The TransportSingleCustomOperationAction `prefer_local` option has been removed as it isn't worth the effort.
The TransportSingleShardAction will execute the operation on the receiving node if a concrete list doesn't provide a list of candite shards routings to perform the operation on.
Moving the query building functionality from the parser to the builders
new toQuery() method analogous to other recent query refactorings.
Relates to #10217
Moving the query building functionality from the parser to the builders
new doToQuery() method analogous to other recent query refactorings.
Relates to #10217Closes#12365
The `_index` field is now a completely virtual field thanks
to #12027. It is no longer necessary to index the actual value
of the index name.
closes#12329
Require urls for URL repository to be listed in repositories.url.allowed_urls setting. This change ensures that only authorized URLs can be accessed by elasticsearch
Moving the query building functionality from the parser to the builders
new toQuery() method analogous to other recent query refactorings.
Relates to #10217
Plugin Manager can now use another simplified form when a user wants to install an official plugin hosted at elasticsearch download service.
The form we use is:
```sh
bin/plugin install pluginname
```
As plugins share now the same version as elasticsearch, we can automatically guess what is the exact current version of the plugin manager script.
Also, download service will now use `/org.elasticsearch.plugins/pluginName/pluginName-version.zip` URL path to download a plugin.
If the older form is provided (`user/plugin/version` or `user/plugin`), we will still use:
* elasticsearch download service at `/user/plugin/plugin-version.zip`
* maven central with groupIp=user, artifactId=plugin and version=version
* github with user=user, repoName=plugin and tag=version
* github with user=user, repoName=plugin and branch=master if no version is set
Note that community plugin providers can use other download services by using `--url` option.
If you try to use the new form with a non core elasticsearch plugin, the plugin manager will reject
it and will give you all known core plugins.
```
Usage:
-u, --url [plugin location] : Set exact URL to download the plugin from
-i, --install [plugin name] : Downloads and installs listed plugins [*]
-t, --timeout [duration] : Timeout setting: 30s, 1m, 1h... (infinite by default)
-r, --remove [plugin name] : Removes listed plugins
-l, --list : List installed plugins
-v, --verbose : Prints verbose messages
-s, --silent : Run in silent mode
-h, --help : Prints this help message
[*] Plugin name could be:
elasticsearch-plugin-name for Elasticsearch 2.0 Core plugin (download from download.elastic.co)
elasticsearch/plugin/version for elasticsearch commercial plugins (download from download.elastic.co)
groupId/artifactId/version for community plugins (download from maven central or oss sonatype)
username/repository for site plugins (download from github master)
Elasticsearch Core plugins:
- elasticsearch-analysis-icu
- elasticsearch-analysis-kuromoji
- elasticsearch-analysis-phonetic
- elasticsearch-analysis-smartcn
- elasticsearch-analysis-stempel
- elasticsearch-cloud-aws
- elasticsearch-cloud-azure
- elasticsearch-cloud-gce
- elasticsearch-delete-by-query
- elasticsearch-lang-javascript
- elasticsearch-lang-python
```
If you are using the default date or the named identifiers of dates,
the current implementation was allowed to read a year with only one
digit. In order to make this more strict, this fixes a year to be at
least 4 digits. Same applies for month, day, hour, minute, seconds.
Also the new default is `strictDateOptionalTime` for indices created
with Elasticsearch 2.0 or newer.
In addition a couple of not exposed date formats have been exposed, as they
have been mentioned in the documentation.
Closes#6158
Moving the query building functionality from the parser to the builders
new toQuery() method analogous to other recent query refactorings.
Relates to #10217
Currently parsing inner queries can return `null` which leads to unnecessary complicated
null checks further up the query hierarchy. By introducing a special EmptyQueryBuilder
that can be used to signal that this query clause should be ignored upstream where possible,
we can avoid additional null checks in parent query builders and still allow for this query
to be ignored when creating the lucene query later.
This new builder returns `null` when calling its `toQuery()` method, so at this point
we still need to handle it, but having an explicit object for the intermediate query
representation makes it easier to differentiate between cases where inner query clauses are
empty (legal) or are not set at all (illegal).
