Topic Last Modified: 2006-07-13

The Microsoft® Exchange Server Analyzer Tool examines the Exchange Function Call Log (FCL), Store.fcl file, for Exchange Extensible Storage Engine (ESE) component events that exceed a response time of 2.5 seconds.

Exchange FCL ESE component events are representations of Microsoft Exchange Information Store service (Store.exe) function calls to the ESE component.

The Exchange Information Store sits on top of an ESE database. ESE is a sophisticated, transaction-based database engine. A transaction is a series of operations that are treated as an atomic (indivisible) unit. All operations in a transaction are either completed and permanently saved, or else no operations are performed.

Exchange Server uses ESE as an embedded database engine that determines the structure of the databases and manages memory. The database engine caches the databases in memory by transferring four-kilobyte (KB) chunks of data (pages) in and out of memory. It updates the pages in memory and writes new or updated pages back to the disk. When requests come to the system, the database engine can buffer data in memory. Therefore, it does not have to access the disk constantly.

Although caching data in memory is the fastest and most efficient way to process data, it means that when Exchange is running, the information on disk is never completely up-to-date, however the transaction log disk is always kept current with information about each transaction. However, because many changes in memory are not yet on disk, the database and memory are not synchronized.

If Exchange Server Analyzer finds that events in the Store.fcl file reflect a response time of more than 2.5 seconds for the ESE component function calls from the Microsoft Exchange Information Store service (Store.exe), Exchange Server Analyzer displays an error.

When cross-component calls from the Microsoft Exchange Information Store service (Store.exe) wait for a response, remote procedure call (RPC) threads can back up behind these requests and lead to Exchange Server performance issues such as delays in server responses to clients.

Ongoing calls from the ESE can be caused by the following conditions:

To resolve this error, take the following steps:

For More Information

For more information about how to configure the online defragmentation time windows, see Microsoft Knowledge Base article 244524, "XADM: How to Configure the Exchange Server Online Defragmentation Time Window" (

For more information about Exchange Server Disk Bottleneck issues, see Disk Bottleneck Detected.

For more information about how to size and optimize disks for Exchange Server, see "How to Calculate Your Disk I/O Requirements" and "Best Practices Common to Multiple Architectures" in Optimizing Storage for Exchange Server 2003 (

For more information about ESE, see "Extensible Storage Engine Architecture" (