Summary

File and semaphore errors (such as SVC-FILREM & SVC-SEMPOST) seen on MarkLogic Servers running on the Microsoft Windows platform can sometimes be attributed to Windows file system handling of MarkLogic Data files.

This article covers a number of possible sources and how to troubleshoot.

Windows File System and background services

Systems running Microsoft Windows Servers are often running Virus Scanners, Corporate Security tools and non-MarkLogic backup programs (for example: Windows Shadow copy). To avoid file access conflicts, MarkLogic recommends that all MarkLogic data files be excluded from access by any background services. As a general rule, *only* MarkLogic Server should be maintaining MarkLogic Server data files.

Troubleshooting Suggestions

If MarkLogic Server is reporting file system or semaphore errors, here are some troubleshooting suggestions: 

1. Make sure that MarkLogic Server is running under an account with adequate file-system permissions.  MarkLogic recommendation is that MarkLogic Server runs under the SYSTEM account (default).

2. If Anti-virus software is installed, configure it so that it excludes all MarkLogic Server Data files from being scanned;

3. If a shadow backup client is installed (for example: Volume shadow copy in Windows XP) configure it so that it excludes all MarkLogic Server Data files from being backed up; Recommendation is that backups of MarkLogic data files are managed by MarkLogic Server backup features.  Also note that a backup of MarkLogic Data files can not be restored unless the MarkLogic Server Database was quiesced at the time and duration of the backup.  

4. Use Process Explorer to check for other process touching ML File Handles.

http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx

You can open the procexp.exe and view->Show Lower Pane and then select view->Lower Pane->Handles.

You can watch other suspect process touching ML related file handles in Lower Pane.

5. Run chkdsk on Windows to see any bad sector or other disk issue.

6. Monitor Disk I/O usage to check for spikes in I/O usage/performance during the time that file errors are being reported by MarkLogic Server.

7. Check the Windows System Log for fsync or file system (remote file-system) related error log entries.

• Windows -> Control Panel -> Administrative tools
• Launch Event Viewer
• Expand "Windows Logs" and select “Application” -> Save All Event as Text file
• Expand "Windows Logs" and select “System” -> Save All Event as Text file