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
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.
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.
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.
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.
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.
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.
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]"
}
```
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.
* plugins/discovery-azure-class.asciidoc
* reference/cluster.asciidoc
* reference/modules/cluster/misc.asciidoc
* reference/modules/indices/request_cache.asciidoc
After this is merged there will be no unconvereted snippets outside
of `reference`.
Related to #18160
In 7560101ec7, the Elasticsearch logger
names were modified to be their fully-qualified class name (with some
exceptions for special loggers like the slow logs and the transport
tracer). This commit updates the docs accordingly.
Relates #20475
David Roberts
Gordon Brown
Mayya Sharipova
Tanguy Leroux
Simon Willnauer
Nik Everett
Jason Tedor
Ali Beyad
Clinton Gormley