Restartable tasks


Can you please tell more about “restartable tasks” feature in Druid v0.8.3?

I thought that they will help recover from failed real-time tasks without removing those tasks from the metadata DB and /tranquility path in ZK, but it seems like the behavior is the same as it was in 0.8.2.

What case should work better with restartable tasks? Is there anything that should be enabled in order to have real-time tasks recover/restart properly?



Hey Michael,

The feature is intended to make it easier to update or restart your middle managers.

Middle Managers can be updated one at a time in a rolling fashion when you set druid.indexer.task.restoreTasksOnRestart=true (it’s off by default). In this case, realtime indexing tasks will restore their state on Middle Manager restart, and will not fail.

But if your tasks are failing for reasons other than middle manager restart, the restorability will not help.