Currently we have a fairly complicated logic in the engine constructor logic to deal with all the
various ways we want to mutate the lucene index and translog we're opening.
We can:
1) Create an empty index
2) Use the lucene but create a new translog
3) Use both
4) Force a new history uuid in all cases.
This leads complicated code flows which makes it harder and harder to make sure we cover all the
corner cases. This PR tries to take another approach. Constructing an InternalEngine always opens
things as they are and all needed modifications are done by static methods directly on the
directory, one at a time.
The current docs on [Indices APIs: PUT Mapping](https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-put-mapping.html) suggests that a having number of different mapping types per index is still possible in elasticsearch versions > 6.0.0 although they have been [removed](https://www.elastic.co/guide/en/elasticsearch/reference/current/removal-of-types.html). The console code has already been updated accordingly but notes (2) and (3) on the console code still name the `user` mapping type.
This PR updates the list with notes after the console code, as well as the first sentence of the docs
to avoid confusion. Also, I have removed the second command from the console code as it no
longer holds any value if the docs are solely on the `_doc` mapping.
Currently the Translog constructor is capable both of opening an existing translog and creating a
new one (deleting existing files). This PR separates these two into separate code paths. The
constructors opens files and a dedicated static methods creates an empty translog.
Allowing `_doc` as a type will enable users to make the transition to 7.0
smoother since the index APIs will be `PUT index/_doc/id` and `POST index/_doc`.
This also moves most of the documentation to `_doc` as a type name.
Closes#27750Closes#27751
Add an index level setting `index.analyze.max_token_count` to control
the number of generated tokens in the _analyze endpoint.
Defaults to 10000.
Throw an error if the number of generated tokens exceeds this limit.
Closes#27038
Today we require users to prepare their indices for split operations.
Yet, we can do this automatically when an index is created which would
make the split feature a much more appealing option since it doesn't have
any 3rd party prerequisites anymore.
This change automatically sets the number of routinng shards such that
an index is guaranteed to be able to split once into twice as many shards.
The number of routing shards is scaled towards the default shard limit per index
such that indices with a smaller amount of shards can be split more often than
larger ones. For instance an index with 1 or 2 shards can be split 10x
(until it approaches 1024 shards) while an index created with 128 shards can only
be split 3x by a factor of 2. Please note this is just a default value and users
can still prepare their indices with `index.number_of_routing_shards` for custom
splitting.
NOTE: this change has an impact on the document distribution since we are changing
the hash space. Documents are still uniformly distributed across all shards but since
we are artificually changing the number of buckets in the consistent hashign space
document might be hashed into different shards compared to previous versions.
This is a 7.0 only change.
This change adds a new `_split` API that allows to split indices into a new
index with a power of two more shards that the source index. This API works
alongside the `_shrink` API but doesn't require any shard relocation before
indices can be split.
The split operation is conceptually an inverse `_shrink` operation since we
initialize the index with a _syntetic_ number of routing shards that are used
for the consistent hashing at index time. Compared to indices created with
earlier versions this might produce slightly different shard distributions but
has no impact on the per-index backwards compatibility. For now, the user is
required to prepare an index to be splittable by setting the
`index.number_of_routing_shards` at index creation time. The setting allows the
user to prepare the index to be splittable in factors of
`index.number_of_routing_shards` ie. if the index is created with
`index.number_of_routing_shards: 16` and `index.number_of_shards: 2` it can be
split into `4, 8, 16` shards. This is an intermediate step until we can make
this the default. This also allows us to safely backport this change to 6.x.
The `_split` operation is implemented internally as a DeleteByQuery on the
lucene level that is executed while the primary shards execute their initial
recovery. Subsequent merges that are triggered due to this operation will not be
executed immediately. All merges will be deferred unti the shards are started
and will then be throttled accordingly.
This change is intended for the 6.1 feature release but will not support pre-6.1
indices to be split unless these indices have been shrunk before. In that case
these indices can be split backwards into their original number of shards.
This commit reformats a paragraph in the template docs to fit in 80
columns as for the rest of the doc, and as-is a standard that we loosely
adhere to.
This commit clarifies the interaction between settings specified in a
create index request, and those that would come from any templates that
apply to the create index request.
