Revises the current 'How to avoid oversharding' docs to incorporate
information from our [shard sizing blog post][0].
Changes:
* Streamlines introduction
* Adds "Things to remember" section to describe how shards work
* Adds "Guidelines" section based on blog tips
* Creates a "Fix an oversharded cluster" section
[0]: https://www.elastic.co/blog/how-many-shards-should-i-have-in-my-elasticsearch-cluster
Changes:
* Moves `Retrieve selected fields` to its own page and adds a title abbreviation.
* Adds existing script and stored fields content to `Retrieve selected fields`
* Adds a xref for `Retrieve selected fields` to `Search your data`
* Adds related redirects and updates existing xrefs
Moves the highlighting docs from the deprecated 'Request Body Search'
chapter to the new subpage of the 'Run a search chapter' section.
No substantive changes were made to the content.
Adds a detailed example to the "Avoid scripts" section of the "Tune
for search speed" docs. The detail outlines how a script used to
transform indexed data can be moved to ingest.
The update also removes an outdated reference to supported script
languages.
This field is a specialization of the `keyword` field for the case when all
documents have the same value. It typically performs more efficiently than
keywords at query time by figuring out whether all or none of the documents
match at rewrite time, like `term` queries on `_index`.
The name is up for discussion. I liked including `keyword` in it, so that we
still have room for a `singleton_numeric` in the future. However I'm unsure
whether to call it `singleton`, `constant` or something else, any opinions?
For this field there is a choice between
1. accepting values in `_source` when they are equal to the value configured
in mappings, but rejecting mapping updates
2. rejecting values in `_source` but then allowing updates to the value that
is configured in the mapping
This commit implements option 1, so that it is possible to reindex from/to an
index that has the field mapped as a keyword with no changes to the source.
Backport of #49713
We should be more explicit about the downsides of disabling replicas and
explain that users should be ready to re-do the entire load in case of
issues mid-way.
One architecture that we have recommended to several users to speed up
indexing involved using CCR to prevent searching from stealing resources
from indexing.
The docs/reference/redirects.asciidoc file stores a list of relocated or
deleted pages for the Elasticsearch Reference documentation.
This prunes several older redirects that are no longer needed and
don't require work to fix broken links in other repositories.
Users often mistakenly map numeric IDs to numeric datatypes. However,
this is often slow for the `term` and other term-level queries.
The "Tune for search speed" docs includes advice for mapping numeric
IDs to `keyword` fields. However, this tip is not included in the
`numeric` or `keyword` field datatype doc pages.
This rewords the tip in the "Tune for search speed" docs, relocates it
to the `numeric` field docs, and reuses it using tagged regions.
Some small clarifications about force-merging and global ordinals, particularly
that global ordinals are cheap on a single-segment index and how this relates
to frozen indices.
Fixes#41687
- new `rank_feature`/`script_score` queries
- new `index_phrases`/`index_prefixes` options
- disabling `_field_names` doesn't help anymore
- adaptive replica selection is on by default
* Default include_type_name to false for get and put mappings.
* Default include_type_name to false for get field mappings.
* Add a constant for the default include_type_name value.
* Default include_type_name to false for get and put index templates.
* Default include_type_name to false for create index.
* Update create index calls in REST documentation to use include_type_name=true.
* Some minor clean-ups around the get index API.
* In REST tests, use include_type_name=true by default for index creation.
* Make sure to use 'expression == false'.
* Clarify the different IndexTemplateMetaData toXContent methods.
* Fix FullClusterRestartIT#testSnapshotRestore.
* Fix the ml_anomalies_default_mappings test.
* Fix GetFieldMappingsResponseTests and GetIndexTemplateResponseTests.
We make sure to specify include_type_name=true during xContent parsing,
so we continue to test the legacy typed responses. XContent generation
for the typeless responses is currently only covered by REST tests,
but we will be adding unit test coverage for these as we implement
each typeless API in the Java HLRC.
This commit also refactors GetMappingsResponse to follow the same appraoch
as the other mappings-related responses, where we read include_type_name
out of the xContent params, instead of creating a second toXContent method.
This gives better consistency in the response parsing code.
* Fix more REST tests.
* Improve some wording in the create index documentation.
* Add a note about types removal in the create index docs.
* Fix SmokeTestMonitoringWithSecurityIT#testHTTPExporterWithSSL.
* Make sure to mention include_type_name in the REST docs for affected APIs.
* Make sure to use 'expression == false' in FullClusterRestartIT.
* Mention include_type_name in the REST templates docs.
This commit changes the format of the `hits.total` in the search response to be an object with
a `value` and a `relation`. The `value` indicates the number of hits that match the query and the
`relation` indicates whether the number is accurate (in which case the relation is equals to `eq`)
or a lower bound of the total (in which case it is equals to `gte`).
This change also adds a parameter called `rest_total_hits_as_int` that can be used in the
search APIs to opt out from this change (retrieve the total hits as a number in the rest response).
Note that currently all search responses are accurate (`track_total_hits: true`) or they don't contain
`hits.total` (`track_total_hits: true`). We'll add a way to get a lower bound of the total hits in a
follow up (to allow numbers to be passed to `track_total_hits`).
Relates #33028
* Replace custom type names with _doc in REST examples.
* Avoid using two mapping types in the percolator docs.
* Rename doc -> _doc in the main repository README.
* Also replace some custom type names in the HLRC docs.
The main benefit of the upgrade for users is the search optimization for top scored documents when the total hit count is not needed. However this optimization is not activated in this change, there is another issue opened to discuss how it should be integrated smoothly.
Some comments about the change:
* Tests that can produce negative scores have been adapted but we need to forbid them completely: #33309Closes#32899
James Rodewig
Rafi Estrada
James Rodewig
Kartika Prasad
Lisa Cawley
Paweł Krześniak
Vanessa Bell
Adrien Grand
Grzegorz Banasiak
David Turner
Tanguy Buchier
markharwood
swstepp
Christoph Büscher
Julie Tibshirani
Peter Dyson
Jim Ferenczi
Jan Jíša