Oracle System Waits Test

The test monitors the system level wait events on the Oracle database server and reports key performance statistics pertaining to every event. Effective wait analysis helps determine where the database spends most of its time, and which current connections are responsible for the reported waits.

Target of the test : An Oracle server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every system 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: Data_file_init_write,db_file_single_write. By default, ‘none’ is displayed here indicating that all system wait events are monitored, by default.

  1. 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.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

New waits:

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

Number

High waits indicate a problem, but not always. Sometimes waits are just a normal part of database operations. For example, high waits on ‘db file sequential read’ events may indicate a disk bottleneck, but you must check your average disk queue length for each disk spindle to be sure that these waits are abnormal.

If a high number of waits are observed on a specific event, you can use the detailed diagnosis capability of the OraSessionWaitTest to figure out whether any current connections have contributed to the increase in waits.

Total waits timedout:

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

Number

A large number of timed out wait events is typically, undesirable. Use the 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.

Secs

By comparing the value of this measure across all monitored wait events, you can determine where the database spends most of its time.

Time waited:

Indicates the total amount of time for which the waits on this wait event persisted.

Secs