A casual look for similar messages using your search engine of choice should show similar historical threads and bugs being filed with different clients.
Summary:
Client is sending invalid or unexpected messages to PostgreSQL.
Where I would start:
1. Ensure pgBouncer and npgsql versions are latest supported for server version.
2. npgsql (.net library?) may also use an ODBC or JDBC driver, ensure that is up to date for server version as well if applicable.
Rational:
Checking client versions is probably less effort than performing packet capture(s) to try to determine which thing is sending bogus messages (pgBouncer or applications).
We're seeing lots of errors in postgres server logs, we have no idea about them. Especially under higher load, it seems to happen more frequently. There are thousands:
ERROR: invalid message format
FATAL: invalid frontend message type 0
FATAL: invalid frontend message type 32
FATAL: invalid frontend message type 101
FATAL: invalid frontend message type 34
FATAL: invalid frontend message type XX
.....
What does it mean and how to solve this problem?
and our environment:
npgsql -> pgBouncer 1.17 ( in transaction mode )-> pg14.4
