Re: Sync Rep v19

On 2011-03-03 11:53, Simon Riggs wrote:
> Latest version of Sync Rep, which includes substantial internal changes
> and simplifications from previous version. (25-30 changes).
>
> Includes all outstanding technical comments, typos and docs. I will
> continue to work on self review and test myself, though actively
> encourage others to test and report issues.
>
> Interesting changes
>
> * docs updated
>
> * names listed in synchronous_standby_names are now in priority order
>
> * synchronous_standby_names = "*" matches all standby names
>
> * pg_stat_replication now shows standby priority - this is an ordinal
> number so "1" means 1st, "2" means 2nd etc, though 0 means "not a sync
> standby".
Some initial remarks:

1) this works nice:
application_name not in synchronous_standby_names -> sync_priority = 0 (OK)
change synchronous_standby_names to default *, reload conf ->
sync_priority = 1 (OK)

message in log file
LOG: 00000: standby "walreceiver" is now the synchronous standby with
priority 1

2) priorities
I have to get used to mapping the integers to synchronous replication
meaning.
0 -> asynchronous
1 -> the synchronous standby that is waited for
2 and higher -> potential syncs

Could it be hidden from the user? I liked asynchronous / synchronous /
potential synchronous

then the log message could be
LOG: 00000: standby "walreceiver" is now the synchronous standby

3) walreceiver is the default application name - could there be problems
when a second standby with that name connects (ofcourse the same
question holds for two the same nondefault application_names)?

regards
Yeb Havinga