What Happens If 6400 Pushed Beyond Its Capacity?
Hi All. I have a 6400 HA pair running 10.2.0 LTM and very recently added ASM with seven ASM policies. Total CPU use varies between ~65% and 100% after enabling ASM. Several of our websites that have ASM policies will experience a 20x increase in traffic later this year. ASM was not part of the picture last season when we experienced the expected spike in traffic to these websites. I am not certain if the 6400 will be able to handle the load with ASM turned on now. What occurs when a dual CPU system running LTM and ASM runs out of CPU? I presume LTM side of things will be alright because my understanding is that TMM grabs one whole CPU when it starts up. I would expect CPU resources for ASM to be the issue point. What is the behaviour one would expect to see with an ASM enabled website in a condition where the BigIP is pushed to 100% CPU use? Does traffic slow down because of ASM processing or does ASM drop some traffic/connections or is ASM possibly rendered ineffective but LTM traffic is not affected?
As you might imagine, I am working on building the case for replacing these 6400s with new equipment. I am trying to establish the urgency and what-if scenarios of deciding to leave it as-is vs replacement. Thanks!