Maximum parallelism determines the maximum number of parallel threads that can process a single pipeline stage. Configure the
property for the Data Integration Service based on the available hardware resources. When you increase the maximum parallelism value, you might decrease the amount of processing time.
Consider the following guidelines when you configure maximum parallelism:
Increase the value based on the number of available CPUs.
Increase the maximum parallelism value based on the number of CPUs available on the nodes where mappings run. When you increase the maximum parallelism value, the Data Integration Service uses more threads to run the mapping and leverages more CPUs. A simple mapping runs faster in two partitions, but typically requires twice the amount of CPU than when the mapping runs in a single partition.
Consider the total number of processing threads.
Consider the total number of processing threads when setting the maximum parallelism value. If a complex mapping results in multiple additional partition points, the Data Integration Service might use more processing threads than the CPU can handle.
The total number of processing threads is equal to the maximum parallelism value.
Consider the other jobs that the Data Integration Service must run.
If you configure maximum parallelism such that each mapping uses a large number of threads, fewer threads are available for the Data Integration Service to run additional jobs.
Optionally change the value for a mapping.
By default, the maximum parallelism for each mapping is set to Auto. Each mapping uses the maximum parallelism value defined for the Data Integration Service.
In the Developer tool, developers can change the maximum parallelism value in the mapping run-time properties to define a maximum value for a particular mapping. When maximum parallelism is set to different integer values for the Data Integration Service and the mapping, the Data Integration Service uses the minimum value of the two.
You cannot use the Developer tool to change the maximum parallelism value for profiles. When the Data Integration Service converts a profile job into one or more mappings, the mappings always use Auto for the mapping maximum parallelism value.