keep bulk data into es during rolling restart,
1.set "cluster.routing.allocation.enable": "none"
2._flush/synced(may not success)
3.restart a esnode;
4.set "cluster.routing.allocation.enable": "all"
5.waiting until the cluster status become green;
6.repeat 1~5 until all esnodes are restarted.
when some esnode stoped,some json response of bulk may be failed,the error is
primary shard is not active Timeout: [1m], request: [BulkShardRequest [[myindex-002]] containing  requests]","type":"unavailable_shards_exception"},"status":503
I consider that when a esnode is shutdown,primary shards on it will soon transfer to the corresponding replica, which means,primary shard become replica, replica become primary shard.
And I tested ,shutdown a esnode when not bulking , the transfer happens in a moment.
So，does anyone has some suggestion？ thanks a lot.