My Oracle Support Banner

The "Blocking Session Count" Metric does not observe the Collection frequency and "number of occurrences" threshold in Enterprise Manager (Doc ID 1279015.1)

Last updated on NOVEMBER 09, 2017

Applies to:

Enterprise Manager for Oracle Database - Version to [Release 10.2 to 12.1]
Information in this document applies to any platform.
This applies to 10g, 11g and certain versions of 12c (only cloud control and below)
Please note that from Cloud Control onwards (which ships with the plug-in), the contents of this article will not apply because UserBlock is calculated by the agent itself from onwards (see for more information on this)


The collection schedule and number of occurrences is not observed for the "Blocking Session Count" metric in Enterprise Manager (10g, 11g and Cloud control (and lower versions))  The Grid Control 11g online hint says:-

"To prevent false alerts due to spikes in metric values, the Number of Occurrences determines the period of time a collected metric value must remain above or below the threshold value before an alert is triggered or cleared. For example, if a metric value is collected every 5 minutes, and the Number of Occurrences is set to 6, the metric values (collected successively) must stay above the threshold value for 30 minutes before an alert is triggered. Likewise, once the alert is triggered, the same metric value must stay below its threshold for 6 consecutive occurrences (30 minutes) before it is cleared."

However when the collection schedule is set for 15 and the "number of occurrences" is set to 2 an alert is received immediately  (rather than waiting for 30 minutes)


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.