Hi Flavio, While I'm not an export on the subject, why can't you load state from db in prepare() method?
-A -----Original Message----- From: Flavio Livide [mailto:[email protected]] Sent: December-20-13 5:42 AM To: [email protected] Subject: How to restore bolt state during failover I'm trying to figure out how to restore the state of a storm bolt task during failover. I can persist the state externally (DB or file system) and associate it to an ID, however once the bolt instance is restarted I need to point to the specific state of that bolt task to recover it. The prepare method of a bolt receives a context, documented here http://nathanmarz.github.io/storm/doc/backtype/storm/task/TopologyContext.html Is there any piece of this context that uniquely identifies the specific task so I can understand which persistent state to point to? Is that ID preserved during failover? Alternatively, is there any variable/object I can set for the specific task that is preserved during failover? I had a look at the Trident documentation, however I'm trying to embed a 3pp inside a bolt, and the 3pp has a state, so trident is not a runner in this case. I'm not in control of how the 3pp persists the state, but I can point at it (file system or or DB) as long as I have an ID. Any help appreciated! /FLAvio
