A few places in the documentation had mentioned 6.7 as the version to
upgrade from, when doing an upgrade to 7.0. While this is technically
possible, this commit will replace all those mentions to 6.8, as this is
the latest version with the latest bugfixes, deprecation checks and
ugprade assistant features - which should be the one used for upgrades.
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
This adds a `rare_terms` aggregation. It is an aggregation designed
to identify the long-tail of keywords, e.g. terms that are "rare" or
have low doc counts.
This aggregation is designed to be more memory efficient than the
alternative, which is setting a terms aggregation to size: LONG_MAX
(or worse, ordering a terms agg by count ascending, which has
unbounded error).
This aggregation works by maintaining a map of terms that have
been seen. A counter associated with each value is incremented
when we see the term again. If the counter surpasses a predefined
threshold, the term is removed from the map and inserted into a cuckoo
filter. If a future term is found in the cuckoo filter we assume it
was previously removed from the map and is "common".
The map keys are the "rare" terms after collection is done.
Following the removal of the `unzip` package from the Elasticsearch
Docker image in #39040, update setup instructions for TLS in Docker.
Also avoid cross-platform ownership+permission issues by not relying
on local bind mounts for storing generated certs and don't require
`curl` locally installed.
Backport of #43748
Removes the suggestion to use IP addresses for `cluster.initial_master_nodes`
in the "important settings" discovery docs, leaving only the suggestion to use
node names.
Relates #41179, #41569
This commit merges the `object-fields` feature branch. The new 'flattened
object' field type allows an entire JSON object to be indexed into a field, and
provides limited search functionality over the field's contents.
This commit adds a wildcard intervals source, similar to the prefix. It
also changes the term parameter in prefix to read prefix, to bring it
in to line with the pattern parameter in wildcard.
Closes#43198
Currently changing resources (like dictionaries, synonym files etc...) of search
time analyzers is only possible by closing an index, changing the underlying
resource (e.g. synonym files) and then re-opening the index for the change to
take effect.
This PR adds a new API endpoint that allows triggering reloading of certain
analysis resources (currently token filters) that will then pick up changes in
underlying file resources. To achieve this we introduce a new type of custom
analyzer (ReloadableCustomAnalyzer) that uses a ReuseStrategy that allows
swapping out analysis components. Custom analyzers that contain filters that are
markes as "updateable" will automatically choose this implementation. This PR
also adds this capability to `synonym` token filters for use in search time
analyzers.
Relates to #29051
We should throw an exception at construction time if a list of
articles is not provided, otherwise we can get random NPEs during
indexing.
Relates to #43002
It is possible for internal ML indices like `.data-frame-notifications-1` to leak,
causing other docs tests to fail when they accidentally search over these
indices. This PR updates the ignore_above tests to only search a specific index.
This commit adds a prefix intervals source, allowing you to search
for intervals that contain terms starting with a given prefix. The source
can make use of the index_prefixes mapping option.
Relates to #43198
* [ML][Data Frame] Add support for allow_no_match for endpoints (#43490)
* [ML][Data Frame] Add support for allow_no_match parameter in endpoints
Adds support for:
* Get Transforms
* Get Transforms stats
* stop transforms
* Update DataFrameTransformDocumentationIT.java
This change introduces a new setting,
xpack.ml.process_connect_timeout, to enable
the timeout for one of the external ML processes
to connect to the ES JVM to be increased.
The timeout may need to be increased if many
processes are being started simultaneously on
the same machine. This is unlikely in clusters
with many ML nodes, as we balance the processes
across the ML nodes, but can happen in clusters
with a single ML node and a high value for
xpack.ml.node_concurrent_job_allocations.
A voting-only master-eligible node is a node that can participate in master elections but will not act
as a master in the cluster. In particular, a voting-only node can help elect another master-eligible
node as master, and can serve as a tiebreaker in elections. High availability (HA) clusters require at
least three master-eligible nodes, so that if one of the three nodes is down, then the remaining two
can still elect a master amongst them-selves. This only requires one of the two remaining nodes to
have the capability to act as master, but both need to have voting powers. This means that one of
the three master-eligible nodes can be made as voting-only. If this voting-only node is a dedicated
master, a less powerful machine or a smaller heap-size can be chosen for this node. Alternatively, a
voting-only non-dedicated master node can play the role of the third master-eligible node, which
allows running an HA cluster with only two dedicated master nodes.