Also added check for empty inner builder list to BoolQueryBuilder and OrQueryBuilder.
Removed setters for positive/negatice query in favour of constructor with
mandatory non-null arguments in BoostingQueryBuilder.
Closes#11915
Following the discussion in #11744, move boost and query _name to base class AbstractQueryBuilder with their getters and setters. Unify their serialization code and equals/hashcode handling in the base class too. This guarantess that every query supports both _name and boost and nothing needs to be done around those in subclasses besides properly parsing the fields in the parsers and printing them out as part of the doXContent method in the builders. More specifically, these are the performed changes:
- Introduced printBoostAndQueryName utility method in AbstractQueryBuilder that subclasses can use to print out _name and boost in their doXContent method.
- readFrom and writeTo are now final methods that take care of _name and boost serialization. Subclasses have to implement doReadFrom and doWriteTo instead.
- toQuery is a final method too that takes care of properly applying _name and boost to the lucene query. Subclasses have to implement doToQuery instead. The query returned will have boost and queryName applied automatically.
- Removed BoostableQueryBuilder interface, given that every query is boostable after this change. This won't have any negative effect on filters, as the boost simply gets ignored in that case.
- Extended equals and hashcode to handle queryName and boost automatically as well.
- Update the query test infra so that queryName and boost are tested automatically, and whenever they are forgotten in parser or doXContent tests fail, so this makes things a lot less error-prone
- Introduced DEFAULT_BOOST constant to make sure we don't repeat 1.0f all the time for default boost values.
SpanQueryBuilder is again a marker interface only. The convenient toQuery that allowed us to override the return type to SpanQuery cannot be supported anymore due to a clash with the toQuery implementation from AbstractQueryBuilder. We have to go back to castin lucene Query to SpanQuery when dealing with span queries unfortunately.
Note that this change touches not only the already refactored queries but also the untouched ones, by making sure that we parse _name and boost whenever we need to and that we print them out as part of QueryBuilder#doXContent. This will result in printing out the default boost all the time rather than skipping it in non refactored queries, something that we would have changed anyway as part of the query refactoring.
The following are the queries that support boost now while previously they didn't (parser now parses it and builder prints it out): and, exists, fquery, geo_bounding_box, geo_distance, geo_distance_range, geo_hash_cell, geo_polygon, indices, limit, missing, not, or, script, type.
The following are the queries that support _name now while previously they didn't (parser now parses it and builder prints it out): boosting, constant_score, function_score, limit, match_all, type.
Range query parser supports now _name at the same level as boost too (_name is still supported on the outer object though for bw comp).
There are two exceptions that despite have getters and setters for queryName and boost don't really support boost and queryName: query filter and span multi term query. The reason for this is that they only support a single inner object which is another query that they wrap, no other elements.
Relates to #11744Closes#10776Closes#11974
In order to be backwards compatible, indices created before 2.x must support
indexing of a unix timestamp and its configured date format. Indices created
with 2.x must configure the `epoch_millis` date formatter in order to
support this.
Relates #10971
As we now have an enum Operator that comes with many useful helper methods switching to use
that instead of the enums defined separately. Also switches to using the new enum's helper
methods where applicable removing duplicate parsing logic.
This breaks backwards compatibility. Documenting the break in
migrate_query_refactoring.asciidoc
Relates to #10217
This is a follow up to #8143 and #6730 for _timestamp. It removes
support for `path`, as well as any field type settings, and
enables docvalues for _timestamp, for 2.0. Users who need to
adjust these settings can use a date field.
Moving the query building functionality from the parser to the builders
new toQuery() method analogous to other recent query refactorings. In
this case this also includes FQueryFilterParser, since both queries are
closely related.
Relates to #10217Closes#11729
This fixes an issue to allow for negative unix timestamps.
An own printer for epochs instead of just having a parser has been added.
Added docs that only 10/13 length unix timestamps are supported
Added docs in upgrade documentation
Fixes#11478
While we had initially planned to keep rivers around in 2.0 to ease migration,
keeping support for rivers is challenging as it conflicts with other important
changes that we want to bring to 2.0 like synchronous dynamic mappings updates.
