pg_upgrade: Use max_protocol_version=3.0 for older servers The grease patch in 4966bd3ed found its first problem: prior to the February 2018 patch releases, no server knew how to negotiate protocol versions, so pg_upgrade needs to take that into account when speaking to those older servers.
This will be true even after the grease feature is reverted; we don't need anyone to trip over this again in the future. Backpatch so that all supported versions of pg_upgrade can gracefully handle an update to the default protocol version. (This is needed for any distributions that link older binaries against newer libpqs, such as Debian.) Branches prior to 18 need an additional version check, for the existence of max_protocol_version. Per buildfarm member crake. Reviewed-by: Tom Lane <[email protected]> Discussion: https://postgr.es/m/CAOYmi%2B%3D4QhCjssfNEoZVK8LPtWxnfkwT5p-PAeoxtG9gpNjqOQ%40mail.gmail.com Backpatch-through: 14 Branch ------ REL_15_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/e726620d208ee1fca37a6cbfe0fc9a7031ff659e Modified Files -------------- src/bin/pg_upgrade/dump.c | 6 +++++- src/bin/pg_upgrade/pg_upgrade.h | 1 + src/bin/pg_upgrade/server.c | 2 ++ src/bin/pg_upgrade/version.c | 31 +++++++++++++++++++++++++++++++ 4 files changed, 39 insertions(+), 1 deletion(-)
