Currently the decision whether to connect to a database or not is made by
checking whether the passed "dbname" parameter is "replication". Unfortunately
this makes it impossible to connect a to a database named replication...
This is useful for future walsender commands which need database interaction.
---
src/backend/postmaster/postmaster.c | 7 ++++--
.../libpqwalreceiver/libpqwalreceiver.c | 4 ++--
src/backend/replication/walsender.c | 27 ++++++++++++++++++----
src/backend/utils/init/postinit.c | 5 ++++
src/bin/pg_basebackup/pg_basebackup.c | 4 ++--
src/bin/pg_basebackup/pg_receivexlog.c | 4 ++--
src/bin/pg_basebackup/receivelog.c | 4 ++--
7 files changed, 41 insertions(+), 14 deletions(-)
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index b223fee..05048bc 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -1806,10 +1806,13 @@ retry1:
if (strlen(port->user_name) >= NAMEDATALEN)
port->user_name[NAMEDATALEN - 1] = '\0';
- /* Walsender is not related to a particular database */
- if (am_walsender)
+ /* Generic Walsender is not related to a particular database */
+ if (am_walsender && strcmp(port->database_name, "replication") == 0)
port->database_name[0] = '\0';
+ if (am_walsender)
+ elog(WARNING, "connecting to %s", port->database_name);
+
/*
* Done putting stuff in TopMemoryContext.
*/
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
index bfaebea..c39062b 100644
--- a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
+++ b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -114,7 +114,7 @@ libpqrcv_connect(char *conninfo, XLogRecPtr startpoint)
"the primary server: %s",
PQerrorMessage(streamConn))));
}
- if (PQnfields(res) != 3 || PQntuples(res) != 1)
+ if (PQnfields(res) != 4 || PQntuples(res) != 1)
{
int ntuples = PQntuples(res);
int nfields = PQnfields(res);
@@ -122,7 +122,7 @@ libpqrcv_connect(char *conninfo, XLogRecPtr startpoint)
PQclear(res);
ereport(ERROR,
(errmsg("invalid response from primary server"),
- errdetail("Expected 1 tuple with 3 fields, got %d tuples with %d fields.",
+ errdetail("Expected 1 tuple with 4 fields, got %d tuples with %d fields.",
ntuples, nfields)));
}
primary_sysid = PQgetvalue(res, 0, 0);
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 8774d7e..6452c34 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -40,6 +40,7 @@
#include "access/transam.h"
#include "access/xlog_internal.h"
#include "catalog/pg_type.h"
+#include "commands/dbcommands.h"
#include "funcapi.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
@@ -202,10 +203,12 @@ IdentifySystem(void)
char tli[11];
char xpos[MAXFNAMELEN];
XLogRecPtr logptr;
+ char* dbname = NULL;
/*
- * Reply with a result set with one row, three columns. First col is
- * system ID, second is timeline ID, and third is current xlog location.
+ * Reply with a result set with one row, four columns. First col is system
+ * ID, second is timeline ID, third is current xlog location and the fourth
+ * contains the database name if we are connected to one.
*/
snprintf(sysid, sizeof(sysid), UINT64_FORMAT,
@@ -216,9 +219,14 @@ IdentifySystem(void)
snprintf(xpos, sizeof(xpos), "%X/%X", (uint32) (logptr >> 32), (uint32) logptr);
+ if (MyDatabaseId != InvalidOid)
+ dbname = get_database_name(MyDatabaseId);
+ else
+ dbname = "(none)";
+
/* Send a RowDescription message */
pq_beginmessage(&buf, 'T');
- pq_sendint(&buf, 3, 2); /* 3 fields */
+ pq_sendint(&buf, 4, 2); /* 4 fields */
/* first field */
pq_sendstring(&buf, "systemid"); /* col name */
@@ -246,17 +254,28 @@ IdentifySystem(void)
pq_sendint(&buf, -1, 2);
pq_sendint(&buf, 0, 4);
pq_sendint(&buf, 0, 2);
