be specific for this CEMLI. My suggestion is rather to name the view XXFA_DEPRN_PERIODS_V and allow herewith reusability for other CEMLIs (although the view will be deployed primarily with CEMLI package XXFA_DEPRN_RPT_02). (check also one of the following Blogs where I will talk about deployment.) How to name Value Sets, Concurrent Programs, etc. For Value Sets I would go with the same convention as for database objects, starting with XX<Module> …. For Concurrent Programs the situation is a bit different. This “object” is seen and used by a lot of users, and they will search for. In many projects it is common to start again with the company short name, or with XX. My proposal would differ. If you have created your own report and you name it “XX: Invoice Report”, the user has to remember that this report does not start with “I”, it starts with X. Would you like typing an X if you are looking for an Invoice report? No, you wouldn’t! So my advise would be to name it: “Invoice Report (XXAP)”. Still we know it is custom (because of the XXAP), but the end user will type the key “i” to get it (and will see similar reports starting also with “i”). I hope that the general schema behind has now become obvious. How to separate customizations from standard objects best? I would not have this section here if the naming would not play an important role. Unfortunately, we can not always link a custom application to our own object, therefore the naming is really important. In the file system structure we use our $XXyy_TOP, in JAVA_TOP it is perhaps also “xx” in front. But in the database itself? Although there are different concepts in place, still many implementations are using the standard “apps” approach, means custom objects are stored in the apps schema (which should not cause any trouble). Final advise: review the naming conventions regularly, once a month. You may have to add more! And, publish them! To summarize: Technical and functional customized objects should always follow a naming convention. This naming convention should be project wide, and only one place shall be used to maintain (like in a Wiki). If the name is for the end user, rather put a customization identifier at the end; if it is an internal name, start with XX…

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CPU Usage in Very Large Coherence Clusters

- by jpurdy

When sizing Coherence installations, one of the complicating factors is that these installations (by their very nature) tend to be application-specific, with some being large, memory-intensive caches, with others acting as I/O-intensive transaction-processing platforms, and still others performing CPU-intensive calculations across the data grid. Regardless of the primary resource requirements, Coherence sizing calculations are inherently empirical, in that there are so many permutations that a simple spreadsheet approach to sizing is rarely optimal (though it can provide a good starting estimate). So we typically recommend measuring actual resource usage (primarily CPU cycles, network bandwidth and memory) at a given load, and then extrapolating from those measurements. Of course there may be multiple types of load, and these may have varying degrees of correlation -- for example, an increased request rate may drive up the number of objects "pinned" in memory at any point, but the increase may be less than linear if those objects are naturally shared by concurrent requests. But for most reasonably-designed applications, a linear resource model will be reasonably accurate for most levels of scale. However, at extreme scale, sizing becomes a bit more complicated as certain cluster management operations -- while very infrequent -- become increasingly critical. This is because certain operations do not naturally tend to scale out. In a small cluster, sizing is primarily driven by the request rate, required cache size, or other application-driven metrics. In larger clusters (e.g. those with hundreds of cluster members), certain infrastructure tasks become intensive, in particular those related to members joining and leaving the cluster, such as introducing new cluster members to the rest of the cluster, or publishing the location of partitions during rebalancing. These tasks have a strong tendency to require all updates to be routed via a single member for the sake of cluster stability and data integrity. Fortunately that member is dynamically assigned in Coherence, so it is not a single point of failure, but it may still become a single point of bottleneck (until the cluster finishes its reconfiguration, at which point this member will have a similar load to the rest of the members). The most common cause of scaling issues in large clusters is disabling multicast (by configuring well-known addresses, aka WKA). This obviously impacts network usage, but it also has a large impact on CPU usage, primarily since the senior member must directly communicate certain messages with every other cluster member, and this communication requires significant CPU time. In particular, the need to notify the rest of the cluster about membership changes and corresponding partition reassignments adds stress to the senior member. Given that portions of the network stack may tend to be single-threaded (both in Coherence and the underlying OS), this may be even more problematic on servers with poor single-threaded performance. As a result of this, some extremely large clusters may be configured with a smaller number of partitions than ideal. This results in the size of each partition being increased. When a cache server fails, the other servers will use their fractional backups to recover the state of that server (and take over responsibility for their backed-up portion of that state). The finest granularity of this recovery is a single partition, and the single service thread can not accept new requests during this recovery. Ordinarily, recovery is practically instantaneous (it is roughly equivalent to the time required to iterate over a set of backup backing map entries and move them to the primary backing map in the same JVM). But certain factors can increase this duration drastically (to several seconds): large partitions, sufficiently slow single-threaded CPU performance, many or expensive indexes to rebuild, etc. The solution of course is to mitigate each of those factors but in many cases this may be challenging. Larger clusters also lead to the temptation to place more load on the available hardware resources, spreading CPU resources thin. As an example, while we've long been aware of how garbage collection can cause significant pauses, it usually isn't viewed as a major consumer of CPU (in terms of overall system throughput). Typically, the use of a concurrent collector allows greater responsiveness by minimizing pause times, at the cost of reducing system throughput. However, at a recent engagement, we were forced to turn off the concurrent collector and use a traditional parallel "stop the world" collector to reduce CPU usage to an acceptable level. In summary, there are some less obvious factors that may result in excessive CPU consumption in a larger cluster, so it is even more critical to test at full scale, even though allocating sufficient hardware may often be much more difficult for these large clusters.

