In Lotus Domino, the Event Correlation cache is used as a holding area in which Domino Domain Monitoring (DDM) events are correlated to previously encountered events. When this cache grows to its maximum size, the server reports the following error:

2009-01-27 23:04:29   Event: Error adding event document to Domino Domain Monitoring: Event correlation cache is full. You can increase its size via the NOTES.INI setting EVENT_CORRELATION_POOL_SIZE.

Maybe you tried to change the EVENT_CORRELATION_POOL_SIZE notes.ini variable, but that doesn´t solve your problem. Even with the maximum configured pool size from 100MB (EVENT_CORRELATION_POOL_SIZE=104857600), you may still see the above error. This occurs because Domino creates cached documents that are 2MB in size and the server allows a maximum of 200 cached documents by default.

Since 2MB x 200 is greater than the maximum allowable pool size, the error can occur unless additional parameters are enacted to control the document size and/or the maximum number of cached documents. The following notes.ini parameters are available for these purposes.

      DDM_MAX_NOTE_CACHE (number of documents in the cache)


    DDM_MAX_DOCSIZE_MB (size in megabytes of documents in the cache)

To finetune these values you need to check your ddm.nsf. The best way is to create a new view which lists all documents and enter a new column which show the size from the documents. The biggest document in this view can be used to finetune the DDM_MAX_DOCSIZE_MB value. In my example the biggest document is a 712KB big document (a event which is 2 years old but reopen from time to time), all the other documents are smaller (+-250KB).

To ensure now that the Event Correlation cache will not be exhausted when configured to the maximum 100MB size, I use these information and the parameters from above so that the following formula is true:







After you set these values (via set config ... on the console) you need to restart the events task.