Hi Isaias,
backend is portal 7.3 (java stack). below is the web dispatcher profile.
when i use old version 7.20 web disp, it is working. the issue is with latest 7.45 web disp.
# unique instance number
SAPSYSTEM = 80
# add default directory settings
DIR_EXECUTABLE = .
DIR_INSTANCE = .
# Accessibility of Message Servers
rdisp/mshost = xxx
ms/http_port = 8123
# SAP Web Dispatcher Parameter
wdisp/auto_refresh = 25
wdisp/max_servers = 100
wdisp/shm_attach_mode = 6
# configuration for large scenario
icm/max_conn = 16384
icm/max_sockets = 16384
icm/req_queue_len = 6000
icm/min_threads = 100
icm/max_threads = 250
mpi/total_size_MB = 500
mpi/max_pipes = 21000
#maximum number of concurrent connections to one server
wdisp/HTTP/max_pooled_con = 2000
wdisp/HTTPS/max_pooled_con = 2000
# SAP Web Dispatcher Ports
icm/server_port_0 = PROT=HTTP,PORT=8080
icm/server_port_1 = PROT=HTTPS,PORT=8443,TIMEOUT=1800,PROCTIMEOUT=1800
# SAP Web Dispatcher Web Administration
icm/HTTP/admin_0 = PREFIX=/sap/wdisp/admin,DOCROOT=./admin,AUTHFILE=icmauth.txt
wdisp/enable_j2ee_groups = FALSE