Sensors

Sensors wrap an Esper CEP engine with sharding logic to load EQL statements and consume PerfEvents that are produced by the collectors. If threshold/statements are violated, then OpsEvents are produced and opamp consumes to produce ActionOrders or WorkOrders.

The sharding logic does a mod of the manifest ID and poolsize global var to load statements from sensor_ksp on DAQ/Cassandra and consume from an opsmq perf-in-q-<shard>.

re-shard

1. Change the SENSORPOOLSIZE global var.
2. Disable opamp (soon to be: disable sensor heartbeat monitoring).
3. Commit and deploy only the sensor.
4. While the sensor is bootstrapping (takes ~10 minutes), touch the update daq collector-artifact and daq logstash. (The env var is set in an attachment for logstash.)
5. Commit and deploy (takes ~10 minutes).
6. Verify that the queues on opsmq are clear and that the number of unhealthy components is normal.
7. Enable opamp / sensor heartbeat monitoring.