Closes#14340
Co-authored-by: David Turner <david.turner@elastic.co>
The existing language was misleading about the model snapshots and where they are located. Saying "to disk" sounds like files external to Elasticsearch IMO. It raises the obvious question, where on disk? which node? Is it in the Elasticsearch snapshot repo? The model snapshots are held in an internal index.
* Example of how to set slow logs dynamically per-index
* Make _settings API example more explicit
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
* Add TEST directive to fix CI
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
the geo-bounding-box and phrase-suggest docs were susceptible to
failing due to other indices in the cluster. This change restricts
the queries to the index that is set up for the test.
relates to #43271.
This commit tweaks the docs for secure settings to ensure the user is
aware adding non secure settings to the keystore will result in
elasticsearch not starting.
fixes#43328
Co-Authored-By: James Rodewig <james.rodewig@elastic.co>
Together with types removal, any mention of "fields with the same name in the same index" doesn't make sense anymore.
(cherry picked from commit c5190106cbd4c007945156249cce462956933326)
* [ML][Data Frame] adds new pipeline field to dest config (#43124)
* [ML][Data Frame] adds new pipeline field to dest config
* Adding pipeline support to _preview
* removing unused import
* moving towards extracting _source from pipeline simulation
* fixing permission requirement, adding _index entry to doc
* adjusting for java 8 compatibility
* adjusting bwc serialization version to 7.3.0
These docs were misleading for package installations of
Elasticsearch. Instead, we should refer to $ES_CONFIG/ingest-geoip as
the path to place the custom database files. For non-package
installations, this is the same as $ES_HOME/config, but for package
installations this is not the case as the config directory for package
installations is /etc/elasticsearch, and is not relative to
$ES_HOME. This commit corrects the docs.
* [DOCS] Add introduction to Elasticsearch.
* [DOCS] Incorporated review comments.
* [DOCS] Minor edits to add an abbreviated title and cross refs.
* [DOCS] Added sizing tips & link to quantatative sizing video.
To be consistent with the `search.max_buckets` default setting,
set the hard limit of the PriorityQueue used for in memory sorting,
when sorting on an aggregate function, to 10000.
Fixes: #43168
(cherry picked from commit 079e012fdea68ea0a7daae078359495047e9c407)
The machine learning feature of xpack has native binaries with a
different commit id than the rest of code. It is currently exposed in
the xpack info api. This commit adds that commit information to the ML
info api, so that it may be removed from the info api.
Now emphasises the test is for indexed values.
Previous documentation only mentioned the state of the input JSON doc (null values) but this is only one of several reasons why an indexed value may not exist.
Closes#24256
The description field of xpack featuresets is optionally part of the
xpack info api, when using the verbose flag. However, this information
is unnecessary, as it is better left for documentation (and the existing
descriptions describe anything meaningful). This commit removes the
description field from feature sets.
Rest docs page update
- have the section be on separate pages
- add an Overview page
- add other formats examples
(cherry picked from commit 309bd691ff3f8625f67ca09fc1dd8e265f7e6c92)
* [ML] Adding support for geo_shape, geo_centroid, geo_point in datafeeds
* only supporting doc_values for geo_point fields
* moving validation into GeoPointField ctor
Previously, a reindex request had two different size specifications in the body:
* Outer level, determining the maximum documents to process
* Inside the source element, determining the scroll/batch size.
The outer level size has now been renamed to max_docs to
avoid confusion and clarify its semantics, with backwards compatibility and
deprecation warnings for using size.
Similarly, the size parameter has been renamed to max_docs for
update/delete-by-query to keep the 3 interfaces consistent.
Finally, all 3 endpoints now support max_docs in both body and URL.
Relates #24344
This change adds the earliest and latest timestamps into
the field stats for fields of type "date" in the output of
the ML find_file_structure endpoint. This will enable the
cards for date fields in the file data visualizer in the UI
to be made to look more similar to the cards for date
fields in the index data visualizer in the UI.
Adds a metadata field to snapshots which can be used to store arbitrary
key-value information. This may be useful for attaching a description of
why a snapshot was taken, tagging snapshots to make categorization
easier, or identifying the source of automatically-created snapshots.
The `replace` option in the phonetic token filter can have suprising side
effects, e.g. such as described in #26921. This PR adds a note to be mindful
about such scenarios and offers alternatives to using the `replace` option.
