So I investigated running the app with -Dakka.log-config-on-start=on. I couldn't get any associated config output until I reverted log.conf to use the default logger:
akka { log-config-on-start=on log-dead-letters = 0 log-dead-letters-during-shutdown = off warn-about-java-serializer-usage = off loglevel = INFO stdout-loglevel = INFO loggers = ["akka.event.Logging$DefaultLogger"] //loggers = ["akka.event.slf4j.Slf4jLogger"] //logging-filter = "akka.event.slf4j.Slf4jLoggingFilter" } ...and then I get loads of config output to the log, especially from reference.conf dragged in from some other dependency. Clearly, my understanding of how {assembly fat jars, configuration loading, external config files, slf4j, logback} hang together is not complete! I'll continue investigation as to why I get no output (at all) with: akka { log-dead-letters = 0 log-dead-letters-during-shutdown = off warn-about-java-serializer-usage = off loglevel = INFO stdout-loglevel = INFO loggers = ["akka.event.slf4j.Slf4jLogger"] logging-filter = "akka.event.slf4j.Slf4jLoggingFilter" } and <?xml version="1.0" encoding="UTF-8"?> <configuration> <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender"> <target>System.out</target> <encoder> <pattern>!check! %X{akkaTimestamp}| %-6level| %logger{36}| %X{sourceActorSystem}| %msg%n</pattern> </encoder> </appender> <logger name="akka" level="error" /> <logger name="akka.cluster.Cluster" level="error" /> <logger name="jobs" level="info" /> <logger name="jobsHttp" level="info" /> <root level="info"> <appender-ref ref="CONSOLE"/> </root> </configuration> -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.