Comments on: Multithreading in Batch Script, Part 1: An Example

By: Jun Cao

Jun Cao — Sat, 26 Feb 2011 22:30:19 +0000

It seems can be done with START in a very simple way as below:

ECHO start run E1.exe
START /B E1.exe
ECHO start run E2.exe
E2.exe
ECHO End

Jun

By: Jun Cao

Jun Cao — Sat, 26 Feb 2011 19:07:10 +0000

Application Author and All users:

Does this â€œMultithreading in Batch Scriptâ€ only work on multiple computers or it can also work in single computer?
I am looking for a way to make â€œMultithreading Batch fileâ€ running in a single computer. For example, I want to start two executables such as E1.exe and E2.exe in a single computer.
E1.exe is a 5 seconds time delay and in its end showing â€œEnd of E1â€.
E2.exe is a 2 seconds time delay and in its end showing â€œEnd of E2â€.
I want this â€œMultithreading Batch fileâ€ starts E1.exe and E2.exe almost same time. The expect results are:
2 seconds after started this â€œMultithreading Batch fileâ€ PC showed â€œEnd of E2â€.
3 more seconds later PC showed â€œEnd of E1â€.

Could you teach me how to do it?

Thanks!

Jun

By: Neil

Neil — Fri, 21 Jan 2011 22:37:37 +0000

Very possibly:
Doing this sort of machination in batch is not going to be very efficient, at all. Plus it’s not all that easy to maintain–it’s kludgy. Writing it was largely just an exercise.

That being said; where this makes all its’ speed up is that things like ping are relatively long-running, external processes. ie, when you ping a machine, you don’t do anything until it gets back; just wait. Waiting for multiple things at once is a performance boost; but *processing* multiple things at once might be a performance hit.

Think of it like this: if you have 5 book reports to write, writing them out all at the same time is not going to be faster than doing them one-at-a-time. And the overhead of switching back and forth is likely to make it slower. OTOH, if you’re waiting for phone calls from 5 different people, you might as well get the balls all rolling at once.

If your jobs are being processed on the local machine–especially if they are processor intensive–you may not see enough gain to make this worthwhile.

If you’re triggering (and waiting for) remote tasks (eg, on a database server) then similarly; if they are intensive, you possibly might do as well to run them one at a time. But aside from doing speed tests, there isn’t a certain answer.

By: B.Torres

B.Torres — Fri, 21 Jan 2011 18:03:35 +0000

I am basically running a set of batch jobs, about 3 and 4 at a time and then checking the database to see if they are completed or not. Once they are completed, I run another set of batch jobs, about 3 or 4 at a time.
Do you think just running them off the command line one after another is just as efficient?

By: Neil

Neil — Thu, 20 Jan 2011 19:33:39 +0000

B.Torres,
It would depend on how you wanted to run things; but since this script just copies a template script and runs it, you would just adjust the template it copies. If you need to cycle them, or something, you would work out a system similar to how this deals with attached drives, or how part 2 deals with multiple computers.
You would need to work out if you were going to run the scripts repeatedly or just once each, and things like that.
If you’re just running 3-4 jobs at once and ending, and don’t really need the return codes, you might be better off just launching them as detached processes (eg, with the START command).

By: B.Torres

B.Torres — Thu, 20 Jan 2011 15:54:27 +0000

How do I use this process to run 3-4 batch jobs simultaneously from potentially the same directory. Also, I will be pinging the database to see when the job is complete.

By: Neil

Neil — Sun, 09 Aug 2009 16:49:52 +0000

Demaster, What you're looking for is covered in Part 2. Part 2 takes a second bat file, and throws it against a list of PCs. A sample second bat is included, which connects to the PC, yadda, yadda, and then cleans up after itself. If you swedge your code into the "Variable Bit" part of the script, it should do what you want.

By: Demaster

Demaster — Wed, 29 Apr 2009 07:50:02 +0000

I’d definitely like to multitask a script I’ve written in BATCH, but this process doesn’t help me. I have a zipped file on 40 servers that I’d like to decompress on each server. Currently my script does the decompression on one server…then moves to the next. Any sample ideas of how I multitask something like this to launch the process of decompression on more than one server at a time? Thanks in advance.

By: Awesome Find #7: Multithreading in Batch Scripts | Daily Cup of Tech

Awesome Find #7: Multithreading in Batch Scripts | Daily Cup of Tech — Thu, 26 Mar 2009 13:00:50 +0000

[...] Case Else: has come to the rescue by providing a two part tutorial on how to perform multithread actions using batch files! From the website: Multithreaded [...]