Nothing impossible to fix, but it would increase the complexity of how we
deal with dynamic mappings updates and manage rivers, while handling dynamic
mappings updates correctly is important for resiliency and rivers are on the go.
So removing rivers in 2.0 may well be a better trade-off.
The ResourceWatcher used settings prefixed `watcher.`, which
potentially could clash with the watcher plugin.
In order to prevent confusion, the settings have been renamed to
`resource.reload` prefixes.
This also uses the deprecation logging infrastructure introduced
in #11033 to log deprecated settings and their alternative at
startup.
Closes#11175
There are different ways to register custom query parsers through plugins, a couple of them work per index via index settings, which is probably even too flexible. There also three different ways to add a global custom query parser through either IndicesQueriesModule or IndicesQueriesRegistry. This commit consolidates the registration of custom query parsers via IndicesQueriesModule#addQuery(Class<? extends QueryParser>). The complexity of supporting parsers per index is not needed hence it got removed. Also the other ways of registering global custom parsers are dropped in favour of the one mentioned above.
Closes#11481
Some of our meta fields (such as _id, _version, ...) are returned as top-level
properties of the json document, while other properties (_timestamp, _routing,
...) are returned under `fields`. This commit makes all meta fields returned
as top-level properties.
So eg. `GET test/test/1?fields=_timestamp,foo` would now return
```json
{
"_index": "test",
"_type": "test",
"_id": "1",
"_version": 1,
"_timestamp": 10000000,
"found": true,
"fields": {
"foo": [ "bar" ]
}
}
```
while it used to return
```json
{
"_index": "test",
"_type": "test",
"_id": "1",
"_version": 1,
"found": true,
"fields": {
"_timestamp": 10000000,
"foo": [ "bar" ]
}
}
```
* Cut the `has_child` and `has_parent` queries over to use Lucene's query time global ordinal join. The main benefit of this change is that parent/child queries can now efficiently execute if parent/child queries are wrapped in a bigger boolean query. If the rest of the query only hit a few documents both has_child and has_parent queries don't need to evaluate all parent or child documents any more.
* Cut the `_parent` field over to use doc values. This significantly reduces the on heap memory footprint of parent/child, because the parent id values are never loaded into memory.
Breaking changes:
* The `type` option on the `_parent` field can only point to a parent type that doesn't exist yet, so this means that an existing type/mapping can't become a parent type any longer.
* The `has_child` and `has_parent` queries can no longer be use in alias filters.
All these changes, improvements and breaks in compatibility only apply for indices created with ES version 2.0 or higher. For indices creates with ES <= 2.0 the older implementation is used.
It is highly recommended to re-index all your indices with parent and child documents to benefit from all the improvements that come with this refactoring. The easiest way to achieve this is by using the scan and bulk apis using a simple script.
Closes#6107Closes#8134
The count api used to have its own execution path, although it would do the same (up to bugs!) of the search api. This commit makes it a shortcut to the search api with size set to 0. The change is made in a backwards compatible manner, by leaving all of the java api code around too, given that you may not want to get back a whole SearchResponse when asking only for number of hits matching a query, also cause migrating from countResponse.getCount() to searchResponse.getHits().totalHits() doesn't look great from a user perspective. We can always decide to drop more code around the count api if we want to break backwards compatibility on the java api, making it a shortcut on the rest layer only.
Closes#9117Closes#11198
This option is broken currently since it potentially interprets an incoming
binary value as compressed while it just happens that the first bytes are the
same as the LZF header.
Mappings conflicts should not be ignored. If I read the history correctly, this
option was added when a mapping update to an existing field was considered a
conflict, even if the new mapping was exactly the same. Now that mapping updates
are smart enough to detect conflicting options, we don't need an option to
ignore conflicts.
The default `false` for `require_field_match` is a bit odd and confusing for users, given that field names get ignored by default and every field gets highlighted if it contains terms extracted out of the query, regardless of which fields were queries. Changed the default to `true`, it can always be changed per request.
