This is a follow-up to some discussions around #36399. Currently we have
relatively confusing compression behavior where compression can be
configured for requests based on transport.compress or a specific
setting for a remote cluster. However, we can only compress responses
based on transport.compress as we do not know where a request is
coming from (currently).
This commit modifies the behavior to NEVER compress responses based on
settings. Instead, a response will only be compressed if the request was
compressed. This commit also updates the documentation to more clearly
described transport level compression.
This commit overhauls the documentation of discovery and cluster coordination,
removing mention of the Zen Discovery module and replacing it with docs for the
new cluster coordination mechanism introduced in 7.0.
Relates #32006
This is related to #36652. In 7.0 we plan to deprecate a number of
settings that make reference to the concept of a tcp transport. We
mostly just have a single transport type now (based on tcp). Settings
should only reference tcp if they are referring to socket options. This
commit updates the settings in the docs. And removes string usages of
the old settings. Additionally it adds a missing remote compress setting
to the docs.
Previously persistent task assignment was checked in the
following situations:
- Persistent tasks are changed
- A node joins or leaves the cluster
- The routing table is changed
- Custom metadata in the cluster state is changed
- A new master node is elected
However, there could be situations when a persistent
task that could not be assigned to a node could become
assignable due to some other change, such as memory
usage on the nodes.
This change adds a timed recheck of persistent task
assignment to account for such situations. The timer
is suspended while checks triggered by cluster state
changes are in-flight to avoid adding burden to an
already busy cluster.
Closes#35792
* Lower fielddata circuit breaker default limit
Lower fielddata circuit breaker default limit from 60% to 40% as we have
moved to doc_values for most of the cases.
* merge master in
* update tests
* update 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
The new limit on the number of open shards in a cluster may be
interpreted by users as a sizing recommendation, but it is not. This
clarifies in the documentation that this is a safety limit, not a
recommendation.
`ScriptDocValues#getValues` was added for backwards compatibility but no
longer needed. Scripts using the syntax `doc['foo'].values` when
`doc['foo']` is a list should be using `doc['foo']` instead.
Closes#22919
This removes the option to run a cluster without enforcing the
cluster-wide shard limit, making strict enforcement the default and only
behavior. The limit can still be adjusted as desired using the cluster
settings API.
This commit adds a rest endpoint for freezing and unfreezing an index.
Among other cleanups mainly fixing an issue accessing package private APIs
from a plugin that got caught by integration tests this change also adds
documentation for frozen indices.
Note: frozen indices are marked as `beta` and available as a basic feature.
Relates to #34352
This changes the current script.max_size_in_bytes to be dynamic so it can be
set through the cluster settings API. This setting is also applied to inline scripts
in the compile method of ScriptService to prevent excessively long inline
scripts from being compiled. The script length limit is removed from Painless as
this is no longer necessary with the protection in compile.
When we connect to remote clusters, there may be a few more routers/firewalls in-between compared to when we connect to nodes in the same cluster. We've experienced cases where firewalls drop connections completely and keep-alives seem not to be enough, or they are not properly configured. With this commit we allow to enable application-level pings specifically from CCS nodes to the selected remote nodes through the new setting `cluster.remote.${clusterAlias}.transport.ping_schedule`. The new setting is similar `transport.ping_schedule` but it does not affect intra-cluster communication, pings are only sent to specific remote cluster when specifically enabled, as they are disabled by default.
Relates to #34405
This change adds a section about the global search setting
`indices.query.bool.max_clause_count` that limits the number of boolean clauses
allowed in a Lucene BooleanQuery.
Closes#19858
In a future major version, we will be introducing a soft limit on the
number of shards in a cluster based on the number of nodes in the
cluster. This limit will be configurable, and checked on operations
which create or open shards and issue a warning if the operation would
take the cluster over the limit.
There is an option to enable strict enforcement of the limit, which
turns the warnings into errors. In a future release, the option will be
removed and strict enforcement will be the default (and only) behavior.
With remote clusters taking on a larger role, we have make the
infrastructure more generic than being tied to cross-cluster search
(CCS). We want to refer to the remote clusters configuration in the
cross-cluster replication (CCR) docs. Yet, these docs are still tied to
CCS. This commit extracts the remote clusters docs from CCS (with some
wording changes to make them more general) so that we can refer to them
in the CCR docs.
