[receiver/vcenter] Adds additional resource pool metrics

[BominRahmani]

Description:

The following PR adds these metrics

- vcenter.resource_pool.memory.swapped
- vcenter.resource_pool.memory.ballooned
- vcenter.resource_pool.memory.granted {memory_granted: shared / private}

It also adds the attribute memory_usage_type and splits up the vcenter.resource_pool.memory.usage metric into the following attributes: host, guest, overhead

Link to tracking Issue: #33607

Testing:
Golden files were generated to show the addition of the new metrics.

Documentation:
Documentation generated by make generate.

[StefanKurek]

Just some minor changes. Otherwise looks good.

[djaglowski]

Is there a reason these are separate metrics, instead of a single metric with an attribute to differentiate the data points?

In other words, are these mutually exclusive sections of memory that can be added together to represent a useful total?

Can we use well defined attributes such as system.memory.state?

[BominRahmani]

Is there a reason these are separate metrics, instead of a single metric with an attribute to differentiate the data points?

In other words, are these mutually exclusive sections of memory that can be added together to represent a useful total?

Can we use well defined attributes such as system.memory.state?

The metrics are not mutually exclusive sections of memory. Summing the different metrics together wouldn't give you any meaningful total.

[djaglowski]

I don't understand the relationship between these metrics but I am skeptical that we need four metrics with the same model to describe memory. Can you link documentation for them?

[BominRahmani]

I don't understand the relationship between these metrics but I am skeptical that we need four metrics with the same model to describe memory. Can you link documentation for them?

Yeah, heres a link for those metrics

[djaglowski]

Based on the descriptions is unclear to me why private, shared, and swapped wouldn't be the same metric. Thoughts?

[BominRahmani]

Based on the descriptions is unclear to me why private, shared, and swapped wouldn't be the same metric. Thoughts?

I'd be alright combining these three metrics and keeping the ballooned separate.

[StefanKurek]

@djaglowski I believe all the memory metrics in question are coming from here.

Also, we do have precedent for the ballooned and swapped memory metrics already exist for VMs.

Private and shared memory could possibly be combined into a single metric with an attribute differentiating them. I'm not sure what a good metric name would be though.