Stuart Bishop <stuart at stuartbishop.net> writes:
On Thu, Nov 18, 2010 at 5:06 AM, Christopher Browne
> <cbbrowne at ca.afilias.info> wrote:
>> A thing that several of us have been ruminating over for a while is the
>> problem that people get confused about how you submit Slonik scripts,
>> you may have some actions that require waits.
>> 
>> For instance if it takes 20 minutes for SUBSCRIBE SET to complete, it's
>> pretty likely that you want to wait for that to be complete before
>> proceeding with other configuration that depends on it.
>> 
>> That is already supported today, after a fashion - you 'merely' need to
>> sprinkle your Slonik script with WAIT FOR EVENT requests.
>> 
>> But the word 'merely' seems unfair; it is rarely particularly obvious
>> what semantics are appropriate.  (It is frequently not obvious to me,
>> and I have touched a lot of the Slony codebase!)
>> 
>> The "obvious" thought which has occurred is to have Slonik commands
>> automatically wait for the appropriate events.  In effect, we'd go thru
>> each Slonik command, and have it automatically call slonik_wait_event()
>> (found in src/slonik/slonik.c), or some refactoring thereof.
>> 
>> A few questions and issues occur to me...
>> 
>> 1.  Does this seem like a worthwhile exercise?  (Alternatively...  Are
>> there other Much Bigger Issues that should be looked at first?)
> 
> I'd love it. I've gotten into the habit of sync/wait after nearly
> every statement to avoid shooting myself in the foot.

I put a sync after practically every statement too.  I've shot my self in the foot because I haven't and it hurts.  It's also not always clear to me when I should/shoudn't be doing it and it can be confusing.   If there was some way to automate this I would be very grateful.