[receiver/azuremonitorreceiver] metrics aggregation filter unused and slightly with current use_batch_api:true implementation

[celian-garcia]

Component(s)

receiver/azuremonitor

What happened?

Description

From the following thread #38895 (comment)

There are two issues that should be fixed at once:

• First The metrics aggregation filter feature has been well backported to the scraper_batch, to add aggregation into composite key but the composite key is not used in the query to get metrics 😲
• Second, there is arbitrarily chosen if metricValue.Average != nil { before processing the metrics, which is obviously unwanted now that we can filter out the metrics. The reason of that choice and possible solutions are explained in the thread.

Steps to Reproduce

Special thanks to @andrewegel with this perfect reproduction #40078
I'm copy pasting it there

azuremonitor:
    auth: default_credentials
    subscription_ids: [...one-subscription...]
    use_batch_api: true
    append_tags_as_attributes: true
    services:
    - "Microsoft.Network/loadBalancers"
    - "Microsoft.Network/natgateways"
    metrics:
      "Microsoft.Network/loadBalancers":
        "VipAvailability": [average]
        "DipAvailability": [average]
        "ByteCount": [total]
        "SYNCount": [count, total]
        "SnatConnectionCount": [total]
        "AllocatedSnatPorts": [average]
        "UsedSnatPorts": [average]
      "Microsoft.Network/natgateways":
        "SNATConnectionCount": [total]
        "ByteCount": [total]
        "DatapathAvailability": [average]
    collection_interval: 300s
    initial_delay: 1s

Expected Result

We expect the metrics for which you don't have average in the filter (e,g ByteCount, SYNCount, ...) to appear in the result.

Actual Result

Only metrics that does have "average" in their filter appear in the result.

Collector version

v0.126.0

Environment information

Environment

OS: (e.g., "Ubuntu 20.04")
Compiler(if manually compiled): (e.g., "go 14.2")

OpenTelemetry Collector configuration

Log output

Additional context

No response

[github-actions]

Pinging code owners:

• receiver/azuremonitor: @nslaughter @celian-garcia

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[celian-garcia]

/labels -needs-triage help-wanted good-first-issue

[celian-garcia]

/labels never-stale

[celian-garcia]

Well considered, I will check it myself, as I have a good understanding of the problem and it's easy to unblock.
/labels -help-wanted