Check_MK Werk 3861: Introduced open event limit mechanism for protecting against message storms

ID: 3861 Title: Introduced open event limit mechanism for protecting against message storms Component: Event Console Level: 3 Class: New Feature Version: 1.4.0i1 The Event Console has been extended to be able to protect agains message storms which can either result in too high load and also in out of memory situations. Because there can be multiple kind of message storms like one device which sends a lot of messages or many different devices sending equal messages, we introduced different limits to match them. There are the following limits: <ul> <li>Limit by host: You can limit the number of open events created by a single host . This is meant to prevent you from message storms created by one device. Once the limit is reached, the Event Console will block all future incoming messages sent by this host until the number of open events has been reduced to be below this limit. In the moment the limit is reached, the Event Console will notify the configured contacts of the host.</li> <li>Limit by rule: You can limit the number of open events created by a single rule here. This is meant to prevent you from too generous rules creating a lot of events. Once the limit is reached, the Event Console will stop the rule creating new open events until the number of open events has been reduced to be below this limit. In the moment the limit is reached, the Event Console will notify the configured contacts of the rule or create a notification with empty contact information.</li> <li>Overall limit: To protect you against a continously growing list of open events created by different hosts or rules, you can configure this overall limit of open events. All currently open events are counted and once the limit is reached, no further events will be opened which means that new incoming messages will be dropped. In the moment the limit is reached, the Event Console will create a notification with empty contact information. </li> </ul> Each of those limits can be configured to different values. By default the limit is set to 1000 for the host and rule based limit and 10000 for the overall limit. Please check carefully whether or not these defaults are OK for you. But they should be way enough for most environments since you really should never have so many open events in the Event Console open. But if you need to change those limits, you can change them in the global settings of the Event Console to fit your needs. Additionally, you can configure the actions the Event Console should perform once the limit is reached instead of the overflow event and notification creation as described above. Another action is for example delete the oldest event (of a host, rule or overall).