You should consider checking and updating your NMIS configuration to reflect these options, at least understand why you are not running the default (which may have changed in the last 15 years).
You can edit the configuration through the NMIS UI or with your favorite editor "vi /usr/local/nmis8/conf/Config.nmis"
Best Practice Configuration Options
There are some updates to improve UI and polling synchronisation. Check the following configuration option for nmis_summary_poll_cycle, it should be set to false and the summary update added to the crontab.
'nmis_summary_poll_cycle' => 'false',
The crontab should now include:
*/2 * * * * /usr/local/nmis8/bin/nmis.pl type=summary
This needs to be set to blank unless you intentionally want it to be "true".
'global_nocollect_noDescription' => '',
We have found that figures between 100 and 200 are a good compromise between maximising the benefits of pinging many nodes in parallel versus the resulting network load and delay; It is strongly recommended that you don't set this to values above 250 because that risks exceeding the linux commandline length limit, which will cause incorrect operation of fpingd.pl. Most of the time the default value for this setting works fine.
'fastping_node_poll' => '200',