Gaps in CPU and memory usage trend

Hello ,

Recently i have seen gaps in CPU and memory usage trend in ignition server

On a particular project I also see some of my event script are getting skipped and delay in OPC UA tag value updation

Are these two related ???.If so what is the root cause of this issue .

I understand this is related to system performance which highly depends on how efficiently we do scripts and run SQL queries in our projects
but is there any method to regularly check for factors which affects system performance?

Does your log show “clock drift” warnings? How much physical ram does your server (or VM) have?

Hi ,

Yes i can see clock drift warning in logs i have 16 gb RAM allocated for ignition .

How much system RAM is there? What other processes are running on the system?

We have 16 GB ram dedicated for the ignition system and there is no other process running in the system

I believe the question that @pturmel and @JordanCClark are asking isn’t how much RAM is dedicated for ignition but rather how much RAM is available to the system total. Ignition or otherwise. We can clearly see from your screen shot that Ignition has been allocated 16GB.

For instance if you have 16GB of RAM available to the system and all (or a significant portion) of it is being used by Ignition, then you’re going to have issues. However, if you have 32GB of RAM available to the system then that is a different story.

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Precisely. Ignition will eventually allocate the maximum memory it is allowed and generally does not give any back. It just recycles internally. The OS needs some memory of its own to run, so it will push some of Ignition’s RAM to swap, which will cause thrashing, and your performance will be crushed. I generally do not allow Ignition to have more than half of the RAM of a system, even if totally alone on the system.


ho ok understood.My server physical have 64 GB of RAM and only runs Ignition and Postgres sql .

That’s good. So you have enough to give your Ignition VM 24GB or 32GB. Or maybe you should review how much RAM Ignition really needs and set Ignition to use, perhaps, 8GB of the 16GB in that VM.