Parameters for Memory Pipes (SAP Library

Parameters for Memory Pipes

Data is transferred between ICM (Internet Communication Manager) and the application server (work processes in AS ABAP, server processes in AS Java) using memory pipes (MPI). These are structures based on the shared memory. The MPI interface is also used for communication between the Web Dispatcher and ICM.

The following parameters relating to memory pipes are provided:

mpi/buffer_size

Data transfer within memory pipes is conducted in blocks of a set length (MPI buffers). Parameter mpi/buffer_size defines the size of these blocks.

Caution

Do not change the default setting of this parameter without consulting SAP first.

Value Range	Unit	Default Value
32768-256K	Bytes	65536

mpi/total_size_MB

This parameter specifies in megabytes the total size of the shared memory area used for the MPIs.

Value Range	Unit	Default Value
5-1000	Megabytes	80

Recommendation

On 64 bit platforms SAP recommends a value of 400.

mpi/max_pipes

The parameter specifies the maximum number of memory pipes.

Two memory pipes are required for each HTTP connection.

The default setting only has to be changed for very big systems or for the Web dispatcher that has to keep open a lot of parallel connections.

Value Range	Unit	Default Value
50-20500	MPIs	4000