Re: PostgreSQL Memory consumption is too high

[Ron Johnson <ronljohnsonjr@xxxxxxxxx>]

On Fri, Mar 14, 2025 at 7:54 AM Siraj G <tosiraj.g@xxxxxxxxx> wrote:

Hello -

I need help in determining what is consuming so much memory in the cloud SQL (GCP managed) instance running with "PostgreSQL 16.6 on x86_64-pc-linux-gnu, compiled by Debian clang version 12.0.1, 64-bit".

Server spec: 16 vcpu and 128GB

Consistently, CACHE % is 59 - 60% and USAGE is around 39 - 40%. Therefore we have just around 0.5% free available memory. 

By design, Linux uses all memory.  What the applications don't use, Linux uses to cache data.

After all, you're paying for 128GB of RAM, so you might as well put it to good use.  Since the application isn't using it, Linux uses it on your behalf..

Be concerned if USAGE is up around 90%.  Be worried if it starts using swap space (if swap even exists in GCP).

 

I ran queries to get shared_buffers and other values.

Here are the details:

shared_buffers: 42GB

work_mem: 4MB

maintenance_work_mem: 64MB

max_connections: 5900 (however, most of the times we have under 150 concurrent sessions)

There are no extensions installed.

You can probably kick work_mem up to 16MB.

 

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