database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-09 06:21:09 +03:00
Code Activity

Separate messages for standby replies and hot standby feedback.

Browse Source 
Allow messages to be sent at different times, and greatly reduce
the frequency of hot standby feedback. Refactor to allow additional
message types.
This commit is contained in:
Simon Riggs
2011-02-18 11:31:49 +00:00
parent 45a6d79b17
commit 06828c5feb
3 changed files with 170 additions and 77 deletions
Download Patch File Download Diff File Expand all files Collapse all files

128
src/backend/replication/walsender.c
View File

@@ -116,7 +116,9 @@ static void WalSndKill(int code, Datum arg);
static bool XLogSend(char *msgbuf, bool *caughtup);
static void IdentifySystem(void);
static void StartReplication(StartReplicationCmd * cmd);
static void ProcessStandbyMessage(void);
static void ProcessStandbyReplyMessage(void);
static void ProcessStandbyHSFeedbackMessage(void);
static void ProcessRepliesIfAny(void);
@@ -456,42 +458,45 @@ ProcessRepliesIfAny(void)
unsigned char firstchar;
int r;
r = pq_getbyte_if_available(&firstchar);
if (r < 0)
for (;;)
{
/* unexpected error or EOF */
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected EOF on standby connection")));
proc_exit(0);
}
if (r == 0)
{
/* no data available without blocking */
return;
}
/* Handle the very limited subset of commands expected in this phase */
switch (firstchar)
{
/*
* 'd' means a standby reply wrapped in a CopyData packet.
*/
case 'd':
ProcessStandbyReplyMessage();
break;
/*
* 'X' means that the standby is closing down the socket.
*/
case 'X':
proc_exit(0);
default:
ereport(FATAL,
r = pq_getbyte_if_available(&firstchar);
if (r < 0)
{
/* unexpected error or EOF */
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid standby closing message type %d",
firstchar)));
errmsg("unexpected EOF on standby connection")));
proc_exit(0);
}
if (r == 0)
{
/* no data available without blocking */
return;
}
/* Handle the very limited subset of commands expected in this phase */
switch (firstchar)
{
/*
* 'd' means a standby reply wrapped in a CopyData packet.
*/
case 'd':
ProcessStandbyMessage();
break;
/*
* 'X' means that the standby is closing down the socket.
*/
case 'X':
proc_exit(0);
default:
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid standby closing message type %d",
firstchar)));
}
}
}
@@ -499,11 +504,9 @@ ProcessRepliesIfAny(void)
* Process a status update message received from standby.
*/
static void
ProcessStandbyReplyMessage(void)
ProcessStandbyMessage(void)
{
StandbyReplyMessage reply;
char msgtype;
TransactionId newxmin = InvalidTransactionId;
resetStringInfo(&reply_message);
@@ -523,22 +526,39 @@ ProcessStandbyReplyMessage(void)
* one type.
*/
msgtype = pq_getmsgbyte(&reply_message);
if (msgtype != 'r')
switch (msgtype)
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected message type %c", msgtype)));
proc_exit(0);
case 'r':
ProcessStandbyReplyMessage();
break;
case 'h':
ProcessStandbyHSFeedbackMessage();
break;
default:
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected message type %c", msgtype)));
proc_exit(0);
}
}
/*
* Regular reply from standby advising of WAL positions on standby server.
*/
static void
ProcessStandbyReplyMessage(void)
{
StandbyReplyMessage reply;
pq_copymsgbytes(&reply_message, (char *) &reply, sizeof(StandbyReplyMessage));
elog(DEBUG2, "write %X/%X flush %X/%X apply %X/%X xmin %u epoch %u",
elog(DEBUG2, "write %X/%X flush %X/%X apply %X/%X",
reply.write.xlogid, reply.write.xrecoff,
reply.flush.xlogid, reply.flush.xrecoff,
reply.apply.xlogid, reply.apply.xrecoff,
reply.xmin,
reply.epoch);
reply.apply.xlogid, reply.apply.xrecoff);
/*
* Update shared state for this WalSender process
@@ -554,6 +574,22 @@ ProcessStandbyReplyMessage(void)
walsnd->apply = reply.apply;
SpinLockRelease(&walsnd->mutex);
}
}
/*
* Hot Standby feedback
*/
static void
ProcessStandbyHSFeedbackMessage(void)
{
StandbyHSFeedbackMessage reply;
TransactionId newxmin = InvalidTransactionId;
pq_copymsgbytes(&reply_message, (char *) &reply, sizeof(StandbyHSFeedbackMessage));
elog(DEBUG2, "hot standby feedback xmin %u epoch %u",
reply.xmin,
reply.epoch);
/*
* Update the WalSender's proc xmin to allow it to be visible