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
Lee Hinman
Daniel Mitterdorfer
Clinton Gormley