shared keyword and queue name defaults.

[petersilva]

So people have queueName in many, many, many configurations only because
the default does not have the hostname in it. but removing the hostname will cause
all cases where queues are shared to be broken, and just move the queueName declaration from one place to another.

Suggestion:

shared flag (default yes)

what is WHERE? 
     if shared is True...
           ... is there a cluster name? say it's ddsr... WHERE=ddsr
              else "shared"
     else:
            WHERE=HOSTNAME
            

queueName defaults to q_${BROKER_USER}_${PROGRAM}.${WHERE}.${CONFIG}

So then people just have shared yes/no in the cluster name.

So this will make it so that the queues never have the random stuff at the end, but
we have a lot less queueName decls.

[petersilva]

@junhu3 @reidsunderland @andreleblanc11 comments?

[petersilva]

an alternative might be a string variable "scope"

queue_scope=host|cluster|shared

[reidsunderland]

I'm not sure if a whole new config options, maybe just define an environment variable?

in default.conf:

queueName q_${BROKER_USER}_${PROGRAM}.${CONFIG}.${QUEUENAME_SUFFIX}

in some configs, we'd set QUEUENAME_SUFFIX to ddsr-shared, and others ${HOSTNAME}.

The other special case is polls, where we have to use ${POST_BROKER_USER} instead of ${BROKER_USER}.

[andreleblanc11]

We could get ${BROKER_USER} to be defaulted to ${POST_BROKER_USER} for polls when it gets defined?

FYI : I haven't gone through the code. Just throwing ideas in the dark.

[petersilva]

in v2, we did a lot of that sort of defaulting stuff... and it got confusing, so have veered away from it in sr3. I'll try digging up some old examples so we can talk it over a bit.

[petersilva]

fwiw... @andreleblanc11 the code that implements ... uh.. I'lll call them inferred? defaults is here:

in sr3:

It's in the config.py finalize() routine:

https://github.com/MetPX/sarracenia/blob/development/sarracenia/config.py#L1861-L2014

in v2... it looks like it's in routines called check() ... about a dozen of them.

in v2 we would do things like guess the post_broker from the broker... I don't remember
all the situations where we did that, but it turned out to confuse more than help ...
It's one of the things that sr3 does a lot less of. Didn't find stuff written up though.

[reidsunderland]

Did this just get resolved with #1128?

[petersilva]

yeah... you're right... this is the same problem ... resolved by the above bug solution.