Some of these characters are special to Asciidoctor and they ruin the
rendering on this page. Instead, we use a macro to passthrough these
characters without Asciidoctor applying any subtitutions to them. This
commit then addresses some rendering issues in the thread pool docs.
Co-authored-by: James Rodewig <james.rodewig@elastic.co>
The use of available processors, the terminology, and the settings
around it have evolved over time. This commit cleans up some places in
the codes and in the docs to adjust to the current terminology.
The `indices.recovery.max_bytes_per_sec` recovery bandwidth limit can differ
between nodes if it is not set dynamically, but today this is not obvious. This
commit adds a paragraph to its documentation clarifying how to set different
bandwidth limits on each node.
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
It is useful to be able to delay state recovery until enough data nodes have
joined the cluster, since this gives the shard allocator a decent opportunity
to re-use as much existing data as possible. However we also have the option to
delay state recovery until a certain number of master-eligible nodes have
joined, and this is unnecessary: we require a majority of master-eligible nodes
for state recovery, and there is no advantage in waiting for more.
This commit deprecates the unnecessary settings in preparation for their
removal.
Relates #51806
The introductory sections of the reference manual contains some simplified
instructions for adding a node to the cluster. Unfortunately they are a little
too simplified and only really work for clusters running on `localhost`. If you
try and follow these instructions for a distributed cluster then the new node
will, confusingly, auto-bootstrap itself into a distinct one-node cluster.
Multiple nodes running on localhost is a valid config, of course, but we should
spell out that these instructions are really only for experimentation and that
it takes a bit more work to add nodes to a distributed cluster. This commit
does so.
Also, the "important config" instructions for discovery say that you MUST set
`discovery.seed_hosts` whereas in fact it is fine to ignore this setting and
use a dynamic discovery mechanism instead. This commit weakens this statement
and links to the docs for dynamic discovery mechanisms.
Finally, this section is also overloaded with some technical details that are
not important for this context and are adequately covered elsewhere, and
completely fails to note that the default discovery port is 9300. This commit
addresses this.
Explicitly notes the Elasticsearch API endpoints that support CCS.
This should deter users from attempting to use CCS with other API
endpoints, such as `GET <index>/_doc/<_id>`.
Updates the cross-cluster search (CCS) documentation to note how
cluster-level settings are applied.
When `ccs_minimize_roundtrips` is `true`, each cluster applies its own
cluster-level settings to the request.
When `ccs_minimize_roundtrips` is `false`, cluster-level settings for
the local cluster is used. This includes shard limit settings, such as
`action.search.shard_count.limit`, `pre_filter_shard_size`, and
`max_concurrent_shard_requests`. If these limits are set too low, the
request could be rejected.
Today we use `cluster.join.timeout` to prevent nodes from waiting indefinitely
if joining a faulty master that is too slow to respond, and
`cluster.publish.timeout` to allow a faulty master to detect that it is unable
to publish its cluster state updates in a timely fashion. If these timeouts
occur then the node restarts the discovery process in an attempt to find a
healthier master.
In the special case of `discovery.type: single-node` there is no point in
looking for another healthier master since the single node in the cluster is
all we've got. This commit suppresses these timeouts and instead lets the node
wait for joins and publications to succeed no matter how long this might take.
Synced flush was a brilliant idea. It supports instant recoveries with a
quite small implementation. However, with the presence of sequence
numbers and retention leases, it is no longer needed. This change
removes it from 8.0.
Relates #5077
* Creates a prerequisites section in the cross-cluster replication (CCR)
overview.
* Adds concise definitions for local and remote cluster in a CCR context.
* Documents that the ES version of the local cluster must be the same
or a newer compatible version as the remote cluster.
The "Restore any snapshots as required" step is a trap: it's somewhere between
tricky and impossible to restore multiple clusters into a single one.
Also add a note about configuring discovery during a rolling upgrade to
proscribe any rare cases where you might accidentally autobootstrap during the
upgrade.
The docs specify that cluster.remote.connect disables cross-cluster
search. This is correct, but not fully accurate as it disables any
functionality that relies on remote cluster connections: cross-cluster
search, remote data feeds, and cross-cluster replication. This commit
updates the docs to reflect this.
Today the docs say that the low watermark has no effect on any shards that have
never been allocated, but this is confusing. Here "shard" means "replication
group" not "shard copy" but this conflicts with the "never been allocated"
qualifier since one allocates shard copies and not replication groups.
This commit removes the misleading words. A newly-created replication group
remains newly-created until one of its copies is assigned, which might be quite
some time later, but it seems better to leave this implicit.
Clarifies not to set `cluster.initial_master_nodes` on nodes that are joining
an existing cluster.
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
Setting `cluster.routing.allocation.disk.include_relocations` to `false` is a
bad idea since it will lead to the kinds of overshoot that were otherwise fixed
in #46079. This setting was deprecated in #47443. This commit removes it.
Setting `cluster.routing.allocation.disk.include_relocations` to `false` is a
bad idea since it will lead to the kinds of overshoot that were otherwise fixed
in #46079. This commit deprecates this setting so it can be removed in the next
major release.
We added docs for proxy mode in #40281 but on reflection we should not be
documenting this setting since it does not play well with all proxies and we
can't recommend its use. This commit removes those docs and expands its Javadoc
instead.
The changes in #32006 mean that the discovery process can no longer use
master-ineligible nodes as a stepping-stone between master-eligible nodes.
This was normally an indication of a strange and possibly-fragile configuration
and was not recommended. This commit clarifies that only master-eligible nodes
are now involved with discovery.
