Stack trace on delete in Elasticsearch

gistfile1.java

[2012-01-05 16:02:32,693][WARN ][river.couchdb            ] [Asmodeus] [couchdb][database_type1] failed to executefailure in bulk execution:
[0]: index [database], type [type1], id [030cc472426e451a6d5e6b0e15000988], message [VersionConflictEngineException[[database][2] [type1][030cc472426e451a6d5e6b0e15000988]: version conflict, current [-1], required [1]]]
[2012-01-05 16:03:17,193][DEBUG][action.bulk              ] [Asmodeus] [database][0] failed to bulk item (delete) delete {[database][type1][030cc472426e451a6d5e6b0e15000c80]}
org.elasticsearch.index.engine.VersionConflictEngineException: [database][0] [type1][030cc472426e451a6d5e6b0e15000c80]: version conflict, current [-1], required [2]
	at org.elasticsearch.index.engine.robin.RobinEngine.innerDelete(RobinEngine.java:646)
	at org.elasticsearch.index.engine.robin.RobinEngine.delete(RobinEngine.java:597)
	at org.elasticsearch.index.shard.service.InternalIndexShard.delete(InternalIndexShard.java:336)
	at org.elasticsearch.action.bulk.TransportShardBulkAction.shardOperationOnPrimary(TransportShardBulkAction.java:178)
	at org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction$AsyncShardOperationAction.performOnPrimary(TransportShardReplicationOperationAction.java:487)
	at org.elasticsearch.action.support.replication.TransportShardReplicationOperationAction$AsyncShardOperationAction$1.run(TransportShardReplicationOperationAction.java:400)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:662)