Poller Tuning - Community Tips

Once in a while I review the number of monitored elements in NPM and find myself retuning both our polling engines a job I truly dread. Not because it is a complex or an arduous task but because poller tuning isn't really an exact science, it is more like pinning the tail on the proverbial donkey.

Mostly this is because the 'max poll' calculation supplied in the admin guide doesn't really work for us; admittedly it’s a good starting point but it is only a small part of the considerations to be aware of when it comes to comprehensively tuning the polling engines. For example, other considerations might be Avg disk queue lengths on SQL server, deadlocks, network slowdowns, packet queues, server hardware performance etc.

So for the benefit of myself and others in this community I am creating this post to hopefully give users a chance to share info about home grown tips and tricks you use to tune your pollers.

Please feel free to add any tips or nuggets of info you use other than what is included in the admin guide; maybe you have you're own calculation for Polls Per Second tuning? Equally if you have any questions about Poller tuning you can submit it here such as; 'Do 'down' nodes slow the polling cycle adversely affecting the polling completion percentage etc?

I’m hoping that with the communities help we can take some of the mystery out of the black art of poller tuning

I will add some tips I use myself when tuning soon

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njoylif

I eagerly await answers to this...I sometimes find my pollers have "gone to lunch" using 95% of CPU or something, usually after a few months of running after an upgrade or something (may or may not be related to tuning .
It would be NICE to have an option to auto-tune or manual so if auto -> auto adjusts recommended polls per second as well.

Ciag

First as a small start, here are a few links to some other posts that contain in them some useful nuggets to be aware of. Some of the posts are old so a bit of the info no longer applies but they are still a good read enjoy!!

Regards

MarieB

Hi Ciaran--

Thank you so much for posting this valuable information. I am going to reference it in our Tips and Tidbits forum.

Thanks again,

mcbridea

Good stuff - also note there is a Orion Level II customer training tomorrow and Aug 19 which will cover poller tunning and other topics. Brandon Shopp will be delivering this and he is a guru on this stuff. Tomorrow is booked full but you can still register for the 19th. Here is the reg link...

https://www1.gotomeeting.com/register/985953089

Ciag

Thanks for that guys I've signed up for the session on the 19th.

I have asked these questions in the past and had intended to add the answers as a part of this post but I must have not retained them as I am unable to find them in my documentation so I'm asking them again.

1. Polling completion percentage:

A. To prevent gaps in graphs it is recommended that the polling completion percentage is above a certain mark. In the past I was told a minimum completion percentage of 99.5% was enough but more recently it was suggested that 99.7% or higher would be minimum. So just what should be the minimum polling completion percentage to aim for to prevent gaps in graphs?

B. JHow is the completion percentage calculated, is it taken directly from the polling engine values or does it consider exactly what gets written to the database as well?

C. Is it possible get a completion percentage of 100%, if not, why?

2. Assuming a poller is correctly tuned and within it's limit of elements, what might be the most likely causes to slowdown or prevent the polling cycle from completing

Eg. Down nodes, slow responding nodes?

I definitely have some useful documentation about tuning that I will fish out and upload when I get some time.

Ciag

Poller Tuning Community Tips

NOTE: Information below only applies the now old Netperfmon polling engine. It does not count for the new Collector services. The Netperfmon service will be soon phased out which will make most of the information herein redundant when that happens.

Intro

This is an adaptation of a document I created for other Admins I work with who use NPM. Within are some of the tips I have used to successfully tune my Orion NPM polling engines to achieve optimal performance from them. The majority of the information within is to be used in addition to that provided in the NPM Admin guide, as such it is assumed that the reader is familiar with the core concepts set out in the admin guide. Please feel free to add your own tips or correct any mistakes. Some of this information has been provided by SW engineers and some of it has been learned through the tuning process. I have tried to be as comprehensive as possible meaning there is probably more detail in here than is required by most but I’m hoping that it will benefit those who are in the midst of tuning or who just want to give the performance of their pollers a little kick.