[receiver/sqlquery] Add connection pool feature

[stef-philipsen-tfs]

Component(s)

receiver/sqlquery

Is your feature request related to a problem? Please describe.

Currently, when adding new metrics with the sqlquery receiver, the receiver sets up a new connection for each query.

We currently have more than 40 of these metrics, which means Open Telemetry opens more than 40 database connections.

Describe the solution you'd like

It would be better if the PostgreSQL Connection pool feature would be available for this receiver too, so that the amount of database connections can be reduced.

Describe alternatives you've considered

Updating the maximum number of connections so that more connections are allowed, but this means the database needs more resources to keep all these connections open.

Additional context

No response

[github-actions]

Pinging code owners:

• receiver/sqlquery: @dmitryax @crobert-1

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[crobert-1]

I took a quick look, sounds like a good enhancement to me.

it looks like this functionality is provided by golang's standard SQL package (example usage here), and can be implemented with all supported SQL drivers. This would require adding new configuration options and plumbing them down to here:

opentelemetry-collector-contrib/receiver/sqlqueryreceiver/receiver.go

Line 48 in 333f016

return sqlOpenerFunc(sqlCfg.Driver, sqlCfg.DataSource)