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Activation Error while testing Exception Handling Application Block

- by CletusLoomis

I'm getting the following error while testing my EHAB implementation: {"Activation error occured while trying to get instance of type ExceptionPolicyImpl, key "LogPolicy""} System.Exception Stack Trace: StackTrace " at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance(Type serviceType, String key) in c:\Home\Chris\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 53 at Microsoft.Practices.ServiceLocation.ServiceLocatorImplBase.GetInstance[TService](String key) in c:\Home\Chris\Projects\CommonServiceLocator\main\Microsoft.Practices.ServiceLocation\ServiceLocatorImplBase.cs:line 103 at Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.GetExceptionPolicy(Exception exception, String policyName) in e:\Builds\EntLib\Latest\Source\Blocks\ExceptionHandling\Src\ExceptionHandling\ExceptionPolicy.cs:line 131 at Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicy.HandleException(Exception exceptionToHandle, String policyName) in e:\Builds\EntLib\Latest\Source\Blocks\ExceptionHandling\Src\ExceptionHandling\ExceptionPolicy.cs:line 55 at Blackbox.Exception.ExceptionMain.LogException(Exception pException) in C:_Work_Black Box\Blackbox.Exception\ExceptionMain.vb:line 14 at BlackBox.Business.BusinessMain.TestExceptionHandling() in C:_Work_Black Box\BlackBox.Business\BusinessMain.vb:line 16 at Blackbox.Service.Service1.TestExceptionHandling() in C:_Work_Black Box\Blackbox.Service\Service.svc.vb:line 43" String Inner Exception: InnerException {"Resolution of the dependency failed, type = "Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl", name = "LogPolicy". Exception occurred while: Calling constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener(System.String source, System.String log, System.String machineName, Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.ILogFormatter formatter). Exception is: ArgumentException - Event log names must consist of printable characters and cannot contain \, *, ?, or spaces At the time of the exception, the container was: Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl,LogPolicy Resolving parameter "policyEntries" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyImpl(System.String policyName, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] policyEntries) Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry,LogPolicy.All Exceptions Resolving parameter "handlers" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.ExceptionPolicyEntry(System.Type exceptionType, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.PostHandlingAction postHandlingAction, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.IExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] handlers, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Instrumentation.IExceptionHandlingInstrumentationProvider instrumentationProvider) Resolving Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler,LogPolicy.All Exceptions.Logging Exception Handler (mapped from Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.IExceptionHandler, LogPolicy.All Exceptions.Logging Exception Handler) Resolving parameter "writer" of constructor Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler(System.String logCategory, System.Int32 eventId, System.Diagnostics.TraceEventType severity, System.String title, System.Int32 priority, System.Type formatterType, Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter writer) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterImpl,LogWriter.default (mapped from Microsoft.Practices.EnterpriseLibrary.Logging.LogWriter, (none)) Resolving parameter "structureHolder" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterImpl(Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder structureHolder, Microsoft.Practices.EnterpriseLibrary.Logging.Instrumentation.ILoggingInstrumentationProvider instrumentationProvider, Microsoft.Practices.EnterpriseLibrary.Logging.ILoggingUpdateCoordinator updateCoordinator) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder,LogWriterStructureHolder.default (mapped from Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder, (none)) Resolving parameter "traceSources" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogWriterStructureHolder(System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.Logging.Filters.ILogFilter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] filters, System.Collections.Generic.IEnumerable1[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] traceSourceNames, System.Collections.Generic.IEnumerable1[[Microsoft.Practices.EnterpriseLibrary.Logging.LogSource, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]] traceSources, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource allEventsTraceSource, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource notProcessedTraceSource, Microsoft.Practices.EnterpriseLibrary.Logging.LogSource errorsTraceSource, System.String defaultCategory, System.Boolean tracingEnabled, System.Boolean logWarningsWhenNoCategoriesMatch, System.Boolean revertImpersonation) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.LogSource,General Resolving parameter "traceListeners" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.LogSource(System.String name, System.Collections.Generic.IEnumerable1[[System.Diagnostics.TraceListener, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] traceListeners, System.Diagnostics.SourceLevels level, System.Boolean autoFlush, Microsoft.Practices.EnterpriseLibrary.Logging.Instrumentation.ILoggingInstrumentationProvider instrumentationProvider) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.ReconfigurableTraceListenerWrapper,Event Log Listener (mapped from System.Diagnostics.TraceListener, Event Log Listener) Resolving parameter "wrappedTraceListener" of constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.ReconfigurableTraceListenerWrapper(System.Diagnostics.TraceListener wrappedTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging.ILoggingUpdateCoordinator coordinator) Resolving Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener,Event Log Listener?implementation (mapped from System.Diagnostics.TraceListener, Event Log Listener?implementation) Calling constructor Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener(System.String source, System.String log, System.String machineName, Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.ILogFormatter formatter) "} System.Exception My web.config is as follows: <?xml version="1.0"?> <configuration> <configSections> <section name="loggingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.LoggingSettings, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" /> <section name="exceptionHandling" type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Configuration.ExceptionHandlingSettings, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="true" /> </configSections> <loggingConfiguration name="" tracingEnabled="true" defaultCategory="General"> <listeners> <add name="Event Log Listener" type="Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners.FormattedEventLogTraceListener, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" listenerDataType="Microsoft.Practices.EnterpriseLibrary.Logging.Configuration.FormattedEventLogTraceListenerData, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" source="Enterprise Library Logging" formatter="Text Formatter" log="C:\Blackbox.log" machineName="." traceOutputOptions="LogicalOperationStack, DateTime, Timestamp, Callstack" /> </listeners> <formatters> <add type="Microsoft.Practices.EnterpriseLibrary.Logging.Formatters.TextFormatter, Microsoft.Practices.EnterpriseLibrary.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" template="Timestamp: {timestamp}{newline}
Message: {message}{newline}
Category: {category}{newline}
Priority: {priority}{newline}
EventId: {eventid}{newline}
Severity: {severity}{newline}
Title:{title}{newline}
Machine: {localMachine}{newline}
App Domain: {localAppDomain}{newline}
ProcessId: {localProcessId}{newline}
Process Name: {localProcessName}{newline}
Thread Name: {threadName}{newline}
Win32 ThreadId:{win32ThreadId}{newline}
Extended Properties: {dictionary({key} - {value}{newline})}" name="Text Formatter" /> </formatters> <categorySources> <add switchValue="All" name="General"> <listeners> <add name="Event Log Listener" /> </listeners> </add> </categorySources> <specialSources> <allEvents switchValue="All" name="All Events" /> <notProcessed switchValue="All" name="Unprocessed Category" /> <errors switchValue="All" name="Logging Errors & Warnings"> <listeners> <add name="Event Log Listener" /> </listeners> </errors> </specialSources> </loggingConfiguration> <exceptionHandling> <exceptionPolicies> <add name="LogPolicy"> <exceptionTypes> <add name="All Exceptions" type="System.Exception, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" postHandlingAction="NotifyRethrow"> <exceptionHandlers> <add name="Logging Exception Handler" type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging.LoggingExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.Logging, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" logCategory="General" eventId="100" severity="Error" title="Enterprise Library Exception Handling" formatterType="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.TextExceptionFormatter, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling" priority="0" /> </exceptionHandlers> </add> </exceptionTypes> </add> <add name="WcfExceptionShielding"> <exceptionTypes> <add name="InvalidOperationException" type="System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" postHandlingAction="ThrowNewException"> <exceptionHandlers> <add type="Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.WCF.FaultContractExceptionHandler, Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.WCF, Version=5.0.414.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" exceptionMessageResourceType="" exceptionMessageResourceName="This is the message" exceptionMessage="This is the exception" faultContractType="Blackbox.Service.WCFFault, Blackbox.Service, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Fault Contract Exception Handler"> <mappings> <add source="{Guid}" name="Id" /> <add source="{Message}" name="MessageText" /> </mappings> </add> </exceptionHandlers> </add> </exceptionTypes> </add> </exceptionPolicies> </exceptionHandling> <connectionStrings> <add name="CompassEntities" connectionString="metadata=~\bin\CompassModel.csdl|~\bin\CompassModel.ssdl|~\bin\CompassModel.msl;provider=Devart.Data.Oracle;provider connection string="User Id=foo;Password=foo;Server=foo64mo;Home=OraClient11g_home1;Persist Security Info=True"" providerName="System.Data.EntityClient" /> <add name="BlackboxEntities" connectionString="metadata=~\bin\BlackboxModel.csdl|~\bin\BlackboxModel.ssdl|~\bin\BlackboxModel.msl;provider=System.Data.SqlClient;provider connection string="Data Source=sqldev1\cps;Initial Catalog=FundServ;Integrated Security=True;MultipleActiveResultSets=True"" providerName="System.Data.EntityClient" /> </connectionStrings> <system.web> <compilation debug="true" strict="false" explicit="true" targetFramework="4.0" /> </system.web> <system.serviceModel> <behaviors> <serviceBehaviors> <behavior>  <serviceMetadata httpGetEnabled="true"/>  <serviceDebug includeExceptionDetailInFaults="false"/> </behavior> </serviceBehaviors> </behaviors> <serviceHostingEnvironment multipleSiteBindingsEnabled="true" /> </system.serviceModel> <system.webServer> <modules runAllManagedModulesForAllRequests="true"/> </system.webServer> </configuration> My code is as follows: Public Shared Function LogException(ByVal pException As System.Exception) As Boolean Return ExceptionPolicy.HandleException(pException, "LogPolicy") End Function Any assistance is appreciated.

