How to increase max_client pool size from 15 to 100 to fix EMAXCONNSESSION errors?

💬 Queries and Resources
1

Hi!

We are running a production application on Retool Cloud and our users are frequently hitting an infrastructure connection bottleneck. Multiple concurrent users are getting a red error banner that blocks their queries and logs from saving.

The Exact Error: submitLogs (EMAXCONNSESSION) max clients reached in session mode - max clients are limited to pool_size: 15

We can see that Retool is hard-limiting our concurrent client connections to a pool size of 15.

Because this is a live app used by our team simultaneously, a pool of 15 is easily exhausted by just a few users loading the page and triggering multiple backend queries at once.

Target Goal: We need to extend this max_client connection limit to 100 so our application can withstand normal business traffic. Is this a setting an admin can modify somewhere hidden in the Resource Advanced Options, or does a Retool Engineer need to adjust this connection proxy pool size on the backend for our subdomain? Any guidance or help from the team would be greatly appreciated!

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3

Welcome to the community, @Volodymyr_Lysenko! Thanks for reaching out.

Is this a Supabase resource? My instinct is this error is actually being thrown on the database side, not from inside Retool's backend.

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1 Like
4

Hi,

According to the supabase/postgres docs there are 2 different ports you can use which control connection pooling behaviour.

Shared pooler (Supavisor) - session mode - Port: 5432 (1 client = 1 connection)
Shared pooler (Supavisor) - transaction mode - Port: 6543 (Connection held only for the query, then returned to pool)

If you use 6543 then the connection pool is shared between clients so you shouldn’t get maxxed out. So change that on the Retool Resource.

Thanks