This change adds a section about the global search setting
`indices.query.bool.max_clause_count` that limits the number of boolean clauses
allowed in a Lucene BooleanQuery.
Closes#19858
With this commit we introduce a new circuit-breaking strategy to the parent
circuit breaker. Contrary to the current implementation which only accounts for
memory reserved via child circuit breakers, the new strategy measures real heap
memory usage at the time of reservation. This allows us to be much more
aggressive with the circuit breaker limit so we bump it to 95% by default. The
new strategy is turned on by default and can be controlled with the new cluster
setting `indices.breaker.total.userealmemory`.
Note that we turn it off for all integration tests with an internal test cluster
because it leads to spurious test failures which are of no value (we cannot
fully control heap memory usage in tests). All REST tests, however, will make
use of the real memory circuit breaker.
Relates #31767
So far the in-flight request circuit breaker has only accounted for the
on-the-wire representation of a request. However, we convert the raw
request into XContent internally which increases the overhead.
Therefore, we increase the value of the corresponding setting
`network.breaker.inflight_requests.overhead` from one to two. While this
value is still rather conservative (we assume that the representation as
structured objects has no overhead compared to the byte[]), it is closer
to reality than the current value.
Relates #31613
The documentation for the account circuit breaker listed the settings for it's limit and overhead to be `network.breaker.accounting.limit` and `network.breaker.accounting.overhead` when in `HieratchyCircuitBreakerService` it seems the settings are actually `indices.breaker.accounting.limit` and `indices.breaker.accounting.overhead`.
* Add accounting circuit breaker and track segment memory usage
This commit adds a new circuit breaker "accounting" that is used for tracking
the memory usage of non-request-tied memory users. It also adds tracking for the
amount of Lucene segment memory used by a shard as a user of the new circuit
breaker.
The Lucene segment memory is updated when the shard refreshes, and removed when
the shard relocates away from a node or is deleted. It should also be noted that
all tracking for segment memory uses `addWithoutBreaking` so as not to fail the
shard if a limit is reached.
The `accounting` breaker has a default limit of 100% and will contribute to the
parent breaker limit.
Resolves#27044
The current script service has a script compilation limit for a one
minute window. This is set to a small default value of 15. Instead of
increasing that default value, this commit introduces a new setting
that allows to configure a rate per time unit, so that the script service can deal with bursts better.
The new setting is named `script.max_compilations_rate`,
requires a nonnegative number and a positive time value.
The default is `75/5m`, which is equivalent to the existing 15 per minute.
* 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
When compiling many dynamically changing scripts, parameterized
scripts (<https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-scripting-using.html#prefer-params>)
should be preferred. This enforces a limit to the number of scripts that
can be compiled within a minute. A new dynamic setting is added -
`script.max_compilations_per_minute`, which defaults to 15.
If more dynamic scripts are sent, a user will get the following
exception:
```json
{
"error" : {
"root_cause" : [
{
"type" : "circuit_breaking_exception",
"reason" : "[script] Too many dynamic script compilations within one minute, max: [15/min]; please use on-disk, indexed, or scripts with parameters instead",
"bytes_wanted" : 0,
"bytes_limit" : 0
}
],
"type" : "search_phase_execution_exception",
"reason" : "all shards failed",
"phase" : "query",
"grouped" : true,
"failed_shards" : [
{
"shard" : 0,
"index" : "i",
"node" : "a5V1eXcZRYiIk8lecjZ4Jw",
"reason" : {
"type" : "general_script_exception",
"reason" : "Failed to compile inline script [\"aaaaaaaaaaaaaaaa\"] using lang [painless]",
"caused_by" : {
"type" : "circuit_breaking_exception",
"reason" : "[script] Too many dynamic script compilations within one minute, max: [15/min]; please use on-disk, indexed, or scripts with parameters instead",
"bytes_wanted" : 0,
"bytes_limit" : 0
}
}
}
],
"caused_by" : {
"type" : "general_script_exception",
"reason" : "Failed to compile inline script [\"aaaaaaaaaaaaaaaa\"] using lang [painless]",
"caused_by" : {
"type" : "circuit_breaking_exception",
"reason" : "[script] Too many dynamic script compilations within one minute, max: [15/min]; please use on-disk, indexed, or scripts with parameters instead",
"bytes_wanted" : 0,
"bytes_limit" : 0
}
}
},
"status" : 500
}
```
This also fixes a bug in `ScriptService` where requests being executed
concurrently on a single node could cause a script to be compiled
multiple times (many in the case of a powerful node with many shards)
due to no synchronization between checking the cache and compiling the
script. There is now synchronization so that a script being compiled
will only be compiled once regardless of the number of concurrent
searches on a node.
