Trunk may actually still hide the issue (possibly), but something really funky seems to have gone on and I can't find it yet. Do you have any custom code interacting with solr?

None whatsoever...I am using out-of-the-box solr 1.3 (build of 10/23). I am using my C# app to http requests to my solr instance.

Is there something you want me to try at my end that might give you a clue? Let me know and I can try to help out.

Best,

- Bill

--------------------------------------------------
From: "Mark Miller" <[EMAIL PROTECTED]>
Sent: Saturday, November 15, 2008 10:59 AM
To: <solr-user@lucene.apache.org>
Subject: Re: Fatal exception in solr 1.3+ replication

Havn't given up, but this has really got me so far. For every path, FSDirectory allows just one instance of FSDirectory to exist, and it keeps a ref count of how many have been returned from openDirectory for a given path. An FSDirectory will not actually be closed unless all references to it are released (it doesn't actually even do anything in close, other than drop the reference). So pretty much, the only way to get into trouble is to call close enough times to equal how many times you called openDirectory, and then try to use the FSDirectory again. This is what your stack trace indicates is happening.

So we can get the call hierarchy for directory.close() in solr, and we find that everything is pretty matched up...at worst it looks that a reference might not be closed - but that doesn't hurt anything...FSDirectory will just think there is something out there holding onto a reference for that directory and allow you to continue using it, even though no such reference might exist. Its only when enough closes are called that an instance will be marked as closed (a further openDirectory will return a new open instance). So to get your error, something has to close a Directory that it did not get from openDirectory.

We know that the IndexReader that is trying to be reopened must have called openDirectory (or something called openDirectory for it) and we know that it hasn't called close (the IndexReader has already held up to an ensureOpen call on itself in that stack trace). Something else must have closed it. I can't find this happening. Nothing else calls close on Directory unless it called openDirectory (that I can find using all of Eclipses magical goodness).

So how does the refcount on the Directory hit 0? I can't find or duplicate yet...

Trunk may actually still hide the issue (possibly), but something really funky seems to have gone on and I can't find it yet. Do you have any custom code interacting with solr?

- Mark

William Pierce wrote:
Mark,

Thanks for your help and lucid exposition of what may be going on....I will await to hear from you before I plough ahead with the latest trunk bits....

Best regards,

-- Bill

--------------------------------------------------
From: "Mark Miller" <[EMAIL PROTECTED]>
Sent: Saturday, November 15, 2008 7:29 AM
To: <solr-user@lucene.apache.org>
Subject: Re: Fatal exception in solr 1.3+ replication

Hang on. The more I look at this, the more I am thinking that was not the problem. Directories are pretty strictly managed by Lucene at the moment, and it should actually be pretty difficult to have one closed out from under you. They are singletons and reference counted. The IndexReader would have to have been closed if it was responsible for closing the Directory, and in that case, we would not be trying to reopen it. The Searcher we get the IndexReader from has been inc ref'd to ensure it won't close. All I can think is that something is grabbing/stealing a Directory that didn't directly ask for it from FSDirectory.getDirectory, and is then closing it. I'm trying to hunt where that could be happening now. Hope to spot something, but appears pretty mysterious at the moment. I suppose another option is a nasty little race condition - I've been trying to repeat the error by sending lots of update/search requests from multiple threads with no luck though. Looks like I may have to throw in snap puller code (havn't look too heavily into any of that before).

At worst, if/when a fix is discovered, you will probably be able to apply just the fix to the revision your working with.

- Mark

William Pierce wrote:
Mark,

Thanks for your response --- I do appreciate all you volunteers working to provide such a nice system!

Anyway, I will try the trunk bits as you said. The only problem is that the later the trunk I use from 1.3, the more of post 1.3 capability I get. And I feel somewhat exposed running these bits in our production environment...

Not sure if there's another approach?

Thanks,
-Bill

--------------------------------------------------
From: "Mark Miller" <[EMAIL PROTECTED]>
Sent: Friday, November 14, 2008 8:43 PM
To: <solr-user@lucene.apache.org>
Subject: Re: Fatal exception in solr 1.3+ replication

Hey William, sorry about the trouble. I have to look at this further, but I think the issue is fixed if you grab the latest trunk build. Solr-465 should inadvertently fix things - before that patch, a deprecated constructor for solrsearcher was being called - this constructor caused the underlying IndexReader to close its own Directory, and since IndexReaders are reopened, we don't want that.

Mark Miller wrote:
Looks like there might be an issue with the reopen - I'm not seeing what it could be offhand though. Have to find what could be closing a Directory unexpectedly...I'll try to take a further look over the weekend.

- Mark

William Pierce wrote:
Folks:

I am using the nightly build of 1.3 as of Oct 23 so as to use the replication handler. I am running on windows 2003 server with tomcat 6.0.14. Everything was running fine until I noticed that certain updated records were not showing up on the slave. Further investigation showed me that the failures have indeed been occurring since early this morning with a fatal exception....here is a segment of the tomcat log:
  INFO: Total time taken for download : 0 secs
Nov 14, 2008 5:34:24 AM org.apache.solr.handler.SnapPuller fetchLatestIndex
  INFO: Conf files are not downloaded or are in sync
Nov 14, 2008 5:34:24 AM org.apache.solr.update.DirectUpdateHandler2 commit INFO: start commit(optimize=false,waitFlush=true,waitSearcher=true) Nov 14, 2008 5:34:24 AM org.apache.solr.handler.ReplicationHandler doSnapPull SEVERE: SnapPull failed org.apache.solr.common.SolrException: Snappull failed : at org.apache.solr.handler.SnapPuller.fetchLatestIndex(SnapPuller.java:278) at org.apache.solr.handler.ReplicationHandler.doSnapPull(ReplicationHandler.java:208)
   at org.apache.solr.handler.SnapPuller$1.run(SnapPuller.java:121)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441) at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317) at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:181) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:205) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
   at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.RuntimeException: org.apache.lucene.store.AlreadyClosedException: this Directory is closed
   at org.apache.solr.core.SolrCore.getSearcher(SolrCore.java:1037)
at org.apache.solr.update.DirectUpdateHandler2.commit(DirectUpdateHandler2.java:350) at org.apache.solr.handler.SnapPuller.doCommit(SnapPuller.java:353) at org.apache.solr.handler.SnapPuller.fetchLatestIndex(SnapPuller.java:265)
   ... 11 more
Caused by: org.apache.lucene.store.AlreadyClosedException: this Directory is closed at org.apache.lucene.store.Directory.ensureOpen(Directory.java:220)
   at org.apache.lucene.store.FSDirectory.list(FSDirectory.java:320)
at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:533) at org.apache.lucene.index.SegmentInfos.readCurrentVersion(SegmentInfos.java:366) at org.apache.lucene.index.DirectoryIndexReader.isCurrent(DirectoryIndexReader.java:188) at org.apache.lucene.index.DirectoryIndexReader.reopen(DirectoryIndexReader.java:124)
   at org.apache.solr.core.SolrCore.getSearcher(SolrCore.java:1016)
   ... 14 more
Nov 14, 2008 5:38:52 AM org.apache.solr.update.DirectUpdateHandler2 commit

Any ideas, anyone?

-- Bill








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