# Failed to flush shard on translog threshold exception

**URL:** <https://discuss.elastic.co/t/failed-to-flush-shard-on-translog-threshold-exception/4959>\
**Category:** Elasticsearch\
**Created:** [July 26, 2011, 7:01am UTC](https://discuss.elastic.co/t/failed-to-flush-shard-on-translog-threshold-exception/4959 "2011-07-26T07:01:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![DKN](https://avatars.discourse-cdn.com/v4/letter/d/77aa72/32.png) [@DKN](https://discuss.elastic.co/u/DKN)\
**Post date:** [July 26, 2011, 7:01am UTC](https://discuss.elastic.co/t/failed-to-flush-shard-on-translog-threshold-exception/4959/1 "2011-07-26T07:01:48Z")

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On one of the nodes, I am seeing this exception. The status of the overall cluster is still "green", but this specific node, has a slightly slower disk attached to it .. [a disk mounted from the network ..].

[2011-07-26 02:34:07,661][WARN][index.translog] [Clive] [mbgl][1] failed to flush shard on translog threshold  
org.elasticsearch.index.engine.FlushFailedEngineException: [mbgl][1] Flush failed  
at org.elasticsearch.index.engine.robin.RobinEngine.flush(RobinEngine.java:702)  
at org.elasticsearch.index.shard.service.InternalIndexShard.flush(InternalIndexShard.java:417)  
at org.elasticsearch.index.translog.TranslogService$TranslogBasedFlush$1.run(TranslogService.java:160)  
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)  
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)  
at java.lang.Thread.run(Thread.java:662)  
Caused by: java.lang.NullPointerException  
at org.apache.lucene.index.IndexWriter.doFlush(IndexWriter.java:3331)  
at org.apache.lucene.index.IndexWriter.flush(IndexWriter.java:3296)  
at org.apache.lucene.index.IndexWriter.prepareCommit(IndexWriter.java:3159)  
at org.apache.lucene.index.IndexWriter.commitInternal(IndexWriter.java:3232)  
at org.apache.lucene.index.IndexWriter.commit(IndexWriter.java:3214)  
at org.apache.lucene.index.IndexWriter.commit(IndexWriter.java:3198)  
at org.elasticsearch.index.engine.robin.RobinEngine.flush(RobinEngine.java:699)  
... 5 more

Any ideas what is the underlying cause for this ?.. How do we debug this further to nail down the problem .. ?

Cheers, DKN ..

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [July 6, 2017, 3:59am UTC](https://discuss.elastic.co/t/failed-to-flush-shard-on-translog-threshold-exception/4959/2 "2017-07-06T03:59:26Z")

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