Closes#26921
This commit adds functionality so that aliases that are manipulated on
leader indices are replicated by the shard follow tasks to the follower
indices. Note that we ignore write indices. This is due to the fact that
follower indices do not receive direct writes so the concept is not
useful.
Relates #41815
Adding notes to the existing docs about how using `preference` might increase
request cache utilization but also add warning about the downsides.
Closes#24278
This commit addresses a few more frequently-asked questions:
* clarifies that bootstrapping doesn't happen even after a full cluster
restart.
* removes the example that uses IP addresses, to try and further encourage the
use of node names for bootstrapping.
* clarifies that auto-bootstrapping might form different clusters on different
hosts, and gives a process for starting again if this wasn't what you wanted.
* adds the "do not stop half-or-more of the master-eligible nodes" slogan that
was notably absent.
* reformats one of the console examples to a narrower width
For `multi_match` query: link `boost` param to the generic reference
for query usage and `slop` to the `match_phrase` query where its usage
is documented.
Fixes: #40091
(cherry picked from commit 69993049a8bd9e7f042935729fe69a8266d95a0a)
Add an explanatory NOTE section to draw attention to the difference
between small and capital letters used for the index date patterns.
e.g.: HH vs hh, MM vs mm.
Closes: #22322
(cherry picked from commit c8125417dc33215651f9bb76c9b1ffaf25f41caf)
Fix a couple of wrong links because of the order of the anchor
and the usage of backquotes.
(cherry picked from commit 4e0c6525153b60a57202937c2ae57968c8e35285)
When analysing a semi-structured text file the
find_file_structure endpoint merges lines to form
multi-line messages using the assumption that the
first line in each message contains the timestamp.
However, if the timestamp is misdetected then this
can lead to excessive numbers of lines being merged
to form massive messages.
This commit adds a line_merge_size_limit setting
(default 10000 characters) that halts the analysis
if a message bigger than this is created. This
prevents significant CPU time being spent subsequently
trying to determine the internal structure of the
huge bogus messages.
This PR updates the docs for `docvalue_fields` and `stored_fields` to clarify
that nested fields must be accessed through `inner_hits`. It also tweaks the
nested fields documentation to make this point more visible.
Addresses #23766.
In AsciiDoc, `subs="attributes,callouts,macros"` options were required
to render `include-tagged::` in a code block.
With elastic/docs#827, Elasticsearch Reference documentation migrated
from AsciiDoc to Asciidoctor.
In Asciidoctor, the `subs="attributes,callouts,macros"` options are no
longer needed to render `include-tagged::` in a code block. This commit
removes those unneeded options.
Resolves#41589
Several `ifdef::asciidoctor` conditionals were added so that AsciiDoc
and Asciidoctor doc builds rendered consistently.
With https://github.com/elastic/docs/pull/827, Elasticsearch Reference
documentation migrated completely to Asciidoctor. We no longer need to
support AsciiDoc so we can remove these conditionals.
Resolves#41722
Several `ifdef::asciidoctor` conditionals were added so that AsciiDoc
and Asciidoctor doc builds rendered consistently.
With https://github.com/elastic/docs/pull/827, Elasticsearch Reference
documentation migrated completely to Asciidoctor. We no longer need to
support AsciiDoc so we can remove these conditionals.
Resolves#41722
* Previously, we mentioned multiple times that each nested object was indexed as its own document. This is repetitive, and is also a bit confusing in the context of `index.mapping.nested_fields.limit`, as that applies to the number of distinct `nested` types in the mappings, not the number of nested objects. We now just describe the issue once at the beginning of the section, to illustrate why `nested` types can be expensive.
* Reference the ongoing example to clarify the meaning of the two settings.
Addresses #28363.
Since the max_score optimization landed in Elasticsearch 7,
the CommonTermsQuery is redundant and slower. Moreover the
cutoff_frequency parameter for MatchQuery and MultiMatchQuery
is redundant.
Relates to #27096
(cherry picked from commit 04b74497314eeec076753a33b3b6cc11549646e8)
Both of these classes are basically a bloated wrapper around a simple
construct that can simply be a DirectoryFactory interface. This change
removes both classes and replaces them with a simple stateless interface
that creates a new `Directory` per shard. The concept of `index.store` is preserved
since it makes sense from a configuration perspective.
This change contains a major refactoring of the timestamp
format determination code used by the ML find file structure
endpoint.
