[SAMZA-1077] SamzaContainer should catch all Throwables instead of only exceptions

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.12.0
• Assignee: Jagadish
• Reporter: Jagadish
• Created: 06/Jan/17 01:31
• Updated: 02/Feb/17 00:50
• Resolved: 30/Jan/17 23:07

Description

Here's the snippet from the startup sequence of the SamzaContainer.

SamzaContainer.scala

      startProducers
      startTask
      startConsumers
      startSecurityManger

      info("Entering run loop.")
      addShutdownHook
      runLoop.run
    } catch {
      case e: Exception =>
        error("Caught exception in process loop.", e)
        throw e
    } finally {
      info("Shutting down.")

      shutdownConsumers
      shutdownTask
      shutdownStores

In this case, the catch block merely catches Exceptions and not Errors.

Consider the following sequence:
1. `NoSuchMethodError` thrown in the startup sequence.
2. The error is not caught in the catch block (hence, not logged) and the control reaches the finally block.
3. The finally block throws an exception in one of the shutdown methods.
4. The thrown exception completely masks the underlying NoSuchMethodError.

Catching all Throwables will atleast help log the error.

Ideally, finally block should be idempotent and not throw exceptions (but, that's for a different ticket since it's larger in scope)

Issue Links

• links to: GitHub Pull Request #40