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ASF GitHub Bot commented on EAGLE-39: ------------------------------------- Github user haoch commented on the pull request: https://github.com/apache/incubator-eagle/pull/55#issuecomment-206893150 It has conflict with master branch now, should we merge this part of code into master firstly? > Policy State Management for robustness - replay events upon node crash > ---------------------------------------------------------------------- > > Key: EAGLE-39 > URL: https://issues.apache.org/jira/browse/EAGLE-39 > Project: Eagle > Issue Type: New Feature > Reporter: Edward Zhang > Assignee: Edward Zhang > > Most useful policies are stateful, for example slide-window based policy is > evaluated not only for current event but also for a sequential set of events > happening before current event. > When the node which runs the stateful policy crashes, the policy would be > built up in another node by Eagle, but problem is we never see the events > which were populated for this policy before node crash. > The problem sometimes will cause serious issues as it may miss some alerts. > Think about a policy which takes one month's data is gone because of the node > crash, how do we recover the one-month data for continuous evaluation. > Unfortunately neither Storm as stream infrastructure nor Siddhi as CEP engine > provides state management of intermediate data generated in the program. > Storm can bring up another bolt when one bolt goes down, but it is not > responsible for replay the events which application were previously received. > Siddhi does not provide any state recover when CEP runtime goes down. > Eagle should provide some API for easy state management between monitoring > application and CEP engine. That would make a lot of sense when we define > complex policies. -- This message was sent by Atlassian JIRA (v6.3.4#6332)