The report() call can come from multiple threads in our code,
yet it was opening/closing a shared graphite client instance in this
method, causing NPE when periodic reporting kicked in during a manual
report() call. We want to be able to do this - thus rewrite to safe impl
Removed metrics-graphite dependency, replaced by in house impl.
The previous was using discrete write() calls, which could be entangled
when called from multiple threads, and produce invalid metric lines.
Current impl is simpler and threadsafe, as the lock for write(String) to
aquired for the entire string lenght's write (unlike multiple write calls).
Resolves#15165
Note: This is NOT aimed to provide an micro-benchmarking solution.
The goal is to provide data for broad trend analysis. For techniques
that fight the inliner and other specialised techniques, refer to JMH.
+ custom console and graphite reporters
- had to be custom because it's not possible to add custom metric
types to the existing reporters
+ initial hdr.Histogram histogram() provider, see
http://latencyutils.github.io/LatencyUtils/
+ Not using timers provided by Metrics, instead use the above histogram
+ Added average Actor size measurement
+ Measuring the "blocking time" when an actor is created, before we fire
of the async part of this process; Measures in loop and will fluctuate
a lot. Times are in `us` -- System.nanoTime should provide good enough
resolution.
+ Measuring total actor creation time by using
`KnownOpsInTimespanTimer`, which given a known number of ops, in a
large amount of time, roughtly estimates time per one operation.
// Yes, we are aware of the possibility of GC pauses and other horrors
+ All classes are `private[akka]`, we should not encourage people to use
this yet
+ Counters use Java 8's `LongAdder`, which is metric's private;
The new trend in Java land will be copy paste-ing this class ;)
+ Metrics are logged to Graphite, so we can long-term analyse these
+ Reporters are configurable using typesafe-config
! I'm not very happy about how I work around Metrics not being too open
for adding additional custom metrics. Seems like a hack at places.
I will consider removing the Metrics dependency all together.
numbers
Example output:
```
-- KnownOpsInTimespanTimer-------------------------------------------
actor-creation.total.creating-100000-actors.Props|new-EmptyArgsActor|…||-same
ops = 100000
time = 1.969 s
ops/s = 50782.22
avg = 19.69 μs
-- AveragingGauge---------------------------------------------------
actor-creation.Props|new-EmptyArgsActor|…||-same.avg-mem-per-actor
avg = 439.67
```
