I am running ElasticSearch V2.1.0 on a single node machine and TransportClient at client side.
The bulk process bulider was set with following parameters:
.setBulkSize(new ByteSizeValue(1, ByteSizeUnit.GB))
The data update process went through correctly except the last bulk API call, whose call back functions were invoked inconsistently, in some occasion no callback (success or failure) was ever returned in 5 minutes.
I understand the last call always has less than 1000 requests, but would that make any difference to the call back? very weird! any clues?