Ongoing Calls to ESE found

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2006-07-13

The Microsoft® Exchange Server Analyzer Tool examines the Exchange Function Call Log (FCL), the Store.fcl file, for events that indicate ongoing cross-component calls from the Microsoft Exchange Information Store service (Store.exe) to the Exchange Extensible Storage Engine (ESE).

Ongoing calls are requests from the Microsoft Exchange Information Store service (Store.exe) to other components that have not received a response at the time the Exchange FCL data is written to the Store.fcl file.

The Microsoft Exchange Information Store sits on top of an Extensible Storage Engine (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 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. The latest version of the database is in memory. However, because many changes in memory are not yet on disk, the database and memory are not synchronized. The transaction log disk is always kept current with information about each transaction.

If the Exchange Server Analyzer finds that events in the Store.fcl logging file reflect ongoing calls from the Microsoft Exchange Information Store service (Store.exe) to the Extensible Storage Engine (ESE) database, the Exchange Server Analyzer displays a warning.

This warning indicates that performance may become an issue for this server. Occasional ongoing calls do not necessarily indicate a problem, but repeated ongoing calls to the same area might.

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 Microsoft Exchange Information Store service to the Extensible Storage Engine (ESE) can be caused by the following conditions:

  • Exchange online defragmentation.

  • Data backups.


    If a data backup or online defragmentation was in process during the Exchange Call Trace logging collection, you can safely ignore this warning as an indicator of an Exchange Server performance issue.

  • Bottlenecks on the database drives, for example, insufficient capacity for the number of users on the server.

  • Bottlenecks on the TEMP and TMP drives.

To resolve this error, take the following steps:

  • As a best practice, we recommend that you not overlap backup windows or online maintenance with peak-user demand intervals.

  • Make sure that the database disk drives are healthy and have sufficient throughput for the I/O load.

  • Run the Exchange Server Analyzer for an additional analysis of server issues such as message and attachment size limits. You can download the Exchange Server Analyzer at "Microsoft Exchange Server Best Practices Analyzer Tool v2.7" (

  • Review the articles in the For More Information section of this document.

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" (