Previously timestamp format determination was done separately
for each piece of text supplied to the timestamp format finder.
This had the drawback that it was not possible to distinguish
dd/MM and MM/dd in the case where both numbers were 12 or less.
In order to do this sensibly it is best to look across all the
available timestamps and see if one of the numbers is greater
than 12 in any of them. This necessitates making the timestamp
format finder an instantiable class that can accumulate evidence
over time.
Another problem with the previous approach was that it was only
possible to override the timestamp format to one of a limited
set of timestamp formats. There was no way out if a file to be
analysed had a timestamp that was sane yet not in the supported
set. This is now changed to allow any timestamp format that can
be parsed by a combination of these Java date/time formats:
yy, yyyy, M, MM, MMM, MMMM, d, dd, EEE, EEEE, H, HH, h, mm, ss,
a, XX, XXX, zzz
Additionally S letter groups (fractional seconds) are supported
providing they occur after ss and separated from the ss by a dot,
comma or colon. Spacing and punctuation is also permitted with
the exception of the question mark, newline and carriage return
characters, together with literal text enclosed in single quotes.
The full list of changes/improvements in this refactor is:
- Make TimestampFormatFinder an instantiable class
- Overrides must be specified in Java date/time format - Joda
format is no longer accepted
- Joda timestamp formats in outputs are now derived from the
determined or overridden Java timestamp formats, not stored
separately
- Functionality for determining the "best" timestamp format in
a set of lines has been moved from TextLogFileStructureFinder
to TimestampFormatFinder, taking advantage of the fact that
TimestampFormatFinder is now an instantiable class with state
- The functionality to quickly rule out some possible Grok
patterns when looking for timestamp formats has been changed
from using simple regular expressions to the much faster
approach of using the Shift-And method of sub-string search,
but using an "alphabet" consisting of just 1 (representing any
digit) and 0 (representing non-digits)
- Timestamp format overrides are now much more flexible
- Timestamp format overrides that do not correspond to a built-in
Grok pattern are mapped to a %{CUSTOM_TIMESTAMP} Grok pattern
whose definition is included within the date processor in the
ingest pipeline
- Grok patterns that correspond to multiple Java date/time
patterns are now handled better - the Grok pattern is accepted
as matching broadly, and the required set of Java date/time
patterns is built up considering all observed samples
- As a result of the more flexible acceptance of Grok patterns,
when looking for the "best" timestamp in a set of lines
timestamps are considered different if they are preceded by
a different sequence of punctuation characters (to prevent
timestamps far into some lines being considered similar to
timestamps near the beginning of other lines)
- Out-of-the-box Grok patterns that are considered now include
%{DATE} and %{DATESTAMP}, which have indeterminate day/month
ordering
- The order of day/month in formats with indeterminate day/month
order is determined by considering all observed samples (plus
the server locale if the observed samples still do not suggest
an ordering)
Relates #38086Closes#35137Closes#35132
Downgrading an Elasticsearch node to an earlier version is unsupported, because
we do not make any attempt to guarantee that a node can read any of the on-disk
data written by a future version. Yet today we do not actively prevent
downgrades, and sometimes users will attempt to roll back a failed upgrade with
an in-place downgrade and get into an unrecoverable state.
This change adds the current version of the node to the node metadata file, and
checks the version found in this file against the current version at startup.
If the node cannot be sure of its ability to read the on-disk data then it
refuses to start, preserving any on-disk data in its upgraded state.
This change also adds a command-line tool to overwrite the node metadata file
without performing any version checks, to unsafely bypass these checks and
recover the historical and lenient behaviour.
The date_histogram accepts an interval which can be either a calendar
interval (DST-aware, leap seconds, arbitrary length of months, etc) or
fixed interval (strict multiples of SI units). Unfortunately this is inferred
by first trying to parse as a calendar interval, then falling back to fixed
if that fails.
This leads to confusing arrangement where `1d` == calendar, but
`2d` == fixed. And if you want a day of fixed time, you have to
specify `24h` (e.g. the next smallest unit). This arrangement is very
error-prone for users.
This PR adds `calendar_interval` and `fixed_interval` parameters to any
code that uses intervals (date_histogram, rollup, composite, datafeed, etc).
Calendar only accepts calendar intervals, fixed accepts any combination of
units (meaning `1d` can be used to specify `24h` in fixed time), and both
are mutually exclusive.