Closes#10627Closes#11067
Our own fork of the lucene PostingsHighlighter is not easy to maintain and doesn't give us any added value at this point. In particular, it was introduced to support the require_field_match option and discrete per value highlighting, used in case one wants to highlight the whole content of a field, but get back one snippet per value. These two features won't
make it into lucene as they slow things down and shouldn't have been supported from day one on our end probably.
One other customization we had was support for a wider range of queries via custom rewrite etc. (yet another way to slow
things down), which got added to lucene and works much much better than what we used to do (instead of or rewrite, term
s are pulled out of the automata for multi term queries).
Removing our fork means the following in terms of features:
- dropped support for require_field_match: the postings highlighter will only highlight fields that were queried
- some custom es queries won't be supported anymore, meaning they won't be highlighted. The only one I found up until now is the phrase_prefix. Postings highlighter rewrites against an empty reader to avoid slow operations (like the ones that we were performing with the fork that we are removing here), thus the prefix will not be expanded to any term. What the postings highlighter does instead is pulling the automata out of multi term queries, but this is not supported at the moment with our MultiPhrasePrefixQuery.
Closes#10625Closes#11077
These clauses filter the document space without affecting scoring and map to
Lucene's BooleanClause.Occur.FILTER. The `filtered` query is now deprecated and
```json
{
"filtered": {
"query": { //query },
"filter": { //filter }
}
}
```
should be replaced with
```json
{
"bool": {
"must": { //query },
"filter": { //filter }
}
}
```
A few meta fields can currently be set within a document's source.
However, the recommended way to set meta fields like this is through
the api, and setting within the document can be a performance trap
(e.g. needing to find _id in order to route the document).
This change removes the ability to set meta fields within
a document source for 2.0+ indexes.
closes#11051closes#11074
As a follow up to #10870, this removes support for
index templates on disk. It also removes a missed
place still allowing disk based mappings.
closes#11052
This commit makes queries and filters parsed the same way using the
QueryParser abstraction. This allowed to remove duplicate code that we had
for similar queries/filters such as `range`, `prefix` or `term`.
Removes the More Like This API, users should now use the More Like This query.
The MLT API tests were converted to their query equivalent. Also some clean
ups in MLT tests.
Closes#10736Closes#11003
Current features (eg. update API) and future features (eg. reindex API)
depend on _source. This change locks down the field so that
it can no longer be disabled. It also removes legacy settings
compress/compress_threshold.
closes#8142closes#10915
This change removes the multiple implementations of different admin interfaces and centralizes it with AbstractClient. It also makes sure *all* executions of actions now go through a single AbstractClient#execute method, taking care of copying headers and wrapping listener.
This also has the side benefit of removing all the code around differnet possible clients, and removes quite a bit of code (most of the + code is actually removal of generics and such).
This change also changes how TransportClient is constructed, requiring a Builder to create it, its a breaking change and its noted in the migration guide.
Yea another step towards simplifying the action infra and making it simpler...
This removes Elasticsearch's filter cache and uses Lucene's instead. It has some
implications:
- custom cache keys (`_cache_key`) are unsupported
- decisions are made internally and can't be overridden by users ('_cache`)
- not only filters can be cached but also all queries that do not need scores
- parent/child queries can now be cached, however cached entries are only
valid for the current top-level reader so in practice it will likely only
be used on read-only indices
- the cache deduplicates filters, which plays nicer with large keys (eg. `terms`)
- better stats: we already had ram usage and evictions, but now also hit count,
miss count, lookup count, number of cached doc id sets and current number of
doc id sets in the cache
- dynamically changing the filter cache size is not supported anymore
Internally, an important change is that it removes the NoCacheFilter infrastructure
in favour of making Query.rewrite specializing the query for the current reader so
that it will only be cached on this reader (look for IndexCacheableQuery).
Note that consuming filters with the query API (createWeight/scorer) instead of
the filter API (getDocIdSet) is important for parent/child queries because
otherwise a QueryWrapperFilter(ParentQuery) would run the wrapped query per
segment while relations might be cross segments.
