NotificationPluginManager seems not very stable, any docs/guideline for this part?
68771 [Thread-11-AlertNotificationExecutor_8] ERROR org.apache.eagle.notification.plugin.NotificationPluginManagerImpl - fail invoking plugin's onAlert, continue java.lang.NullPointerException: null at org.apache.eagle.notification.plugin.NotificationPluginManagerImpl.notifyAlert(NotificationPluginManagerImpl.java:83) ~[eagle-topology-0.3.0-incubating-assembly.jar:na] at org.apache.eagle.alert.notification.AlertNotificationExecutor.processAlerts(AlertNotificationExecutor.java:98) [eagle-topology-0.3.0-incubating-assembly.jar:na] at org.apache.eagle.alert.notification.AlertNotificationExecutor.flatMap(AlertNotificationExecutor.java:93) [eagle-topology-0.3.0-incubating-assembly.jar:na] at org.apache.eagle.datastream.storm.JavaStormBoltWrapper.execute(JavaStormBoltWrapper.scala:38) [eagle-topology-0.3.0-incubating-assembly.jar:na] at backtype.storm.daemon.executor$fn__4722$tuple_action_fn__4724.invoke(executor.clj:633) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.daemon.executor$mk_task_receiver$fn__4645.invoke(executor.clj:401) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.disruptor$clojure_handler$reify__1446.onEvent(disruptor.clj:58) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.utils.DisruptorQueue.consumeBatchToCursor(DisruptorQueue.java:125) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.utils.DisruptorQueue.consumeBatchWhenAvailable(DisruptorQueue.java:99) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.disruptor$consume_batch_when_available.invoke(disruptor.clj:80) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.daemon.executor$fn__4722$fn__4734$fn__4781.invoke(executor.clj:748) [storm-core-0.9.4.jar:0.9.4] at backtype.storm.util$async_loop$fn__458.invoke(util.clj:463) [storm-core-0.9.4.jar:0.9.4] at clojure.lang.AFn.run(AFn.java:24) [eagle-topology-0.3.0-incubating-assembly.jar:na] at java.lang.Thread.run(Thread.java:745) [na:1.7.0_75] Thanks, Hao
