Uncaught exception in debug logging

[janikdotzel]

Description

When debug logging is enabled for Akka Remoting and log-received-messages=on or log-sent-messages=on, an exception thrown by a message's toString() method is not caught.

Problem

The debug logging statements pass objects directly to log.debug(). If the message's toString() method throws an exception (e.g. NullPointerException due to a null field in the message), this exception propagates up.

Reproduction Steps

1. Enable debug logging for Akka Remoting
2. Set akka.remote.artery.log-received-messages = on or akka.remote.artery.log-sent-messages = on
3. Send a message where toString() throws an exception (e.g. a case class with a null field that causes NPE during string conversion)

Code Locations

(There might be more locations)

• Three places for receiving:

  akka-core/akka-remote/src/main/scala/akka/remote/artery/MessageDispatcher.scala

  Line 50 in 3c1e5d2

  if (LogReceive && debugLogEnabled)

• One Place for sending:

  akka-core/akka-remote/src/main/scala/akka/remote/artery/Codecs.scala

  Line 163 in 3c1e5d2

  if (debugLogSendEnabled)

Expected Behavior

Exceptions thrown during debug logging should be caught and handled gracefully. A warning could be logged instead indicating that the message could not be logged due to a toString() failure.

[patriknw]

Sound good to catch that for the logging of log-received-messages=on or log-sent-messages=on, but we will not add it around all logging. It should be noted that we are very diligent with avoiding logging of application specific or unknown payloads, because it could contain sensitive information or be of huge size.