To observe Heron’s runtime metrics, you can integrate Heron and the Heron UI with Graphite and Grafana.

To accomplish this, you need to do the following:

  • Export topology metrics from Heron
  • Gather Aurora and Linux metrics with Diamond
  • Set up a scripted dashboard with Grafana
  • Configure the Heron UI to link to Grafana

Exporting Topology Metrics From Heron

Heron supports custom metric exporters from the Metrics Manager. You can build your own metrics sink or use the provided Graphite sink.

Gathering Metrics From Aurora

In addition to the topology-specific data available from Heron, much more data is available directly from Aurora and the Linux kernel. These can help identify many operational problems, such as CPU throttling or crashes.

A common way to collect data from these sources is via a system metrics collection daemon such as collectd or Diamond

Diamond has the following relevant collectors available:

Creating A Scripted Grafana Dashboard

A convienent way to view topology-specific metrics in Graphite is to create a scripted dashboard in Grafana. The scripted dashboard should accept information such as the topology name as query arguments, which will allow the Heron UI to deep link to a specific topology’s dashboard.

Suggested targets for the scripted dashboard include:

Component Backpressure:

'aliasByNode(sortByMaxima(highestAverage(heron.' + topology_name + '.stmgr.stmgr-*.
time_spent_back_pressure_by_compid.*, 5)), 5)'

Fail Count by Component:

'sumSeriesWithWildcards(aliasByNode(heron.' + topology_name + '.*.*.fail-count.default,2),3)'`

CPU Throttling periods:

aliasByNode(nonNegativeDerivative(*.' + topology_name + '.*.cpu.
nr_throttled), 4,5)

JVM Deaths:

'aliasByNode(drawAsInfinite(maximumAbove(removeAboveValue(heron.' + topology_name + '.*.*.jvm.
uptime-secs, 60),1)),2,3)'

Top 5 worst GC components:

'aliasByNode(highestMax(nonNegativeDerivative(heron.' + topology_name + '.*.*.jvm.gc-time-ms.
PS-*),5), 2,3,6)'

Finally, you can configure the Heron UI to deep link to scripted dashboards by specifying an observability URL format (viz.url.format) in the Heron Tracker’s configuration. This will add topology-specific buttons to the Heron UI enabling you to drill-down into your Grafana dashboards.