CA-GTS new option KEEPALIVE and TCPKEEPALIVE to prevent losing connection

Products

• JCLCheck Workload Automation

Issue/Introduction

PTF RO88556 supports new parameters KEEPALIVE and TCPKEEPALIVE in the CA GTS TCPIPCxx and TCPIPSxx parmlib members.  These new parameters affect the ChekPlex feature of JCLCheck.  

How do these parameters work? 

Environment

JCLCheck Workload Automation release 12.0
CA GTS release 12.0

Resolution

To prevent losing connections between the GTS servers, two new CA GTS parameters KEEPALIVE(ON), and TCPKEEPALIVE(value) are available to allow you to specify a timeout value to be used in place of the configuration default value from the TCP/IP stack.  These parameters are set in the CA GTS, and therefore no change to TCP/IP is necessary.

Usage: Add the following parameters to member TCPIPCxx, and TCPIPSxx in the CA GTS CAGSPARM library.

KEEPALIVE(ON)  - Make a SETSOCKOPT call to enable 'SO_KEEPALIVE' for the TCP/IP connection.  The default is KEEPALIVE(OFF).
TCPKEEPALIVE(number) -  Make a SETSOCKOPT call to set a value (in seconds) for TCP_KEEPALIVE.  The default value is TCPKEEPALIVE(0).   
 

Example:

KEEPALIVE(ON)
TCPKEEPALIVE(600)

 

The above parameters set a timeout value of 600 seconds.  This means that every 10 minutes we ask TCP/IP to send a small packet to keep the connection alive.  The packet that is sent is low overhead.  A low value of TCPKEEPALIVE helps to ensure that the connection remains.   

 

These parameters may be set on both ends of the connections.   If you are not experiencing connection problems between the GTS servers, then it's not necessary to set these parameters.

To display the connection status, run the following console commands:
> F cagts,TCPCLNT INFO
> F cagts,TCPSRVR INFO           
 

 

Additional Information

 Information on SO_KEEPALIVE and TCP_KEEPALIVE:
 IBM manual "z/OS Communications Server:  IP Sockets Application Programming Interface Guide and Reference