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AbstractMethodError on org.apache.xalan.processor.TransformerFactoryImpl

- by JBristow

With the following code: private Document transformDoc(Source source) throws TransformerException, IOException { Transformer xslTransformer = TransformerFactory.newInstance().newTransformer(new StreamSource(pdfTransformXslt.getInputStream())); xslTransformer.setParameter("http://apache.org/xml/features/nonvalidating/load-external-dtd", false); xslTransformer.setParameter("http://xml.org/sax/features/validation", false); JDOMResult result = new JDOMResult(); xslTransformer.transform(source, result); return result.getDocument(); } I'm getting the following error: java.lang.AbstractMethodError: org.apache.xalan.processor.TransformerFactoryImpl.setFeature(Ljava/lang/String;Z)V Why is this? Here's my Maven dependency tree: ------------------------------------------------------------------------ Building mc-hub-batch task-segment: [dependency:tree] ------------------------------------------------------------------------ snapshot com.billmelater:mc-test-support:2.0.0.11-SNAPSHOT: checking for updates from repository.jboss.org [dependency:tree {execution: default-cli}] com.billmelater:mc-hub-batch:jar:2.0.0.11-SNAPSHOT +- com.billmelater:mc-hub-core:jar:2.0.0.11-SNAPSHOT:compile | +- commons-lang:commons-lang:jar:2.4:compile | +- commons-collections:commons-collections:jar:3.2.1:compile | +- commons-beanutils:commons-beanutils:jar:1.8.0:compile | +- commons-digester:commons-digester:jar:2.0:compile | | +- (commons-beanutils:commons-beanutils:jar:1.8.0:compile - omitted for duplicate) | | \- (commons-logging:commons-logging:jar:1.1.1:compile - version managed from 1.0.4; omitted for duplicate) | \- (org.springframework.batch:spring-batch-core:jar:2.0.2.RELEASE:compile - omitted for duplicate) +- com.billmelater:mc-test-support:jar:2.0.0.11-SNAPSHOT:test | +- (com.billmelater:mc-hub-core:jar:2.0.0.11-SNAPSHOT:test - omitted for duplicate) | +- (org.springframework:spring:jar:2.5.6:test - omitted for duplicate) | +- org.springframework:spring-jdbc:jar:2.5.6.SEC01:test | | +- (commons-logging:commons-logging:jar:1.1.1:test - omitted for duplicate) | | +- (org.springframework:spring-beans:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6) | | +- (org.springframework:spring-context:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6) | | +- (org.springframework:spring-core:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6) | | \- (org.springframework:spring-tx:jar:2.5.6.SEC01:test - omitted for conflict with 2.5.6) | +- (org.dbunit:dbunit:jar:2.4.5:test - omitted for duplicate) | +- (log4j:log4j:jar:1.2.15:test - omitted for duplicate) | +- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.5.8; scope updated from test; omitted for duplicate) | +- (org.slf4j:slf4j-log4j12:jar:1.5.6:test - omitted for duplicate) | +- org.jboss.seam:jboss-seam:jar:2.2.0.GA:test | | +- xstream:xstream:jar:1.1.3:test | | +- (xpp3:xpp3_min:jar:1.1.3.4.O:compile - scope updated from test; omitted for duplicate) | | \- org.jboss.el:jboss-el:jar:1.0_02.CR4:test | +- (org.testng:testng:jar:jdk15:5.8:test - omitted for duplicate) | +- (org.hibernate:hibernate-core:jar:3.3.2.GA:test - version managed from 3.3.0.SP1; omitted for duplicate) | +- org.hibernate:hibernate-entitymanager:jar:3.4.0.GA:test | | +- (org.hibernate:ejb3-persistence:jar:1.0.2.GA:test - omitted for duplicate) | | +- (org.hibernate:hibernate-commons-annotations:jar:3.1.0.GA:test - omitted for duplicate) | | +- (org.hibernate:hibernate-annotations:jar:3.4.0.GA:test - omitted for duplicate) | | +- (org.hibernate:hibernate-core:jar:3.3.2.GA:test - version managed from 3.3.0.SP1; omitted for duplicate) | | +- (org.slf4j:slf4j-api:jar:1.5.6:test - version managed from 1.4.2; omitted for duplicate) | | +- (dom4j:dom4j:jar:1.6.1-jboss:test - version managed from 1.6.1; omitted for duplicate) | | +- (javax.transaction:jta:jar:1.0.1B:test - version managed from 1.1; omitted for duplicate) | | \- javassist:javassist:jar:3.4.GA:test | +- (org.hibernate:hibernate-validator:jar:3.1.0.GA:test - omitted for duplicate) | +- (org.apache.velocity:velocity:jar:1.6.2:test - omitted for duplicate) | \- (ojdbc:ojdbc:jar:14:test - omitted for duplicate) +- org.springframework:spring:jar:2.5.6:compile +- org.springframework.batch:spring-batch-core:jar:2.0.2.RELEASE:compile | +- org.springframework.batch:spring-batch-infrastructure:jar:2.0.2.RELEASE:compile | | +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate) | | +- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate) | | \- (stax:stax:jar:1.2.0:compile - omitted for duplicate) | +- org.aspectj:aspectjrt:jar:1.5.4:compile | +- org.aspectj:aspectjweaver:jar:1.5.4:compile | +- com.thoughtworks.xstream:xstream:jar:1.3:compile | | \- xpp3:xpp3_min:jar:1.1.4c:compile | +- org.codehaus.jettison:jettison:jar:1.0:compile | +- org.springframework:spring-aop:jar:2.5.6:compile | | +- aopalliance:aopalliance:jar:1.0:compile | | +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate) | | +- (org.springframework:spring-beans:jar:2.5.6:compile - omitted for duplicate) | | \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate) | +- org.springframework:spring-beans:jar:2.5.6:compile | | +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate) | | \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate) | +- org.springframework:spring-context:jar:2.5.6:compile | | +- (aopalliance:aopalliance:jar:1.0:compile - omitted for duplicate) | | +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate) | | +- (org.springframework:spring-beans:jar:2.5.6:compile - omitted for duplicate) | | \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate) | +- org.springframework:spring-core:jar:2.5.6:compile | | \- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate) | +- org.springframework:spring-tx:jar:2.5.6:compile | | +- (commons-logging:commons-logging:jar:1.1.1:compile - omitted for duplicate) | | +- (org.springframework:spring-beans:jar:2.5.6:compile - omitted for duplicate) | | +- (org.springframework:spring-context:jar:2.5.6:compile - omitted for duplicate) | | \- (org.springframework:spring-core:jar:2.5.6:compile - omitted for duplicate) | \- stax:stax:jar:1.2.0:compile | \- stax:stax-api:jar:1.0.1:compile +- commons-dbcp:commons-dbcp:jar:1.2.2:compile | \- commons-pool:commons-pool:jar:1.3:compile +- org.hibernate:hibernate-core:jar:3.3.2.GA:compile | +- antlr:antlr:jar:2.7.7:compile (version managed from 2.7.6) | +- dom4j:dom4j:jar:1.6.1-jboss:compile (version managed from 1.6.1) | +- javax.transaction:jta:jar:1.0.1B:compile (version managed from 1.1) | \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate) +- org.hibernate:hibernate-validator:jar:3.1.0.GA:compile | +- (org.hibernate:hibernate-core:jar:3.3.2.GA:compile - version managed from 3.3.0.SP1; omitted for duplicate) | +- org.hibernate:hibernate-commons-annotations:jar:3.1.0.GA:compile | | \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate) | \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate) +- org.hibernate:hibernate-annotations:jar:3.4.0.GA:compile | +- org.hibernate:ejb3-persistence:jar:1.0.2.GA:compile | +- (org.hibernate:hibernate-commons-annotations:jar:3.1.0.GA:compile - omitted for duplicate) | +- (org.hibernate:hibernate-core:jar:3.3.2.GA:compile - version managed from 3.3.0.SP1; omitted for duplicate) | +- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate) | \- (dom4j:dom4j:jar:1.6.1-jboss:compile - version managed from 1.6.1; omitted for duplicate) +- ojdbc:ojdbc:jar:14:compile +- org.slf4j:slf4j-api:jar:1.5.6:compile +- org.slf4j:slf4j-log4j12:jar:1.5.6:compile | \- (org.slf4j:slf4j-api:jar:1.5.6:compile - version managed from 1.4.2; omitted for duplicate) +- log4j:log4j:jar:1.2.15:compile +- org.apache.velocity:velocity:jar:1.6.2:compile | +- (commons-collections:commons-collections:jar:3.2.1:compile - omitted for duplicate) | +- (commons-lang:commons-lang:jar:2.4:compile - omitted for duplicate) | \- oro:oro:jar:2.0.8:compile +- org.testng:testng:jar:jdk15:5.8:test +- org.dbunit:dbunit:jar:2.4.5:test | +- junit:junit:jar:4.7:test (version managed from 3.8.2) | +- (org.slf4j:slf4j-api:jar:1.5.6:test - version managed from 1.4.2; omitted for duplicate) | \- (commons-collections:commons-collections:jar:3.2.1:test - omitted for duplicate) +- hsqldb:hsqldb:jar:1.8.0.7:test +- jboss:javassist:jar:3.3.ga:provided +- org.jdom:jdom:jar:1.1:compile +- jaxen:jaxen:jar:1.1.1:provided +- org.apache.xmlgraphics:fop:jar:0.95:compile | +- (org.apache.xmlgraphics:xmlgraphics-commons:jar:1.3.1:compile - omitted for duplicate) | +- org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile | | +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for cycle) | | +- org.apache.xmlgraphics:batik-anim:jar:1.7:compile | | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate) | | | \- (org.apache.xmlgraphics:batik-parser:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | +- org.apache.xmlgraphics:batik-css:jar:1.7:compile | | | +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | | \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate) | | +- org.apache.xmlgraphics:batik-dom:jar:1.7:compile | | | +- (org.apache.xmlgraphics:batik-css:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-xml:jar:1.7:compile - omitted for duplicate) | | | +- (xalan:xalan:jar:2.6.0:compile - omitted for duplicate) | | | \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate) | | +- org.apache.xmlgraphics:batik-parser:jar:1.7:compile | | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | | +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | | \- (org.apache.xmlgraphics:batik-xml:jar:1.7:compile - omitted for duplicate) | | +- org.apache.xmlgraphics:batik-util:jar:1.7:compile | | \- xml-apis:xml-apis-ext:jar:1.3.04:compile | +- org.apache.xmlgraphics:batik-bridge:jar:1.7:compile | | +- (org.apache.xmlgraphics:batik-anim:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-css:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for cycle) | | +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-parser:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for cycle) | | +- org.apache.xmlgraphics:batik-script:jar:1.7:compile | | +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | +- org.apache.xmlgraphics:batik-xml:jar:1.7:compile | | | \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | +- xalan:xalan:jar:2.6.0:compile | | \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate) | +- org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile | | \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | +- org.apache.xmlgraphics:batik-gvt:jar:1.7:compile | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for cycle) | | +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for duplicate) | | \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | +- org.apache.xmlgraphics:batik-transcoder:jar:1.7:compile | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for duplicate) | | +- org.apache.xmlgraphics:batik-svggen:jar:1.7:compile | | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | | \- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-xml:jar:1.7:compile - omitted for duplicate) | | \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate) | +- org.apache.xmlgraphics:batik-extension:jar:1.7:compile | | +- (org.apache.xmlgraphics:batik-awt-util:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-bridge:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-css:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-dom:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-ext:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-gvt:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-parser:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-svg-dom:jar:1.7:compile - omitted for duplicate) | | +- (org.apache.xmlgraphics:batik-util:jar:1.7:compile - omitted for duplicate) | | \- (xml-apis:xml-apis-ext:jar:1.3.04:compile - omitted for duplicate) | +- org.apache.xmlgraphics:batik-ext:jar:1.7:compile | +- commons-logging:commons-logging:jar:1.1.1:compile | +- commons-io:commons-io:jar:1.3.1:compile | \- org.apache.avalon.framework:avalon-framework-api:jar:4.3.1:compile +- org.apache.xmlgraphics:xmlgraphics-commons:jar:1.3.1:compile | +- (commons-io:commons-io:jar:1.3.1:compile - omitted for duplicate) | \- (commons-logging:commons-logging:jar:1.1.1:compile - version managed from 1.0.4; omitted for duplicate) +- org.easymock:easymock:jar:2.0:test \- org.easymock:easymockclassextension:jar:2.2:test +- (org.easymock:easymock:jar:2.2:test - omitted for conflict with 2.0) \- cglib:cglib-nodep:jar:2.2:test (version managed from 2.1_3) Can anyone tell me how to clear out intellij's classpath too?

