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| author | Noah Misch <noah@leadboat.com> | 2020-04-25 10:17:26 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2020-04-25 10:17:26 -0700 |
| commit | 72a3dc321d76c93842d502793f93b9dc2d2305b2 (patch) | |
| tree | 6746db005f6b8d687164347dc38246966532d2f0 /src | |
| parent | d9a4cce29d563e4e6f6eec8b807736d98b1ad553 (diff) | |
| download | postgresql-72a3dc321d76c93842d502793f93b9dc2d2305b2.tar.gz postgresql-72a3dc321d76c93842d502793f93b9dc2d2305b2.zip | |
Revert "When WalSndCaughtUp, sleep only in WalSndWaitForWal()."
This reverts commit 421685812290406daea58b78dfab0346eb683bbb. It caused
idle physical walsenders to busy-wait, as reported by Fujii Masao.
Discussion: https://postgr.es/m/20200417054146.GA1061007@rfd.leadboat.com
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/replication/walsender.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c index 0e933228fc9..0813c830269 100644 --- a/src/backend/replication/walsender.c +++ b/src/backend/replication/walsender.c @@ -1428,10 +1428,8 @@ 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, 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. + * possibly are waiting for a later location. So we send pings + * containing the flush location every now and then. */ if (MyWalSnd->flush < sentPtr && MyWalSnd->write < sentPtr && @@ -2316,16 +2314,20 @@ WalSndLoop(WalSndSendDataCallback send_data) WalSndKeepaliveIfNecessary(); /* - * Block if we have unsent data. Let WalSndWaitForWal() handle any - * other blocking; idle receivers need its additional actions. + * 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. */ - if (pq_is_send_pending()) + if ((WalSndCaughtUp && !streamingDoneSending) || pq_is_send_pending()) { long sleeptime; int wakeEvents; wakeEvents = WL_LATCH_SET | WL_EXIT_ON_PM_DEATH | WL_TIMEOUT | - WL_SOCKET_READABLE | WL_SOCKET_WRITEABLE; + WL_SOCKET_READABLE; /* * Use fresh timestamp, not last_processing, to reduce the chance @@ -2333,6 +2335,9 @@ 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, |