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Summary



In some circumstance, SSNDMPC on the Filer Proxy node may intermittently fail with an Application Fault error. The problem may be addressed by introducing a new option, --svrcache, for the ssndmpc module on the Proxy server.

Symptoms



The Windows Application Event log may display:

[Error 3/22/2013 20:30 Application Error 1000 -100 Faultingapplication name: ssndmpc.EXE, version: 4.1.20743.2542, timestamp: 0x51070a57]

This may happen if the Proxy node serves multiple filers or many jobs are running at the same time. Once the ssndmpc module crashes, all running jobs fail as well.



Resolution



The problem may be addressed by introducing a new option, --svrcache, for the ssndmpc module on the Proxy server.

On a Windows installation, update the registry location:

HKEY_LOCAL_MACHINE\Software\Syncsort\BackupExpress\<your-Proxy-name-here>\0

It may display like "--filehistory=local -loglog --svrcache"

On a UNIX/Linux installation, update the file /opt/DPX/bin/ssndmpc

The content of the file may be: exec ./ndmpc --filehistory=local --logllog --svrcache

After this registry key update, the Cmagent Service on this Proxy node must be recycled.

The "--svrcache" option forces the ndmpc process to use the already cached filers configuration information instead of querying it from the filers multiple times for each Job/Task.

Note: Refreshing a filers configuration information has some side effects such that some changes of the filer is not dynamically available to the product, for example:

  • New volumes may be created on the filer, but cannot be used in the newly defined jobs since new volumes are not visible until SSNDPMC is recycled.
  • Volume was resized after reaching 10% threshold message, however, not reflected in subsequent backups until SSNDPMC is recycled.
  • Filers password may be changed, but jobs continue to run until SSNDPMC is recycled.

  1. If the "--svrcache" option is set on Proxy - refresh the filers information manually by going to Configure > Enterprise and click the filer that is using this Proxy and click the Apply button.
  2. If the "--svrcache" option is not set on Proxy - starting from DPX 4.1 and alter filer's parameters should be reflected in the product correctly.