Attachment failures with "Unable to acquire a repository session. File not uploaded" error at peak hour

Document ID : KB000028427
Last Modified Date : 14/02/2018
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During peak usage hours attachments stop functioning with a message, "Unable to acquire a repository session. File not uploaded" error can be seen in the stdlog.



One possible reason is that on a busy system, the maxThreads limit of tomcat can be reached which can cause attachments to stop functioning.



 Edit server.xml in


and add the maxThreads parameter  


For example:

 change the Connector element from

 <Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443"/>


 <Connector maxThreads="300" connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="8443"/>


The maxThreads determines the maximum number of simultaneous requests that can be handled,  the default value of maxThreads is 200.


 NOTE: Ensure the system has enough hardware resource to support more concurrent sessions of tomcat.


 After modifying the server.xml, Tomcat must be restarted for the change to take effect. You can restart Tomcat by running the following commands:


 pdm_tomcat_nxd -c STOP


 pdm_tomcat_nxd -c START