March 2010 - infinispan-issues - Jboss List Archives

[JBoss JIRA] Created: (ISPN-244) Enable external user/framework defined Externalizers

by Galder Zamarreno (JIRA)

Enable external user/framework defined Externalizers ---------------------------------------------------- Key: ISPN-244 URL: https://jira.jboss.org/jira/browse/ISPN-244 Project: Infinispan Issue Type: Feature Request Components: RPC Reporter: Galder Zamarreno Fix For: 4.1.0.BETA1 Create an internal magic number (i.e. -1 or 255) for user defined externalizers. This is done to avoid users using our number space. So, internally: <magic_number> <stream> Users: <magic_number><user defined magic number (int)> <stream> Mandate unsigned ints so that we can optimise by sending them as variable lenght Internal frameworks could use high enough numbers for example up to 2 bytes: 5000, 7000, 20000 1 byte: 128 2 bytes: 32767 3 bytes: ... GlobalConfiguration.registerMarshallable(Class type, Externalizer ext, int id); Maybe CacheManager better? CacheManager.registerMarshallable(Class type, Externalizer ext, int id); Future improvement, maybe generate ids automatically for user defined classes? -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 4 months

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[JBoss JIRA] Created: (ISPN-352) Add per-cache coordinator.

by Alexander Gavrilov (JIRA)

Add per-cache coordinator. -------------------------- Key: ISPN-352 URL: https://jira.jboss.org/jira/browse/ISPN-352 Project: Infinispan Issue Type: Feature Request Components: Core API Reporter: Alexander Gavrilov Assignee: Manik Surtani We trying to use Infinispan for our cluster. We have two types of nodes in cluster. "Type 1" nodes use all set of caches defined in system, but "Type 2" nodes uses only small subset of nodes. For each cache on each node we have job, that fetch data from external store and put that data in the cache. We need this job to be executed only in one node from whole cluster and is natural to test if node is cache coordinator and execute job only if it is. In current implementation it's possible to determinate only cluster coordinator. But when node of "Type 2" becomes coordinator it is impossible to update some caches, because they are not defined in this node. It would be fine to declare not only oldest node in cluster as cluster coordinator but oldest node containing cache as this concrete cache coordinator. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 4 months

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[JBoss JIRA] Created: (ISPN-222) Package according to OSGi specs

by Manik Surtani (JIRA)

Package according to OSGi specs ------------------------------- Key: ISPN-222 URL: https://jira.jboss.org/jira/browse/ISPN-222 Project: Infinispan Issue Type: Feature Request Reporter: Manik Surtani Assignee: Manik Surtani Fix For: 4.0.0.CR1, 4.0.0.GA Should be trivial, as there is a Maven plugin to do this. Will ensure Infinispan is easily consumed by OSGi apps. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 7 months

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[JBoss JIRA] Created: (ISPN-373) Deadlock between lock and put under heavy concurrency

by Nigel Slack-Smith (JIRA)

