indices.asciidoc

Indices changes

: is no longer allowed in index name

Due to cross-cluster search using : to separate a cluster and index name, index names may no longer contain :.

index.unassigned.node_left.delayed_timeout may no longer be negative

Negative values were interpreted as zero in earlier versions but are no longer accepted.

_flush and _force_merge will no longer refresh

In previous versions issuing a _flush or _force_merge (with flush=true) had the undocumented side-effect of refreshing the index which made new documents visible to searches and non-realtime GET operations. From now on these operations don’t have this side-effect anymore. To make documents visible an explicit _refresh call is needed unless the index is refreshed by the internal scheduler.

Limit to the difference between max_size and min_size in NGramTokenFilter and NGramTokenizer

To safeguard against creating too many index terms, the difference between max_ngram and min_ngram in NGramTokenFilter and NGramTokenizer has been limited to 1. This default limit can be changed with the index setting index.max_ngram_diff. Note that if the limit is exceeded a error is thrown only for new indices. For existing pre-7.0 indices, a deprecation warning is logged.

Limit to the difference between max_size and min_size in ShingleTokenFilter

To safeguard against creating too many tokens, the difference between max_shingle_size and min_shingle_size in ShingleTokenFilter has been limited to 3. This default limit can be changed with the index setting index.max_shingle_diff. Note that if the limit is exceeded a error is thrown only for new indices. For existing pre-7.0 indices, a deprecation warning is logged.

Document distribution changes

Indices created with version 7.0.0 onwards will have an automatic index.number_of_routing_shards value set. This might change how documents are distributed across shards depending on how many shards the index has. In order to maintain the exact same distribution as a pre 7.0.0 index, the index.number_of_routing_shards must be set to the index.number_of_shards at index creation time. Note: if the number of routing shards equals the number of shards _split operations are not supported.

Skipped background refresh on search idle shards

Shards belonging to an index that does not have an explicit index.refresh_interval configured will no longer refresh in the background once the shard becomes "search idle", ie the shard hasn’t seen any search traffic for index.search.idle.after seconds (defaults to 30s). Searches that access a search idle shard will be "parked" until the next refresh happens. Indexing requests with wait_for_refresh will also trigger a background refresh.

Remove deprecated url parameters for Clear Indices Cache API

The following previously deprecated url parameter have been removed:

• filter - use query instead

• filter_cache - use query instead

• request_cache - use request instead

• field_data - use fielddata instead

network.breaker.inflight_requests.overhead increased to 2

Previously the in flight requests circuit breaker considered only the raw byte representation. By bumping the value of network.breaker.inflight_requests.overhead from 1 to 2, this circuit breaker considers now also the memory overhead of representing the request as a structured object.

Parent circuit breaker changes

The parent circuit breaker defines a new setting indices.breaker.total.use_real_memory which is true by default. This means that the parent circuit breaker will trip based on currently used heap memory instead of only considering the reserved memory by child circuit breakers. When this setting is true, the default parent breaker limit also changes from 70% to 95% of the JVM heap size. The previous behavior can be restored by setting indices.breaker.total.use_real_memory to false.

fix value for index.shard.check_on_startup is removed

Deprecated option value fix for setting index.shard.check_on_startup is not supported.