asynchronous

Specify local evaluation or analysis concurrency

Topics

concurrency_and_parallelism

Specification

• Alias: None

• Arguments: None

• Default: synchronous interface usage

Child Keywords:

Required/Optional	Description of Group	Dakota Keyword	Dakota Keyword Description
Optional		evaluation_concurrency	Determine how many concurrent evaluations Dakota will schedule
Optional		local_evaluation_scheduling	Control how local asynchronous jobs are scheduled
Optional		analysis_concurrency	Limit the number of analysis drivers within an evaluation that Dakota will schedule

Description

The optional asynchronous keyword specifies use of asynchronous protocols (i.e., background system calls, nonblocking forks, POSIX threads) when evaluations or analyses are invoked. Evaluation and analysis concurrency can be independently controlled, as can the scheduling mode (static vs. dynamic) of the local evaluations.

Default Behavior

• when running Dakota on a single processor in asynchronous mode, the default concurrency of evaluations and analyses is all concurrency that is available. The evaluation_concurrency and analysis_concurrency specifications can be used to limit this concurrency in order to avoid machine overload or usage policy violation.

• when running Dakota on multiple processors in message passing mode, the default concurrency of evaluations and analyses on each of the servers is one (i.e., the parallelism is exclusively that of the message passing). With the evaluation_concurrency and analysis_concurrency specifications, a hybrid parallelism can be selected through combination of message passing parallelism with asynchronous parallelism on each server.