postgresml/pgcat

Pgcat is not working with asyncpg python client and I am getting this error in logs ERROR `pgcat::client] Unexpected code: H`

Opened this issue · 12 comments

chethankumar4046 commented

** Pgcat is not working with asyncpg python client, but working psycopg2 python client**
Basically i am going to say pgcat not working with synchronisation with python

To Reproduce
Steps to reproduce the behavior:

  1. use this image and deploy either in docker or kubernets ghcr.io/postgresml/pgcat:latest

  2. And use bellow config to run deployment
    pgcat_config.txt

  3. by running this code you will get issue
    pgcat_test.txt

levkk commented

Hi,

Thank you for reporting the issue. Could you run PgCat with RUST_LOG=debug and provide us with the output? Also curious what errors you get in Python. I think I have a hunch about what could be wrong (async protocol is slightly different than sync - PgCat actually implements the sync protocol I believe). We may need to listen for both server and client messages at the same time, since async sends multiple queries without waiting for server responses.

chethankumar4046 commented

@levkk
As you sugguested i have run deployment with RUST_LOG=debug here is the log
[2023-04-10T07:21:56.208307Z DEBUG pgcat::client] Password authentication successful [2023-04-10T07:21:56.208456Z INFO pgcat::client] Client 127.0.0.1:57072 connected (plain) [2023-04-10T07:21:56.498748Z DEBUG pgcat::query_router] Query parser enabled: false [2023-04-10T07:21:56.498775Z DEBUG pgcat::client] Waiting for connection from pool [2023-04-10T07:21:56.498780Z DEBUG pgcat::pool] Address { id: 0, host: "db-cluster-ha.postgresql.svc.cluster.local", port: 5432, shard: 0, database: "test", role: Primary, replica_number: 0, address_index: 0, username: "temp_test4", pool_name: "temp", mirrors: [], stats: AddressStats { total_xact_count: 1, total_query_count: 3, total_received: 666, total_sent: 234, total_xact_time: 0, total_query_time: 2, total_wait_time: 29218, total_errors: 0, avg_query_count: 0, avg_query_time: 0, avg_recv: 41, avg_sent: 14, avg_errors: 0, avg_xact_time: 0, avg_xact_count: 0, avg_wait_time: 1826 } } is ok [2023-04-10T07:21:56.498805Z DEBUG pgcat::client] Got connection from pool [2023-04-10T07:21:56.498810Z DEBUG pgcat::client] Client 127.0.0.1:57072 talking to server Address { id: 0, host: "db-cluster-ha.postgresql.svc.cluster.local", port: 5432, shard: 0, database: "test", role: Primary, replica_number: 0, address_index: 0, username: "temp_test4", pool_name: "temp", mirrors: [], stats: AddressStats { total_xact_count: 1, total_query_count: 3, total_received: 666, total_sent: 234, total_xact_time: 0, total_query_time: 2, total_wait_time: 29221, total_errors: 0, avg_query_count: 0, avg_query_time: 0, avg_recv: 41, avg_sent: 14, avg_errors: 0, avg_xact_time: 0, avg_xact_count: 0, avg_wait_time: 1826 } } [2023-04-10T07:21:56.498823Z ERROR pgcat::client] Unexpected code: H

And output of python script is hungs for ever

  • 👍1
levkk commented

I see. Looks like we just need to implement H (Flush) 1. When receiving that message, we need to write out the client buffer to the server.

martiGIT commented

Its still in-motion as pull request failed build in CI #412
any option to fix that?

levkk commented

Yeah, that PR isn't quite right. I haven't had a chance to take a look at it yet, but if you have some time, a PR implementing support for async is welcome.

decarbonise commented

Just wanted to bump this. I'd love to use pgcat but we rely on asyncg so we need this feature before we can do so. Thanks!

  • 👍3
olivierACRI commented

Hi,
I am facing the same error using Nodejs Async library (node-postgres) but it looks like the query are working, so I would say that most of the issue is in the flooding errors in the logs.

ayZagen commented

My application with https://github.com/porsager/postgres library is not working also. I tried different pool modes (session and transaction) with prepared_statements_cache_size set to 0 or any number, still the queries fail with this error.

optroodt commented

Adding to this, hoping to give the issue some more attention. 😇

We are running into the same issue (pgcat-1 | 2024-08-02T09:15:29.638103Z ERROR ThreadId(07) pgcat::client: Unexpected code: H) and then hangs.

Our stack:

  • FastAPI (async)
  • SqlAlchemy
  • asyncpg

It works fine using Flask (sync).

We'd love to start using PgCat!

pchaseh commented

I have the same problem, missing async support makes this project non-viable for a lot of users so it would be great to have

AkritW commented

I also would love to have async support

mattaltberg commented

Following