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"The name 'WithTable' does not exist in the current context" using Fluent NHibernate

- by Byron Sommardahl

Might be a really easy problem to fix, but it the solution is eluding me! I'm using Fluent NHibernate 1.0 RTM (and using NHibernate bins that ships with it). I'm trying to map my entities and cannot use the WithTable() method. It's not available in Intelligence and VS doesn't suggest any namespaces to reference. Here's my code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using GeoCodeThe.Net.Domain.Entities; using FluentNHibernate.Mapping; namespace GeoCodeThe.Net.Domain.Mappings { class CategoryMap: ClassMap<ICategory> { public CategoryMap() { WithTable("Categories"); // <----- Compile error: The name 'WithTable' does not exist in the current context Id(x => x.Id); Map(x => x.Name); Map(x => x.Tags); } } My bin folder has: Antlr3.Runtime.dll Castle.Core.dll Castle.DynamicProxy2.dll FluentNHibernate.dll Iesi.Collections.dll log4net.dll NHibernate.ByteCode.Castle.dll NHibernate.dll FluentNHibernate.pdb Castle.Core.xml Castle.DynamicProxy2.xml FluentNHibernate.xml Iesi.Collections.xml log4net.xml NHibernate.ByteCode.Castle.xml NHibernate.xml Any clue what I'm missing? Let me know if you need any more clarification.

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Javascript html5 database transaction problem in loops

- by Marek

I'm hittig my head on this and i will be glad for any help. I need to store in a database a context (a list of string ids) for another page. I open a page with a list of artworks and this page save into the database those artowrks ids. When i click on an artwork i open its webpage but i can access the database to know the context and refer to the next and prev artwork. This is my code to retrieve the contex: updateContext = function () { alert("updating context"); try { mydb.transaction( function(transaction) { transaction.executeSql("select artworks.number from artworks, collections where collections.id = artworks.section_id and collections.short_name in ('cro', 'cra', 'crp', 'crm');", [], contextDataHandler, errorHandler); }); } catch(e) { alert(e.message); } } the contextDatahandler function then iterates through the results and fill again the current_context table: contextDataHandler = function(transaction, results) { try { mydb.transaction( function(transaction) { transaction.executeSql("drop table current_context;", [], nullDataHandler, errorHandler); transaction.executeSql("create table current_context(id String);", [], nullDataHandler, errorHandler); } ) } catch(e) { alert(e.message); } var s = ""; for (var i=0; i < results.rows.length; i++) { var item = results.rows.item(0); s += item['number'] + " "; mydb.transaction( function(tx) { tx.executeSql("insert into current_context(id) values (?);", [item['number']]); } ) } alert(s); } the result is, i get the current_context table deleted, recreated, and filled, but all the rows are filled with the LAST artwork id. the query to retrieve the artworks ids works, so i think it's a transaction problem, but i cant figure out where. thanks for any help

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Cannot resolve Dictionary in Unity container

- by IanR

Hi, I've just stumbled upon this: within a Unity container, I want to register IDictionary<TK, TV>; assume that it's IDictionary<string, int> _unityContainer = new UnityContainer() .RegisterType<IDictionary<string, int>, Dictionary<string, int>>(); but if I try var d = _unityContainer.Resolve<IDictionary<string, int>>(); it fails to resolve... I get... Microsoft.Practices.Unity.ResolutionFailedException: Microsoft.Practices.Unity.ResolutionFailedException: Resolution of the dependency failed, type = "System.Collections.Generic.IDictionary`2[System.String,System.Int32]", name = "(none)". Exception occurred while: while resolving. Exception is: InvalidOperationException - The type Dictionary`2 has multiple constructors of length 2. Unable to disambiguate. At the time of the exception, the container was: Resolving System.Collections.Generic.Dictionary2[System.String,System.Int32],(none) (mapped from System.Collections.Generic.IDictionary2[System.String,System.Int32], (none)) --- System.InvalidOperationException: The type Dictionary`2 has multiple constructors of length 2. Unable to disambiguate.. So it looks like it has found the Type to resolve (being Dictionary<string, int>) but failed to new it up... How come unity can't resolve this type? If I type IDictionary<string, int> d = new Dictionary<string, int>() that works... any ideas? thanks!

