Thanks Shwan, that was good point to consider but we had porblem with holdability param in data-config.xml and Oracle 12c version of DB and client.
BY remove Holdability parameter we are able to solve the issue. On 28 March 2017 at 18:19, Shawn Heisey <apa...@elyograg.org> wrote: > On 3/27/2017 7:13 PM, santosh sidnal wrote: > > i am facing closed connection issue while doing dataimporter, any > solution > > to this> stack trace is as below > > > > > > [3/27/17 8:54:41:399 CDT] 000000b4 OracleDataSto > findMappingClass for > : > > Entry > > java.sql.SQLRecoverableException: > Closed > > Connection > > Does the import appear to work correctly at first, then stop before it's > done with this exception after a few hours? If so, then I think you may > be running into a situation where the merge scheduler has multiple > merges scheduled and stops the incoming indexing thread until the > largest merge is done. If the indexing thread is stopped for long > enough, JDBC will disconnect the database, and when the indexing thread > finally starts back up, the dataimporter finds that it cannot read from > the database any more. > > If this is what's happening, then the solution is to allow the merge > scheduler to schedule more merges simultaneously. Here's the > indexConfig that I use in solrconfig.xml: > > <indexConfig> > <mergePolicy class="org.apache.lucene.index.TieredMergePolicy"> > <int name="maxMergeAtOnce">35</int> > <int name="segmentsPerTier">35</int> > <int name="maxMergeAtOnceExplicit">105</int> > </mergePolicy> > <mergeScheduler class="org.apache.lucene.index. > ConcurrentMergeScheduler"> > <int name="maxThreadCount">1</int> > <int name="maxMergeCount">6</int> > </mergeScheduler> > </indexConfig> > > You don't need the mergePolicy part of this config to solve this issue. > That is the settings that I use, but this greatly increases the number > of files that can be in an index, which may require OS tuning for max > open files. > > The mergeScheduler is the important part, and specifically > maxMergeCount. These settings are for standard spinning-magnetic > disks. I increase the maxMergeCount to 6, so more merges can be > scheduled without halting the indexing thread. The maxThreadCount value > should be set to 1 if you're using standard disks. If you're using SSD, > then you can bump it a little bit, because SSD can easily handle > multiple threads randomly writing to the disk. I don't know what values > are appropriate for SSD, but I would probably start with 2-4. > > Thanks, > Shawn > > -- Regards, Santosh Sidnal