Nephron 
Streaming analytics for flows.
Architecture
Sentinel -> Kafka -> Nephron / Beam / Flink -> (Elasticsearch | Cortex | Kafka)
Building
Build & run:
mvn clean package
Run on Flink
We require Flink 1.10.x
Run on Flink
./bin/flink run --parallelism 1 --class org.opennms.nephron.Nephron /root/git/nephron/assemblies/flink/target/nephron-flink-bundled-*.jar --runner=FlinkRunner --jobName=nephron --checkpointingInterval=600000 --autoCommit=false
Persistence
See: persistence.
Upgrading the code
To restart the job and keep the current state, see the instructions bellow.
To restart the job without keeping the state, cancel the job and re-run a new one.
Metrics
Prometheus
Load Prometheus exporter on Flink:
cp opt/flink-metrics-prometheus-1.9.2.jar lib/
Append to conf/flink-conf.yaml:
metrics.reporter.prom.class: org.apache.flink.metrics.prometheus.PrometheusReporter
metrics.reporter.prom.port: 9250-9260
SLF4J
Load the SLF4J report on Flink:
cp opt/flink-metrics-slf4j-1.9.2.jar lib/
Append to conf/flink-conf.yaml:
metrics.reporter.slf4j.class: org.apache.flink.metrics.slf4j.Slf4jReporter
metrics.reporter.slf4j.interval: 60 SECONDS
Restart job w/ savepoints
Rebuild the artifact in place.
Find the job id:
./bin/flink list
Stop the job with a savepoint:
./bin/flink stop 99d87bc4d3a271a72f3f89dfe5a904d7 -p /tmp/state
Now restart the job with:
./bin/flink run --parallelism 1 --fromSavepoint /tmp/state/savepoint-5cfdc5-00788010255a --class org.opennms.nephron.Nephron /root/git/nephron/assemblies/flink/target/nephron-flink-bundled-*.jar --runner=FlinkRunner --jobName=nephron --checkpointingInterval=600000 --autoCommit=false
Elasticsearch
Install the template using:
curl -XPUT -H 'Content-Type: application/json' http://localhost:9200/_template/netflow_agg -d@./main/src/main/resources/netflow_agg-template.json
OpenNMS Configuration
On OpenNMS or Sentinel, enable the Kafka exporter for flows:
config:edit org.opennms.features.flows.persistence.kafka
config:property-set topic opennms-flows
config:property-set bootstrap.servers 127.0.0.1:9092
config:update
config:edit org.opennms.features.flows.persistence.elastic
config:property-set enableForwarding true
config:update