[Swift-devel] Running applications with Swift on Surveyor

[Jonathan Monette]

Hey Emalayan,
   My answers are below.

On Feb 28, 2012, at 1:53 PM, Emalayan Vairavanathan wrote:

> Hi All,
> 
> I have a quick question. 
> 
> It seems the step I was following to run the applications on BG/P with swift is different from the steps suggested by https://sites.google.com/site/exmproject/development/mosaswift. I was running applications+Swift from head node by just submitting a command below.
> 
> swift -config cf  -tc.file tc -sites.file sites.xml ftdock.swift -n=1 -list=pdb.list -grid=10
> 
> I didnt start the coaster-service but my site file was using coaster as execution-provider (in site files). Then Swift allocated some nodes and executed the job and placed the result in my home directory. (My assumption here was coaster-service and workers will be started automatically by swift). 
> 
> But the above link suggests me to use persistent-coasters, changes to coaster-config files and also to start coaster-service in the head node.
> 
> 
> Basically I have three questions:
> 
> 1) What is the different between Coasters and Persistent-Coasters?

The mechanism is name Coaster.  The persistent part of the name is for the workers, they are persistent through swift executions.  You can re-use the same workers you started with the 'start-coaster-service' script for many swift executions.  When not running in a persistent mode(i.e. the automatic mode) they coaster service and the workers are killed before swift comes to completion.

> 2) How I was able to run the swift+application without starting the coaster-service, since coaster-service is expected to be started manually (according to the above link) ? Does swift use some other mechanisms to send a job if coaster-service is not started explicitly?

So if you just say the execution provider is coaster, then Swift will start the coaster service and the workers automatically.  Swift  will then shut down the coaster service and the workers once they the swift script is done executing.  Persistent-coasters will wait until you stop the service explicitly with the 'stop-coaster-service' script.  This script will shutdown the service and any workers connected to it.

> 3) How I need to run my experiments in future with MosaStore and Swift ? Should I use Coasters / Persistent-Coasters ?

I think you want to use the persistent-coaster mode where you start the workers manually with the 'start-coaster-service' script.
> 
> Thank you
> Emalayan
> _______________________________________________
> Swift-devel mailing list
> Swift-devel at ci.uchicago.edu
> https://lists.ci.uchicago.edu/cgi-bin/mailman/listinfo/swift-devel

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/swift-devel/attachments/20120228/83a0da4c/attachment.html>