# Running multiple simultaneous interpreters/scripts **URL:** \ **Category:** Ruby\ **Created:** [June 1, 2007, 9:37pm UTC](https://www.ruby-forum.com/t/running-multiple-simultaneous-interpreters-scripts/105731 "2007-06-01T21:37:48Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![eclubb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ecc23a/32.png) [@eclubb](https://www.ruby-forum.com/u/eclubb)\ **Post date:** [June 1, 2007, 9:37pm UTC](https://www.ruby-forum.com/t/running-multiple-simultaneous-interpreters-scripts/105731/1 "2007-06-01T21:37:48Z")
I have a setup where cron is calling N instances of a particular Ruby script simultaneously. It seems that as N increases, the delay before each script executes its first line of code increases by a little less than N seconds. I’m not sure if this is an issue with cron or if it’s the cumulative startup time for N ruby interpreters. An ideas on how to speed this up to a near constant (~\<1sec) delay? Is there a way to run all N scripts simultaneously with a single interpreter process? Thanks. I’m using 1.8.5 on fc6. Earle ---
**Author:** ![eclubb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ecc23a/32.png) [@eclubb](https://www.ruby-forum.com/u/eclubb)\ **Post date:** [June 1, 2007, 9:58pm UTC](https://www.ruby-forum.com/t/running-multiple-simultaneous-interpreters-scripts/105731/2 "2007-06-01T21:58:02Z")
Earle C. wrote: > I have a setup where cron is calling N instances of a particular Ruby > script simultaneously. It seems that as N increases, the delay before > each script executes its first line of code increases by a little less > than N seconds. I’m not sure if this is an issue with cron or if it’s > the cumulative startup time for N ruby interpreters. An ideas on how to > speed this up to a near constant (~\<1sec) delay? Is there a way to run > all N scripts simultaneously with a single interpreter process? Thanks. > > I’m using 1.8.5 on fc6. Why not fork the N instances from one ruby script called by cron? ---
**Author:** ![eclubb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ecc23a/32.png) [@eclubb](https://www.ruby-forum.com/u/eclubb)\ **Post date:** [June 2, 2007, 11:03am UTC](https://www.ruby-forum.com/t/running-multiple-simultaneous-interpreters-scripts/105731/3 "2007-06-02T11:03:15Z")
On 01.06.2007 21:57, Joel VanderWerf wrote: > Why not fork the N instances from one ruby script called by cron? Or use threads to implement parallel execution. OP, what do your scripts do? Kind regards robert ---
**Author:** ![eclubb](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/ecc23a/32.png) [@eclubb](https://www.ruby-forum.com/u/eclubb)\ **Post date:** [June 2, 2007, 3:01pm UTC](https://www.ruby-forum.com/t/running-multiple-simultaneous-interpreters-scripts/105731/4 "2007-06-02T15:01:42Z")
On Sat, Jun 02, 2007 at 06:00:43PM +0900, Robert K. wrote: > > Earle C. wrote: > > > > > I have a setup where cron is calling N instances of a particular Ruby > > > script simultaneously. It seems that as N increases, the delay before > > > each script executes its first line of code increases by a little less > > > than N seconds. I’m not sure if this is an issue with cron or if it’s > > > the cumulative startup time for N ruby interpreters. An ideas on how to > > > speed this up to a near constant (~\<1sec) delay? Is there a way to run > > > all N scripts simultaneously with a single interpreter process? Thanks. Well, you can’t make a CPU run faster than itself. So let’s say for the sake of argument Ruby has a one-second startup time, and this is a CPU limitation. Then if you run five Ruby scripts in five separate interpreters, it’s going to take 5 CPU-seconds of CPU time to start them all. If they all share the CPU time equally, then it’ll be shared 5 ways, so it will take each of them 5 seconds of real time to execute their 1 CPU-second of work. If the startup overhead is a problem to you, you could just try running all the scripts one after the other within the same Ruby interpreter: #!/usr/bin/ruby # allscripts.rb require ‘script1.rb’ require ‘script2.rb’ require ‘script3.rb’ require ‘script4.rb’ require ‘script5.rb’ This may work as long as they are written in such a way that this doesn’t matter (e.g. they don’t pollute the interpreter so badly that the following one doesn’t run, or depend on atexit {} or the like to function) Alternatively, you write a single ruby process which starts and then: (1) forks off a new child for each script, or (2) starts each script in a new thread. Brian.