Deadlock between lock and put under heavy concurrency ----------------------------------------------------- Key: ISPN-373 URL: https://jira.jboss.org/jira/browse/ISPN-373 Project: Infinispan Issue Type: Bug Components: Locking and Concurrency Affects Versions: 4.0.0.Final Environment: Mac OS-X 10.6, 2.8Ghz Core 2, 8GB RAM Reporter: Nigel Slack-Smith Assignee: Manik Surtani Concurrent calls to lock and then put seem to be deadlocking. After AdvancedCache.lock is called under a transaction a subsequent call to Cache.put on the same key normally does not attempt to take out a lock, but after a variable number of concurrent calls Cache.put is attempting to take out a lock and then deadlocking with the AdvancedCache.lock call. Here's my test case which hits the deadlock. public class DataGridTest { @Test public void testCreate() { CacheManager cacheManager = new DefaultCacheManager(); final String cacheName = "TestCache"; Configuration config = new Configuration(); config.setTransactionManagerLookupClass("org.infinispan.transaction.lookup.DummyTransactionManagerLookup"); cacheManager.defineConfiguration(cacheName, config); final Cache<Object, Object> cache = cacheManager.getCache(cacheName); cache.start(); ExecutorService executorService = Executors.newFixedThreadPool(2); for (int i = 0; i < 1000000; ++i) { final String valueStr = "V" + i; executorService.execute(new Runnable() { @Override public void run() { TransactionManager txnMgr = cache.getAdvancedCache().getTransactionManager(); try { txnMgr.begin(); } catch (Exception e) { fail(e.getMessage()); } cache.getAdvancedCache().lock("K1"); cache.put("K1", valueStr); try { txnMgr.commit(); } catch (Exception e) { fail(e.getMessage()); } } }); } executorService.shutdown(); try { if (executorService.awaitTermination(300, TimeUnit.SECONDS) == false) { fail("Termination timeout"); } } catch (InterruptedException e) { fail("Thread interrupted exception: " + e.getMessage()); } } } ...and here's the stack trace showing what appears to be a deadlock timeout. 2010-03-16 08:35:57,821 1 ERROR [org.infinispan.interceptors.InvocationContextInterceptor] Execution error: org.infinispan.util.concurrent.TimeoutException: Unable to acquire lock after [10 seconds] on key [K1] for requestor [GlobalTransaction:<null>:114691]! Lock held by [GlobalTransaction:<null>:114690] at org.infinispan.container.EntryFactoryImpl.acquireLock(EntryFactoryImpl.java:213) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:148) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:106) at org.infinispan.interceptors.LockingInterceptor.visitPutKeyValueCommand(LockingInterceptor.java:197) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.base.CommandInterceptor.handleDefault(CommandInterceptor.java:132) at org.infinispan.commands.AbstractVisitor.visitPutKeyValueCommand(AbstractVisitor.java:57) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.TxInterceptor.enlistWriteAndInvokeNext(TxInterceptor.java:183) at org.infinispan.interceptors.TxInterceptor.visitPutKeyValueCommand(TxInterceptor.java:132) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.InvocationContextInterceptor.handleAll(InvocationContextInterceptor.java:48) at org.infinispan.interceptors.InvocationContextInterceptor.handleDefault(InvocationContextInterceptor.java:34) at org.infinispan.commands.AbstractVisitor.visitPutKeyValueCommand(AbstractVisitor.java:57) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.InterceptorChain.invoke(InterceptorChain.java:269) at org.infinispan.CacheDelegate.put(CacheDelegate.java:434) at org.infinispan.CacheDelegate.put(CacheDelegate.java:205) at com.kasm.core.test.DataGridTest$1.run(DataGridTest.java:47) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:637) 2010-03-16 08:35:57,821 1 ERROR [org.infinispan.interceptors.InvocationContextInterceptor] Execution error: org.infinispan.util.concurrent.TimeoutException: Unable to acquire lock after [10 seconds] on key [K1] for requestor [GlobalTransaction:<null>:114692]! Lock held by [GlobalTransaction:<null>:114690] at org.infinispan.container.EntryFactoryImpl.acquireLock(EntryFactoryImpl.java:213) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:148) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:106) at org.infinispan.interceptors.LockingInterceptor.visitLockControlCommand(LockingInterceptor.java:146) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.base.CommandInterceptor.handleDefault(CommandInterceptor.java:132) at org.infinispan.commands.AbstractVisitor.visitLockControlCommand(AbstractVisitor.java:147) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.TxInterceptor.enlistReadAndInvokeNext(TxInterceptor.java:171) at org.infinispan.interceptors.TxInterceptor.visitLockControlCommand(TxInterceptor.java:115) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.InvocationContextInterceptor.handleAll(InvocationContextInterceptor.java:48) at org.infinispan.interceptors.InvocationContextInterceptor.handleDefault(InvocationContextInterceptor.java:34) at org.infinispan.commands.AbstractVisitor.visitLockControlCommand(AbstractVisitor.java:147) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.InterceptorChain.invoke(InterceptorChain.java:269) at org.infinispan.CacheDelegate.lock(CacheDelegate.java:305) at org.infinispan.CacheDelegate.lock(CacheDelegate.java:298) at com.kasm.core.test.DataGridTest$1.run(DataGridTest.java:46) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:637) Exception in thread "pool-2-thread-2" org.infinispan.util.concurrent.TimeoutException: Unable to acquire lock after [10 seconds] on key [K1] for requestor [GlobalTransaction:<null>:114691]! Lock held by [GlobalTransaction:<null>:114690] at org.infinispan.container.EntryFactoryImpl.acquireLock(EntryFactoryImpl.java:213) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:148) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:106) at org.infinispan.interceptors.LockingInterceptor.visitPutKeyValueCommand(LockingInterceptor.java:197) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.base.CommandInterceptor.handleDefault(CommandInterceptor.java:132) at org.infinispan.commands.AbstractVisitor.visitPutKeyValueCommand(AbstractVisitor.java:57) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.TxInterceptor.enlistWriteAndInvokeNext(TxInterceptor.java:183) at org.infinispan.interceptors.TxInterceptor.visitPutKeyValueCommand(TxInterceptor.java:132) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.InvocationContextInterceptor.handleAll(InvocationContextInterceptor.java:48) at org.infinispan.interceptors.InvocationContextInterceptor.handleDefault(InvocationContextInterceptor.java:34) at org.infinispan.commands.AbstractVisitor.visitPutKeyValueCommand(AbstractVisitor.java:57) at org.infinispan.commands.write.PutKeyValueCommand.acceptVisitor(PutKeyValueCommand.java:76) at org.infinispan.interceptors.InterceptorChain.invoke(InterceptorChain.java:269) at org.infinispan.CacheDelegate.put(CacheDelegate.java:434) at org.infinispan.CacheDelegate.put(CacheDelegate.java:205) at com.kasm.core.test.DataGridTest$1.run(DataGridTest.java:47) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:637) Exception in thread "pool-2-thread-1" org.infinispan.util.concurrent.TimeoutException: Unable to acquire lock after [10 seconds] on key [K1] for requestor [GlobalTransaction:<null>:114692]! Lock held by [GlobalTransaction:<null>:114690] at org.infinispan.container.EntryFactoryImpl.acquireLock(EntryFactoryImpl.java:213) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:148) at org.infinispan.container.EntryFactoryImpl.wrapEntryForWriting(EntryFactoryImpl.java:106) at org.infinispan.interceptors.LockingInterceptor.visitLockControlCommand(LockingInterceptor.java:146) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.base.CommandInterceptor.handleDefault(CommandInterceptor.java:132) at org.infinispan.commands.AbstractVisitor.visitLockControlCommand(AbstractVisitor.java:147) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.TxInterceptor.enlistReadAndInvokeNext(TxInterceptor.java:171) at org.infinispan.interceptors.TxInterceptor.visitLockControlCommand(TxInterceptor.java:115) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:118) at org.infinispan.interceptors.InvocationContextInterceptor.handleAll(InvocationContextInterceptor.java:48) at org.infinispan.interceptors.InvocationContextInterceptor.handleDefault(InvocationContextInterceptor.java:34) at org.infinispan.commands.AbstractVisitor.visitLockControlCommand(AbstractVisitor.java:147) at org.infinispan.commands.control.LockControlCommand.acceptVisitor(LockControlCommand.java:82) at org.infinispan.interceptors.InterceptorChain.invoke(InterceptorChain.java:269) at org.infinispan.CacheDelegate.lock(CacheDelegate.java:305) at org.infinispan.CacheDelegate.lock(CacheDelegate.java:298) at com.kasm.core.test.DataGridTest$1.run(DataGridTest.java:46) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:637) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 7 months

