Thanks for that! I’ll give it a try as soon as I can. Br Flavio
From: James Xu [mailto:[email protected]] Sent: 20 December 2013 11:37 To: [email protected] Cc: James Xu Subject: Re: How to restore bolt state during failover task id is what you are looking for: http://nathanmarz.github.io/storm/doc/backtype/storm/task/TopologyContext.html#getThisTaskId() On 2013年12月20日, at 下午6:41, Flavio Livide <[email protected]<mailto:[email protected]>> wrote: 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