+
+ /* fourth field */
+ pq_sendstring(&buf, "dbname");
+ pq_sendint(&buf, 0, 4);
+ pq_sendint(&buf, 0, 2);
+ pq_sendint(&buf, TEXTOID, 4);
+ pq_sendint(&buf, -1, 2);
+ pq_sendint(&buf, 0, 4);
+ pq_sendint(&buf, 0, 2);
pq_endmessage(&buf);
/* Send a DataRow message */
pq_beginmessage(&buf, 'D');
- pq_sendint(&buf, 3, 2); /* # of columns */
+ pq_sendint(&buf, 4, 2); /* # of columns */
pq_sendint(&buf, strlen(sysid), 4); /* col1 len */
pq_sendbytes(&buf, (char *) &sysid, strlen(sysid));
pq_sendint(&buf, strlen(tli), 4); /* col2 len */
pq_sendbytes(&buf, (char *) tli, strlen(tli));
pq_sendint(&buf, strlen(xpos), 4); /* col3 len */
pq_sendbytes(&buf, (char *) xpos, strlen(xpos));
+ pq_sendint(&buf, strlen(dbname), 4); /* col4 len */
+ pq_sendbytes(&buf, (char *) dbname, strlen(dbname));
pq_endmessage(&buf);
}
diff --git a/src/backend/utils/init/postinit.c b/src/backend/utils/init/postinit.c
index 2eb456d..3463d3d 100644
--- a/src/backend/utils/init/postinit.c
+++ b/src/backend/utils/init/postinit.c
@@ -690,7 +690,12 @@ InitPostgres(const char *in_dbname, Oid dboid, const char *username,
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser or replication role to start walsender")));
+ }
+ if (am_walsender &&
+ (in_dbname == NULL || in_dbname[0] == '\0') &&
+ dboid == InvalidOid)
+ {
/* process any options passed in the startup packet */
if (MyProcPort != NULL)
process_startup_options(MyProcPort, am_superuser);
diff --git a/src/bin/pg_basebackup/pg_basebackup.c b/src/bin/pg_basebackup/pg_basebackup.c
index 4f22116..48c68e9 100644
--- a/src/bin/pg_basebackup/pg_basebackup.c
+++ b/src/bin/pg_basebackup/pg_basebackup.c
@@ -970,11 +970,11 @@ BaseBackup(void)
progname, "IDENTIFY_SYSTEM", PQerrorMessage(conn));
disconnect_and_exit(1);
}
- if (PQntuples(res) != 1 || PQnfields(res) != 3)
+ if (PQntuples(res) != 1 || PQnfields(res) != 4)
{
fprintf(stderr,
_("%s: could not identify system: got %d rows and %d fields, expected %d rows and %d fields\n"),
- progname, PQntuples(res), PQnfields(res), 1, 3);
+ progname, PQntuples(res), PQnfields(res), 1, 4);
disconnect_and_exit(1);
}
sysidentifier = pg_strdup(PQgetvalue(res, 0, 0));
diff --git a/src/bin/pg_basebackup/pg_receivexlog.c b/src/bin/pg_basebackup/pg_receivexlog.c
index 843fc69..d6677ca 100644
--- a/src/bin/pg_basebackup/pg_receivexlog.c
+++ b/src/bin/pg_basebackup/pg_receivexlog.c
@@ -242,11 +242,11 @@ StreamLog(void)
progname, "IDENTIFY_SYSTEM", PQerrorMessage(conn));
disconnect_and_exit(1);
}
- if (PQntuples(res) != 1 || PQnfields(res) != 3)
+ if (PQntuples(res) != 1 || PQnfields(res) != 4)
{
fprintf(stderr,
_("%s: could not identify system: got %d rows and %d fields, expected %d rows and %d fields\n"),
- progname, PQntuples(res), PQnfields(res), 1, 3);
+ progname, PQntuples(res), PQnfields(res), 1, 4);
disconnect_and_exit(1);
}
timeline = atoi(PQgetvalue(res, 0, 1));
diff --git a/src/bin/pg_basebackup/receivelog.c b/src/bin/pg_basebackup/receivelog.c
index de82ff5..b07e522 100644
--- a/src/bin/pg_basebackup/receivelog.c
+++ b/src/bin/pg_basebackup/receivelog.c
@@ -363,11 +363,11 @@ ReceiveXlogStream(PGconn *conn, XLogRecPtr startpos, uint32 timeline,
PQclear(res);
return false;
}
- if (PQnfields(res) != 3 || PQntuples(res) != 1)
+ if (PQnfields(res) != 4 || PQntuples(res) != 1)
{
fprintf(stderr,
_("%s: could not identify system: got %d rows and %d fields, expected %d rows and %d fields\n"),
- progname, PQntuples(res), PQnfields(res), 1, 3);
+ progname, PQntuples(res), PQnfields(res), 1, 4);
PQclear(res);
return false;
}
--
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