Query on PMM-QAN

Hi @Ivan_Groenewold ,

Hope you are doing good.

I have a query regarding PMM-QAN for MongoDB.
How can we correlate the data collected by QAN with the data captured under system.profile collection?

Say for example, I want to capture a long running query from PMM and kill it, how can I search for that query in system.profile collection? I don’t see operation ID being captured by PMM-QAN under explain section.

Request you to help me out.

Kiran Gelli

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Hello Kiran, I am not sure that can be done. Did you check on the “Examples” tab of PMM query analytics? there is some additional info that might be useful.

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Thanks for your response @Ivan_Groenewold

However, I’m unable to view any operation ID being captured under QAN examples section.

Also, what is the min server configuration required for PMM server to monitor around 40 MongoDB Instances?

Our PMM server has 4 cores CPU/32 GB RAM

The reason for this ask - I see failed to establish 2 way communication errors on the PMM-agent service logs and I had to restart the agent to fix.

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In terms of resources your server looks good for that number of instances.

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Hi @Ivan_Groenewold

Currently, I am seeing the below errors with respect to pmm-agent service on the monitored mongoDB Instances.

Error 1:

couldn’t add document to aggregator agentID=/agent_id/5f4075d5-c97e-47a5-b042-3ae28084cbad component=agent-builtin type=qan_mongodb_profiler_agent

Error 2:

incomplete read of message header: context deadline exceeded: cannot explain this type of query. component=actions-runner id=/action_id/0577e31a-81d7-4acc-9220-98c49275b02c type=mongodb-explain

I am seeing these errors very often and I had to restart pmm-agent service to fix.

How can we avoid these errors? Please help me out.

Thank you,

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