title: Failing to start shard in ElasticSearch IndexShardGatewayRecoveryException "sending failed"
body: <p>I'm getting this error, in my ES log  I'm using three nodes.</p>
  
  <pre><code>Caused by: java.lang.ArrayIndexOutOfBoundsException
  [2014-09-08 13:53:56,167][WARN ][cluster.action.shard     ] [Dancing Destroyer] [events][3] sending failed shard for [events][3], node[RDZy21y7SRep7n6oWT8ogg], [P], s[INITIALIZING], indexUUID [gzj1aHTnQX6XDc0SxkvxDQ], reason [Failed to start shard, message [IndexShardGatewayRecoveryException[[events][3] failed recovery]; nested: FlushFailedEngineException[[events][3] Flush failed]; nested: ArrayIndexOutOfBoundsException; ]]
  [2014-09-08 13:53:56,357][WARN ][indices.cluster          ] [Dancing Destroyer] [events][3] failed to start shard
  org.elasticsearch.index.gateway.IndexShardGatewayRecoveryException: [events][3] failed recovery
          at org.elasticsearch.index.gateway.IndexShardGatewayService$1.run(IndexShardGatewayService.java:185)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
          at java.lang.Thread.run(Thread.java:744)
  Caused by: org.elasticsearch.index.engine.FlushFailedEngineException: [events][3] Flush failed
          at org.elasticsearch.index.engine.internal.InternalEngine.flush(InternalEngine.java:805)
          at org.elasticsearch.index.shard.service.InternalIndexShard.performRecoveryFinalization(InternalIndexShard.java:726)
          at org.elasticsearch.index.gateway.local.LocalIndexShardGateway.recover(LocalIndexShardGateway.java:249)
          at org.elasticsearch.index.gateway.IndexShardGatewayService$1.run(IndexShardGatewayService.java:132)
          ... 3 more
  Caused by: java.lang.ArrayIndexOutOfBoundsException
  [2014-09-08 13:53:56,381][WARN ][cluster.action.shard     ] [Dancing Destroyer] [events][3] sending failed shard for [events][3], node[RDZy21y7SRep7n6oWT8ogg], [P], s[INITIALIZING], indexUUID [gzj1aHTnQX6XDc0SxkvxDQ], reason [Failed to start shard, message [IndexShardGatewayRecoveryException[[events][3] failed recovery]; nested: FlushFailedEngineException[[events][3] Flush failed]; nested: ArrayIndexOutOfBoundsException; ]]
  </code></pre>
  
  <p>This means that the status of ES is red and I'm missing nearly 10 million documents.
  What does this error mean, so that I'd might be able to recover?</p>