As user-defined cluster metadata is accessible to anyone with access to
get the cluster settings, stored in the logs, and likely to be tracked
by monitoring solutions, it is useful to clarify in the documentation
that it should not be used to store secret information.
It is not obvious that a filesystem-level backup may capture an inconsistent
set of files that may fail on restore, or (worse) succeed having silently
discarded some data. This change spells the out, and reorganises the first page
or so of the snapshot/restore docs to make this warning fit more nicely.
This change adds a `_source` only snapshot repository that allows to wrap
any existing repository as a _backend_ to snapshot only the `_source` part
including live docs markers. Snapshots taken with the `source` repository
won't include any indices, doc-values or points. The snapshot will be reduced in size and
functionality such that it requires full re-indexing after it's successfully restored.
The restore process will copy the `_source` data locally starts a special shard and engine
to allow `match_all` scrolls and searches. Any other query, or get call will fail with and unsupported operation exception. The restored index is also marked as read-only.
This feature aims mainly for disaster recovery use-cases where snapshot size is
a concern or where time to restore is less of an issue.
**NOTE**: The snapshot produced by this repository is still a valid lucene index. This change doesn't allow for any longer retention policies which is out of scope for this change.
With features like CCR building on the CCS infrastructure, the settings
prefix search.remote makes less sense as the namespace for these remote
cluster settings than does a more general namespace like
cluster.remote. This commit replaces these settings with cluster.remote
with a fallback to the deprecated settings search.remote.
Adds a place for users to store cluster-wide data they wish to associate
with the cluster via the Cluster Settings API. This is strictly for
user-defined data, Elasticsearch makes no other other use of these
settings.
Today we support a static list of seed hosts in core Elasticsearch, and allow a
dynamic list of seed hosts to be provided via a file using the `discovery-file`
plugin. In fact the ability to provide a dynamic list of seed hosts is
increasingly useful, so this change moves this functionality to core
Elasticsearch to avoid the need for a plugin.
Furthermore, in order to start up nodes in integration tests we currently
assign a known port to each node before startup, which unfortunately sometimes
fails if another process grabs the selected port in the meantime. By moving the
`discovery-file` functionality into the core product we can use it to avoid
this race.
This change also moves the expected path to the file from
`$ES_PATH_CONF/discovery-file/unicast_hosts.txt` to
`$ES_PATH_CONF/unicast_hosts.txt`. An example of this file is not included in
distributions.
For BWC purposes the plugin still exists, but does nothing more than create the
example file in the old location, and issue a warning when it is used. We also
continue to support the old location for the file, but warn about its
deprecation.
Relates #29244Closes#33030
We do not support intra-cluster connections on multiple interfaces, but the
documentation indicates that we will in future. In fact there is currently no
plan to support this, so the forward-looking documentation is misleading. This
commit
- removes the misleading sentence
- fixes that a transport profile affects outbound connections, not inbound ones
- tidies up some nearby text
With this commit we introduce a new circuit-breaking strategy to the parent
circuit breaker. Contrary to the current implementation which only accounts for
memory reserved via child circuit breakers, the new strategy measures real heap
memory usage at the time of reservation. This allows us to be much more
aggressive with the circuit breaker limit so we bump it to 95% by default. The
new strategy is turned on by default and can be controlled with the new cluster
setting `indices.breaker.total.userealmemory`.
Note that we turn it off for all integration tests with an internal test cluster
because it leads to spurious test failures which are of no value (we cannot
fully control heap memory usage in tests). All REST tests, however, will make
use of the real memory circuit breaker.
Relates #31767
So far the in-flight request circuit breaker has only accounted for the
on-the-wire representation of a request. However, we convert the raw
request into XContent internally which increases the overhead.
Therefore, we increase the value of the corresponding setting
`network.breaker.inflight_requests.overhead` from one to two. While this
value is still rather conservative (we assume that the representation as
structured objects has no overhead compared to the byte[]), it is closer
to reality than the current value.