Using files that must be specified on each node is an anti-pattern
from the API based goal of ES. This change removes the ability
to specify the default mapping with a file on each node.
closes#10620
The assumption is that gaps in histogram are generally undesirable, for instance
if you want to build a visualization from it. Additionally, we are building new
aggregations that require that there are no gaps to work correctly (eg.
derivatives).
this commit removes the obsolete settings for distributors and updates
the documentation on multiple data.path. It also adds an explain to the
migration guide.
Relates to #9498Closes#10770
Regardless of the outcome of #8142, we should at least enforce that
when _source is enabled, it is sufficient to reindex. This change
removes the excludes and includes settings, since these modify
the source, causing us to lose the ability to reindex some fields.
closes#10814
Groovy sandboxing was disabled by default from 1.4.3 on though since we found out that it could be worked around, so it makes little sense to keep it and maintain it.
Closes#10156Closes#10480
This changes the default ranking behaviour of single-term queries on numeric fields to use the usual Lucene TermQuery scoring logic rather than a constant-scoring wrapper.
Closes#10628
Disabling doc values or trying to index hash values are not
correct uses of this the murmur3 field type, and just cause
problems. This disallows changing doc values or index options
for 2.0+.
closes#10465
In Lucene 5.1 lots of filters got deprecated in favour of equivalent queries.
Additionally, random-access to filters is now replaced with approximations on
scorers. This commit
- replaces the deprecated NumericRangeFilter, PrefixFilter, TermFilter and
TermsFilter with NumericRangeQuery, PrefixQuery, TermQuery and TermsQuery,
wrapped in a QueryWrapperFilter
- replaces XBooleanFilter, AndFilter and OrFilter with a BooleanQuery in a
QueryWrapperFilter
- removes DocIdSets.isBroken: the new two-phase iteration API will now help
execute slow filters efficiently
- replaces FilterCachingPolicy with QueryCachingPolicy
Close#8960
This is really a Collector instead of a filter. This commit deprecates the
`limit` filter, makes it a no-op and recommends to use the `terminate_after`
parameter instead that we introduced in the meantime.
Today we check every regular expression eagerly against every possible term.
This can be very slow if you have lots of unique terms, and even the bottleneck
if your query is selective.
This commit switches to Lucene regular expressions instead of Java (not exactly
the same syntax yet most existing regular expressions should keep working) and
uses the same logic as RegExpQuery to intersect the regular expression with the
terms dictionary. I wrote a quick benchmark (in the PR) to make sure it made
things faster and the same request that took 750ms on master now takes 74ms with
this change.
Close#7526
For bacwards compatibility reasons routing_nodes were previously printed out when routing_table was requested, together with the actual routing_table. Now they are printed out only when requests through `routing_nodes` flag.
Relates to #10412Closes#10486
Removed the following methods from `ScriptService`, which don't require the `ScriptContext` argument:
```
public CompiledScript compile(String lang, String script, ScriptType scriptType)
public ExecutableScript executable(String lang, String script, ScriptType scriptType, Map<String, Object> vars)
public SearchScript search(SearchLookup lookup, String lang, String script, ScriptType scriptType, @Nullable Map<String, Object> vars)
```
Also removed the ScriptContext.Standard.GENERIC_PLUGIN enum value, as it was used only for backwards compatibility.
Plugins that make use of scripts should declare their own script contexts through `ScriptModule#registerScriptContext` and use them when compiling/executing scripts.
Closes#10476
This pull request makes boolean handled like dates and ipv4 addresses: things
are stored as as numerics under the hood and aggregations add some special
formatting logic in order to return true/false in addition to 1/0.
For example, here is an output of a terms aggregation on a boolean field:
```
"aggregations": {
"top_f": {
"doc_count_error_upper_bound": 0,
"buckets": [
{
"key": 0,
"key_as_string": "false",
"doc_count": 2
},
{
"key": 1,
"key_as_string": "true",
"doc_count": 1
}
]
}
}
```
Sorted numeric doc values are used under the hood.
Close#4678Close#7851
Now that fine-grained script settings are supported (#10116) we can remove support for the script.disable_dynamic setting.
