Cube Cluster

Methodology

Cube Cluster uses two methods to distribute model processes:

Intrastep distributed processing (IDP):
Cube Cluster splits the zone-based processing from a single step into zone groups, and distributes the groups to available computer processorss. For example, when running a mode choice model, Cube Cluster might process origin zones 1–100 on one PC and origin zones 101–200 on a second PC.

Multistep distributed processing (MDP):
Cube Cluster distributes blocks of one or more independent modeling steps across available processors. For example, Cube Cluster might run the trip generation model on one PC and the network building and skimming on a second PC.

Cube Cluster is an extension to Cube Base. In the initial version, Cube Cluster supports MDP with all Cube-initiated processes and IDP with two Cube Voyager programs:

> Highway — Used for traffic assignments and skimming
> Matrix — Used for demand model and matrix manipulation

Many travel models use these two programs for large and complex processes.

For example, you might use both IDP and MDP to complete morning (AM), evening (PM), and off-peak (OP) assignments in parallel on twelve computers. You could divide your computers into separate categories:

> Main computer
> Group A (computers 1-4)
> Group B (computers 1-4)
> Group C (computers 2-4)
cluster
Cube Cluster

Methodology

Cube Cluster uses two methods to distribute model processes:

Intrastep distributed processing (IDP):
Cube Cluster splits the zone-based processing from a single step into zone groups, and distributes the groups to available computer processorss. For example, when running a mode choice model, Cube Cluster might process origin zones 1–100 on one PC and origin zones 101–200 on a second PC.

Multistep distributed processing (MDP):
Cube Cluster distributes blocks of one or more independent modeling steps across available processors. For example, Cube Cluster might run the trip generation model on one PC and the network building and skimming on a second PC.

Cube Cluster is an extension to Cube Base. In the initial version, Cube Cluster supports MDP with all Cube-initiated processes and IDP with two Cube Voyager programs:

> Highway — Used for traffic assignments and skimming
> Matrix — Used for demand model and matrix manipulation

Many travel models use these two programs for large and complex processes.

For example, you might use both IDP and MDP to complete morning (AM), evening (PM), and off-peak (OP) assignments in parallel on twelve computers. You could divide your computers into separate categories:

> Main computer
> Group A (computers 1-4)
> Group B (computers 1-4)
> Group C (computers 2-4)
cluster