Dynamic load balancing

General issues of interest both for network and
individual cell parallelization.

Moderator: hines

Post Reply
sandeepb
Posts: 6
Joined: Tue Apr 21, 2015 2:16 am

Dynamic load balancing

Post by sandeepb » Mon May 04, 2015 5:45 am

Hi,

What kind of load balancing algorithm is used in parallel context ? Is it static or dynamic . I assume it is static since round robin scheduling is used. Is there any chance if it is dynamic? Can anyone suggest the work related with dynamic load balancing for parallelization?

Thank you
Sandeep

ted
Site Admin
Posts: 5724
Joined: Wed May 18, 2005 4:50 pm
Location: Yale University School of Medicine
Contact:

Re: Dynamic load balancing

Post by ted » Tue May 05, 2015 1:50 pm

sandeepb wrote:What kind of load balancing algorithm is used in parallel context ?
It's static regardless of whether you're doing multithreaded or MPI-style parallelization. If you're doing the usual MPI-style parallelization, it happens during model setup, and you're responsible for doing it.

The term "round robin scheduling" applies to time-slice multitasking, and has nothing to do with parallelization.

In the context of parallelized models, the term "round robin" refers to a very simple strategy of distributing model cells over a set of processors that "deals out" the cells, one at a time to each processor in turn, as one would deal out a deck of cards to players. It ignores the "computational complexity" of the model cells, but in most cases it works reasonably well; in those cases where it fails, other strategies such as cell splitting can be used to improve balance.

sandeepb
Posts: 6
Joined: Tue Apr 21, 2015 2:16 am

Re: Dynamic load balancing

Post by sandeepb » Wed May 06, 2015 10:39 am

Dear Ted,
Thank you for clearing the confusions.

"cell splitting" you mean multisplit and split-cell methods can be used to improve the balance ?

I came across references for multisplit method, can you please suggest any references and work related to split-cell method?

Thank you

ted
Site Admin
Posts: 5724
Joined: Wed May 18, 2005 4:50 pm
Location: Yale University School of Medicine
Contact:

Re: Dynamic load balancing

Post by ted » Wed May 06, 2015 9:50 pm

Split was a waystop on NEURON's development path toward multisplit. Multisplit is more general and is preferred for future development of user-written code.

Post Reply