Same result as `script.disable_dynamic: false` can be obtained as follows:
```
script.inline: on
script.indexed: on
```
An exception is thrown at startup when the old setting is set, so we make sure we tell users they have to change it rather than ignoring the setting.
Closes#10286
This commit brings the benefits of the `count` search type to search requests
that have a `size` of 0:
- a single round-trip to shards (no fetch phase)
- ability to use the query cache
Since `count` now provides no benefits over `query_then_fetch`, it has been
deprecated.
Close#7630
Deleting a type from an index is inherently dangerous because
the type can be recreated with new mappings which may conflict
with existing segments still using the old mappings. This
removes the ability to delete a type (similar to how deleting
fields within a type is not allowed, for the same reason).
closes#8877closes#10231
This commit changes the behaviour of the delete api when processing a delete request that refers to a type that has routing set to required in the mapping, and the routing is missing in the request. Up until now the delete api sent a broadcast delete request to all of the shards that belong to the index, making sure that the document could be found although the routing value wasn't specified. This was probably not the best choice: if the routing is set to required, an error should be thrown instead.
A `RoutingMissingException` gets now thrown instead, like it happens in the same situation with every other api (index, update, get etc.). Last but not least, this change allows to get rid of a couple of `TransportAction`s, `Request`s and `Response`s and simplify the codebase.
Closes#9123Closes#10136
There are two implications to this change.
First, percolator now uses _uid internally, extracting the id portion
when needed. Second, sorting on _id is no longer possible, since you
can no longer index _id. However, _uid can still be used to sort, and
is better anyways as indexing _id just to make it available to
fielddata for sorting is wasteful.
see #8143closes#9842
This change removes the deprecated script parameter names ('file', 'id', and 'scriptField').
It also removes the ability to load file scripts using the 'script' parameter. File scripts should be loaded using the 'script_file' parameter only.
This commit makes the `postings_format` and `doc_values_format` options of
mappings illegal on 2.0 and ignored on 1.x (meaning that the default postings
and doc values formats from the codec will be used in such a case).
This removes a fair amount of code.
Close#8746#9741
Removed the existing `pre_zone` and `post_zone` option in `date_histogram` in favor of
the simpler `time_zone` option. Previously, specifying different values for these could
lead to confusing scenarios where ES would return bucket keys that are not UTC.
Now `time_zone` is the only option setting, the calculation of date buckets to take place in the
preferred time zone, but after rounding converting the bucket key values back to UTC.
Closes#9062Closes#9637
When multiple fields under object fields share the same name, accessing
by short name is ambiguous. This removes support for short names,
always requiring the full name when used in queries.
closes#8872
Add offset option to 'date_histogram' replacing and simplifying the previous 'pre_offset' and 'post_offset' options.
This change is part of a larger clean up task for `date_histogram` from issue #9062.
This change makes the response API object for Histogram Aggregations the same for all types of Histogram, and does the same for all types of Ranges.
The change removes getBucketByKey() from all aggregations except filters and terms. It also reduces the methods on the Bucket class to just getKey() and getKeyAsString().
The getKey() method returns Object and the actual Type is returns will be appropriate for the type of aggregation being run. e.g. date_histogram will return a DateTime for this method and Histogram will return a Number.
Today we give the HTTP status back within the HTTP response itself and within the JSON response as well:
```sh
curl localhost:9200/
```
```js
{
"status" : 200,
"name" : "Red Wolf",
"version" : {
"number" : "2.0.0",
"build_hash" : "6837a61d8a646a2ac7dc8da1ab3c4ab85d60882d",
"build_timestamp" : "2014-08-19T13:55:56Z",
"build_snapshot" : true,
"lucene_version" : "4.9"
},
"tagline" : "You Know, for Search"
}
```
Before Elasticsearch 1.0, the type was allowed to be passed as the root
element when uploading a document. However, this was ambiguous if the
mappings also contained a field with the same name as the type. The
behavior was changed in 1.0 to not allow this, but a setting was added
for backwards compatibility. This change removes the setting for 2.0.