Relates #26994
Adds the wait_for_active_shards parameter to the index open command. Similar to the index creation command, the index open command will now, by default, wait until the primaries have been allocated.
Closes#20937
The new ops based recovery, introduce as part of #10708, is based on the assumption that all operations below the global checkpoint known to the replica do not need to be synced with the primary. This is based on the guarantee that all ops below it are available on primary and they are equal. Under normal operations this guarantee holds. Sadly, it can be violated when a primary is restored from an old snapshot. At the point the restore primary can miss operations below the replica's global checkpoint, or even worse may have total different operations at the same spot. This PR introduces the notion of a history uuid to be able to capture the difference with the restored primary (in a follow up PR).
The History UUID is generated by a primary when it is first created and is synced to the replicas which are recovered via a file based recovery. The PR adds a requirement to ops based recovery to make sure that the history uuid of the source and the target are equal. Under normal operations, all shard copies will stay with that history uuid for the rest of the index lifetime and thus this is a noop. However, it gives us a place to guarantee we fall back to file base syncing in special events like a restore from snapshot (to be done as a follow up) and when someone calls the truncate translog command which can go wrong when combined with primary recovery (this is done in this PR).
We considered in the past to use the translog uuid for this function (i.e., sync it across copies) and thus avoid adding an extra identifier. This idea was rejected as it removes the ability to verify that a specific translog really belongs to a specific lucene index. We also feel that having a history uuid will serve us well in the future.
Get mappings HEAD requests incorrectly return a content-length header of
0. This commit addresses this by removing the special handling for get
mappings HEAD requests, and just relying on the general mechanism that
exists for handling HEAD requests in the REST layer.
Relates #23192
This removes the parsing of things like `GET /idx/_aliases,_mappings`, instead,
a user must choose between retriving all index metadata with `GET /idx`, or only
a specific form such as `GET /idx/_settings`.
Relates to (and is a prerequisite of) #24437
The response is attempting to illustrate the sync_id marker, but in
the test the index is too "fresh" to have a sync marker. So the test
needs to execute a sync flush behind the scenes so that the marker
is present
This adds the `index.mapping.single_type` setting, which enforces that indices
have at most one type when it is true. The default value is true for 6.0+ indices
and false for old indices.
Relates #15613
Elasticsearch v5.0.0 uses allocation IDs to safely allocate primary shards whereas prior versions of ES used a version-based mode instead. Elasticsearch v5 still has support for version-based primary shard allocation as it needs to be able to load 2.x shards. ES v6 can drop the legacy support.
This change also removes the reference to the difference bewteen full name and index name.
They are always the same since 2.x and `name` does not refer anymore to `author.name` automatically.
A simple pattern must be used instead.
Remove redundant code that checks the field name twice.
Relates to #22024
On top of documentation, the PR adds deprecation loggers and deals with the resulting warning headers.
The yaml test is set exclude versions up to 6.0. This is need to make sure bwc tests pass until this is backported to 5.2.0 . Once that's done, I will change the yaml test version limits
Today we try to pull stats from index writer but we do not get a
consistent view of stats. Under heavy indexing, this inconsistency can
be very skewed indeed. In particular, it can lead to the number of
deleted docs being reported as negative and this leads to serialization
issues. Instead, we should provide a consistent view of the stats by
using an index reader.
Relates #22317
Today when parsing a stats request, Elasticsearch silently ignores
incorrect metrics. This commit removes lenient parsing of stats requests
for the nodes stats and indices stats APIs.
Relates #21417
* Allows for an array of index template patterns to be provided to an
index template, and rename the field from 'template' to 'index_pattern'.
Closes#20690
Boaz Leskes
Joost Rothweiler
Arne Neumann
Adrien Grand
Mayya Sharipova
Simon Willnauer
Nhat
Jason Tedor
Pius
Alexander Kazakov
Tanguy Leroux
markwalkom
Clinton Gormley
Wesley Merkel
Jun Ohtani
javanna
Sergey Novikov
Lee Hinman
Brian Lesperance
glefloch
Zachary Tong
Zachary Tong
Emir Beganović
Himanshu Bhandoh
Ryan Ernst
Yannick Welsch
Jim Ferenczi
Shubham Aggarwal
Jeffery Bradberry
Sakthipriyan Vairamani
Alexander Lin