When I run transaction SM59 and then Expand TCP/IP Connections
Select SOLMANDIAG or WEBADMIN and then Click on Connection Test
"SOLMANDIAG:Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmRc=2 thRc=679")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=17 thrc=2")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=27 thrc=2")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=2 thrc=67")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=20 thrc=2")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=20 thrc=4")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=2 thrc=679")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=17 thrc=2")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=20 thrc=236")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : cmrc=19 thrc=7")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : communication rc: cm_product_specif")
"Error when opening an RFC connection (CPIC-CALL: 'ThSAPOCMINIT' : 'thsapocminit', communication")
It looks like that the connection parameters are not adjusted to the landscape size or SOLMANDIAG is not configured correctley for all instances
1. Set parameter gw/keepalive and gw/reg_keepalive to 0
Adjust the WEBADMIN Server Count
2. Run Tcode SE37
3.Call function module FM_DIAGLS_CALC_RFC_LIST_NUMBER
4.Leave all fields blank, and press F8
5.Note down the number of EX_LISTENERS
Open the link http://<solman>:<port>/smd/Support -> Diagnostics System -> Advanced Setup -> ABAP Connectivity -> expand Configuration -> modify Server Count according to the EX_LISTENERS result -> Hit Save.
OR
Set for ABAP connectivity server count and in Visual Admin > Server > Services > Jco RFC Provider