We kept getting this message on our forum. (like every 3-4 hours). We have 16 cores of CPU and 32GB of ram. I don’t think the resources is an issue. Oops The software powering this discussion forum encountered an unexpected problem. We apologize for the inconvenience. Detailed information about the error was logged, and an automatic notification generated. We'll take a look at it. No further action is necessary. However, if the error condition persists, you can provide additional detail, including steps to reproduce the error, by posting a discussion topic in the site's feedback category. The production log shows app/models/user_auth_token.rb:125:in `lookup' lib/auth/default_current_user_provider.rb:131:in `current_user' lib/current_user.rb:35:in `current_user' app/controllers/application_controller.rb:1047:in `rate_limit_crawlers' lib/middleware/omniauth_bypass_middleware.rb:64:in `call' lib/content_security_policy/middleware.rb:12:in `call' lib/middleware/anonymous_cache.rb:393:in `call' lib/middleware/csp_script_nonce_injector.rb:12:in `call' config/initializers/008-rack-cors.rb:14:in `call' config/initializers/100-silence_logger.rb:27:in `call' lib/middleware/enforce_hostname.rb:24:in `call' lib/middleware/request_tracker.rb:236:in `call' Unexpected error in Message Bus : ActiveRecord::ConnectionNotEstablished : connection to server at "172.17.0.2", port 5432 failed: FATAL: remaining connection slots are reserved for non-replication superuser connections Unexpected error in Message Bus : ActiveRecord::ConnectionNotEstablished : connection to server at "172.17.0.2", port 5432 failed: FATAL: remaining connection slots are reserved for non-replication superuser connections Unexpected error in Message Bus : ActiveRecord::ConnectionNotEstablished : connection to server at "172.17.0.2", port 5432 failed: FATAL: remaining connection slots are reserved for non-replication superuser connections Unexpected error in Message Bus : ActiveRecord::ConnectionNotEstablished : connection to server at "172.17.0.2", port 5432 failed: FATAL: remaining connection slots are reserved for non-replication superuser connections We set the following config in UNICORN_WORKERS: 32 UNICORN_SIDEKIQS: 2 and for psql db_shared_buffers: "4096MB" Please let me know what else I can do to improve the config and make sure the server won’t crash.

I’d give postgres (db_shared_buffers) at least 16GB if not 20. But you need to make more DB connections. I can’t remember just how to do that. I think it’s max_connections in /etc/postgresql/postgresql.conf (inside the container that’s running postgres) that you need to change.

[imagem] Jay Pfaffman: But you need to make more DB connections I think so too. :+1: [imagem] Jay Pfaffman: I’d give postgres (db_shared_buffers) at least 16GB if not 20 Are you sure about that? That seems high. See PostgreSQL: Documentation: 13: 19.4. Resource Consumption If you have a dedicated database server with 1GB or more of RAM, a reasonable starting value for shared_buffers is 25% of the memory in your system. There are some workloads where even larger settings for shared_buffers are effective, but because PostgreSQL also relies on the operating system cache, it is unlikely that an allocation of more than 40% of RAM to shared_buffers will work better than a smaller amount And this is not a dedicated database server, there are 32 unicorn processes on it as well.

[imagem] Richard - Communiteq: Are you sure about that? That seems high. I always defer to you on matters like this, and I thought I was quoting advice you’d given in the past, so, NO I am not sure. :rofl: It’s pretty clear that the connections is the issue and increasing the RAM to 25% of 32GB might help in general, but isn’t the cause of the error. EDIT: [imagem]How to scale further (2+MM posts, +80k per month) Ignore all the advice you find on the internet and set it to 40-50% of your memory. Ha! That’s exactly what I remembered, except it looks like I was going to go over 50%. . .

[imagem] Jay Pfaffman: I thought I was quoting advice you’d given in the past I plead sort-of-guilty [imagem]How to scale further (2+MM posts, +80k per month) Ignore all the advice you find on the internet and set it to 40-50% of your memory. But that was then … :wink: [imagem] Jay Pfaffman: It’s pretty clear that the connections is the issue and increasing the RAM to 25% of 32GB might help in general, but isn’t the cause of the error. :100:

[imagem] jimmy0017: We set the following config in UNICORN_WORKERS: 32 UNICORN_SIDEKIQS: 2 Why? Those are the cause of you running out of connection slots.

I believe I saw somewhere saying UNICORN WORKER should be 2 * CPU. So i did the math to be 32. Should i scale down?

We tried to change the timeout setting for PSQL by running this ALTER ROLE discourse SET statement_timeout = '30000'; . And this query is the one got blocked, once every couple hours. [image] Not sure if you or anybody else has any idea on what happened?

[imagem] jimmy0017: I believe I saw somewhere saying UNICORN WORKER should be 2 * CPU. So i did the math to be 32. Should i scale down? No, please remove this and let the defaults values take place. This is the classic case of premature optimization.

[imagem] jimmy0017: We tried to change the timeout setting for PSQL by running this ALTER ROLE discourse SET statement_timeout = '30000'; . [imagem] jimmy0017: Not sure if you or anybody else has any idea on what happened? Yes, you touched stuff you shouldn’t touch :wink:

Falha no Discourse devido a problema de conexão com PSQL

Suporte ao Produto Instalação

RGJ (Richard - Communiteq) 14 Março , 2024 20:16 5

Eu me declaro mais ou menos culpado

Mas isso foi antes…

Tópico		Respostas	Vistas
Primary Postgres database process (postmaster) eating all CPU Self-hosting server-resources	13	4504	28 Maio , 2020
Too many connections to DB, how to optimize Product Support	17	4168	27 Julho , 2017
Should I change the value of db_shared_buffers and UNICORN_WORKERS with a multi discourses server? Product Support	2	699	14 Dezembro , 2020
Digital Ocean Droplet Size Self-hosting	6	1313	19 Agosto , 2019
Postgresql OOM Errors? Product Support postgres	1	219	26 Fevereiro , 2025

Falha no Discourse devido a problema de conexão com PSQL

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