From 6980497f7d7f4d17b918a7a433aa904943a4bb97 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon, 25 Mar 2013 11:02:55 +0200
Subject: [PATCH] Add a server version check to pg_basebackup and
pg_receivexlog.
These programs don't work against 9.0 or earlier servers, so check that when
the connection is made. That's better than a cryptic error message you got
before.
Also, these programs won't work with a 9.3 server, because the WAL streaming
protocol was changed in a non-backwards-compatible way. As a general rule,
we don't make any guarantee that an old client will work with a new server,
so check that. However, allow a 9.1 client to connect to a 9.2 server, to
avoid breaking environments that currently work; a 9.1 client happens to
work with a 9.2 server, even though we didn't make any great effort to
ensure that.
This patch is for the 9.1 and 9.2 branches, I'll commit a similar patch to
master later. Although this isn't a critical bug fix, it seems safe enough
to back-patch. The error message you got when connecting to a 9.3devel
server without this patch was cryptic enough to warrant backpatching.
---
src/bin/pg_basebackup/pg_basebackup.c | 18 ++++++++++++++++++
src/bin/pg_basebackup/pg_receivexlog.c | 18 ++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index bddd3718d44..19cc9e864e3 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -947,6 +947,9 @@ BaseBackup(void)
int i;
char xlogstart[64];
char xlogend[64];
+ int minServerMajor,
+ maxServerMajor;
+ int serverMajor;
/*
* Connect in replication mode to the server
@@ -956,6 +959,21 @@ BaseBackup(void)
/* Error message already written in GetConnection() */
exit(1);
+ /*
+ * Check server version. BASE_BACKUP command was introduced in 9.1, so
+ * we can't work with servers older than 9.1. And we don't support servers
+ * newer than the client.
+ */
+ minServerMajor = 901;
+ maxServerMajor = PG_VERSION_NUM / 100;
+ serverMajor = PQserverVersion(conn) / 100;
+ if (serverMajor < minServerMajor || serverMajor > maxServerMajor)
+ {
+ fprintf(stderr, _("%s: unsupported server version %s\n"),
+ progname, PQparameterStatus(conn, "server_version"));
+ disconnect_and_exit(1);
+ }
+
/*
* Run IDENTIFY_SYSTEM so we can get the timeline
*/
diff --git a/src/bin/pg_basebackup/pg_receivexlog.c b/src/bin/pg_basebackup/pg_receivexlog.c
index 4d91addc56d..b7df693f2dd 100644
--- a/src/bin/pg_basebackup/pg_receivexlog.c
+++ b/src/bin/pg_basebackup/pg_receivexlog.c
@@ -220,6 +220,9 @@ StreamLog(void)
PGresult *res;
uint32 timeline;
XLogRecPtr startpos;
+ int minServerMajor,
+ maxServerMajor;
+ int serverMajor;
/*
* Connect in replication mode to the server
@@ -229,6 +232,21 @@ StreamLog(void)
/* Error message already written in GetConnection() */
return;
+ /*
+ * Check server version. IDENTIFY_SYSTEM didn't return the current xlog
+ * position before 9.1, so we can't work with servers older than 9.1. And
+ * we don't support servers newer than the client.
+ */
+ minServerMajor = 901;
+ maxServerMajor = PG_VERSION_NUM / 100;
+ serverMajor = PQserverVersion(conn) / 100;
+ if (serverMajor < minServerMajor || serverMajor > maxServerMajor)
+ {
+ fprintf(stderr, _("%s: unsupported server version %s\n"),
+ progname, PQparameterStatus(conn, "server_version"));
+ disconnect_and_exit(1);
+ }
+
/*
* Run IDENTIFY_SYSTEM so we can get the timeline and current xlog
* position.
--
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