On Tue, Jul 7, 2026 at 4:29 AM Noah Misch <[email protected]> wrote:
>
> On Mon, Jul 06, 2026 at 01:41:35PM +0800, Xuneng Zhou wrote:
> > On Mon, Jul 6, 2026 at 9:26 AM Noah Misch <[email protected]> wrote:
> > > commit 7a39f43 wrote:
> > > > --- a/src/backend/utils/activity/wait_event_names.txt
> > > > +++ b/src/backend/utils/activity/wait_event_names.txt
> > > > @@ -76,34 +76,35 @@ ABI_compatibility:
> > > >  # Wait Events - Client
> > > >  #
> > > >  # Use this category when a process is waiting to send data to or 
> > > > receive data
> > > >  # from the frontend process to which it is connected.  This is never 
> > > > used for
> > > >  # a background process, which has no client connection.
> > > >  #
> > > >
> > > >  Section: ClassName - WaitEventClient
> > > >
> > > >  CLIENT_READ  "Waiting to read data from the client."
> > > >  CLIENT_WRITE "Waiting to write data to the client."
> > > >  GSS_OPEN_SERVER      "Waiting to read data from the client while 
> > > > establishing a GSSAPI session."
> > > >  LIBPQWALRECEIVER_CONNECT     "Waiting in WAL receiver to establish 
> > > > connection to remote server."
> > > >  LIBPQWALRECEIVER_RECEIVE     "Waiting in WAL receiver to receive data 
> > > > from remote server."
> > > >  SSL_OPEN_SERVER      "Waiting for SSL while attempting connection."
> > > >  WAIT_FOR_STANDBY_CONFIRMATION        "Waiting for WAL to be received 
> > > > and flushed by the physical standby."
> > > > -WAIT_FOR_WAL_FLUSH   "Waiting for WAL flush to reach a target LSN on a 
> > > > primary."
> > > > +WAIT_FOR_WAL_FLUSH   "Waiting for WAL flush to reach a target LSN on a 
> > > > primary or standby."
> > > >  WAIT_FOR_WAL_REPLAY  "Waiting for WAL replay to reach a target LSN on 
> > > > a standby."
> > > > +WAIT_FOR_WAL_WRITE   "Waiting for WAL write to reach a target LSN on a 
> > > > standby."
> > > >  WAL_SENDER_WAIT_FOR_WAL      "Waiting for WAL to be flushed in WAL 
> > > > sender process."
> > > >  WAL_SENDER_WRITE_DATA        "Waiting for any activity when processing 
> > > > replies from WAL receiver in WAL sender process."
> > > >
> > > >  ABI_compatibility:
> > >
> > > WaitEventClient is about waiting for a socket to become readable or 
> > > writable,
> > > so I think WAIT_FOR_WAL_* events don't fit in its scope.  Sockets are 
> > > just one
> > > of the ways to be in WAIT_FOR_WAL_*; other delay sources include local 
> > > fsync
> > > and local replay, which could be disk-bound or CPU-bound.
> > >
> > > I think WAIT_FOR_WAL_* belong in WaitEventIPC.  In the absence of 
> > > objections,
> > > I'll change it that way:
> >
> > Thanks for raising this. It makes sense to me to move these events to
> > the WaitEventIPC session. I'm wondering whether this reasoning also
> > applies to WAIT_FOR_STANDBY_CONFIRMATION.
>
> It partially does.  In favor of WAIT_FOR_STANDBY_CONFIRMATION in WaitEventIPC:
>
> - It's much like SYNC_REP, which is in WaitEventIPC.
> - It's a condition variable wait, not a socket wait.
>
> In favor of keeping WAIT_FOR_STANDBY_CONFIRMATION in WaitEventClient:
>
> - The standard for reclassifying a wait event post-release is higher, since it
>   impedes comparing waits across versions.
> - The condition variable is set based on a socket read, and it's fair to treat
>   the condition variable layer as an implementation detail of little concern
>   to users.
>
> Overall, I lean toward not changing WAIT_FOR_STANDBY_CONFIRMATION.

Thanks for clarification. I'm also ok with the status quo.

-- 
Regards,
Xuneng Zhou
HighGo Software Co., Ltd.


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