Logging#

Note

Verified against node-scala v1.7.0.

Docker#

The image writes two streams:

  • Console — at the level in DCC_LOG_LEVEL (default INFO). Read it with docker logs.

  • Files — under /var/log/dcc (volume), written at TRACE level by the entrypoint.

docker logs -f dcc-node               # follow
docker logs --tail 200 dcc-node       # last 200 lines

Levels, from quietest to noisiest: OFF, ERROR, WARN, INFO, DEBUG, TRACE. Use INFO in production; DEBUG helps with sync and peer issues but is very verbose.

Custom logback configuration#

Logging is configured with Logback. Point the JVM at your own file through JAVA_OPTS:

-e JAVA_OPTS="-Dlogback.configurationFile=/etc/dcc/logback.xml"

For a JAR install, pass the same -Dlogback.configurationFile=... system property to java.

Logs worth watching#

  • Fork and InvalidBlock messages — the node is on a different chain or received a bad block.

  • Out-of-memory exits — the entrypoint starts the JVM with ExitOnOutOfMemoryError, so raise DCC_HEAP_SIZE.