mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-30 22:51:14 +02:00
When WalSndCaughtUp, sleep only in WalSndWaitForWal().
Before sleeping, WalSndWaitForWal() sends a keepalive if MyWalSnd->write < sentPtr. That is important in logical replication. When the latest physical LSN yields no logical replication messages (a common case), that keepalive elicits a reply, and processing the reply updates pg_stat_replication.replay_lsn. WalSndLoop() lacks that; when WalSndLoop() slept, replay_lsn advancement could stall until wal_receiver_status_interval elapsed. This sometimes stalled src/test/subscription/t/001_rep_changes.pl for up to 10s. Discussion: https://postgr.es/m/20200406063649.GA3738151@rfd.leadboat.com
This commit is contained in:
parent
969f9d0b4b
commit
4216858122
@ -1428,8 +1428,10 @@ WalSndWaitForWal(XLogRecPtr loc)
|
||||
/*
|
||||
* We only send regular messages to the client for full decoded
|
||||
* transactions, but a synchronous replication and walsender shutdown
|
||||
* possibly are waiting for a later location. So we send pings
|
||||
* containing the flush location every now and then.
|
||||
* possibly are waiting for a later location. So, before sleeping, we
|
||||
* send a ping containing the flush location. If the receiver is
|
||||
* otherwise idle, this keepalive will trigger a reply. Processing the
|
||||
* reply will update these MyWalSnd locations.
|
||||
*/
|
||||
if (MyWalSnd->flush < sentPtr &&
|
||||
MyWalSnd->write < sentPtr &&
|
||||
@ -2314,20 +2316,16 @@ WalSndLoop(WalSndSendDataCallback send_data)
|
||||
WalSndKeepaliveIfNecessary();
|
||||
|
||||
/*
|
||||
* We don't block if not caught up, unless there is unsent data
|
||||
* pending in which case we'd better block until the socket is
|
||||
* write-ready. This test is only needed for the case where the
|
||||
* send_data callback handled a subset of the available data but then
|
||||
* pq_flush_if_writable flushed it all --- we should immediately try
|
||||
* to send more.
|
||||
* Block if we have unsent data. Let WalSndWaitForWal() handle any
|
||||
* other blocking; idle receivers need its additional actions.
|
||||
*/
|
||||
if ((WalSndCaughtUp && !streamingDoneSending) || pq_is_send_pending())
|
||||
if (pq_is_send_pending())
|
||||
{
|
||||
long sleeptime;
|
||||
int wakeEvents;
|
||||
|
||||
wakeEvents = WL_LATCH_SET | WL_EXIT_ON_PM_DEATH | WL_TIMEOUT |
|
||||
WL_SOCKET_READABLE;
|
||||
WL_SOCKET_READABLE | WL_SOCKET_WRITEABLE;
|
||||
|
||||
/*
|
||||
* Use fresh timestamp, not last_processing, to reduce the chance
|
||||
@ -2335,9 +2333,6 @@ WalSndLoop(WalSndSendDataCallback send_data)
|
||||
*/
|
||||
sleeptime = WalSndComputeSleeptime(GetCurrentTimestamp());
|
||||
|
||||
if (pq_is_send_pending())
|
||||
wakeEvents |= WL_SOCKET_WRITEABLE;
|
||||
|
||||
/* Sleep until something happens or we time out */
|
||||
(void) WaitLatchOrSocket(MyLatch, wakeEvents,
|
||||
MyProcPort->sock, sleeptime,
|
||||
|
Loading…
Reference in New Issue
Block a user