Is it possible to write to multiple indexes with an ElasticSearch alias?

Question

The ElasticSearch Docs reads:

An alias can also be mapped to more than one index, and when specifying it, the alias will automatically expand to the aliases indices.

But when I try to add an alias to 2 indices and write to both, neither seem to get updated with the document. If I remove one of the aliases, it will write correctly to the alias that still exists.

Fails with multiple write aliases:

$ curl -XGET 'http://localhost:9200/_aliases' 

result:

{   "dev_01": {     "aliases": {       "dev_read": {},       "dev_write": {}     }   },   "dev": {     "aliases": {       "dev_write": {}     }   } } 

Works with single alias:

$ curl -XGET 'http://localhost:9200/_aliases' 

result:

{   "dev_01": {     "aliases": {       "dev_read": {},       "dev_write": {}     }   },   "dev": {     "aliases": {}   } } 

Does elasticsearch support writing to multiple indices? Are aliases Read-Only if pointed at multiple indices?

Answer 1

the answer is No

So it appears I should have triaged this a beep deeper, but the response my client gets from es is:

ElasticSearchIllegalArgumentException[Alias [dev_write] has more than one indices associated with it [[dev_01, dev]], can't execute a single index op

Just wish the docs were a little more explicit up front, as they confused me a bit

At first seems to imply you can:

The index aliases API allow to alias an index with a name, with all APIs automatically converting the alias name to the actual index name. An alias can also be mapped to more than one index...

Associating an alias with more than one index are simply several add actions...

Further down the page lets you know you can not:

It is an error to index to an alias which points to more than one index.