A service like the JSON-RPC service is opened up, only serving /metrics
requests in a file format for prometheus.
New CLI flags are --metrics-enabled and --metrics-listen, just like the
--rpc and --ws variants of the same.
--host-whitelist is respected the same as the JSON-RPC endpoint.
* Time all tasks
This is fairly high touch consisting of 3 things:
* Moving to Prometheus's Summary for timers
* Timing at .2, .5, .8, .9, .99, and 1.0 (1.0 actually gets max I believe)
* Timing all abstract EthTasks
* The bulk of the changes: plumbing the timing context everywhere we need it
* Plumb in three more metrics
* add blockchain_height gauge
* add blockchain_difficulty_total gauge
* add blockchain_announcedBlock_ingest histogram
This involved some deep pluming such that the metrics system needs to be
created in the PantheonCommand, along with trickle down effects into other
consensus engines. This is likely where it should live anyway.
Metrics being captured initially:
Total number of peers ever connected to
Total number of peers disconnected, by disconnect reason and whether the disconnect was initiated locally or remotely.
Current number of peers
Timing for processing JSON-RPC requests, broken down by method name.
Generic JVM and process metrics (memory used, heap size, thread count, time spent in GC, file descriptors opened, CPU time etc).
Danno Ferrin
Adrian Sutton