Mark,
That sounds great! Good luck with the cleaning :-)
Let me know how I can get a patch --- I'd prefer not do a solr build from
source since we are not Java savvy here....:-(
- Bill
--------------------------------------------------
From: "Mark Miller" <[EMAIL PROTECTED]>
Sent: Saturday, November 15, 2008 12:43 PM
To: <solr-user@lucene.apache.org>
Subject: Re: Fatal exception in solr 1.3+ replication
Okay, I'm fairly certain I've found it. As usual, take a walk and the
solution pops into your head out of the blue.
It looks like Lucene's IndexReader reopen call is not very friendly with
the FSDirectory implementation. If you call reopen and it returns a new
IndexReader, it creates a new reference on the Directory - so if you
reopen an IndexReader that was originally opened with a non Directory
parameter (String or File instead), both Readers (the reopened one and the
one your reopening on) will close the Directory when they close. Thats not
right. Thats how we get to 0 faster than we should. So its kind of a
Lucene issue.
My guess that this is hidden in the trunk was right, because I think we
are no longer using String, File based IndexReader opens, which means our
IndexReaders don't attempt to close their underlying Directories now.
I can probably send you patch for the revision your on to hide this as
well, but I'm already in the doghouse on cleaning right now ; ) The way my
brain works, I'll probably be back to this later though.
- Mark
William Pierce wrote:
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
