MsXDBTest

This test monitors the performance of Exchange Server Database. The information store is key to database management in Exchange Server. This server-side component is responsible for storing data, such as e-mail messages in user mailboxes and information in public folders. The information store is actually two separate databases. The private information store database, called Priv.eb and Public information store, called Pub.ebd.

The private information store manages data in user mailboxes. The public information store manages data in public folders.

Microsoft Exchange Server relies on an embedded database engine that lays out the structure of the disk for Exchange Server and manages memory. The Exchange database engine caches the disk in memory by swapping 4 KB chunks of data, called pages, in and out of memory. The engine updates the pages in memory and takes care of writing new or updated pages back to the disk. The database engine commits a transaction only when it can guarantee that the data is durable and protected from crashes or other failures. The database engine will only successfully commit data when it is sure it has flushed that data from memory to the transaction log file on disk.

Target of the test : An MS Exchange Server 5.5

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every Exchange Server 5.5 being monitored.

Configurable parameters for the test
Parameters Description

Test Period

This indicates how often should the test be executed.

Host

The IP address of the machine where the Exchange Server 5.5 is installed.

Port

The port number through which the Exchange Server 5.5 communicates. The default port number is 25.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Database cache hit ratio

This measure shows the percentage of database requests that were fulfilled by the information store cache without incurring disk input/output activity.

Percent

A significantly low value indicates that the Exchange Server 5.5 is not having enough free memory. Increasing the memory may solve this problem.

Database tables cache hit ratio

This measure shows the percentage of database tables opened using the cached schema information.

Percent

A significantly low value indicates that the Exchange Server 5.5 is not having enough free memory. Increasing the memory may solve this problem.

Log record waiting rate

This measure shows the number of log records that cannot be added to the log buffers because the log buffers are full.

Recrds/Sec

This measure should be as close to zero as possible.

If it is not, it might indicate that the size of the log buffer might be a bottleneck. Increasing the memory may solve this problem.

Log threads waiting

This measure shows the number of threads waiting for their data to be written to the log buffer so that the update of the database can be completed.

Number

This measure should be as low as possible.

A high value for this measure may indicate that the log buffer might be a bottleneck. Increasing the memory may solve this problem.