Oracle RAC System 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 an Oracle server in an RAC, and pulls out information pertaining to the system-level cluster-related events that wait on the global cache or any other global resource on that Oracle server. Using this information, administrators determine the cluster events on which the database spends most of its time, and which current connections are responsible for the reported waits.

Note:

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

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.

Target of the test : An Oracle server in an RAC environment

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
TEST PERIOD - How often should the test be executed Host – The host for which the test is to be configured Port - The port on which the server is listening 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. 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. Confirm password – Confirm the password by retyping it here. 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 system wait events are monitored, by default. 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. SSL- By default, this flag is set to No, as the target Oracle database is not SSL-enabled by default. If the target database is SSL-enabled, then set this flag to Yes. SSL Cipher-This parameter is applicable only if the target Oracle database is SSL-enabled, if not, set this parameter to none. A cipher suite is a set of cryptographic algorithms that are used before a client application and server exchange information over an SSL/TLS connection. It consist of sets of instructions on how to secure a network through SSL (Secure Sockets Layer) or TLS (Transport Layer Security). In this text box, provide a comma-seperated list of cipher suites that are allowed for SSL/TLS connection to the target database. By default, this parameter is set to none. TRUSTSTORE FILE- This parameter is applicable only if the target Oracle database is SSL-enabled, if not, set this parameter to none. TrustStore is used to store certificates from Certified Authorities (CA) that verify and authenticate the certificate presented by the server in an SSL connection. Therefore, the eG agent should have access to the truststore where the certificates are stored to authenticate and connect with the target database and collect metrics. For this, first import the certificates into the following default location <eG_INSTALL_DIR>/lib/security/mytruststore.jks. To know how to import the certificate into the truststore, refer toPre-requisites for monitoring Oracle Cluster. Then, provide the truststore file name in this text box. For example: mytruststore.jks. By default, none is specified against this text box. TRUSTSTORE TYPE-This parameter is applicable only if the target Oracle database is SSL-enabled, if not, set this parameter to none.Specify the type of truststore that contains the certificates for server authentication in this text box. For eg.,JKS. By default, this parameter is set to the value none. TRUSSTORE PASSWORD-This parameter is applicable only if the target Oracle database is SSL-enabled, if not, set this parameter to none. If a Truststore File name is provided, then, in this text box, provide the password that is used to obtain the associated certificate details from the Truststore File. By default, this parameter is set to none.

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