Receiving alert from Exchange_monitor Probe, without seeing a problem on that server, Niscache is abnormally large.

Document ID : KB000006168
Last Modified Date : 02/03/2018
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  • In this case below alert from exchange probe was continuously received, however there were no issues from the services running on exchange server. 

Alert:- (services_check): Find services status - communication error, Nimsoft Alarm from: server_name 


  • During research we noticed in the exchange_monitor log that services_check started but failed to lookup ntservices probe:

 exchange_monitor: services_check... 

... and failed with

 exchange_monitor: nimNamedSession: failed lookup ntservices (2) 

  • Similar messages were showing up also for ntevl, processes and perfmon probes.
  • Lookups into the controller start to fail when the alarm is seen.
  • On checking the niscache directory we saw >100,000 files.
  • A very large niscache directory can adversely impact the robot operation/connection anytime information is retrieved from it. 
UIM version - 8.4.0 Database used : Microsoft SQL exchange probe 5.20 Exchange Server 2010 Perfmon Ver:- 1.52 Ntservices Ver:- 3.24 Ntevl Ver:- 4.22 Processes Ver:- 3.75
  • The errors are due to the abnormally large niscache.
  • The large niscache is caused by the perfmon probe
Additional Information:

There is a KB Article KB000034717 niscache - what it is, what it does