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[JBoss JIRA] Created: (ISPN-334) CloudCacheStore should use metadata to store expiration information for more efficient purging

by Manik Surtani (JIRA)

CloudCacheStore should use metadata to store expiration information for more efficient purging ---------------------------------------------------------------------------------------------- Key: ISPN-334 URL: https://jira.jboss.org/jira/browse/ISPN-334 Project: Infinispan Issue Type: Feature Request Components: Loaders and Stores Reporter: Manik Surtani Assignee: Manik Surtani Priority: Minor Fix For: 4.1.0.ALPHA1, 4.1.0.GA CloudCacheStore currently uses the BucketBasedCacheStore facilities to encode expiry information into the buckets. This means buckets need to be loaded (expensive) before such information can be read. It would be more efficient to encode this as metadata so that it can be read before potentially loading large blob values, and if the entry has expired, simply delete the entry rather than load it. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 8 months

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[JBoss JIRA] Created: (ISPN-307) Lucene Directory not supporting Lucene's ConcurrentMergeScheduler

by Sanne Grinovero (JIRA)

Lucene Directory not supporting Lucene's ConcurrentMergeScheduler ----------------------------------------------------------------- Key: ISPN-307 URL: https://jira.jboss.org/jira/browse/ISPN-307 Project: Infinispan Issue Type: Bug Components: Lucene Directory Reporter: Sanne Grinovero Assignee: Manik Surtani It's currently mandatory to use a SerialMergeScheduler as the threads used by the concurrent scheduler can't share the transaction wrapping index changes. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 8 months

3
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[JBoss JIRA] Created: (ISPN-275) Update Lucene Directory to work with newer Lucene versions v.3.0.x

by Sanne Grinovero (JIRA)

Update Lucene Directory to work with newer Lucene versions v.3.0.x ------------------------------------------------------------------ Key: ISPN-275 URL: https://jira.jboss.org/jira/browse/ISPN-275 Project: Infinispan Issue Type: Feature Request Components: Lucene Directory Affects Versions: 4.0.0.CR2 Reporter: Sanne Grinovero Assignee: Sanne Grinovero Fix For: 4.0.0.GA Current implementation is being tested only towards Lucene 2.4.1; Lucene developers have just released 2.9.1 and version 3 is coming very soon. It should be possible to have a single version supporting all of them, but needs separate tests. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 8 months

