Oracle Redo Log Switch Frequency Test

The Oracle Redo Log Switch Frequency test monitors the rate at which an Oracle database instance switches between redo log files. Its primary objective is to verify that the redo log configuration is optimized for the current transaction workload. Frequent log switches - typically more than five per hour - trigger frequent checkpoints, causing excessive disk I/O and potential database freezes that degrade user performance.

By tracking these switches, administrators can determine if redo log files are undersized for the volume of data changes being processed. This visibility allows for proactive adjustments to log file sizes and group configurations, reducing I/O contention and ensuring the database remains stable and performant during high - activity periods.

This test monitors the Redo log switching frequency and collects key metrics like number of log switches and time since last log switch. These metrics provide an insight to administrators if the switching is excessive or optimal. By analyzing these metrics, administrators can take corrective actions if log switching is increasing beyond a point before it affects system performance.

Target of the test : An Oracle server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for Oracle database server.

Configurable parameters for the test
Parameter	Description
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.
Username	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 of the specified database user.
Confirm Password	Confirm the Password by retyping it here.
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. If the certificates in your environment are contained within a different type of truststore, then specify the exact type here - eg., PKCS12.
Truststore 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.
Keystore File	This parameter is applicable only if the target Oracle database 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 /opt/egurkha/jre/lib/security/egmqsslstore.jks.
Keystore Password	This parameter is applicable only if the target Oracle database 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: 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
Log switches	Indicates the number redo log switches that occurred during the last measurement period.	Number	It helps administrators assess redo generation rate and workload intensity. A high count indicates excessive redo activity or undersized redo logs, potentially causing checkpoint contention and I/O pressure. A low count may suggest oversized logs or reduced transaction throughput.
Time since last log switch	Indicates the time elapsed since the most recent redo log switch happened.	Minutes	It helps determine whether switching frequency aligns with operational best practices (commonly 15–30 minutes in OLTP environments). A very short duration signals frequent switching and potential performance overhead, while an unusually long duration may increase recovery time and delay archive log creation. The detailed diagnosis of this measure further reveal details like switch time, sequence number, and descriptions. These additional measures prove pivotal in investigating the reasons of last switch.