Using Query Profiling

A Coveo search interface typically returns results in less than one second. When you experience slower query performances, you can temporarily enable query profiling to gather information that can help identify the cause of the problem.

To use query profiling

1. On the various Coveo servers (master, mirrors, slices, etc.) whose queries need profiling, go to the appropriate C:\tmp\ folder. Create the folder if it does not already exist.

   Note: The folder must be C:\tmp\, not C:\temp\, D:\tmp\ or any other variation.

2. In all C:\tmp\ folders where queries need profiling, create an empty KIEQueryProfiling.flag file.

3. Flags become effective (profiling activated) only once the next transaction is committed, which, by default, can take up to 5 minutes. You can make the flag effective immediately by manually forcing a commit (see Forcing the Commit of a Transaction).

4. Once the flag is effective, ensure that query performance issues occur:

   • If performance issues occur only from time to time, let query profiling run for a few days.

   • If performance issues can easily be reproduced, perform 10 to 15 slow queries.

5. Once query profiling files are acquired, turn off query profiling, in the C:\tmp\ folders, by renaming or deleting all relevant KIEQueryProfiling.flag files.

   Note: It is recommended to turn off query profiling as soon as possible to minimize the impact on server resources, particularly when the rate of queries is high.

6. Gather the master server configuration and all relevant query profiling files for each mirror and slice for the appropriate dates: 

   • [Index_Path]\Index\[Mirror_Name]\Profiling\CESProfiling-MirrorQuery_yyyy_mm-dd.txt
   • [Index_Path]\Index\[Mirror_Name]\[Slice_Name]\Profiling\CESProfiling-SliceQuery_yyyy_mm-dd.txt
   • [Index_Path]\Index\[Mirror_Name]\[Slice_Name]\Profiling\CESProfiling-SliceNestedQueries_yyy-mm-dd.txt

   Notes:

   • CES 7.0.5989– (October 2013) Profiling subfolders did not exist. Query profiling files were saved directly in the mirror and slice folders.

   • The name for both the default mirror and the default slice is Default, so a typical query profiling file path is:

     D:\CES7\Index\Default\Default\Profiling\

7. Send the gathered configuration and query profiling files to Coveo Support to get assistance in identifying the cause and solution to your query performance issue.