Relates to #19396
This adds new circuit breaking with the "request" breaker, which adds
circuit breaks based on the number of buckets created during
aggregations. It consists of incrementing during AggregatorBase creation
This also bumps the REQUEST breaker to 60% of the JVM heap now.
The output when circuit breaking an aggregation looks like:
```json
{
"shard" : 0,
"index" : "i",
"node" : "a5AvjUn_TKeTNYl0FyBW2g",
"reason" : {
"type" : "exception",
"reason" : "java.util.concurrent.ExecutionException: QueryPhaseExecutionException[Query Failed [Failed to execute main query]]; nested: CircuitBreakingException[[request] Data too large, data for [<agg [otherthings]>] would be larger than limit of [104857600/100mb]];",
"caused_by" : {
"type" : "execution_exception",
"reason" : "QueryPhaseExecutionException[Query Failed [Failed to execute main query]]; nested: CircuitBreakingException[[request] Data too large, data for [<agg [myagg]>] would be larger than limit of [104857600/100mb]];",
"caused_by" : {
"type" : "circuit_breaking_exception",
"reason" : "[request] Data too large, data for [<agg [otherthings]>] would be larger than limit of [104857600/100mb]",
"bytes_wanted" : 104860781,
"bytes_limit" : 104857600
}
}
}
}
```
Relates to #14046
Previously if the size of the search request was greater than zero we would not cache the request in the request cache.
This change retains the default behaviour of not caching requests with size > 0 but also allows the `request_cache=true` query parameter
to enable the cache for requests with size > 0
With this commit we limit the size of all in-flight requests on
transport level. The size is guarded by a circuit breaker and is
based on the content size of each request.
By default we use 100% of available heap meaning that the parent
circuit breaker will limit the maximum available size. This value
can be changed by adjusting the setting
network.breaker.inflight_requests.limit
Relates #16011
Today we throttle recoveries only for incoming recoveries. Nodes that have a lot
of primaries can get overloaded due to too many recoveries. To still keep that at bay
we limit the number of threads that are sending files to the target to overcome this problem.
The right solution here is to also throttle the outgoing recoveries that are today unbounded on
the master and don't start the recovery until we have enough resources on both source and target nodes.
The concurrency aspects of the recovery source also added a lot of complexity and additional threadpools
that are hard to configure. This commit removes the concurrent streamns notion completely and sends files
in the thread that drives the recovery simplifying the recovery code considerably.
Outgoing recoveries are not throttled on the master via a allocation decider.
In order to be more consistent with what they do, the query cache has been
renamed to request cache and the filter cache has been renamed to query
cache.
A known issue is that package/logger names do no longer match settings names,
please speak up if you think this is an issue.
Here are the settings for which I kept backward compatibility. Note that they
are a bit different from what was discussed on #11569 but putting `cache` before
the name of what is cached has the benefit of making these settings consistent
with the fielddata cache whose size is configured by
`indices.fielddata.cache.size`:
* index.cache.query.enable -> index.requests.cache.enable
* indices.cache.query.size -> indices.requests.cache.size
* indices.cache.filter.size -> indices.queries.cache.size
Close#11569
Christoph Büscher
Daniel Mitterdorfer
Colin Goodheart-Smithe
Lee Jones
Lee Hinman
Alexander Reelsen
Robin Clarke
Stefan Gorgiovski
alamzeeshan
Nik Everett
Lee Hinman
Adrien Grand
Daniel Mitterdorfer
Michael McCandless
Simon Willnauer
xuzha
Martijn van Groningen
Clinton Gormley