Relates #31613
The documentation for the account circuit breaker listed the settings for it's limit and overhead to be `network.breaker.accounting.limit` and `network.breaker.accounting.overhead` when in `HieratchyCircuitBreakerService` it seems the settings are actually `indices.breaker.accounting.limit` and `indices.breaker.accounting.overhead`.
Include size of snapshot in snapshot metadata
Adds difference of number of files (and file sizes) between prev and current snapshot. Total number/size reflects total number/size of files in snapshot.
Closes#18543
This commit reintroduces 31251c9 and 63a5799. These commits introduced a
memory leak and were reverted. This commit brings those commits back
and fixes the memory leak by removing unnecessary retain method calls.
This reverts commit 31251c9 introduced in #30695.
We suspect this commit is causing the OOME's reported in #30811 and we will use this PR to test this assertion.
This is related to #29500 and #28898. This commit removes the abilitiy
to disable http pipelining. After this commit, any elasticsearch node
will support pipelined requests from a client. Additionally, it extracts
some of the http pipelining work to the server module. This extracted
work is used to implement pipelining for the nio plugin.
This commit removes the http.enabled setting. While all real nodes (started with bin/elasticsearch) will always have an http binding, there are many tests that rely on the quickness of not actually needing to bind to 2 ports. For this case, the MockHttpTransport.TestPlugin provides a dummy http transport implementation which is used by default in ESIntegTestCase.
closes#12792
A NullPointerException is thrown when trying to create or delete
a snapshot in a repository that has been written to by an older
Elasticsearch after writing to it with a newer Elasticsearch version.
This is because the way snapshots are formatted in the repository
snapshots index file changed in #24477.
This commit changes the parsing of the repository index file so that
it now detects a corrupted index file and fails early the snapshot
operation.
closes#29052
This commit renames the bulk thread pool to the write thread pool. This
is to better reflect the fact that the underlying thread pool is used to
execute any document write request (single-document index/delete/update
requests, and bulk requests).
With this change, we add support for fallback settings
thread_pool.bulk.* which will be supported until 7.0.0.
We also add a system property so that the display name of the thread
pool remains as "bulk" if needed to avoid breaking users.
Now that single-document indexing requests are executed on the bulk
thread pool the index thread pool is no longer needed. This commit
removes this thread pool from Elasticsearch.
We want to remove the index thread pool as it is no longer needed since
single-document indexing requests are executed as bulk requests
now. Analyze requests are also executed on the index thread pool though
and they need a thread pool to execute on. The bulk thread does not seem
like the right thread pool, let us keep that thread pool conceptually
for bulk requests and free for bulk requests. None of the existing
thread pools make sense for analyze requests either. The generic thread
pool would be a terrible choice since it has an unbounded queue and that
is a bad idea for user-facing APIs. This commit introduces a small by
default (size=1, queue_size=16) thread pool for analyze requests.
Control max size and count of warning headers
Add a static persistent cluster level setting
"http.max_warning_header_count" to control the maximum number of
warning headers in client HTTP responses.
Defaults to unbounded.
Add a static persistent cluster level setting
"http.max_warning_header_size" to control the maximum total size of
warning headers in client HTTP responses.
Defaults to unbounded.
With every warning header that exceeds these limits,
a message will be logged in the main ES log,
and any more warning headers for this response will be
ignored.
I am not sure why we have this leniency for HTTP max content length, it
has been there since the beginning
(5ac51ee93f) with no explanation of its
source. That said, our philosophy today is different than the philosophy
of the past where Elasticsearch would be quite lenient in its handling
of settings and today we aim for predictability for both users and
us. This commit removes leniency in the parsing of
http.max_content_length.
This commit adds a new setting `cluster.persistent_tasks.allocation.enable`
that can be used to enable or disable the allocation of persistent tasks.
The setting accepts the values `all` (default) or `none`. When set to
none, the persistent tasks that are created (or that must be reassigned)
won't be assigned to a node but will reside in the cluster state with
a no "executor node" and a reason describing why it is not assigned:
```
"assignment" : {
"executor_node" : null,
"explanation" : "persistent task [foo/bar] cannot be assigned [no
persistent task assignments are allowed due to cluster settings]"
}
```
Update allocation awareness docs
Today, the docs imply that if multiple attributes are specified the the
whole combination of values is considered as a single entity when
performing allocation. In fact, each attribute is considered separately. This
change fixes this discrepancy.
