Oracle RAC Session Waits Test

Like the wait activity on stand-alone Oracle servers, administrators also need to observe the wait activity on Oracle servers that are part of a Real Application Cluster (RAC). This test connects to the global view on the monitored Oracle server in an RAC, and pulls out critical statistics pertaining to the session-level cluster-related events that wait on the global cache or any other global resource on that Oracle server. Using this information, administrators can determine the cluster events on which the database spends most of its time, and which Oracle instances and current connections are responsible for the reported waits. This test is disabled by default. To enable the test, go to the enable / disable tests page using the menu sequence : Agents -> Tests -> Enable/Disable, pick Oracle Database as the Component type, Performance as the Test type, choose this test from the disabled tests list, and click on the << button to move the test to the ENABLED TESTS list. Finally, click the Update button.


This test needs to be enabled only while monitoring the Oracle servers in an RAC environment.

Target of the test : An Oracle server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every cluster-related session wait event monitored on the Oracle server.

Configurable parameters for the test
  1. TEST PERIOD - How often should the test be executed
  2. Host – The host for which the test is to be configured
  3. Port - The port on which the server is listening
  4. User – In order to monitor an Oracle database server, a special database user account has to be created in every Oracle database instance that requires monitoring. A Click here hyperlink is available in the test configuration page, using which a new oracle database user can be created. Alternatively, you can manually create the special database user. When doing so, ensure that this user is vested with the select_catalog_role and create session privileges.

    The sample script we recommend for user creation (in Oracle database server versions before 12c) for eG monitoring is:

    create user oraeg identified by oraeg

    create role oratest;

    grant create session to oratest;

    grant select_catalog_role to oratest;

    grant oratest to oraeg;

    The sample script we recommend for user creation (in Oracle database server 12c) for eG monitoring is:

    alter session set container=<Oracle_service_name>;

    create user <user_name>identified by <user_password> container=current default tablespace <name_of_default_tablespace> temporary tablespace <name_of_temporary_tablespace>;

    Grant create session to <user_name>;                                

    Grant select_catalog_role to <user_name>;

    The name of this user has to be specified here.

  5. Password – Password of the specified database user

    This login information is required to query Oracle’s internal dynamic views, so as to fetch the current status / health of the various database components.

  6. Confirm password – Confirm the password by retyping it here.
  7. EXCLUDE - Provide a comma-separated list of wait events that need not be monitored. For example, your specification can be: gc cr request,gc buffer busy. By default, ‘none’ is displayed here indicating that all wait events are monitored, by default.
  8. ISPASSIVE – If the value chosen is yes, then the Oracle server under consideration is a passive server in an Oracle cluster. No alerts will be generated if the server is not running. Measures will be reported as “Not applicable" by the agent if the server is not up.
  9. DETAILED DIAGNOSIS – To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

    The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

    • The eG manager license should allow the detailed diagnosis capability
    • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Total waits:

Indicates the total number of times waits happened on this event since the last measurement period.


If the value of this measure is very high, then you can drill down further using the detailed diagnosis capability (if enabled) of the eG Enterprise to discover which Oracle instances and current connections may be responsible for this. The detailed diagnosis of this measure reveals the Oracle instance on which the events are waiting, the session IDs of the sessions that caused the wait events to occur, the users who initiated the sessions, and the total number of waits, wait time, and the maximum wait time for every session.

Total waits timedout:

Indicates the total number of waits on this event that timed out since the last measurement period.


A large number of timed out wait events is typically, undesirable. Use Oracle-specific documentation to probe the cause of the timeout.

Avg time waited:

Indicates the average duration for which the waits on this wait event persisted since the last measurement period.


Ideally, the value of this measure should be low. A very high value or a consistent increase in this value is indicative of a problem situation requiring further investigation. Use the detailed diagnosis capability to zoom into the session that has contributed to the abnormal increase in wait time.

Max time waited:

Indicates the high watermark of wait time for this wait event.