pgbouncer_exporter VS pgcat

Pgbouncer does have stats, you can get them using the `SHOW STATS` family of commands. You can then either manually scrape them or use something like pgbouncer_exporter[1] for Prometheus.

[1] https://github.com/prometheus-community/pgbouncer_exporter

You should check out https://github.com/levkk/pgcat

I created a pool called "yugabyte" (pools.yugabyte), with pool mode 'session', so that a session remains connected to a backend. I created a pool of servers in pools.yugabyte.shards.0 (yugabyte shards pool 0), with all three of the YSQL nodes in the YugabyteDB cluster, and gave one the role of "primary" and the two others the role of "replica". For YugabyteDB YSQL this does not make sense. Currently, pgcat allows to have the roles to be all "replica", but not have more than one "primary".

pgcat is pgbouncer rewritten in Rust with support for load balancing between replicas, failover in case a replica fails a health check, and sharding at the pooler level.

Show HN: PgCat, Postgres pooler with sharding, load balancing and failover\ (38 comments)

This is actually pretty amazing. I wouldn't normally trust a single author implemented project to sit between my application and my database, since that is a rather critical single point of failure. However, a grep that fails to find `unsafe` in a rust code base lets me know that this code is in fact pretty safe[1]. I don't need to trust the author, as much as I trust the Rust core team, and LLVM.

Since I can see basic functionality exercised in the test suites, and trust that Rust has validated its more general correctness, this gives me more confidence in your project than I would historically expect to be able to gather in such a short amount of time.

1: https://github.com/levkk/pgcat/search?q=unsafe