Database Buffer Test

This test reports statistics pertaining to the buffer cache for database operations.

Target of the test : A SAP ABAP instance

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for every SAP ABAP instance being monitored.

Configurable parameters for the test
Parameter	Description
Test Period	How often should the test be executed
Host	Host name of the server for which the test is to be configured.
PortNo	Enter the port to which the specified host listens.
ClientName	Specify the ID of the client system as what the eG agent will be connecting to the SAP ABAP instance. To know how to determine the client ID to use, follow the instructions provided in Determining the Client ID/Name for the eG Agent to Connect to the SAP ABAP Instance.
SAPUser	Typically, to connect to a SAP ABAP instance and run tests, the eG agent requires the permissions of a SAP user who has been assigned with certain authorization objects. Ideally, you will have to create a new user role on the SAP ABAP instance for this purpose, associate the above-mentioned authorization objects with that role, and assign the new role to an existing SAP user. The procedure for the same has been provided in Creating a New User Role for Monitoring and Assigning it to a SAP User. Once the new role is assigned to a SAP user, specify the name of this user against SAPUser.
Password	The password of the specified SAPUser.
Confirm Password	Confirm the password by retyping it here.
SysNo	An indicator of the TCP/IP port at which the SAP server listens. For example, for a server that listens at port 3200, the SysNo will be ‘00’. Similarly, if the SAP server port is 3201, the SysNo will have to be specified as ‘01’. Therefore, in the SysNo text box specify the system number of the SAP server with which the specified client communicates. To know the system number for the ABAP server being monitored, follow the procedure detailed in Identifying the SAP Router String and System Number.
Router	If the SAP client with the specified ClientName exists in a network external to the SAP server, then a router will be used to enable the server-client communication. In such a case, specify the router string of the router in the Router text box. If both the client and the server exist in the same network, then specify ‘none’ against the Router text box. To know what is the SAP Router string for the ABAP server being monitored, follow the procedure detailed in Identifying the SAP Router String and System Number.
InstanceName	This is set to none by default. This implies that the eG agent automatically discovers the instance name at run time.
Timeout	Indicate the duration (in seconds) for which this test should wait for a response from the SAP ABAP instance. By default, this is set to 120 seconds.
JCO Version	The eG agent uses the SAP JCO library to connect to the SAP ABAP system and pull out metrics. To enable the eG agent to make this connection and query the metrics, you need to specify the version of the SAP JCO library that the agent needs to use. For instance, to instruct the eG agent to use JCO v2.1.19, it would suffice if you specify the ‘major version number’ alone against JCO Version – in the case of this example, this will be 2.x. Note that if you have downloaded the SAP JCO CONNECTOR files for SAP JCO version 3 from the SAP market place (as instructed by Downloading the SAP JCO Connector files Required for Monitoring ), then the JCO Version configuration should be 3.x.
IsPassive	If the value chosen is Yes, then the server under consideration is a passive server in a SAP ABAP 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
Buffer cache hit ratio	The percentage of time the database server is able to satisfy a request directly from the cache.	Percent	Physical I/O takes significant amount of time and also increases CPU resources required. The database configuration should be tuned to ensure that a required block will be most likely in memory. The extent to which this is achieved is measured using this measure. Ratio should be 80% or higher. A lower value indicates insufficient memory allocation to the database buffer cache.
Library cache hit ratio	Library cache is a buffer that contains the shared SQL and PL/SQL areas. The library cache hit ratio indicates the percentage of shared SQL statements being reparsed.	Percent	For a well-tuned database, this ratio is 90%. A lower hit ratio may indicate that the memory allocation to the library cache is insufficient. A low value can degrade the database performance.
Redo log buffer entries	The number of entries in the redo log buffer describing changes made to the database.	Number	The changes made to the database are first written to the redo log buffer. The database then periodically writes batches of the redo entries to the online redo log files. The lesser the number of entries in the Redo Buffer, the lesser the database changes are reflected in the buffer. Therefore, there will be higher disk reads and system performance will decrease.