Deploying APM Hotfix to address MVC tracer issue of having instance field in its implementation

Document ID : KB000006221
Last Modified Date : 14/02/2018
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Issue:

  While using a MVC tracer with instance fields, the following side effects may be seen:


 - "Aborted transactions" on agent logs. (However, this does not affect customer transactions.)
 - Incorrect associations of start trace/finish trace for MVC leading to incorrect timings.

Note: These conditions occur under high concurrency.

Environment:
APM 10.5.0 and APM 10.5.1 .Net agent with MVC Tracer enabled.
Cause:

 The MVC Tracer improperly handling instance fields. (This issue is only specific to .Net Agents with MVC Tracers enabled.)

 

Resolution:

   Request APM 10.5.0 Hotfix#6 and APM 10.5.1 Hotfix#5 from Support and deploy. Or upgrade the .Net agent to APM 10.5.2 and later where this issue is resolved. The file changed is MVC.ext.dll.

   The implementation steps are the following: 

   1. Stop the monitored .NET applications.

   2. Backup and replace MVC.ext.dll under the <.NET Agent Install>\wily\ext\.

   3. Check the GAC (Global Assembly Cache) to see if the MVC.exe.dll can be found there. If found, then back up and then delete the DLL file from GAC.

   4. Restart the monitored .NET applications.