Today Elasticsearch can act as a tribe node that fully joins another cluster to support operations across all different clusters. While tribe is a popular feature it also has it's downsides like:
* non-trivial testing
* special configuration
* receives a non trivial amount of cluster-state updates
* maintains connections to all nodes in all clusters and vice versa
* has to be restarted to join another cluster
* needs special strategies to disambiguate indices with identical names
That said, from a functionality standpoint the only feature in elasticsearch that needs cross cluster communication is in-fact the search layer. Everything else can be done on the client side by communicating with each cluster individually. For `_search` the merge of aggregations etc. is non trivial and can't be done on the client side.
The feature added in this PR is called `cross cluster search` and allows any node to act as a federated search node without joining any of the other clusters. There are 2 basic modes of operations:
* globally configured remote clusters via cluster state settings
* locally configured remote clusters via elasticsearch.yaml
A node with such a configuration will `connect` to the remote cluster and discover a set of nodes that it can communicate with for federated search (Default # of nodes is 3). It won't connect to all nodes but only eligible nodes in the remote cluster (depending on their version and optionally on a node attribute (`node.addr`).
Remote clusters can be configured and updated at any time via cluster settings without the need of a node-restart. Each remote cluster specified via a `name` -> `seed node IP list` ie:
* `search.remote.my_cluster.seeds: 127.0.0.1:9300, 127.0.0.1:9301`
indices of this cluster can then be addressed via the clusters alias: `GET index_1,my_cluster:index_1, my_cluster:other*/_search`
Closes#21473
This change makes it possible for custom routing values to go to a subset of shards rather than
just a single shard. This enables the ability to utilize the spatial locality that custom routing can
provide while mitigating the likelihood of ending up with an imbalanced cluster or suffering
from a hot shard.
This is ideal for large multi-tenant indices with custom routing that suffer from one or both of
the following:
- The big tenants cannot fit into a single shard or there is so many of them that they will likely
end up on the same shard
- Tenants often have a surge in write traffic and a single shard cannot process it fast enough
Beyond that, this should also be useful for use cases where most queries are done under the context
of a specific field (e.g. a category) since it gives a hint at how the data can be stored to minimize
the number of shards to check per query. While a similar solution can be achieved with multiple
concrete indices or aliases per value today, those approaches breakdown for high cardinality fields.
A partitioned index enforces that mappings have routing required, that the partition size does not
change when shrinking an index (the partitions will shrink proportionally), and rejects mappings
that have parent/child relationships.
Closes#21585
This commit corrects the grammar in a list in the how-to docs; namely,
the word "and" was missing preceding the final element in a list.
Relates #22663
Instead of forcing each task to register all nodes where its children are running, this commit runs cancellation on all nodes. The task cancellation operation doesn't run too frequently, so this optimization doesn't seem to be worth additional complexity of the interface.
The extra plugins that may be attached to the elasticsearch build
contain their own license. In the past, the ASL license elasticsearch
uses was avoided by specially checking for the gradle project prefix of
`:x-plugins`. However, since refactoring to the elasticsearch-extra dir
structure, this mechanism was broken. This change fixes the pom license
adding to only be applied to projects that fall under the root project
(ie elasticsearch).
* Grammatical correction
* Add note for legacy string mapping type
* Update truncate token filter to not mention the keyword tokenizer
The advice predates the existence of the keyword field
Closes#22650
Previously, certain settings that could take multiple comma delimited
values would pick up incorrect values for all entries but the first if
each comma separated value was followed by a whitespace character. For
example, the multi-value "A,B,C" would be correctly parsed as
["A", "B", "C"] but the multi-value "A, B, C" would be incorrectly parsed
as ["A", " B", " C"].
This commit allows a comma separated list to have whitespace characters
after each entry. The specific settings that were affected by this are:
cluster.routing.allocation.awareness.attributes
index.routing.allocation.require.*
index.routing.allocation.include.*
index.routing.allocation.exclude.*
cluster.routing.allocation.require.*
cluster.routing.allocation.include.*
cluster.routing.allocation.exclude.*
http.cors.allow-methods
http.cors.allow-headers
For the allocation filtering related settings, this commit also provides
validation of each specified entry if the filtering is done by _ip,
_host_ip, or _publish_ip, to ensure that each entry is a valid IP
address.
