Hello
I want to return to this discussion, since primary_conninfo is now PGC_SIGHUP
(and I hope will not be reverted)
> On 2019-02-08 09:19:31 +0900, Michael Paquier wrote:
>> On Thu, Feb 07, 2019 at 11:06:27PM +0100, Peter Eisentraut wrote:
>> > Probably right. I figured it would be useful to see what the outcome is
>> > with primary_conninfo, so they can be treated similarly.
>>
>> The interactions with waiting for WAL to be available and the WAL
>> receiver stresses me a bit for restore_command, as you could finish
>> with the startup process switching to use restore_command with a WAL
>> receiver still working behind and overwriting partially the recovered
>> segment, which could lead to corruption. We should be *very* careful
>> about that.
>
> I'm not clear on the precise mechanics you're imagining here, could you
> expand a bit? We kill the walreceiver when switching from receiver to
> restore command, and wait for it to acknowledge that, no?
> C.F. ShutdownWalRcv() call in the lastSourceFailed branch of
> WaitForWALToBecomeAvailable().
So...
We call restore_command only when walreceiver is stopped.
We use restore_command only in startup process - so we have no race condition
between processes.
We have some issues here? Or we can just make restore_command reloadable as
attached?
regards, Sergei
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 2de21903a1..454bf95d9b 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -3303,7 +3303,8 @@ restore_command = 'copy "C:\\server\\archivedir\\%f" "%p"' # Windows
</para>
<para>
- This parameter can only be set at server start.
+ This parameter can only be set in the <filename>postgresql.conf</filename>
+ file or on the server command line.
</para>
</listitem>
</varlistentry>
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 79bc7ac8ca..f340369dcf 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -3641,7 +3641,7 @@ static struct config_string ConfigureNamesString[] =
},
{
- {"restore_command", PGC_POSTMASTER, WAL_ARCHIVE_RECOVERY,
+ {"restore_command", PGC_SIGHUP, WAL_ARCHIVE_RECOVERY,
gettext_noop("Sets the shell command that will retrieve an archived WAL file."),
NULL
},
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index e9f8ca775d..8078249e1f 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -247,7 +247,6 @@
# placeholders: %p = path of file to restore
# %f = file name only
# e.g. 'cp /mnt/server/archivedir/%f %p'
- # (change requires restart)
#archive_cleanup_command = '' # command to execute at every restartpoint
#recovery_end_command = '' # command to execute at completion of recovery