The header indicates to how many shard copies (primary and replicas shards) a write was supposed to go to, to how many
shard copies to write succeeded and potentially captures shard failures if writing into a replica shard fails.
For async writes it also includes the number of shards a write is still pending.
Closes#7994
This is our only cache which is not 'exact' and might allow for stalled results.
Additionally, a similar cache that we have and needs to perform lookups in other
indices in order to run queries is the script index, and for this index we rely
on the filesystem cache, so we should probably do the same with terms filters
lookups.
Close#9056
Related to #8667:
Some QueryBuilders have been deprecated in 1.x branches. We removed them in 2.0.
Removed
-------
* `textPhrase(...)`
* `textPhrasePrefix(...)`
* `textPhrasePrefixQuery(...)`
* `filtered(...)`
* `inQuery(...)`
* `commonTerms(...)`
* `queryString(...)`
* `simpleQueryString(...)`
Closes#8721.
We speak of the term vectors of a document, where each field has an associated
stored term vector. Since by default we are requesting all the term vectors of
a document, the HTTP request endpoint should rather be called `_termvectors`
instead of `_termvector`. The usage of `_termvector` is now deprecated, as
well as the transport client call to termVector and prepareTermVector.
Closes#8484
Previous to this change all features (_alias,_mapping,_settings,_warmer) are run regardless of which features are actually requested. This change fixes the request object to resolve this bug
We currently use the djb2 hash function in order to compute the shard a
document should go to. Unfortunately this hash function is not very
sophisticated and you can sometimes hit adversarial cases, such as numeric ids
on 33 shards.
Murmur3 generates hashes with a better distribution, which should avoid the
adversarial cases.
Here are some examples of how 100000 incremental ids are distributed to shards
using either djb2 or murmur3.
5 shards:
Murmur3: [19933, 19964, 19940, 20030, 20133]
DJB: [20000, 20000, 20000, 20000, 20000]
3 shards:
Murmur3: [33185, 33347, 33468]
DJB: [30100, 30000, 39900]
33 shards:
Murmur3: [2999, 3096, 2930, 2986, 3070, 3093, 3023, 3052, 3112, 2940, 3036, 2985, 3031, 3048, 3127, 2961, 2901, 3105, 3041, 3130, 3013, 3035, 3031, 3019, 3008, 3022, 3111, 3086, 3016, 2996, 3075, 2945, 2977]
DJB: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 900, 900, 900, 900, 1000, 1000, 10000, 10000, 10000, 10000, 9100, 9100, 9100, 9100, 9000, 9000, 0, 0, 0, 0, 0, 0]
Even if djb2 looks ideal in some cases (5 shards), the fact that the
distribution of its hashes has some patterns can raise issues with some shard
counts (eg. 3, or even worse 33).
Some tests have been modified because they relied on implementation details of
the routing hash function.
Close#7954
The MLT field query is simply replaced by a MLT query set to specififc field.
To simplify code maintenance we should deprecate it in 1.4 and remove it in
2.0.
Closes#8238
Returns information about settings, aliases, warmers, and mappings. Basically returns the IndexMetadata. This new endpoint replaces the /{index}/_alias|_aliases|_mapping|_mappings|_settings|_warmer|_warmers and /_alias|_aliases|_mapping|_mappings|_settings|_warmer|_warmers endpoints whilst maintaining the same response formats. The only exception to this is on the /_alias|_aliases|_warmer|_warmers endpoint which will now return a section for 'aliases' or 'warmers' even if no aliases or warmers exist. This backwards compatibility change is documented in the reference docs.
Closes#4069
Martijn van Groningen
Christoph Büscher
Chris Earle
Ryan Ernst
Chris Roche
Igor Motov
Clinton Gormley
Colin Goodheart-Smithe
Jay Modi
jaymode
David Pilato
Alexander Reelsen
javanna
Isabel Drost-Fromm
David Pursehouse
Adrien Grand
Lee Hinman
Jun Ohtani
Alex Ksikes
Pascal Borreli
Shay Banon
Robert Muir
Simon Willnauer
markharwood
Reuben Sutton
Colin Goodheart-Smithe
Christoph Büscher
Karel Minarik