Deployments-->EJB --> Monitoring --> Stateful Session EJBs

Cache Miss Ratio

The cache miss ratio is a ratio of the number of times a container cannot find a bean in the cache (cache miss) to the number of times it attempts to find a bean in the cache (cache access). In general, the lower your cache miss ratio, the better your EJB will perform.

The amount of time saved by getting a bean from the cache depends on the cost of the bean's ejbActivate method as well as the bean's cache-between-transactions setting. When a cache miss occurs, a bean must be obtained from the free pool and its ejbActivate method must be called. The more expensive it is to invoke ejbActivate, the more the cache miss will hurt performance. If the EJB is configured with cache-between-transactions set to true, the cache miss will also force the EJB container to make an extra call to the database to load the bean.

For information on what to tune in response to the cache miss ratio statistic, see Cache Miss Ratio in the WebLogic Server Performance and Tuning Guide.

Lock Manager Waiter Ratio

This is the ratio of the number of times a thread had to wait to obtain a lock on a bean to the total amount of lock requests issued. For best performance, you want the lock waiter ratio to be as low as possible.

For information on what to tune in response to the lock waiter ratio statistic, see Lock Waiter Ratio in the WebLogic Server Performance and Tuning Guide.

Lock Manager Timeout Ratio

This is the ratio of timeouts to accesses for the lock manager. Timeouts are very detrimental to performance and therefore, you should strive to keep your lock timeout ratio to an absolute minimum. Timeouts hurt performance on several levels. First, each thread waiting for a lock is one less thread that the server can be using to service other requests. Second, a lock timeout will result in an exception that will roll back the current transaction, erasing any work already done in the transaction and causing the current request to fail.

For information on what to tune in response to the lock timeout ratio statistic, see Lock Timeout Ratio in the WebLogic Server Performance and Tuning Guide

Transaction Rollback Ratio

The transaction rollback ratio is the ratio of transactions that have rolled back to the number of total transactions involving the EJB. This information is useful for several reasons. First, it may be useful for signaling a problem with an application. For example, an unexpectedly high rollback ratio may be caused by a problem with a resource used by the application. It may also be useful in gauging the efficiency of an application. A high transaction rollback ratio may mean that a lot of work is being done only to eventually be rolled back, which is inefficient.

For information on what to tune in response to the transaction rollback ratio statistic, see Transaction Rollback Ratio in the WebLogic Server Performance and Tuning Guide.

Transaction Timeout Ratio

The transaction timeout ratio is the ratio of transactions that have timed out to the total number of transactions involving an EJB. Timeouts can be especially concerning because they are a signal of inefficiency.

Every EJB request uses valuable server resources such as threads and bean instances. A timed out transaction means that server resources were tied up in vein. The transaction timeout ratio is a good indicator of a problem with an application.

For information on what to tune in response to the transaction timeout ratio statistic, see Transaction Timeout Ratio in the WebLogic Server Performance and Tuning Guide.

Activation Count

Displays the number of EJB instances that have been activated.

Beans In Use Current Count

Displays the number of bean instances currently in use from the free pool. This information is useful for tracking demand for your EJB. For example, this can be important when investigating an abnormal pool miss ratio.

Cache Access Count

Displays the total number of attempts to access a bean from the cache. This information is useful for giving context to other counts such as cache hits.

Cache Miss Count

Displays the total number of times an attempt to access a bean from the cache failed. This information is useful for determining the effectiveness of the EJB cache.

Cached Beans Current Count

Displays the total number of EJB instances currently in cache.

Destroyed Total Count

Displays the number of bean instances that have been destroyed.

EJB Name

Displays the name of EJB.

Lock Mgr Access Count

Displays the total number of attempts to obtain a lock on a bean. This includes attempts to obtain a lock on a bean that is already locked on behalf of the client. This information is useful for giving context to the waiter and timeout total counts.

Lock Mgr Entries Current Count

Displays the current number of lock entries in the lock manager. This information can be helpful in detecting stale lock entries.

Lock Mgr Timeout Total Count

Displays the total number of threads that have timed out waiting for a lock on a bean. This information is useful for calculating the lock timeout ratio.

Lock Mgr Waiter Total Count

Displays the total number of threads that have waited for a lock on a bean. This information is useful for calculating the lock waiter ratio.

Passivation Count

Displays the total number of EJBs that have been passivated.

Server

Displays the server instance upon which the EJB runs.

Transactions Committed Total Count

Displays the total number of transactions that have been committed.

Transactions Rolled Back Total Count

Displays the total number of transactions that have been rolled back.

Transactions Timed out Total Count

Displays the total number of transactions that have timed out.