Installations can enhance the performance of their JES2 members by controlling the amount of storage allocated for NJE headers and trailers through the HDRBUF= parameter on the NJEDEF initialization statement.The HDRBUF= parameter allows you to specify the number of cells allocated at initialization through the LIMIT subparameter. Use this subparameter with great care; specifying too small a value could decrease member throughput by creating resource contention for the headers and trailers.

Consider the number of jobs actively transmitted or received by your installation at one time when setting this parameter. For most installations, the JES2 default provides enough cells for NJE headers and trailers.

However, if your installation transmits many small jobs (100 lines or less) across multiple active NJE lines, JES2 transmits headers more frequently and might need a larger number of buffers. One sign that indicates your installation requires a larger LIMIT value is a shortage of virtual storage. For the exact specifications of this parameter, see z/OS JES2 Initialization and Tuning Reference.