The old interval behavior is deprecated and will throw a deprecation warning.
It is also mutually exclusive with the two new parameters. In the future the
old dual-purpose interval will be removed.
The change applies to both REST and java clients.
This commit updates the default ciphers and TLS protocols that are used
when the runtime JDK supports them. New cipher support has been
introduced in JDK 11 and 12 along with performance fixes for AES GCM.
The ciphers are ordered with PFS ciphers being most preferred, then
AEAD ciphers, and finally those with mainstream hardware support. When
available stronger encryption is preferred for a given cipher.
This is a backport of #41385 and #41808. There are known JDK bugs with
TLSv1.3 that have been fixed in various versions. These are:
1. The JDK's bundled HttpsServer will endless loop under JDK11 and JDK
12.0 (Fixed in 12.0.1) based on the way the Apache HttpClient performs
a close (half close).
2. In all versions of JDK 11 and 12, the HttpsServer will endless loop
when certificates are not trusted or another handshake error occurs. An
email has been sent to the openjdk security-dev list and #38646 is open
to track this.
3. In JDK 11.0.2 and prior there is a race condition with session
resumption that leads to handshake errors when multiple concurrent
handshakes are going on between the same client and server. This bug
does not appear when client authentication is in use. This is
JDK-8213202, which was fixed in 11.0.3 and 12.0.
4. In JDK 11.0.2 and prior there is a bug where resumed TLS sessions do
not retain peer certificate information. This is JDK-8212885.
The way these issues are addressed is that the current java version is
checked and used to determine the supported protocols for tests that
provoke these issues.
Adds a note that restarting half-or-more of the master-eligible nodes means
you're no longer doing a rolling upgrade, and may need to upgrade all the
things before the cluster returns to health.
Configurations are stored in the .data-frame-internal-1
index, but users should not add configurations directly to
the index as additional information to enable access control
is added. This adds a warning against allowing access to the
internal index.
The migrate tool was added when the native realm was created, to aid
users in converting from file realms that were per node, into the
cluster managed native realm. While this tool was useful at the time,
users should now be using the native realm directly. This commit
deprecates the tool, to be removed in a followup for 8.0.
Adds an initial limited implementations of geo features to SQL. This implementation is based on the [OpenGIS® Implementation Standard for Geographic information - Simple feature access](http://www.opengeospatial.org/standards/sfs), which is the current standard for GIS system implementation. This effort is concentrate on SQL option AKA ISO 19125-2.
Queries that are supported as a result of this initial implementation
Metadata commands
- `DESCRIBE table` - returns the correct column types `GEOMETRY` for geo shapes and geo points.
- `SHOW FUNCTIONS` - returns a list that includes supported `ST_` functions
- `SYS TYPES` and `SYS COLUMNS` display correct types `GEO_SHAPE` and `GEO_POINT` for geo shapes and geo points accordingly.
Returning geoshapes and geopoints from elasticsearch
- `SELECT geom FROM table` - returns the geoshapes and geo_points as libs/geo objects in JDBC or as WKT strings in console.
- `SELECT ST_AsWKT(geom) FROM table;` and `SELECT ST_AsText(geom) FROM table;`- returns the geoshapes ang geopoints in their WKT representation;
Using geopoints to elasticsearch
- The following functions will be supported for geopoints in queries, sorting and aggregations: `ST_GeomFromText`, `ST_X`, `ST_Y`, `ST_Z`, `ST_GeometryType`, and `ST_Distance`. In most cases when used in queries, sorting and aggregations, these function are translated into script. These functions can be used in the SELECT clause for both geopoints and geoshapes.
- `SELECT * FROM table WHERE ST_Distance(ST_GeomFromText(POINT(1 2), point) < 10;` - returns all records for which `point` is located within 10m from the `POINT(1 2)`. In this case the WHERE clause is translated into a range query.
Limitations:
Geoshapes cannot be used in queries, sorting and aggregations as part of this initial effort. In order to fully take advantage of geoshapes we would need to have access to geoshape doc values, which is coming in #37206. `ST_Z` cannot be used on geopoints in queries, sorting and aggregations since we don't store altitude in geo_point doc values.
