Oracle RAC Interconnect Latency
Oracle RAC (Real Application Clusters) interconnect latency refers to the time it takes for messages to travel between RAC nodes over the private interconnect network. This latency is critical because RAC nodes frequently exchange data blocks using Cache Fusion, and any delay can impact overall database performance.
Monitoring Oracle RAC interconnect latency is essential for maintaining the performance, stability, and scalability of a clustered database environment.
This test continuously monitors the Oracle RAC interconnect latency, and reports the metrics like - Number of 8 KB pings, Average latency of 8 KB pings,Wait time of 500 Bytes pings and Average latency of 500 Bytes pings.
Target of the test : An Oracle Cluster
Agent deploying the test : An internal agent
Outputs of the test : One set of results for each instance on the Oracle Cluster that is being monitored
| Parameters | Description |
|---|---|
|
Test period |
How often should the test be executed. By default, this is set to 60 minutes. |
|
Host |
The IP address of the Oracle server. |
|
Port |
The port number through which the Oracle server communicates. The default port is 1521. |
|
SCAN Name |
SCAN stands for Single Client Access Name, it is a feature used in Oracle RAC environments that provide a single name for clients to access any Oracle Database running in the cluster. You can provide SCAN as an alternative to IP/Host Name. If this parameter value is provided, it will be used for connectivity otherwise IP/Hostname will be used. |
|
Connecting Port |
Specify the port number at which eG Enterprise will connect to Oracle Cluster. |
|
OraSID |
The variable name of the oracle instance. |
|
ServiceName |
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, this is set to none. In this case, the test connects to the cluster using the OraaSID 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’ |
|
Username |
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. |
|
Password |
Specify the password corresponding to the mentioned user. |
|
Confirm Password |
Confirm the password by retyping it. |
|
SSL |
By default, this flag is set to No, as the target Oracle cluster is not SSL-enabled by default. If the target cluster is SSL-enabled, then set this flag to Yes. |
|
SSL Cipher |
This parameter is applicable only if the target Oracle Cluster 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 cluster. By default, this parameter is set to none. |
|
Truststore File |
This parameter is applicable only if the target Oracle Cluster 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 cluster 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 Cluster 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. |
|
Truststore Password |
This parameter is applicable only if the target Oracle Cluster 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. |
|
Keystore File |
This parameter is applicable only if the target Oracle Cluster is SSL-enabled, if not, set this parameter to none. Keystore contains the private keys for the certificates that the client can provide to the server upon request. eG agent requires access to the keystore where client certificate is stored to send that to the server so that the server validates the certificate against the one contained in its trustore. For this purpose, first create the client certificate in the following default location EG_INSTALL_DIR/jre/lib/security/mykeystore.jks. Then, provide the keystore file name in this text box. For example: mykeystore.jks. By default, none is specified against this text box. |
|
Keystore Password |
This parameter is applicable only if the target Oracle Cluster is SSL-enabled, if not, set this parameter to none. If a Keystore File name or file path is provided, then, in this text box, provide the password that is used to obtain the associated certificate details from the Keystore File. |
|
Confirm Password |
Confirm the Password for Keystore by retyping it here. |
|
DD Frequency |
Refers to the frequency with which detailed diagnosis measures are to be generated for this test. 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. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency. |
|
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:
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|
Measurement |
Description |
Measurement Unit |
Interpretation |
|---|---|---|---|
|
Number of 8 KB pings
|
Indicates the number of 8 KB pings sent to the network as a part of the test. |
Number |
8 KB is standard mimicking an Oracle data block. For a meaningful test, send 10,000 to 1,000,000 8 KB messages are sent. Ideally the target latency < 500 microseconds, acceptable up to ~1 millisecond. |
|
Wait time of 8 KB pings |
Indicates the wait time for 8 KB pings over the interconnect. |
Seconds |
These numbers represent round-trip latency (send + receive) for 8 KB payloads, which simulate a full Oracle block being transferred between RAC nodes. |
|
Average latency of 8 KB pings |
Indicates the average time from when a node sends a request for a block (e.g., "I need a current block") to when the block arrives from another node. |
Seconds |
500 bytes is much smaller than Oracle's standard 8 KB block, but it’s useful for measuring raw latency, |
|
Number of 500 Bytes pings |
Indicates the number of 500 byte pings sent to the network as a part of the test. |
Number |
500-byte pings are used to test latency and responsiveness, not throughput. |
|
Wait time of 500 Bytes pings |
Indicates the wait time for 500 byte pings over the interconnect. |
Seconds |
|
|
Average latency of 500 Bytes pings |
Indicates the average time from when a node sends a request for a block (e.g., "I need a current block") to when the block arrives from another node. |
Seconds |
The result helps assess network performance baseline, especially for control messages in RAC. |