3
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[JBoss JIRA] Created: (ISPN-250) Replace transactions with async methods combined with batching

by Sanne Grinovero (JIRA)

Replace transactions with async methods combined with batching -------------------------------------------------------------- Key: ISPN-250 URL: https://jira.jboss.org/jira/browse/ISPN-250 Project: Infinispan Issue Type: Patch Components: Lucene Directory Affects Versions: 4.0.0.CR1 Reporter: Sanne Grinovero Assignee: Sanne Grinovero -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 8 months

4
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[JBoss JIRA] Created: (ISPN-332) Add ability to create GlobalConfiguration and DefaultConfiguration objects from XML files

by Noel O'Connor (JIRA)

Add ability to create GlobalConfiguration and DefaultConfiguration objects from XML files ------------------------------------------------------------------------------------------ Key: ISPN-332 URL: https://jira.jboss.org/jira/browse/ISPN-332 Project: Infinispan Issue Type: Feature Request Components: Configuration Reporter: Noel O'Connor Assignee: Noel O'Connor Priority: Minor -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

13 years, 9 months

2
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[JBoss JIRA] Created: (ISPN-366) Document CAS-like operations in Hot Rod clearly

by Galder Zamarreno (JIRA)

Document CAS-like operations in Hot Rod clearly ----------------------------------------------- Key: ISPN-366 URL: https://jira.jboss.org/jira/browse/ISPN-366 Project: Infinispan Issue Type: Task Components: Cache Server Reporter: Galder Zamarreno Assignee: Galder Zamarreno Fix For: 4.1.0.Final <mmarkus_> galderz: ping <mmarkus_> what is the meaning of "replaceIfUnmodified"? * amontenegro_ (~amonteneg(a)200.111.187.74) has joined #infinispan * amontenegro_ is now known as aamonten * clebert (~clebert@redhat/jboss/clebert) has joined #infinispan * baileyje (~baileyje@redhat/jboss/baileyje) has joined #infinispan * clebert (~clebert@redhat/jboss/clebert) has left #infinispan <galderz> manik__, hi mmarkus_ <galderz> replaceIfUnmodified ? <galderz> one sec <galderz> mmarkus_, manik_, r u planning to produce diff jars for server and client? <galderz> if so, it'd make sense for the client to be a separate module <galderz> wouldn't it? <manik_> galderz: yes, I think diff jars would make sense <mmarkus_> galderz: i think yes, because I'd like the client to be light <galderz> same here <manik_> no one would want server code (+ server deps) on their client <galderz> exactly <galderz> so, the client should be in server/hotrod-client or similar module <mmarkus_> not sure we need another module for that, only different packaging <galderz> mmarkus_, u're lucky i don't have java classes <galderz> and u can use src/java <galderz> while I use main/scala <galderz> i mean, u use main/java <galderz> but once u give a maven module scala nature <galderz> i think it ignores main/java <galderz> at least that's what I found out doing some testing <mmarkus_> even so, can't we produce two jars for the same module? <galderz> mmarkus_, u prob can but u have to start filtering classes./..etc <manik_> mmarkus_: thats a real PITA <galderz> iow, it's a probably a PITA <manik_> try wrestling with maven assemblies to do that ! ;) <sannegrinovero> hi all; nice to see activity here :) hi galderz recovered from all the walking? <galderz> sannegrinovero, yup, fully recovered now :) <sannegrinovero> nice :) <manik_> mmarkus_: much easier to just use a separate maven module <mmarkus_> manik_: I don't want to do that for sure. Not a big fan o mvn (not to say more) <galderz> mmarkus_, replaceIfUnmodified is all about the cas <sannegrinovero> can't build the snapshot currently as I'm missing a jgroups:jar:2.10.0.Alpha2 <galderz> it's a way to do a replace remotely <galderz> u want to replace, only if no one changed the value <galderz> so what do u do? <galderz> each modification has a unique value associated to it <galderz> so, when u want to mayeb replace, u get the cas first with: getWithCas <galderz> and then use the cas to make the modification <sannegrinovero> galderz is this "replaceIfUnmodified" already in trunk? sounds very useful <galderz> if the cas values do not match, someone has changed the value and replace is not execited <galderz> sannegrinovero, not yet <sannegrinovero> ok <galderz> mmarkus_, it's the same technique used by memcached: see http://github.com/trondn/memcached/blob/master/doc/protocol.txt <galderz> see cas command in that document <galderz> cas is our replaceIfUnmodified <galderz> mmarkus_, is it clear? <mmarkus_> what is