Horton

Re: Make query cancellation keys longer

Heikki Linnakangas <hlinnaka@iki.fi>

View thread View on postgr.es
From: Heikki Linnakangas <hlinnaka@iki.fi>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jelte Fennema-Nio <postgres@jeltef.nl>, pgsql-hackers <pgsql-hackers@postgresql.org>, Thomas Munro <thomas.munro@gmail.com>
Date: 2024-08-15T22:07:25Z
Lists: pgsql-hackers 
On 15/08/2024 23:20, Robert Haas wrote:
> On Thu, Aug 15, 2024 at 1:13 PM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
>> Added a "protocol_version" libpq option for that. It defaults to "auto",
>> but you can set it to "3.1" or "3.0" to force the version. It makes it
>> easier to test that the backwards-compatibility works, too.
> 
> Over on the "Add new protocol message to change GUCs for usage with
> future protocol-only GUCs" there is a lot of relevant discussion about
> how bumping the protocol version should work. This thread shouldn't
> ignore all that discussion. Just to take one example, Jelte wants to
> bump the protocol version to 3.2, not 3.1, for some reasons that are
> in the commit message for the relevant patch over there.

Ok, I've read through that thread now, and opined there too. One 
difference is with libpq option name: My patch adds "protocol_version", 
while Jelte proposes "max_protocol_version". I don't have strong 
opinions on that. I hope the ecosystem catches up to support 
NegotiateProtocolVersion quickly, so that only few people will need to 
set this option. In particular, I hope that there will never be need to 
use "max_protocol_version=3.2", because by the time we introduce version 
3.3, all the connection poolers that support 3.2 will also implement 
NegotiateProtocolVersion.

-- 
Heikki Linnakangas
Neon (https://neon.tech)

Commits

  1. Add timingsafe_bcmp(), for constant-time memory comparison

  2. Add missing declarations to pg_config.h.in

  3. docs: Add a new section and a table listing protocol versions

  4. Make cancel request keys longer

  5. libpq: Add min/max_protocol_version connection options

  6. libpq: Handle NegotiateProtocolVersion message differently

  7. docs: Update phrase on message lengths in the protocol

  8. libpq: Trace all NegotiateProtocolVersion fields

  9. libpq: Add PQfullProtocolVersion to exports.txt

  10. Move cancel key generation to after forking the backend