esper

Currently I am working on a project where I have setup a Storm cluster across four Unix hosts. The topology itself is as follows: JMS Spout listens to an MQ for new messages JMS Spout parses and then emits the result to an Esper Bolt The Esper Bolt then processes the event and emits a result to a JMS Bolt The JMS Bolt then publishes the message back onto the MQ on a different topic I realize that Storm is a "at least-once" framework. However, if I receive 5 events and pass these onto the Esper Bolt for counting then for some reason I am receiving 5 count results in the JMS Bolt(all the same

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 由 翻译 强力驱动 问题: I found data loss in Esper (v.7.1.0) in case if inbound thread pool is enabled. Here is simple example that demonstrates this strange behaviour: Configuration config = new Configuration (); // set up concurrent processing config . getEngineDefaults (). getThreading (). setThreadPoolInbound ( true ); EPServiceProvider epService = EPServiceProviderManager . getDefaultProvider ( config ); // simple schema epService . getEPAdministrator (). createEPL ( "create objectarray schema LogLine as (account_name string, value int) " ); // event