Metric Extension : CPU usage and capacity planning

CPU usage is one of the KPIs usually used for capacity planning, it’s supposed to allow us to determine the remaining available capacity. But with hyper-threading enabled things can become much more complicated as the Linux operating system assumes that all threads are equal and thus overstates the CPU capacity. So the CPU usage may be wrongly interpreted if we don’t take into account that !

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Metric Extension : HugePages & capacity planning

For big database servers (used for consolidating multiple databases) with a lot of memory and a lot of preallocated free HugePages it’s important to take into consideration the number of free HugePage for capacity planning .

The default “memory used” metric calculated as (MemTotal – (MemFree + Buffers + Cached)) and as (MemTotal – (MemFree – Buffers – Cached – Slab)) in recent version as shown by the free command  (Ref: https://access.redhat.com/solutions/406773) don’t take into consideration the amount of Free HugePages. Using the metric extension feature of cloud control we can easily alleviate that.

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