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Possible to create an implicit cast for an anonymous type to a dictionary?

- by Ralph

I wrote a method like this: using AttrDict = System.Collections.Generic.Dictionary<string, object>; using IAttrDict = System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string, object>>; static string HtmlTag(string tagName, string content = null, IAttrDict attrs = null) { var sb = new StringBuilder("<"); sb.Append(tagName); if(attrs != null) foreach (var attr in attrs) sb.AppendFormat(" {0}=\"{1}\"", attr.Key, attr.Value.ToString().EscapeQuotes()); if (content != null) sb.AppendFormat(">{0}</{1}>", content, tagName); else sb.Append(" />"); return sb.ToString(); } Which you can call like HtmlTag("div", "hello world", new AttrDict{{"class","green"}}); Not too bad. But what if I wanted to allow users to pass an anonymous type in place of the dict? Like HtmlTag("div", "hello world", new {@class="green"}); Even better! I could write the overload easily, but the problem is I'm going to have about 50 functions like this, I don't want to overload each one of them. I was hoping I could just write an implicit cast to do the work for me... public class AttrDict : Dictionary<string, object> { public static implicit operator AttrDict(object obj) { // conversion from anonymous type to AttrDict here } } But C# simply won't allow it: user-defined conversions to or from a base class are not allowed So what can I do?

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Worse is better. Is there an example?

- by J.F. Sebastian

Is there a widely-used algorithm that has time complexity worse than that of another known algorithm but it is a better choice in all practical situations (worse complexity but better otherwise)? An acceptable answer might be in a form: There are algorithms A and B that have O(N**2) and O(N) time complexity correspondingly, but B has such a big constant that it has no advantages over A for inputs less then a number of atoms in the Universe. Examples highlights from the answers: Simplex algorithm -- worst-case is exponential time -- vs. known polynomial-time algorithms for convex optimization problems. A naive median of medians algorithm -- worst-case O(N**2) vs. known O(N) algorithm. Backtracking regex engines -- worst-case exponential vs. O(N) Thompson NFA -based engines. All these examples exploit worst-case vs. average scenarios. Are there examples that do not rely on the difference between the worst case vs. average case scenario? Related: The Rise of ``Worse is Better''. (For the purpose of this question the "Worse is Better" phrase is used in a narrower (namely -- algorithmic time-complexity) sense than in the article) Python's Design Philosophy: The ABC group strived for perfection. For example, they used tree-based data structure algorithms that were proven to be optimal for asymptotically large collections (but were not so great for small collections). This example would be the answer if there were no computers capable of storing these large collections (in other words large is not large enough in this case). Coppersmith–Winograd algorithm for square matrix multiplication is a good example (it is the fastest (2008) but it is inferior to worse algorithms). Any others? From the wikipedia article: "It is not used in practice because it only provides an advantage for matrices so large that they cannot be processed by modern hardware (Robinson 2005)."

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Using a profile property of type List in .NET Membership

- by hancock

Hi, I'm working on a C# Webservice that needs to provide authentication as well as roles and profile management. I need each profile to have a property of type List. The profile section in the web.config looks like this: <profile defaultProvider="MyProfileProvider" enabled="true"> <providers> <remove name="MyProfileProvider"/> <add connectionStringName="MySqlServer" applicationName="MyApp" name="MyProfileProvider" type="System.Web.Profile.SqlProfileProvider" /> </providers> <properties> <add name="Websites" type="System.Collections.Generic.List<String>" serializeAs="Binary"/> </properties> </profile> However, when I start the webservice and try to access that property it returns the following error: System.Configuration.ConfigurationErrorsException: Attempting to load this property's type resulted in the following error: Could not load type 'System.Collections.Generic.List<String>'. (C:\Projects\MyProject\web.config line 58) --- System.Web.HttpException: Could not load type 'System.Collections.Generic.List<String>'. Is there a way to use a generic collection for this purpose?

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Powershell / .Net: Get a reference to an object returned by a method

- by Dan Menes

I am teaching myself PowerShell by writing a simple parser. I use the .Net framework class Collections.Stack. I want to modify the object at the top of the stack in place. I know I can pop() the object off, modify it, and then push() it back on, but that strikes me as inelegant. First, I tried this: $stk = new-object Collections.Stack $stk.push( (,'My first value') ) ( $stk.peek() ) += ,'| My second value' Which threw an error: Assignment failed because [System.Collections.Stack] doesn't contain a settable property 'peek()'. At C:\Development\StackOverflow\PowerShell-Stacks\test.ps1:3 char:12 + ( $stk.peek <<<< () ) += ,'| My second value' + CategoryInfo : InvalidOperation: (peek:String) [], RuntimeException + FullyQualifiedErrorId : ParameterizedPropertyAssignmentFailed Next I tried this: $ary = $stk.peek() $ary += ,'| My second value' write-host "Array is: $ary" write-host "Stack top is: $($stk.peek())" Which prevented the error but still didn't do the right thing: Array is: My first value | My second value Stack top is: My first value Clearly, what is getting assigned to $ary is a copy of the object at the top of the stack, so when I the object in $ary, the object at the top of the stack remains unchanged. Finally, I read up on teh [ref] type, and tried this: $ary_ref = [ref]$stk.peek() $ary_ref.value += ,'| My second value' write-host "Referenced array is: $($ary_ref.value)" write-host "Stack top is still: $($stk.peek())" But still no dice: Referenced array is: My first value | My second value Stack top is still: My first value I assume the peek() method returns a reference to the actual object, not the clone. If so, then the reference appears to be being replaced by a clone by PowerShell's expression processing logic. Can somebody tell me if there is a way to do what I want to do? Or do I have to revert to pop() / modify / push()?