It also replaces the use of the term "awareness zone" with "zone or domain", and
reformats some paragraphs to the right width.
Fixes#29105
Values for the network.host setting can often contain a colon which is a
character that is considered special by YAML (these arise in IPv6
addresses and some of the special tags like ":ipv4"). As such, these
values need to be quoted or a YAML parser will be unhappy with
them. This commit adds a note to the docs regarding this.
Cluster settings shouldn't leak into the next test.
I played with failing the test if it left over any settings but that
felt like it added more ceremony then it was worth. The advantage is
that any test that intentionally wants to leave settings in place after
the test would fail and require looking at but, so far as I can tell, we
don't have any such tests.
Clear the disk watermark after the snippet showing users how to set it.
Without this our tests will fail if the disks have less than 10GB free.
Closes#28325
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 accounting circuit breaker and track segment memory usage
This commit adds a new circuit breaker "accounting" that is used for tracking
the memory usage of non-request-tied memory users. It also adds tracking for the
amount of Lucene segment memory used by a shard as a user of the new circuit
breaker.
The Lucene segment memory is updated when the shard refreshes, and removed when
the shard relocates away from a node or is deleted. It should also be noted that
all tracking for segment memory uses `addWithoutBreaking` so as not to fail the
shard if a limit is reached.
The `accounting` breaker has a default limit of 100% and will contribute to the
parent breaker limit.
Resolves#27044
Today Cross Cluster Search requires at least one node in each remote cluster to be up once the cross cluster search is run. Otherwise the whole search request fails despite some of the data (either local and/or remote) is available. This happens when performing the _search/shards calls to find out which remote shards the query has to be executed on. This scenario is different from shard failures that may happen later on when the query is actually executed, in case e.g. remote shards are missing, which is not going to fail the whole request but rather yield partial results, and the _shards section in the response will indicate that.
This commit introduces a boolean setting per cluster called search.remote.$cluster_alias.skip_if_disconnected, set to false by default, which allows to skip certain clusters if they are down when trying to reach them through a cross cluster search requests. By default all clusters are mandatory.
Scroll requests support such setting too when they are first initiated (first search request with scroll parameter), but subsequent scroll rounds (_search/scroll endpoint) will fail if some of the remote clusters went down meanwhile.
The search API response contains now a new _clusters section, similar to the _shards section, that gets returned whenever one or more clusters were disconnected and got skipped:
"_clusters" : {
"total" : 3,
"successful" : 2,
"skipped" : 1
}
Such section won't be part of the response if no clusters have been skipped.
The per cluster skip_unavailable setting value has also been added to the output of the remote/info API.
Removing several occurrences of this typo in the docs and javadocs, seems to be
a common mistake. Corrections turn up once in a while in PRs, better to correct
some of this in one sweep.
The current script service has a script compilation limit for a one
minute window. This is set to a small default value of 15. Instead of
increasing that default value, this commit introduces a new setting
that allows to configure a rate per time unit, so that the script service can deal with bursts better.
The new setting is named `script.max_compilations_rate`,
requires a nonnegative number and a positive time value.
The default is `75/5m`, which is equivalent to the existing 15 per minute.
The names of two settings in the script security docs are incorrect,
referring to the prefix as "scripts" instead of "script". This commit
fixes this issue.
Relates #26236
This commit adds a small note to the discovery docs to include a note
that we recommend that the unicast hosts list be maintained as the list
of master-eligible nodes in the cluster.
Relates #25991
Requests that execute a stored script will no longer be allowed to specify the lang of the script. This information is stored in the cluster state making only an id necessary to execute against. Putting a stored script will still require a lang.
This commit adds cross-settings validation for the low/high/flood stage
disk watermark settings. This validation was enabled by the introduction
of multiple settings validation.
Relates #25600
Today when we run out of disk all kinds of crazy things can happen
and nodes are becoming hard to maintain once out of disk is hit.
