[procstat] Include information about number of cores

[ghost]

Feature Request

When I use cpu_usage from procstat with a multicore system, cpu percentage can be greater than 100%.
example on a 8core system and a process consuming 2 cpu :

• on top global cpu reporting with cpu
• on bottom, cpu reporting for a spécific process that consume 2 cores
  

Proposal:

Adding information of number of core on the system in order to make a graph with maxi 100% of cpu

[KostyaSha]

The same is must have for load_average devision to get single load variables.
ie. load average 15 means different for different number of cores. And resulted value may show the exact processes queue load.

Any progress for it?

[danielnelson]

It occurs to me that you could get the number of cpus by enabling the cpu plugin and performing a query like this:

show tag values cardinality from "cpu" with key = "cpu" where "cpu" != 'cpu-total' and host = 'myhost';

To do the division in a single query I think you would need ifql. We will probably not add a num cpu field to all measurements with fields that require knowing it to interpret.

[UnAfraid]

It occurs to me that you could get the number of cpus by enabling the cpu plugin and performing a query like this:

show tag values cardinality from "cpu" with key = "cpu" where "cpu" != 'cpu-total' and host = 'myhost';

To do the division in a single query I think you would need ifql. We will probably not add a num cpu field to all measurements with fields that require knowing it to interpret.

This query worked fine in Grafana/influxdb-cli, but i cannot get it to work in Chronograf, i tried:
SHOW TAG VALUES CARDINALITY FROM "cpu" WITH KEY="cpu" WHERE "cpu" != 'cpu-total' AND "host"=:host: returns no results
SHOW TAG VALUES CARDINALITY FROM "telegraf"."autogen"."cpu" WITH KEY="cpu" WHERE "cpu" != 'cpu-total' AND "host"=:host: returns empty string
SHOW TAG VALUES CARDINALITY ON "telegraf" FROM "cpu" WITH KEY="cpu" WHERE "cpu" != 'cpu-total' AND "host"=:host: returns empty string

What do i do wrong?

[danielnelson]

@UnAfraid I'm not sure what the issue might be, could you open a new issue with Chronograf?

[UnAfraid]

@UnAfraid I'm not sure what the issue might be, could you open a new issue with Chronograf?

Done: influxdata/chronograf#5237

[glinton]

Regarding the original request: would it suffice to add a flag to turn irix mode off (cpu_perc would be divided by float64(runtime.NumCPU()) before setting the cpu_used field)?

[UnAfraid]

Regarding the original request: would it suffice to add a flag to turn irix mode off (cpu_perc would be divided by float64(runtime.NumCPU()) before setting the cpu_used field)?

That would be lovely

[sjwang90]

Fixed in #6165