When using LVM or software raid on Linux the kernel, or specific
distribution rules, may use higher ergonomic defaults for the
readahead of resulting block device(s). This can adversely affect
search performance due to high page cache thrashing, in search
heavy scenarios when mmap is involved.
Add a clarification section in the docs raising awareness about this
value and preferring the lower default.
Asciidoc source blocks are to be delimited with four dashes. This adds missing delimiters, and updates some that contained only three dashes. It matters for parsing purposes.
(cherry picked from commit 5ef77ef370)
Co-authored-by: edh-oss <42759970+edh-oss@users.noreply.github.com>
Today the _Size your shards_ docs focus on shard size and count, but in
fact index count and field count are also important. This commit expands
these docs a bit to cover this observation too.
Today we indicate that the `unassigned.reason` field in various APIs
indicates the reason why a shard is unassigned. This isn't really true,
it tells you some information about the event that caused the shard to
_become_ unassigned (or which most recently changed its routing table
entry while remaining unassigned) but tells you almost nothing about why
the shard _is now_ unassigned and how to fix it. That's what the
allocation explain API is for. This commit clarifies this point in the
docs.
Closes#80892
Co-authored-by: James Rodewig <james.rodewig@elastic.co>
Co-authored-by: James Rodewig <james.rodewig@elastic.co>
This PR changes uses of transient cluster settings to
persistent cluster settings.
The PR also deprecates the transient settings usage.
Relates to #49540
In production, we recommend you run {es} on a dedicated host or as a primary service.
This adds that best practice to our setup documentation.
Co-authored-by: James Rodewig <40268737+jrodewig@users.noreply.github.com>
Co-authored-by: Stef Nestor <steffanie.nestor@gmail.com>
The current shrink API snippet doesn't show you how to remove replicas or reduce primary shards.
Rather than duplicate those instructions from the shrink API docs, this removes the snippet. A link to the shrink API and shrink ILM action docs is already provided.
It also updates a delete index API snippet to avoid wildcards. Wildcard expansion for the delete index API is disabled by default in 8.0.
Changes:
* Adds a troubleshooting section and documents the `maximum shards open` error.
* Retitles the `Fix an oversharded cluster` to `Reduce a cluster's shard count`.
Co-authored-by: James Rodewig <40268737+jrodewig@users.noreply.github.com>
Co-authored-by: Stef Nestor <steffanie.nestor@gmail.com>
* Mention match_only_text in disk usage docs
Previously we explained how to manually disable norms, freqs, and positions. We
now have a ready-made solution in the new `match_only_text` field type.
* Fixing typo and minor grammar changes
Co-authored-by: Adam Locke <adam.locke@elastic.co>
Co-authored-by: Adam Locke <adam.locke@elastic.co>
On the "Size your shards" page, the shard size recommendation assumes a time
series use case. Similarly, users shouldn't count nearly empty and rarely used
Enterprise Search system indices against the recommended shard count limit.
Closes#76328.
Changes:
* Revises the size your shards guide to use a 50GB shard guideline. This better aligns with our default in the ILM policy UI.
* Updates the language to indicate that the 50GB shard guideline is not a hard limit. Larger shards may work depending on the network and use case.
Reverts some changes added in #71367.
We mention Elasticsearch returns 429 if the circuit breaker trips in https://www.elastic.co/blog/improving-node-resiliency-with-the-real-memory-circuit-breaker, but there is no mention in the docs.
This adds an xref to circuit breaker errors section.
Co-authored-by: James Rodewig <40268737+jrodewig@users.noreply.github.com>
Co-authored-by: Luca Belluccini <luca.belluccini@elastic.co>
Today's network config docs are split into "Network", "HTTP" and
"Transport" pages, with unclear relationships between them. We often
encounter users with weird configs that indicate they don't really
understand how these settings all relate. In fact these pages are all
very interrelated, and the HTTP and Transport pages are almost all only
for advanced users. This commit brings these docs into a single page and
rewords some things to try and guide users away from the advanced
settings unless their configuration needs all the extra complexity.
It also adds a section entitled "Binding and publishing" which clarifies
the meanings of the `bind_host` and `publish_host` parameters. This is
also a common source of confusion amongst users.
It also clarifies that many of these settings accept a list of
addresses, and warns that this may not be what you want. Closes#67956.
Co-authored-by: Adam Locke <adam.locke@elastic.co>
* Clarify that field data cache includes global ordinals
* Describe that the cache should be cleared once the limit is reached
* Clarify that the `_id` field does not supported aggregations anymore
* Fold the `fielddata` mapping parameter page into the `text field docs
* Improve cross-linking
Revises the current 'How to avoid oversharding' docs to incorporate
information from our [shard sizing blog post][0].
Changes:
* Streamlines introduction
* Adds "Things to remember" section to describe how shards work
* Adds "Guidelines" section based on blog tips
* Creates a "Fix an oversharded cluster" section
[0]: https://www.elastic.co/blog/how-many-shards-should-i-have-in-my-elasticsearch-cluster
Changes:
* Moves `Retrieve selected fields` to its own page and adds a title abbreviation.
* Adds existing script and stored fields content to `Retrieve selected fields`
* Adds a xref for `Retrieve selected fields` to `Search your data`
* Adds related redirects and updates existing xrefs
