Re: [Fab-user] How to use parallel execution via API

[Mohamed Lrhazi]

I think that's clear for me now. Thanks a lot.

Mohamed.

On Sun, Jul 15, 2012 at 7:18 PM, Jeff Forcier <address@hidden> wrote:
> On Sun, Jul 15, 2012 at 4:02 PM, Mohamed Lrhazi <address@hidden> wrote:
>> Thanks Jeff.
>>
>> If I enable parallel execution, would my disconnect_all() interrupt
>> all dispatched ssh sessions, or just the one in my iteration?
>
> I haven't tested this but I believe the answer is "yes, the latter",
> assuming you're calling disconnect_all() inside your task function.
>
> When execute()* runs a task in parallel, it creates a new subprocess
> for each host, and that process gets its own distinct copy of Fabric's
> global module state. (In fact, that copy of the cache is emptied
> before the subprocess run, so that no external connections end up
> shared between parent & children.)
>
> * Forgot to make this explicit before, but you *must* use the
> execute() function for parallelism to work, simply setting
> env.parallel and then calling eg run("foo") will not do what you want.
> Have to put run() statements inside a function and hand that function
> to execute().
>
> -Jeff
>
>> On Sun, Jul 15, 2012 at 6:42 PM, Jeff Forcier <address@hidden> wrote:
>>> On Sun, Jul 15, 2012 at 3:31 PM, Mohamed Lrhazi <address@hidden> wrote:
>>>> Is this possible? I went through the docs and it does not show any
>>>> examples of such usage, only via command line or a decorator.
>>>
>>> It could be more explicit, but it's in there if you read carefully :)
>>>
>>>     http://docs.fabfile.org/en/1.4.3/usage/parallel.html#command-line-flags
>>>
>>>     "One may also force all tasks to run in parallel by using the
>>> command-line flag -P or the env variable env.parallel."
>>>
>>> So you can tickle env.parallel directly or via 'with settings', and
>>> then task executions via execute() will run in parallel. E.g.:
>>>
>>>     with settings(parallel=True):
>>>         execute(mytaskfunction, hosts=[...])
>>>
>>> In addition, decorators are simply functions themselves and can be
>>> used to temporarily wrap otherwise un-decorated functions, so you
>>> could also:
>>>
>>>     execute(parallel(mytaskfunction), hosts=[...])
>>>
>>> Hope that helps,
>>> Jeff
>>>
>>>>
>>>> Is there a way?
>>>>
>>>> Thanks a lot,
>>>> Mohamed.
>>>>
>>>> _______________________________________________
>>>> Fab-user mailing list
>>>> address@hidden
>>>> https://lists.nongnu.org/mailman/listinfo/fab-user
>>>
>>>
>>>
>>> --
>>> Jeff Forcier
>>> Unix sysadmin; Python/Ruby engineer
>>> http://bitprophet.org
>
>
>
> --
> Jeff Forcier
> Unix sysadmin; Python/Ruby engineer
> http://bitprophet.org