While we try to move shards away if we hit watermarks this might not
be possible in many situations. Based on the discussion in #24299
this change monitors disk utilization and adds a flood-stage watermark
that causes all indices that are allocated on a node hitting the flood-stage
mark to be switched read-only (with the option to be deleted). This allows users to react on the low disk
situation while subsequent write requests will be rejected. Users can switch
individual indices read-write once the situation is sorted out. There is no
automatic read-write switch once the node has enough space. This requires
user interaction.
The flood-stage watermark is set to `95%` utilization by default.
Closes#24299
This commit adds a note to the docs regarding explicilty setting a
publish host if the network.host setting results in multiple bind
addresses.
Relates #25496
This commit removes path.conf as a valid setting and replaces it with a
command-line flag for specifying a non-default path for configuration.
Relates #25392
This commit adds back "id" as the key within a script to specify a
stored script (which with file scripts now gone is no longer ambiguous).
It also adds "source" as a replacement for "code". This is in an attempt
to normalize how scripts are specified across both put stored scripts and script usages, including search template requests. This also deprecates the old inline/stored keys.
This PR adds a new thread pool type: `fixed_auto_queue_size`. This thread pool
behaves like a regular `fixed` threadpool, except that every
`auto_queue_frame_size` operations (default: 10,000) in the thread pool,
[Little's Law](https://en.wikipedia.org/wiki/Little's_law) is calculated and
used to adjust the pool's `queue_size` either up or down by 50. A minimum and
maximum is taken into account also. When the min and max are the same value, a
regular fixed executor is used instead.
The `SEARCH` threadpool is changed to use this new type of thread pool. However,
the min and max are both set to 1000, meaning auto adjustment is opt-in rather
than opt-out.
Resolves#3890
In scripts (at least some of the languages), the terms dictionary and
postings can be access with the special _index variable. This is for
very advanced use cases which want to do their own scoring. The problem
is segment level statistics must be recomputed for every document.
Additionally, this is not friendly to the terms index caching as the
order of looking up terms should be controlled by lucene.
This change removes _index from scripts. Anyone using it can and should
instead write a Similarity plugin, which is explicitly designed to allow
doing the calculations needed for a relevance score.
closes#19359
Today when an index is `read-only` the index is also blocked from
being deleted which sometimes is undesired since in-order to make
changes to a cluster indices must be deleted to free up space. This is
a likely scenario in a hosted environment when disk-space is limited to switch
indices read-only but allow deletions to free up space.
This commit documents how to write a `ScriptEngine` in order to use
expert internal apis, such as using Lucene directly to find index term
statistics. These documents prepare the way to remove both native
scripts and IndexLookup.
The example java code is actually compiled and tested under a new gradle
subproject for example plugins. This change does not yet breakup
jvm-example into the new examples dir, which should be done separately.
relates #19359
relates #19966
Currently, the get snapshots API (e.g. /_snapshot/{repositoryName}/_all)
provides information about snapshots in the repository, including the
snapshot state, number of shards snapshotted, failures, etc. In order
to provide information about each snapshot in the repository, the call
must read the snapshot metadata blob (`snap-{snapshot_uuid}.dat`) for
every snapshot. In cloud-based repositories, this can be expensive,
both from a cost and performance perspective. Sometimes, all the user
wants is to retrieve all the names/uuids of each snapshot, and the
indices that went into each snapshot, without any of the other status
information about the snapshot. This minimal information can be
retrieved from the repository index blob (`index-N`) without needing to
read each snapshot metadata blob.
This commit enhances the get snapshots API with an optional `verbose`
parameter. If `verbose` is set to false on the request, then the get
snapshots API will only retrieve the minimal information about each
snapshot (the name, uuid, and indices in the snapshot), and only read
this information from the repository index blob, thereby giving users
the option to retrieve the snapshots in a repository in a more
cost-effective and efficient manner.
Closes#24288
Adds CONSOLE to cross-cluster-search docs but skips them for testing
because we don't have a second cluster set up. This gets us the
`VIEW IN CONSOLE` and `COPY AS CURL` links and makes sure that they
are valid yaml (not json, technically) but doesn't get testing.