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Why can't I define a case-insensitve Dictionary in C#?

- by Edward Tanguay

This WPF code: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; namespace TestDict28342343 { public partial class Window1 : Window { public Window1() { InitializeComponent(); Dictionary<string, string> variableNamesAndValues = new Dictionary<string, string>(StringComparison.InvariantCultureIgnoreCase); } } } gives me the error: The best overloaded method match for 'System.Collections.Generic.Dictionary.Dictionary(System.Collections.Generic.IDictionary)' has some invalid arguments Yet I find this code example everywhere such as here and here. How can I define a Dictionary whose keys are case-insensitve?

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How to display two ObservableCollections as a single list in WPF?

- by nareshbhatia

I have two ObservableCollections, say ObservableCollection<Cat> and ObservableCollections<Dog>. Cat and Dog both derive from class Pet. I want to display a list of all Pets. How do I do this? I prefer not want create a new ObservableCollection<Pet> by adding items from the two source lists because this list will become stale as more Cats and Dogs are added to the source lists. I can think of two approaches: 1) Create a "Decorator" ObservableCollection that keeps the two source collections as members and iterates over them every time. 2) Create an ObservableCollection<Pet> that does have the combined elements of the two source collections, but is also dependent on the source collections. Thus if a Cat is added to the Cat collection, this collection is notified and it adds the new Cat to itself. Is there a standard way to solve this issue? I don't want to reinvent the wheel!

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Using LINQ on observable with GroupBy and Sum aggregate

- by Mark Oates

I have the following block of code which works fine; var boughtItemsToday = (from DBControl.MoneySpent bought in BoughtItemDB.BoughtItems select bought); BoughtItems = new ObservableCollection<DBControl.MoneySpent>(boughtItemsToday); It returns data from my MoneySpent table which includes ItemCategory, ItemAmount, ItemDateTime. I want to change it to group by ItemCategory and ItemAmount so I can see where I am spending most of my money, so I created a GroupBy query, and ended up with this; var finalQuery = boughtItemsToday.AsQueryable().GroupBy(category => category.ItemCategory); BoughtItems = new ObservableCollection<DBControl.MoneySpent>(finalQuery); Which gives me 2 errors; Error 1 The best overloaded method match for 'System.Collections.ObjectModel.ObservableCollection.ObservableCollection(System.Collections.Generic.List)' has some invalid arguments Error 2 Argument 1: cannot convert from 'System.Linq.IQueryable' to 'System.Collections.Generic.List' And this is where I'm stuck! How can I use the GroupBy and Sum aggregate function to get a list of my categories and the associated spend in 1 LINQ query?! Any help/suggestions gratefully received. Mark

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NHibernate correct way to reattach cached entity to different session

- by Chris Marisic

I'm using NHibernate to query a list of objects from my database. After I get the list of objects over them I iterate over the list of objects and apply a distance approximation algorithm to find the nearest object. I consider this function of getting the list of objects and apply the algorithm over them to be a heavy operation so I cache the object which I find from the algorithm in HttpRuntime.Cache. After this point whenever I'm given the supplied input again I can just directly pull the object from Cache instead of having to hit the database and traverse the list. My object is a complex object that has collections attached to it, inside the query where I return the full list of objects I don't bring back any of the sub collections eagerly so when I read my cached object I need lazy loading to work correctly to be able to display the object fully. Originally I tried using this to re-associate my cached object back to a new session _session.Lock(obj, LockMode.None); However when accessing the page concurrently from another instance I get the error Illegal attempt to associate a collection with two open sessions I then tried something different with _session.Merge(obj); However watching the output of this in NHProf shows that it is deleting and re-associating my object's contained collections with my object, which is not what I want although it seems to work fine. What is the correct way to do this? Neither of these seem to be right.

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How to use Comparator in Java to sort

- by Dan

I learned how to use the comparable but I'm having difficulty with the Comparator. I am having a error in my code: Exception in thread "main" java.lang.ClassCastException: New.People cannot be cast to java.lang.Comparable at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.sort(Unknown Source) at java.util.Collections.sort(Unknown Source) at New.TestPeople.main(TestPeople.java:18) Here is my code: import java.util.Comparator; public class People implements Comparator{ private int id; private String info; private double price; public People(int newid, String newinfo, double newprice){ setid(newid); setinfo(newinfo); setprice(newprice); } public int getid() { return id; } public void setid(int id) { this.id = id; } public String getinfo() { return info; } public void setinfo(String info) { this.info = info; } public double getprice() { return price; } public void setprice(double price) { this.price = price; } public int compare(Object obj1, Object obj2) { Integer p1 = ((People)obj1).getid(); Integer p2 = ((People)obj2).getid(); if (p1 p2 ){ return 1; } else if (p1 < p2){ return -1; } else return 0; } } import java.util.ArrayList; import java.util.Collections; public class TestPeople { public static void main(String[] args) { ArrayList peps = new ArrayList(); peps.add(new People(123, "M", 14.25)); peps.add(new People(234, "M", 6.21)); peps.add(new People(362, "F", 9.23)); peps.add(new People(111, "M", 65.99)); peps.add(new People(535, "F", 9.23)); Collections.sort(peps); for(int i=0;i I believe it has to do something with the casting in the compare method but I was playing around with it and still could not find the solution

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Select rows from table1 and all the children from table2 into an object

