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.
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
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
Alexander Reelsen
Lee Hinman
Daniel Mitterdorfer
Clinton Gormley