Oracle Exam 1Z0-599 Topic 1 Question 52 Discussion

A:

* Troubleshooting Slow Response Time from the Client and Low Database Usage

These symptoms are usually caused by a bottleneck upstream of the database, perhaps in the JDBC connectionpooling. Monitor the active JDBC connections in the WebLogic Console and watch for excessive waiters and wait times; increase the pool size, if necessary.

* Attribute: Maximum Capacity

Maximum number of physical database connections that this connection pool can contain. Different JDBC Drivers and database servers may limit the number of possible physical connections.

C: Attribute: Statement Cache Size

The algorithm used to maintain the statement cache:

LRU - After the statementCacheSize is met, the Least Recently Used statement is removed when a new statement is used.

Fixed - The first statementCacheSize number of statements is stored and stay fixed in the cache. No new statements are cached unless the cache is manually cleared.

E: If the queue appears starved but adding execute threads does not improve performance,

there may be resource contention. Because CPU utilization is low, the threads are probably

spending much of their time waiting for some resource, quite often a database connection.

Use the JDBC monitoring facilities in the console to check for high levels of waiters or long

wait times. Adding connections to the JDBC connection pool may be all that is required to

fix the problem.

Note:

* If you had a JDBC connection pool where the Initial Capacity and Maximum Capacity attributes were different, you might want to create a gauge monitor to monitor the maximum and minimum number of connections.

By setting the Threshold Low value to be one less than the Initial Capacity, your gauge monitor trapcould monitor the ActiveConnectionsCurrentCount attribute of the JDBCDataSourceRuntime MBean and alert you whenever the number of active connections are less than the Initial Capacity (which might indicate database connectivity problems).