Closes#22297
This commit tries to simplify the way ElasticsearchException are rendered to xcontent. It adds some documentation and renames and merges some methods. Current behavior is preserved, the goal is to be more readable and centralize everything in the ElasticsearchException class.
`EngineClosedException` is a ES level exception that is used to indicate that the engine is closed when operation starts. It doesn't really add much value and we can use `AlreadyClosedException` from Lucene (which may already bubble if things go wrong during operations). Having two exception can just add confusion and lead to bugs, like wrong handling of `EngineClosedException` when dealing with document level failures. The latter was exposed by `IndexWithShadowReplicasIT`.
This PR also removes the AwaitFix from the `IndexWithShadowReplicasIT` tests (which was what cause this to be discovered). While debugging the source of the issue I found some mismatches in document uid management in the tests. The term that was passed to the engine didn't correspond to the uid in the parsed doc - those are fixed as well.
Today we have quite some abstractions that are essentially providing a simple
dispatch method to the plugins defining a `HttpServerTransport`. This commit
removes `HttpServer` and `HttpServerAdaptor` and introduces a simple `Dispatcher` functional
interface that delegate to `RestController` by default.
Relates to #18482
All the language clients support a special ignore parameter that doesn't get passed to elasticsearch with the request, but used to indicate which error code should not lead to an exception if returned for a specific request.
Moving this to the low level REST client will allow the high level REST client to make use of it too, for instance so that it doesn't have to intercept ResponseExceptions when the get api returns a 404.
This is related to #22116. A number of modules (reindex, etc) use the
rest client. The rest client opens connections using the apache http
client. To avoid throwing SecurityException when using the
SecurityManager these operations must be privileged. This is tricky
because connections are opened within the httpclient code on its
reactor thread. The way I confronted this was to wrap the creation
of the client (and creation of reactor thread) in a doPrivileged
block. The new thread inherits the existing security context.
#22025 deprecated this setting (pending it's removal) but it's frequent usage will spam the deprecation logs and also fails test. As temporary work around we should not use the setting object directly.
Currently both ProfileResult and CollectorResult print the time field in a human readable string format
(e.g. "time": "55.20315000ms"). When trying to parse this back to a long value, for example to use in
the planned high level java rest client, we can lose precision because of conversion and rounding issues.
This change adds a new additional field (`time_in_nanos`) to the profile response to be able to get the
original time value in nanoseconds back.
The old `time` field is only printed when the `?`human=true` flag in the url is set. This follow the behaviour for
all other stats-related apis. Also the format of the `time` field is slightly changed. Instead of always formatting
the output as a 10-digit ms value, by using the `XContentBuilder#timeValueField()` method we now print
the largest time unit present is used (e.g. "s", "ms", "micros").
An operation that completed successfully on a primary can result in a
version conflict on a replica due to the asynchronous nature of
operations. When a replica operation results in a version conflict, the
operation is not added to the translog. This leads to gaps in the
translog which is problematic as it can lead to situations where a
replica shard can never advance its local checkpoint. As such operations
are just normal course of business for a replica shard, these operations
should be treated as if they completed successfully. This commit adds
these operations to the translog.
Relates #22626
For certain situations, end-users need the base path for Elasticsearch
logs. Exposing this as a property is better than hard-coding the path
into the logging configuration file as otherwise the logging
configuration file could easily diverge from the Elasticsearch
configuration file. Additionally, Elasticsearch will only have
permissions to write to the log directory configured in the
Elasticsearch configuration file. This commit adds a property that
exposes this base path.
One use-case for this is configuring a rollover strategy to retain logs
for a certain period of time. As such, we add an example of this to the
documentation.
Additionally, we expose the property es.logs.cluster_name as this is
used as the name of the log files in the default configuration.
Finally, we expose es.logs.node_name in cases where node.name is
explicitly set in case users want to include the node name as part of
the name of the log files.
Relates #22625
When logger.level is set, we end up configuring a logger named "level"
because we look for all settings of the form "logger\..+" as configuring
a logger. Yet, logger.level is special and is meant to only configure
the default logging level. This commit causes is to avoid not
configuring a logger named level.
Relates #22624