- by Patrick

I want to pull data from table "Province_Notifiers" and also fetch all corresponding items from table "Province_Notifier_Datas". The table "Province_Notifier" has a guid to identify it (PK), table "Province_Notifier_Datas" has a column called BelongsToProvinceID witch is a foreign key to the "Province_Notifier" tables guid. I tried something like this: var records = from data in ctx.Province_Notifiers where DateTime.Now >= data.SendTime && data.Sent == false join data2 in ctx.Province_Notifier_Datas on data.Province_ID equals data2.BelongsToProvince_ID select new Province_Notifier { Email = data.Email, Province_ID = data.Province_ID, ProvinceName = data.ProvinceName, Sent = data.Sent, UserName = data.UserName, User_ID = data.User_ID, Province_Notifier_Datas = (new List<Province_Notifier_Data>().AddRange(data2)) }; This line is not working and i am trying to figure out how topull the data from table2 into that Province_Notifier_Datas variable. Province_Notifier_Datas = (new List<Province_Notifier_Data>().AddRange(data2)) I can add a record easily by adding the second table row into the Province_Notifier_Datas but i can't fetch it back. Province_Notifier dbNotifier = new Province_Notifier(); // set some values for dbNotifier dbNotifier.Province_Notifier_Datas.Add( new Province_Notifier_Data { BelongsToProvince_ID = userInput.Value.ProvinceId, EventText = GenerateNotificationDetail(notifierDetail) }); This works and inserts the data correctly into both tables. Edit: These error messages is thrown: Cannot convert from 'Province_Notifier_Data' to 'System.Collections.Generic.IEnumerable' If i look in Visual Studio, the variable "Province_Notifier_Datas" is of type System.Data.Linq.EntitySet The best overloaded method match for 'System.Collections.Generic.List.AddRange(System.Collections.Generic.IEnumerable)' has some invalid arguments Edit: var records = from data in ctx.Province_Notifiers where DateTime.Now >= data.SendTime && data.Sent == false join data2 in ctx.Province_Notifier_Datas on data.Province_ID equals data2.BelongsToProvince_ID into data2list select new Province_Notifier { Email = data.Email, Province_ID = data.Province_ID, ProvinceName = data.ProvinceName, Sent = data.Sent, UserName = data.UserName, User_ID = data.User_ID, Province_Notifier_Datas = new EntitySet<Province_Notifier_Data>().AddRange(data2List) }; Error 3 The name 'data2List' does not exist in the current context.

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WCF: collection proxy type on client

- by Unholy

I have the following type in wsdl (it is generated by third party tool): <xsd:complexType name="IntArray"> <xsd:sequence> <xsd:element maxOccurs="unbounded" minOccurs="0" name="Elements" type="xsd:int" /> </xsd:sequence> </xsd:complexType> Sometimes Visual Studio generates: public class IntArray : System.Collections.Generic.List<int> {} And sometimes it doesn't generate any proxy type for this wsdl and just uses int[]. Collection type in Web Service configuration is System.Array. What could be the reason for such upredictable behavior? Edited: I found the way how I can reproduce this behavior. For examle we have two types: <xsd:complexType name="IntArray"> <xsd:sequence> <xsd:element maxOccurs="unbounded" minOccurs="0" name="Elements" type="xsd:int" /> </xsd:sequence> </xsd:complexType> <xsd:complexType name="StringArray"> <xsd:sequence> <xsd:element maxOccurs="unbounded" minOccurs="0" name="Elements" type="xsd:string" /> </xsd:sequence> </xsd:complexType> VS generates: public class IntArray : System.Collections.Generic.List<int> {} public class StringArray : System.Collections.Generic.List<string> {} Now I change StringArray type: <xsd:complexType name="StringArray"> <xsd:sequence> <xsd:element maxOccurs="unbounded" minOccurs="0" name="Elements" type="xsd:string" /> <xsd:any minOccurs="0" maxOccurs="unbounded" namespace="##any" processContents="lax" /> </xsd:sequence> <xsd:anyAttribute namespace="##any" processContents="lax"/> </xsd:complexType> VS generates proxy type for StringArray only. But not for IntArray.

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C++ compiler unable to find function (namespace related)

- by CS student

I'm working in Visual Studio 2008 on a C++ programming assignment. We were supplied with files that define the following namespace hierarchy (the names are just for the sake of this post, I know "namespace XYZ-NAMESPACE" is redundant): (MAIN-NAMESPACE){ a bunch of functions/classes I need to implement... (EXCEPTIONS-NAMESPACE){ a bunch of exceptions } (POINTER-COLLECTIONS-NAMESPACE){ Set and LinkedList classes, plus iterators } } The MAIN-NAMESPACE contents are split between a bunch of files, and for some reason which I don't understand the operator<< for both Set and LinkedList is entirely outside of the MAIN-NAMESPACE (but within Set and LinkedList's header file). Here's the Set version: template<typename T> std::ostream& operator<<(std::ostream& os, const MAIN-NAMESPACE::POINTER-COLLECTIONS-NAMESPACE::Set<T>& set) Now here's the problem: I have the following data structure: Set A Set B Set C double num It's defined to be in a class within MAIN-NAMESPACE. When I create an instance of the class, and try to print one of the sets, it tells me that: error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'const MAIN-NAMESPACE::POINTER-COLLECTIONS-NAMESPACE::Set' (or there is no acceptable conversion) However, if I just write a main() function, and create Set A, fill it up, and use the operator- it works. Any idea what is the problem? (note: I tried any combination of using and include I could think of).

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implementing interface

- by 1ace1

hello guys so i have this assignment that i need to implement interface to go over an ArrayList and sort it (ascending or descnding).I dont want "the" answer i just need some suggestions on my approach and why i get this error Exception in thread "main" java.lang.ClassCastException: Week7.Check cannot be cast to java.lang.Comparable at java.util.Arrays.mergeSort(Unknown Source) at java.util.Arrays.sort(Unknown Source) at java.util.Collections.sort(Unknown Source) at Week7.TestCheck.main(TestCheck.java:18) This is how i did it: comparable had one method called public int compairTo(Object o) public class Check implements comparable { private Integer checkNumber; public Check(Integer newCheckNumber) { setCheckNumber(newCheckNumber); } public String toString() { return getCheckNumber().toString(); } public void setCheckNumber(Integer checkNumber) { this.checkNumber = checkNumber; } public Integer getCheckNumber() { return checkNumber; } @Override public int compairTo(Object o) { Check compair = (Check)o; int result = 0; if (this.getCheckNumber() > compair.getCheckNumber()) result = 1; else if(this.getCheckNumber() < compair.getCheckNumber()) result = -1; return result; } } in my main i had this import java.util.ArrayList; import java.util.Collections; public class TestCheck { public static void main(String[] args) { ArrayList checkList = new ArrayList(); checkList.add(new Check(445)); checkList.add(new Check(101)); checkList.add(new Check(110)); checkList.add(new Check(553)); checkList.add(new Check(123)); Collections.sort(checkList); for (int i =0; i < checkList.size(); i++){ System.out.println(checkList.get(i)); } } }

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