#877 High CPU Usage With nHaystack

Keith Bishoρ Thu 10 Dec 2020

We’ve run into an issue where a Haystack connection is substantially raising the CPU usage on a Jace. The CPU is pegged at/near 100% whenever the Haystack connection is established. We’ve tried different combinations of Niagara 4.4, 4.7 and 4.9 with nHaystack 2.1.2 and 3.0.1 all with the same results (there is slightly less CPU usage on 4.4/2.1.2, but still greater than 90%)

(These images are with 4.9 and 3.0.1)

Has anyone else run into a similar issue? Or have any idea of the cause?

Alper Üzmezler Thu 10 Dec 2020


Call me since you have an environment that is in place. Let's enable spy log for these and check errors. If we can't see it, we might need to place log outs for the nhaystack. I will try to help. Also can you create a ticket on github as well.

Let's track it from here.


Mike Melillo Wed 16 Dec 2020

I have ran into high CPU Usage as well on JACEs with 2 or 3.0.1 with N4.4, 4.7, and 4.9. SoftJaces/Supervisors seem to have enough horsepower to deal with nHaystack queries from SkySpark, but on JACEs I usually resort to a process other than haystackReadAll(...) to build (either exporting portions of the system to csv, or building manually on small sites).

From what I could remember, it seemed like every time I initiated a query against the nHaystack driver, it caused a new login session with the JACE (something in how Tridium handles login sessions). Supposedly using an HTTP Basic Auth Scheme helps with this, but I didn't have much luck.

Would be curious to see the results of your guys investigation, and/or if you want to throw up your troubleshooting steps/what you modify for spy logging and maybe compare notes!

Richard McElhinney Wed 27 Jan

Hi Keith et al,

Just wanted to follow up on this. We are doing some work on nhaystack and some performance improvements have been identified. We are hoping to do a new release soon and these will be included.

I'll keep you posted.

Cheers, Richard

dan moore Wed 10 Feb

Hi Richard,

We are following developments on this issue as we have several J8000s experiencing heavy resource loading when the haystack service is activated.

If you have any progress updates, we are keen to hear them. Thank you.

Richard McElhinney Thu 11 Mar

Hi Keith and everyone following this topic.

I have just posted on the forum that a new version of nhaystack is available. There have been a number of performance improvements and I would very much like to work with you to see this update solves your challenges.

Please reach out if you have any questions.

Login or Signup to reply.