相关的NOTE:
https://launchpad.support.sap.com/#/notes/0002148910
https://launchpad.support.sap.com/#/notes/737625
https://launchpad.support.sap.com/#/notes/2007212
Cause
The task of a MPI buffer is to connect the ICM with the work processes that will process the requests:
Browser <--- network ---> ICM <--- MPI ---> work process
737625 - Parameter recommendations for Internet Communication Manager (ICM)
2007212 - Tuning SAP Web Dispatcher and ICM for high load
Proposed parameter values
You can copy/paste the following lines to your SAP Web Dispatcher or ICM profile. Then adapt icm/max_conn to suit your scenario. Leave the other values untouched except in special cases of which a few are described below. Find tables of maximum allowed values for icm/max_conn and of memory consumption depending on the value of icm/max_conn below.
# Example value for icm/max_conn
icm/max_conn = 2000
# Remaining parameters need not be touched
icm/req_queue_len = 6000
icm/min_threads = 10
icm/max_threads = 500
mpi/total_size_MB = (min(0.06 * $(icm/max_conn) + 50, 2000))
mpi/max_pipes = ($(icm/max_conn) * 2 + 100)
wdisp/HTTP/max_pooled_con = ($(icm/max_conn))
wdisp/HTTPS/max_pooled_con = ($(icm/max_conn))
As of kernel release 7.43, these values are kernel defaults. You should only set icm/max_conn in your profile.
ICM for AS ABAP (all versions) and AS Java (7.40 and higher) ignores the parameters wdisp/HTTP/max_pooled_con and wdisp/HTTPS/max_pooled_con because it communicates with the backend via shared memory.