Oracle RAC User Connections Test

This test reports the number and state of sessions of each user who is currently connected to the Oracle cluster. Using the metrics reported by this test, administrators can promptly isolate idle sessions, which are a drain on a cluster’s resources.

Target of the test : Oracle RAC

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for every user who is currently connected to the Oracle cluster

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. orasid - The variable name of the oracle instance
  5. service name - A ServiceName exists for the entire Oracle RAC system. When clients connect to an Oracle cluster using the ServiceName, then the cluster routes the request to any available database instance in the cluster. By default, the service name is set to none. In this case, the test connects to the cluster using the orasid and pulls out the metrics from that database instance which corresponds to that orasid. If a valid service name is specified instead, then, the test will connect to the cluster using that service name, and will be able to pull out metrics from any available database instance in the cluster.

    To know the ServiceName of a cluster, execute the following query on any node in the target cluster:

    select name, value from v$parameter where name =’service_names’

  6. User – In order to monitor an Oracle RAC, a special database user account has to be 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.

  7. Password – Password of the specified database user
  8. Confirm password – Confirm the password by retyping it here.
  9. excludeuser -  In the EXCLUDEUSER text box, specify a comma-separated list of user names that need to be excluded from monitoring. By default, none is displayed here indicating that this test monitors connections initiated by all current users to the MS SQL server, by default.
  10. dd frequency - Refers to the frequency with which detailed diagnosis measures are to be generated. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. If you want the detailed diagnosis of this test to be generated at a different frequency, set a different dd frequency here. To disable the detailed diagnosis capability for a test, you can set this parameter to 0:0.
  11. 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 connections:

Indicates the total number of connections currently established by this user on the cluster.

Number

 

Active connections:

Indicates the number of connections of this user that are currently active.

Number

The detailed diagnosis of this measure, if enabled, will provide the complete details of the active sessions of a particular user. Using this information, you can understand how each of the connections were made - i.e., using which program - from where - i.e., from which host – and to which cluster node.

Inactive connections:

Indicates the number of sessions initiated by this user that are currently idle.

Number

Ideally, the value of this measure should be low. A high value is indicative of a large number of idle sessions, which in turn causes the unnecessary consumption of critical server resources. Idle sessions also unnecessarily lock connections from the connection pool, thereby denying other users access to the server for performing important tasks.

The detailed diagnosis of this measure, if enabled, will provide the complete details of the idle sessions of a particular user. Using this information, you can understand how each of the idle connections were made - i.e., using which program - from where - i.e., from which host - and to which cluster node.

Background connections:

Indicates the number of background processes that were started when sessions are initiated by this user.

Number

Ideally, the value of this measure should be low.

The detailed diagnosis of this measure, if enabled, will provide the complete details of the background sessions of a particular user. Using this information, you can understand how each of the background connections were made - i.e., using which program -  from where - i.e., from which host – and to which cluster node.

Blocked connections:

Indicates the number of sessions initiated by this user were blocked.

Number

Blocking occurs when one session holds a lock on a resource that another session is requesting. As a result, the requesting session will be blocked - it will hang until the holding session gives up the locked resource. In almost every case, blocking is avoidable. In fact, if you find that your session is blocked in an interactive application, then you have probably been suffering from the lost update bug as well, perhaps without realizing it. That is, your application logic is flawed and that is the cause of blocking.

The five common DML statements that will block in the database are INSERT, UPDATE, DELETE, MERGE and SELECT FOR UPDATE.

Ideally, the value of this measure should be low. A high value may cause unnecessary consumption of critical server resources thereby blocking access to potential active sessions.

The detailed diagnosis of this measure, if enabled, will provide the complete details of the blocked sessions of a particular user. Using this information, you can understand how each of the blocked connections were made - i.e., using which program - and from where - i.e., from which host.

Cached connections:

Indicates the number of sessions of this user that were cached for future use.

Number

Ideally, the value of this measure should be low.

The detailed diagnosis of this measure, if enabled, will provide the complete details of the cached sessions of a particular user. Using this information, you can understand how each of the cached connections were made - i.e., using which program - from where - i.e., from which host – and to which cluster node.

 

Killed connections:

Indicates the number of sessions of this user that were terminated due to inactivity.

Number

Ideally, the value of this measure should be low.

The detailed diagnosis of this measure, if enabled, will provide the complete details of the killed sessions of a particular user. Using this information, you can understand how each of the killed connections were made - i.e., using which program - from where - i.e., from which host – and to which cluster node.

Sniped connections:

Indicates the number of sessions of this user that were idle for a period more than the profile’s maximum idle time while waiting for a client’s response.

Number

Ideally, the value of this measure should be low.

The detailed diagnosis of this measure, if enabled, will provide the complete details of the sniped sessions of a particular user. Using this information, you can understand how each of the sniped connections were made - i.e., using which program - from where - i.e., from which host – and to which cluster node.