Index APIs changes

In previous versions of Elasticsearch, closing or deleting an index during a full snapshot would make the snapshot fail. In 5.0, the close/delete index request will fail instead. The behavior for partial snapshots remains unchanged: Closing or deleting an index during a partial snapshot is still possible. The snapshot result is then marked as partial.

Thanks to several changes like doc values by default and disk-based norms, warmers are no longer useful. As a consequence, warmers and the warmer API have been removed: it is no longer possible to register queries that will run before a new IndexSearcher is published.

Don’t worry if you have warmers defined on your indices, they will simply be ignored when upgrading to 5.0.

The recent CPU usage (as a percent) has been added to the OS stats reported under the node stats API and the cat nodes API. The breaking change here is that there is a new object in the os object in the node stats response. This object is called cpu and includes percent and load_average as fields. This moves the load_average field that was previously a top-level field in the os object to the cpu object. The format of the load_average field has changed to an object with fields 1m, 5m, and 15m representing the one-minute, five-minute and fifteen-minute loads respectively. If any of these fields are not present, it indicates that the corresponding value is not available.

In the cat nodes API response, the cpu field is output by default. The previous load field has been removed and is replaced by load_1m, load_5m, and load_15m which represent the one-minute, five-minute and fifteen-minute loads respectively. The field will be null if the corresponding value is not available.

Finally, the API for org.elasticsearch.monitor.os.OsStats has changed. The getLoadAverage method has been removed. The value for this can now be obtained from OsStats.Cpu#getLoadAverage but it is no longer a double and is instead an object encapsulating the one-minute, five-minute and fifteen-minute load averages. Additionally, the recent CPU usage can be obtained from OsStats.Cpu#getPercent.

Suggest stats exposed through suggest in indices stats has been merged with search stats. suggest stats is exposed as part of search stats.

Elasticsearch no longer allows indices to be created started with - or +, so that the multi-index matching and expansion is not confused. It was previously possible (but a really bad idea) to create indices starting with a hyphen or plus sign. Any index already existing with these preceding characters will continue to work normally.

The /_aliases API no longer supports indexRouting and index-routing, only index_routing. It also no longer support searchRouting and search-routing, only search_routing. These were removed because they were untested and we prefer there to be only one (obvious) way to do things like this.

As of 5.0 indexing a document with op_type=create without specifying an ID is not supported anymore.

The wait_if_ongoing flag default has changed to true causing _flush calls to wait and block if another flush operation is currently running on the same shard. In turn, if wait_if_ongoing is set to false and another flush operation is already running the flush is skipped and the shards flush call will return immediately without any error. In previous versions flush_not_allowed exceptions where reported for each skipped shard.