Tripp Lite B098048 Owners Manual for B093- B097- and B098-Series Console Serve - Page 194

10. Nagios Integration To configure additional checks, the downloaded plug-in program must be saved in the tftp addins directory on the USB flash and the downloaded text plug-in file saved in /etc/config. To enable these new additional checks, select Serial & Network: Network Port. Select Edit for the network host to be monitored and New Checks. The additional check option will be included in the updated Nagios Checks list, where you can again customize the arguments. 10.3.4 Number of Supported Devices The number of devices that can be supported by a console server is a function of the number of checks being made and how often they are performed. Access method also plays a role. The table below shows the performance of three console server models (1/2 port, 8 port and 16/48 port): Time NSCA for single check NSCA for 100 sequential checks NSCA for 10 sequential checks, batched upload NSCA for 100 sequential checks, batched upload No encryption ~ ½ second 100 seconds 1 ½ seconds 7 seconds 3DES ~ ½ second 100 seconds 2 seconds 11 seconds SSH tunnel ~ ½ second 100 seconds 1 second 6 seconds NRPE time to service 1 check NRPE time to service 10 simultaneous checks Maximum number of simultaneous checks before timeouts No encryption 1/10th second 1 second 30 SSL 1/3rd second 3 seconds 20 (1,2 and 8) or 25 (16 and 48 port) no encryption - tunneled over existing SSH session 1/8th second 1 ¼ seconds 25 (1,2 and 8 port), 35 (16 and 48 port) The results were from running tests five times in succession with no timeouts on any runs. However, there are a number of ways to increase the number of checks you can do: When using NRPE checks, an individual request will need to set up and tear down an SSL connection. This overhead can be avoided by setting up an SSH session to the console server and tunneling the NRPE port. This allows the NRPE daemon to run securely without SSL encryption, as SSH will handle security. When the console server submits NSCA results, it staggers them over a time period (e.g., 20 checks over 10 minutes will result in two check results every minute). Staggering the results like this means that in the event of a power failure or other incident that causes multiple problems, the individual refresh checks will be staggered too. NSCA checks are also batched. In the previous example, the two checks per minute will be sent through in a single transaction. 194