Okay, let’s talk about this ‘red pgs’ thing I was messing with recently.
Getting Started
So, I was getting really tired of my database acting up. You know how it is, things just slow down, or you get weird errors, and you’re digging through logs forever trying to figure out what went wrong after the fact. I wanted something more… immediate. Like, tell me when things are going sideways, right now. Someone mentioned this idea, kind of nicknamed ‘red pgs’ in our chat, basically making PostgreSQL shout when it’s unhappy. Sounded good to me, so I decided to dive in and see if I could make it work for my setup.
The First Steps
Naturally, I started by looking at the standard PostgreSQL logs. Set `log_statement = ‘all’` for a bit. Man, that was a firehose. Completely useless for catching specific problems in real-time, just filled up the disk. Then I fiddled with `log_min_duration_statement`. Setting it low caught too much noise, setting it high missed the sneaky slow queries. It was just annoying trying to find a balance. I realized just passively logging wasn’t gonna cut it for what I wanted.
Trying Things Out
I figured I needed active checks. My first thought was super basic: maybe just write a shell script. Something that uses `ps` to look for PostgreSQL processes running for too long? Seemed simple enough. I hacked something together. It kinda worked? Ish?
- Checked `pg_stat_activity` using psql commands inside the script.
- Tried grepping for queries running longer than, say, 30 seconds.
- If it found something, it would just echo a big red warning to my terminal.
But it felt clumsy. Really clumsy. And hitting the database with constant checks like that didn’t feel right either. Plus, `ps` doesn’t know about idle transactions holding locks, which was another pain point I wanted to catch.
Hitting Walls
Yeah, the simple script idea had problems. It would flag perfectly normal long-running reports as ‘red alerts’. Woke me up a couple of times overnight for literally nothing. False positives drive you crazy. Then I looked at some monitoring extensions for Postgres. Stuff like `pg_stat_statements` is useful, sure, but setting up a whole monitoring stack felt like overkill. I saw tools like Nagios plugins, Zabbix templates… seemed like a lot of work to configure and maintain. More stuff to potentially break. I just wanted simple flags for immediate problems, not a full dashboard.
Figuring It Out (Sort Of)
Okay, so after getting frustrated with my hacky scripts and not wanting a complex tool, I took a step back. What were the real ‘red’ situations I cared about most?
- Queries running way too long (indicating maybe a bad plan or contention).
- Transactions staying idle for ages while holding locks (blocking others).
- A sudden spike in connections (maybe a connection leak).
I decided to focus just on querying the built-in statistics views directly, but smarter this time. Instead of a constant barrage, maybe check every minute or so. I wrote slightly better scripts (still pretty basic, mind you) that specifically checked:
Long active queries: `SELECT count() FROM pg_stat_activity WHERE state = ‘active’ AND (now() – query_start) > interval ‘1 minute’;`
Idle in transaction: `SELECT count() FROM pg_stat_activity WHERE state = ‘idle in transaction’ AND (now() – state_change) > interval ‘5 minutes’;`
If these counts went above a small threshold (like, 1 or 2), then send an alert. This was way less noisy. The alert wasn’t fancy, just a simple notification using a webhook to a chat channel.
Where I Landed
So, that’s my ‘red pgs’ setup now. It’s not a product, it’s not an extension, it’s just a couple of simple, scheduled scripts querying `pg_stat_activity` for very specific conditions I care about. It checks for long runners and nasty idle transactions. It’s crude, really. But it mostly works.
It doesn’t catch everything, I’m sure. And maybe one day it’ll break or I’ll need something more robust. But for now? It gives me a heads-up on the big stuff, the real ‘red’ problems, without burying me in noise or forcing me to manage a whole new system. Took a bit of trial and error, mostly error, but I learned a lot about what goes on inside Postgres just by poking at `pg_stat_activity`. Sometimes doing it the ‘wrong’ simple way is better than the ‘right’ complex way, at least to get started.