cas? <galderz> Compare And Swap <galderz> used all over java.util.concurrent <mmarkus_> I know that one, just I don't see how it maps in hotrod <mmarkus_> e.g. getWithCas? <galderz> mmarkus_, each modification has a unique value associated: <galderz> for example: <galderz> if u key=k value=v1, let's say the unique value is 12345 <galderz> get with cas returns that 12345 <galderz> 12345 and v1 of course <galderz> now, u call replaceIfUnmodified on key=k with value=v2 and cas 12345 <galderz> key=k will only be replaced by v2 if, and only if, the cas in that node is still 12345 <galderz> if someone else had made a modification in the mean time, the unique value would have changed <galderz> hence, replaceIfUnmodified call would not have succeded <galderz> mmarkus_, does it make sense now? <galderz> it's a way to do a remote CAS <galderz> as memcached says: " "cas" is a check and set operation which means "store this data but <galderz> only if no one else has updated since I last fetched it."" <mmarkus_> so cas is generated on the server, each modification to the cache (cluster) resulting in a new cas value? <galderz> that cas operation does exactly the same as replaceIfUnmodified <galderz> indeed mmarkus_ <galderz> see the memcached module for an example <galderz> we discussed this in the list as well <mmarkus_> is the cache set per key or per whole cache? <galderz> cas u mean? <galderz> it's associated with each value, so is per key <mmarkus_> cas, sorry <galderz> mmarkus_, see http://anonsvn.jboss.org/repos/infinispan/trunk/server/memcached/src/main... <galderz> and <galderz> AddCommand <galderz> or SetCommand <galderz> in memcached, we set it to current time millis <galderz> and we increment it for each modification <mmarkus_> yep, makes sense. And it's not returned by default, the only way to retrieve it is through getWithCas, right? <galderz> mmarkus_, indeed <mmarkus_> galderz: I'm just thinking, is there a way to do a put AND obtain the cas value atomically? * mmarkus_ i.e. the way I understand it. if one does a 1.put (k1,v1) <galderz> not at the moment <mmarkus_> then he will need to to a getWithCas(k1) to get this value back <galderz> i wonder how often this would be needed <galderz> indeed <galderz> by making getWithCas a separate command and not using cas anywhere, i'm assuming this is rare occurrence <galderz> but maybe it's not that rar <galderz> rare <mmarkus_> now, the cas he gets on getWithCas(k1), might be the cas of a different put that happened after put(k1,v1), e.g. put(k1,v2) <galderz> mmarkus_, well, that means someone has changed it then <galderz> i think i know what u mean though <galderz> if u have a put and replaceIfUnmodified one after the other, put returning the cas would cut one network call <mmarkus_> not necesarelly <mmarkus_> (that also) <galderz> i'm all ears :) <mmarkus_> considering your example with cas= 12345 (see few lines bellow) <mmarkus_> I do a put that results in cas 12345 <mmarkus_> then immediately after, one does another put(k), resulting in cas 54321 <mmarkus_> then you do an getWithCas and obtain cas=54321 on the server <mmarkus_> now you do a replaceIfUnmodified(k, 54321) <mmarkus_> the cas will match, and the replace operation will take place. But you really wanted it not to take place, as per your example, isn't it? <galderz> well, depends who does the getWithCas <galderz> or more specifically, who did the other put <galderz> what u know is that since u called getWithCas till u do replace, no one else has modified it <galderz> and that's what u do with cas <galderz> u get something, u check the value <mmarkus_> ah, you want to use cas for getting the following gurante: you read data, and based on what you read you want to modify it. Now you only modify it if it hasn't changed in between, correct? <galderz> it matches <galderz> indeed :) <galderz> that's what a cas does :) <galderz> u get something <galderz> u assume that it has X <mmarkus_> I see it now! <galderz> :) <mmarkus_> I was thinking at a different scenario. <mmarkus_> you put data, and at a further point you want to modify it only if it hasn't changed <mmarkus_> but, yeah, this doesn't sound as common as the other scenario, with read * aslak has quit (Quit: Ex-Chat) <mmarkus_> I got it now - thanks for the explanation! * manik_ has quit (Quit: manik_) <galderz> mmarkus_, u're welcome :) <galderz> we'll have to make sure this is explained properly in the docu <galderz> i'll add a jira -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://jira.jboss.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira

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infinispan-issues March 2010