In #17198, we removed suggest transport action, which
used the `suggest` threadpool to execute requests. Now
`suggest` threadpool is unused and suggest requests are
executed on the `search` threadpool.
Currently if you run an `exists` query on an object, it will resolve all sub
fields and create a disjunction for all those fields. However the `_field_names`
mapper indexes paths for objects so we could query object paths directly.
I also changed the query parser to reject `exists` queries if the `_field_names`
field is disabled since it would be a big performance trap.
In 5.0 we don't allow index settings to be specified on the node level ie.
in yaml files or via commandline argument. This can cause problems during
upgrade if this was used extensively. For instance if analyzers where
specified on a node level this might cause the index to be closed when
imported (see #17187). In such a case all indices relying on this
must be updated via `PUT /${index}/_settings`. Yet, this API has slightly
different semantics since it overrides existing settings. To make this less
painful this change adds a `preserve_existing` parameter on that API to ensure
we have the same semantics as if the setting was applied on the node level.
This change also adds a better error message and a change to the migration guide
to ensure upgrades are smooth if index settings are specified on the node level.
If a index setting is detected this change fails the node startup and prints a message
like this:
```
*************************************************************************************
Found index level settings on node level configuration.
Since elasticsearch 5.x index level settings can NOT be set on the nodes
configuration like the elasticsearch.yaml, in system properties or command line
arguments.In order to upgrade all indices the settings must be updated via the
/${index}/_settings API. Unless all settings are dynamic all indices must be closed
in order to apply the upgradeIndices created in the future should use index templates
to set default values.
Please ensure all required values are updated on all indices by executing:
curl -XPUT 'http://localhost:9200/_all/_settings?preserve_existing=true' -d '{
"index.number_of_shards" : "1",
"index.query.default_field" : "main_field",
"index.translog.durability" : "async",
"index.ttl.disable_purge" : "true"
}'
*************************************************************************************
```
Also replaced the PercolatorQueryRegistry with the new PercolatorQueryCache.
The PercolatorFieldMapper stores the rewritten form of each percolator query's xcontext
in a binary doc values field. This make sure that the query rewrite happens only during
indexing (some queries for example fetch shapes, terms in remote indices) and
the speed up the loading of the queries in the percolator query cache.
Because the percolator now works inside the search infrastructure a number of features
(sorting fields, pagination, fetch features) are available out of the box.
The following feature requests are automatically implemented via this refactoring:
Closes#10741Closes#7297Closes#13176Closes#13978Closes#11264Closes#10741Closes#4317
Today, certain bootstrap properties are set and read via system
properties. This action-at-distance way of managing these properties is
rather confusing, and completely unnecessary. But another problem exists
with setting these as system properties. Namely, these system properties
are interpreted as Elasticsearch settings, not all of which are
registered. This leads to Elasticsearch failing to startup if any of
these special properties are set. Instead, these properties should be
kept as local as possible, and passed around as method parameters where
needed. This eliminates the action-at-distance way of handling these
properties, and eliminates the need to register these non-setting
properties. This commit does exactly that.
Additionally, today we use the "-D" command line flag to set the
properties, but this is confusing because "-D" is a special flag to the
JVM for setting system properties. This creates confusion because some
"-D" properties should be passed via arguments to the JVM (so via
ES_JAVA_OPTS), and some should be passed as arguments to
Elasticsearch. This commit changes the "-D" flag for Elasticsearch
settings to "-E".