We have solved it temporarily by using a KeepLastTwoCommits del policy. We don't get these exceptions now!!!
Btw, I see that pread calls in FSDataInputStream.java are synchronized. Is it possible that merge DFS read calls could potentially block search DFS read calls? Would it be a good idea to have 2 DFSInputStreams for every file, one for merge & another for search? On Tue, May 10, 2016 at 7:43 PM, Ravikumar Govindarajan < [email protected]> wrote: > Sorry, I mis-understood the code. > I see that it has 2 locks IndexRefreshWriteLock & IndexRefreshReadLock. > They look to be separate > > On Tue, May 10, 2016 at 7:16 PM, Ravikumar Govindarajan < > [email protected]> wrote: > >> Thanks a lot Aaron. >> >> I guess we took a commit of 0.2.2 that doesn't have the >> IndexRefreshWriteLock (IRWL). It looks like it co-ordinates between >> searches & incoming mutation commits. If so, then it will likely solve the >> first issue for us (AlreadyClosedException) >> >> >> Can you recollect if that was the reason IRWL was introduced? >> >> On Tue, May 10, 2016 at 6:40 PM, Aaron McCurry <[email protected]> >> wrote: >> >>> On Tue, May 10, 2016 at 2:30 AM, Ravikumar Govindarajan < >>> [email protected]> wrote: >>> >>> > Actually there are 2 issues... >>> > >>> > 1. IndexReaderClosedException >>> > 2. HDFS Stream Closed >>> > >>> >>> Likely when the index is closed it closes the underlying indexinputs as >>> well causing the HDFS Stream closed exception. >>> >>> >>> > >>> > Merge completion results in File Deletion & ultimately HDFS Stream >>> Closed >>> > during Search.... >>> > >>> > I use IndexFileDeleter with KeepOnlyLastCommitDeletionPolicy. This >>> blindly >>> > deletes the file, without bothering to cross-check >>> IndexReader.RefCount > >>> > 0. >>> > >>> >>> Hmm. You can see here: >>> >>> >>> https://github.com/apache/incubator-blur/blob/release-0.2.2-incubating/blur-core/src/main/java/org/apache/blur/manager/writer/BlurIndexSimpleWriter.java#L303 >>> >>> That once the new index is available it is swapped into the index ref >>> object and the old one is sent to the index closer. Once the ref to the >>> index are low enough it closes the index. Or at least it should. >>> >>> I will continue looking into the problem but I don't have a solution for >>> you yet. >>> >>> Aaron >>> >>> >>> >>> > >>> > >>> > *Exception(message:Unknown error during rewrite, >>> > stackTraceStr:java.io.IOException: Stream closed* >>> > at >>> org.apache.hadoop.hdfs.DFSInputStream.pread(DFSInputStream.java:1385) >>> > at org.apache.hadoop.hdfs.DFSInputStream.read(DFSInputStream.java:1374) >>> > at >>> org.apache.hadoop.fs.FSDataInputStream.read(FSDataInputStream.java:89) >>> > at >>> > >>> > >>> org.apache.blur.store.hdfs.HdfsIndexInput.readInternal(HdfsIndexInput.java:62) >>> > at >>> > >>> > >>> org.apache.blur.store.buffer.ReusedBufferedIndexInput.readBytes(ReusedBufferedIndexInput.java:167) >>> > at >>> > >>> > >>> org.apache.blur.store.buffer.ReusedBufferedIndexInput.readBytes(ReusedBufferedIndexInput.java:122) >>> > at >>> > >>> > >>> org.apache.blur.store.hdfs.MmapCacheIndexInput.readAndcache(MmapCacheIndexInput.java:24) >>> > at >>> > >>> > >>> org.apache.blur.store.blockcache_v2.CacheIndexInput.fillNormally(CacheIndexInput.java:354) >>> > at >>> > >>> > >>> org.apache.blur.store.blockcache_v2.CacheIndexInput.fill(CacheIndexInput.java:379) >>> > at >>> > >>> > >>> org.apache.blur.store.blockcache_v2.CacheIndexInput.tryToFill(CacheIndexInput.java:297) >>> > at >>> > >>> > >>> org.apache.blur.store.blockcache_v2.CacheIndexInput.readByte(CacheIndexInput.java:151) >>> > at >>> > >>> > >>> org.apache.blur.lucene.warmup.TraceableIndexInput.readByte(TraceableIndexInput.java:62) >>> > at org.apache.lucene.store.DataInput.readVInt(DataInput.java:108) >>> > at >>> > >>> > >>> org.apache.lucene.codecs.BlockTreeTermsReader$FieldReader$SegmentTermsEnum$Frame.loadBlock(BlockTreeTermsReader.java:2366) >>> > at >>> > >>> > >>> org.apache.lucene.codecs.BlockTreeTermsReader$FieldReader$SegmentTermsEnum.seekCeil(BlockTreeTermsReader.java:1949) >>> > at >>> > >>> > >>> org.apache.blur.index.ExitableReader$ExitableTermsEnum.seekCeil(ExitableReader.java:250) >>> > at >>> > >>> org.apache.lucene.index.FilteredTermsEnum.next(FilteredTermsEnum.java:225) >>> > at >>> > >>> > >>> org.apache.lucene.search.TermCollectingRewrite.collectTerms(TermCollectingRewrite.java:78) >>> > at >>> > >>> > >>> org.apache.lucene.search.ConstantScoreAutoRewrite.rewrite(ConstantScoreAutoRewrite.java:95) >>> > at >>> > >>> > >>> org.apache.lucene.search.MultiTermQuery$ConstantScoreAutoRewrite.rewrite(MultiTermQuery.java:220) >>> > at >>> org.apache.lucene.search.MultiTermQuery.rewrite(MultiTermQuery.java:288) >>> > at org.apache.lucene.search.BooleanQuery.rewrite(BooleanQuery.java:412) >>> > at org.apache.lucene.search.BooleanQuery.rewrite(BooleanQuery.java:412) >>> > at org.apache.lucene.search.BooleanQuery.rewrite(BooleanQuery.java:412) >>> > at >>> > >>> > On Mon, May 9, 2016 at 4:42 PM, Ravikumar Govindarajan < >>> > [email protected]> wrote: >>> > >>> > > One extra info we gleaned from the logs... >>> > > >>> > > 1. Merge Starts & is about to complete >>> > > 2. Searcher is opened >>> > > 3. Merge Completes >>> > > 4. Ref-count drops to 0 in IndexReader >>> > > 5. IndexReader closed while Searcher is still open >>> > > >>> > > This seems to be the main pattern for causing the Exception >>> > > >>> > > -- >>> > > Ravi >>> > > >>> > > On Mon, May 9, 2016 at 3:08 PM, Ravikumar Govindarajan < >>> > > [email protected]> wrote: >>> > > >>> > >> Thanks Aaron... >>> > >> >>> > >> Just a quick question. Lucene itself has ref-counting to close it's >>> > >> readers no? Or Blur has it's own logic to handle it? >>> > >> >>> > >> -- >>> > >> Ravi >>> > >> >>> > >> On Fri, May 6, 2016 at 7:56 PM, Aaron McCurry <[email protected]> >>> > wrote: >>> > >> >>> > >>> Likely yes. If have a few minutes this weekend I can look through >>> that >>> > >>> version and see if I can point you in the right direction. >>> > >>> >>> > >>> On Fri, May 6, 2016 at 8:46 AM, Ravikumar Govindarajan < >>> > >>> [email protected]> wrote: >>> > >>> >>> > >>> > Sometimes during an ongoing search we receive an >>> > >>> > IndexReaderClosedException... >>> > >>> > >>> > >>> > We are on an older version of Blur (0.2.2). Has this been fixed >>> in >>> > >>> newer >>> > >>> > versions or we have been using it wrongly? >>> > >>> > >>> > >>> > *stackTraceStr:org.apache.lucene.store.AlreadyClosedException: >>> this >>> > >>> > IndexReader cannot be used anymore as one of its child readers >>> was >>> > >>> closed* >>> > >>> > at >>> > org.apache.lucene.index.IndexReader.ensureOpen(IndexReader.java:257) >>> > >>> > at >>> > >>> > >>> > >>> > >>> > >>> >>> > >>> org.apache.lucene.index.FilterAtomicReader.fields(FilterAtomicReader.java:380) >>> > >>> > at >>> > >>> > >>> > >>> > >>> > >>> >>> > >>> org.apache.blur.index.ExitableReader$ExitableFilterAtomicReader.fields(ExitableReader.java:81) >>> > >>> > at >>> > >>> > >>> > >>> > >>> > >>> >>> > >>> org.apache.lucene.search.TermCollectingRewrite.collectTerms(TermCollectingRewrite.java:52) >>> > >>> > at >>> > >>> > >>> > >>> > >>> > >>> >>> > >>> org.apache.lucene.search.ConstantScoreAutoRewrite.rewrite(ConstantScoreAutoRewrite.java:95) >>> > >>> > at >>> > >>> > >>> > >>> > >>> > >>> >>> > >>> org.apache.lucene.search.MultiTermQuery$ConstantScoreAutoRewrite.rewrite(MultiTermQuery.java:220) >>> > >>> > at >>> > >>> >>> > >>> org.apache.lucene.search.MultiTermQuery.rewrite(MultiTermQuery.java:288) >>> > >>> > at >>> > org.apache.lucene.search.BooleanQuery.rewrite(BooleanQuery.java:412) >>> > >>> > >>> > >>> >>> > >> >>> > >> >>> > > >>> > >>> >> >> >
