Ever since I upgraded to 8.1.21 a week ago I have been having performance issues system wide. I upgraded from 8.1.2.
System Info:
My ignition VM has 16GB of RAM (gateway is only allocated 8GB) and has 8 virtual processors.
mySQL VM has 16GB of RAM and 4 virtual processors.
The physical server is only a few years old and is pretty high end.
64GB RAM
Intel Xeon Gold 6244 (2x)
RAID 5 configuration with SAS SSD drives. 7x drives in the RAID with a few hot spares.
Things I have noticed:
Disk utilization is extremely high all the time (80% or more)
System response time is flickers between 1ms and 1000-2000ms. Clicking through my screens and performing normal tasks are slow.
My CPU usage looks okay. Before the upgrade I averaged 12% CPU usage. After upgrade it sits around 22% give or take 4%. My logfile maintenance thread has been using about 10% CPU on average so this may be the culprit.
Memory profile is also slightly different. I allocate 8192MB of memory to the gateway. Before the upgrade I had a very consistent sawtooth pattern. The heap would usually go up to 5-5.5 GB and then after garbage collection I would drop to 1.8-2.0 GB. After the upgrade I usually go up to 6-6.2 GB and still drop down to the same 1.8-2.0 GB. There is still a sawtooth pattern.
Pretty much right after I upgraded Ignition I also put in a new PLC which has its own OPC-UA server. That is the only other thing that I changed externally.
Can answer any other questions to help figure this out. The disk utilization being very high and logfile maintenance using 10% CPU seem to be the main issues (at least I think).