Relates to #29872
Backport of #42031
This commit slightly reworks the recommendations in the docs about setting the
heap size:
* the "rules of thumb" are actually instructions that should be followed
* the reason for setting `Xmx` to 50% of the heap size is more subtle than just
leaving space for the filesystem cache
* it is normal to see Elasticsearch using more memory than `Xmx`
* replace `cutoff` and `limit` with `threshold` since all three terms are used
interchangeably
* since we recommend setting `Xmx` equal to `Xms`, avoid talking about setting
`Xmx` in isolation
Relates #41954
This processor uses the lucene HTMLStripCharFilter class to remove HTML
entities from a field. This adds to the char filter, so that there is
possibility to store the stripped version as well.
Note, that the characeter filter replaces tags with a newline, so that
the produced HTML will look slightly different than the incoming HTML
with regards to newlines.
The `bulk` threadpool is now called `write`, but `bulk` is still
used in some examples. This commit fixes that.
Also, the only way `threadpool.bulk.write: 30` is a valid increase in the size
of this threadpool is if you have 29 processors, which is an odd number of
processors to have. This commit removes the "more threads" bit.
In cases where node names and transport addresses can be muddled, it is unclear
that `cluster.initial_master_nodes: master-a:9300` means to look for a node
called `master-a:9300` rather than a node called `master-a` with transport port
`9300`. This commit adds docs to that effect.
Today Elasticsearch accepts, but silently ignores, port ranges in the
`discovery.seed_hosts` setting:
```
discovery.seed_hosts: 10.1.2.3:9300-9400
```
Silently ignoring part of a setting like this is trappy. With this change we
reject seed host addresses of this form.
Closes#40786
Backport of #41404
The settings listed under the "Default values for TLS/SSL settings"
heading are not actual settings, rather they are common suffixes that
are used for settings that exist in a variety of contexts.
This commit changes the way they are presented to reduce this
confusion.
Backport of: #41779
The CircuitBreaker was introduced as means of preventing a
`StackOverflowException` during the build of the AST by the parser.
The ANTLR4 grammar causes a weird behaviour for a Parser Listener.
The `enterEveryRule()` method is often called with a different parsing
context than the respective `exitEveryRule()`. This makes it difficult
to keep track of the tree's depth, and a custom Map was used as an
attempt of matching the contextes as they are encounter during `enter`
and during `exit` of the rules.
This approach had 2 important drawbacks:
1. It's hard to maintain this custom Map as the grammar changes.
2. The CircuitBreaker could often lead to false positives which caused
valid queries to return an Exception and prevent them from executing.
So, this removes completely the CircuitBreaker which is replaced be
a simple handling of the `StackOverflowException`
Fixes: #41471
(cherry picked from commit 1559a8e2dbd729138b52e89b7e80264c9f4ad1e7)
The `path_match` and `path_unmatch` parameters in dynamic templates match on
object fields in addition to leaf fields. This is not obvious and can cause
surprising errors when a template is meant for a leaf field, but there are
object fields that match. This PR adds a note to the docs to describe the
current behavior.
We received some feedback that it is not completely clear why `_doc` is present
in the typeless document APIs:
> The new index APIs are PUT {index}/_doc/{id} in case of explicit ids and POST
{index}/_doc for auto-generated ids."_ Isn't this contradicting? Specifying
*types in requests is deprecated*, but we are supposed to still mention *_doc*
in write requests?
This PR updates the 'removal of types' documentation to try to clarify that
`_doc` now represents the endpoint name, as opposed to a type.
Add a TIP on how to use CASE to achieve custom bucketing
with GROUP BY.
Follows: #41349
(cherry picked from commit eb5f5d45533c5f81e57dd0221d902a73ec400098)
As negative scores will now cause an error, and it is easy to
accidentally produce negative scores with some of the built-in modifiers
(especially `ln` and `log`), this adjusts the documentation to more
strongly recommend the use of `ln1p` and `log1p` instead.
Also corrects some awkward formatting on the note sections following the
table.
Today's `docker-compose` docs are missing the `discovery.seed_nodes` config on
one of the nodes. With today's configuration the cluster can still form the
first time it is started, because `cluster.initial_master_nodes` requires both
nodes to bootstrap the cluster which ensures that each discover the other.
However if `es02` is elected master it will remove `es01` from the voting
configuration and then when restarted it will form a cluster on its own without
needing to do any discovery. Meanwhile `es01` doesn't know how to find `es02`
after a restart so will be unable to join this cluster.
This commit fixes this by adding the missing configuration.
Relates #41394, which fixes a different `docker-compose.yml` in the same way.