Which is better than we had before.
Adds CONSOLE to the dynamic templates docs and ingest-node docs.
The ingest-node docs contain a *ton* of non-console snippets. We
might want to convert them to full examples later, but that can be
a separate thing.
Relates to #18160
This commit adds a link to the minimum master nodes section of the
important settings docs from the Zen discovery docs to clarify the
meaning and importance of setting minimum master nodes to a quorum of
master-eligible nodes.
Relates #24311
I just spent ages debugging a script I wrote after following the documentation. It was not clear to me that _index is not defined when using painless; if it was mentioned on this page I would have saved myself a lot of time.
Drops any mention of non-sandboxed scripting languages other than a
brief "we don't support them and we shouldn't because A and B"
statement.
Relates to #23930
They needed to be updated now that Painless is the default and
the non-sandboxed scripting languages are going away or gone.
I dropped the entire section about customizing the classloader
whitelists. In master this barely does anything (exposes more
things to expressions).
This commit enforces the requirement of Content-Type for the REST layer and removes the deprecated methods in transport
requests and their usages.
While doing this, it turns out that there are many places where *Entity classes are used from the apache http client
libraries and many of these usages did not specify the content type. The methods that do not specify a content type
explicitly have been added to forbidden apis to prevent more of these from entering our code base.
Relates #19388
This commit brings the snapshot documentation in conformity
with the CONSOLE format, and fixes the docs so that the documentation
tests can be run against them.
Painless uses Ruby-like method dispatch (reciever type, method name,
and arity) rather than Java-like (reciever type, method name, and
argument compile time types) or Groovy-like method dispatch (receiver
type, method name, and argument run time types). We do this for
mostly good reasons but we never documented it.
Relates to #22720
Today either all nodes in the cluster connect to remote clusters of only nodes
that have remote clusters configured in their node config. To allow global remote
cluster configuration but restrict connections to a set of nodes in the cluster
this change adds a new setting `search.remote.connect` (defaults to `true`) to allow
to disable remote cluster connections on a per node basis.
This change adds a strict mode for xcontent parsing on the rest layer. The strict mode will be off by default for 5.x and in a separate commit will be enabled by default for 6.0. The strict mode, which can be enabled by setting `http.content_type.required: true` in 5.x, will require that all incoming rest requests have a valid and supported content type header before the request is dispatched. In the non-strict mode, the Content-Type header will be inspected and if it is not present or not valid, we will continue with auto detection of content like we have done previously.
The content type header is parsed to the matching XContentType value with the only exception being for plain text requests. This value is then passed on with the content bytes so that we can reduce the number of places where we need to auto-detect the content type.
As part of this, many transport requests and builders were updated to provide methods that
accepted the XContentType along with the bytes and the methods that would rely on auto-detection have been deprecated.
In the non-strict mode, deprecation warnings are issued whenever a request with body doesn't provide the Content-Type header.
See #19388
Lisa Cawley
Josh Soref
Tim Brooks
David Turner
David Roberts
debadair
Yu
Armin Braun
Jim Ferenczi
Gordon Brown
Jeff Hajewski
Simon Willnauer
Alexander Zhukov
Jack Conradson
Alexandru Rusanescu
Luca Cavanna
Christoph Büscher
Jason Tedor
Or Bin
lipsill
Daniel Mitterdorfer
Colin Goodheart-Smithe
Vladimir Dolzhenko
Lee Jones
Tanguy Leroux
Ryan Ernst
Mayya Sharipova
Yannick Welsch
Ali El broudi
Nik Everett
Peter Dyson
Adrien Grand
Glen Smith
Lee Hinman
Christoph Büscher
Ulrich Reffle
Shubham Aggarwal
Igor Motov
javanna
Clinton Gormley
Anton Pozhidaev
Shane Connelly
Christoph Büscher
marcocova
Alexander Reelsen
Aron Szanto
Herman Schaaf
Robin Clarke
Jack Conradson
Lee Hinman
Chris Ivens
Ali Beyad
Till Backhaus
farisk
Iliiaz Akhmedov
wyukawa
Stefan Gorgiovski
Jay Modi
Boaz Leskes