ElasticSearch (4) cluster -- sharding test

 

 

cluster setting 

shards : 5

replica : 0

There are 3 ES nodes.

NODE_1 master

NODE_2

NODE_3

After some indices are completed, using the segment api we can see that there are 5 primary active shards.

NODE_1 (master)  shard1, shard2

NODE_2           shard3

NODE_3           shard4, shard5

Then master node service is shutdown(kill process directly), using the segment api we can see that there are 3 primary active shards.

NODE_2  (master)         shard3

NODE_3           shard4, shard5  

Then bring back the NODE_1,  using the segment api we can see that there are 5 primary active shards.

NODE_1           shard1, shard2

NODE_2  (master)         shard3

NODE_3           shard4, shard5  

It means the index segments can be brought back after the ES service is back.

But with replica 0 , is it possible to copy the sharding to other nodes?

 

 

Even using the shutdown service rest api, the shard is not available after node is shutdown.

Wrapper service is necesary to use if you want to restart the ES service using rest api.

 

Every time a node is restarted, the node id changes.