Configuring IPIC High Availability
An IPIC connection can use port sharing or sysplex distributor to connect to a cluster of CICS® regions. The CICS regions must be configured with the same programs, transactions, and security settings. These connections can be configured to use TLS.
Before you begin
- You should be familiar with the information on CICS IPIC high availability, which describes how IPIC HA connections are established, how high availability is maintained and how the HA reconnection feature works.
- A shared TCP/IP port must be configured by using z/OS TCP/IP port sharing or sysplex distributor, which each of the CICS regions in the cluster then listens on.
About this task
This task illustrates how to configure two IBM z/OS Connect servers (
zosConn2) each with an IPIC connection to a cluster of two CICS regions (CICS-A and CICS-B). The two CICS
regions are both configured with a generic TCPIPSERVICE that listens on shared port 2222. CICS-A is configured with a specific TCPIPSERVICE that listens on
port 1091 and CICS-B is configured with a specific
TCPIPSERVICE that listens on port 1092. Figure 1
illustrates the connections that are established on the specific ports. In normal operation,
zosConn1 is connected to CICS-A and
zosConn2 is connected to CICS-B. Each
connection can fail over to the other CICS region if one CICS regionCICS fails.
Each CICS region requires a separate IPCONN definition for
each IBM z/OS Connect server that can connect to it. Table 1 details the required settings.
|IBM z/OS Connect server||IPIC connection reference ID||zosConnectNetworkid, zosConnectApplid||CICS region||Specific TCPIPSERVICE port number||IPCONN Networkid, Applid|
|zosConn1||cicsConn||NET1, ZCONN1||CICS-A||1091||NET1, ZCONN1|
|zosConn2||cicsConn||NET2, ZCONN2||CICS-A||1091||NET2, ZCONN2|
- When using predefined IPCONNs with IPIC HA, each CICS region must have a separate IPCONN definition for each
zosconnect_cicsIpicConnectiondefinition in each IBM z/OS Connect server.
- Within a sysplex, each IPIC connection that is defined in IBM z/OS Connect must have a unique Networkid.APPLID
identifier that is specified by using the
zosConnectNetworkidattributes on the
zosconnect_cicsIpicConnectionelement. In CICS, these values must match the Applid and Networkid parameters in the IPCONN definition.
- You can share a
zosconnect_cicsIpicConnectionelement definition between IBM z/OS Connect servers only if you use autoinstalled IPCONNs and do not specify the
zosConnectNetworkidattributes on the element definition.
Configure the connections in IBM z/OS Connect.
Perform the following steps to configure each IBM z/OS Connect IPIC definition.
For example, in the server.xml for
sharedPort="true"and specify the shared port in the
portattribute.The shared port is the port number that is configured in TCP/IP port sharing or sysplex distributor, which the CICS regions listen on.
- If using predefined IPCONNs in CICS, specify
zosConnectNetworkidattributes to uniquely identify this specific connection. If using auto-installed IPCONNs, specifying these attributes is optional, and if they are not specified, names are automatically generated by CICS. Do not set the
cicsNetworkidattributes; these attributes are ignored by CICS when using a shared port.
and in the server.xml for
<zosconnect_cicsIpicConnection id="cicsConn" host="220.127.116.115" port="2222" sharedPort="true" zosConnectApplid="ZCONN1" zosConnectNetworkid="NET1"/>
<zosconnect_cicsIpicConnection id="cicsConn" host="18.104.22.1685" port="2222" sharedPort="true" zosConnectApplid="ZCONN2" zosConnectNetworkid="NET2"/>
- Define a
Configure the connections in CICS.
Perform the following steps for each CICS region.
For example, configure a generic TCPIPSERVICE for port 2222 on CICS-A and CICS-B, and a specific TCPIPSERVICE on CICS-A for port 1091 and a specific TCPIPSERVICE on CICS-B for port 1092.
- Define a specific TCPIPSERVICE to listen on a nonshared port specific to that CICS region.
Define a generic TCPIPSERVICE to listen on the shared port and set the SPECIFTCPS value to the
name of the specific TCPIPSERVICE.
For more information, see Configuring an IPIC connection in CICS.
- Optional: If using predefined IPCONNs, define an IPCONN for each
zosconnect_cicsIpicConnectiondefinition in each IBM z/OS Connect server that can connect to that CICS region.In the IPCONN definitions, the values of the Applid and Networkid parameters must match the values of the
zosConnectNetworkidattributes on the corresponding
zosconnect_cicsIpicConnectionelement in server.xml.For example, on both CICS-A and CICS-B, define two IPCONNs with Networkid.APPLIDs of NET1.ZCONN1 and NET2.ZCONN2.
- Optional: Configure a reconnect interval to periodically rebalance connections.
For example, if CICS-A and CICS-B are on different LPARS, to configure
zosConn1to preferentially connect to CICS-A and
zosConn2to preferentially connect to CICS-B, and for connections to be rebalanced every 30 minutes, update the IPIC connection definitions to add those preferences. If a time unit is not specified for the
reconnectInterval, the time is in milliseconds.
In the server.xml for
and in the server.xml for
<zosconnect_cicsIpicConnection id="cicsConn" host="22.214.171.1245" port="2222" sharedPort="true" zosConnectApplid="ZCONN1" zosConnectNetworkid="NET1" reconnectInterval="30m" preferredSpecificHost="126.96.36.199"/>
<zosconnect_cicsIpicConnection id="cicsConn" host="188.8.131.525" port="2222" sharedPort="true" zosConnectApplid="ZCONN2" zosConnectNetworkid="NET2" reconnectInterval="30m" preferredSpecificHost="184.108.40.2063"/>When a connection to CICS is established, message BAQR0680I shows the IP address of the specific port for that CICS region. If the
preferredSpecificHostis specified as a DNS address, ensure that the DNS name is for this IP address. For example, BAQR0680I: CICS connection cicsConn established to host 220.127.116.11 on port 1091 with 100 sessions.. If there is more than one CICS region on any LPAR listening on the shared port, to specify a preference, set the
preferredSpecificPortattribute to specify the preferred CICS region.Note: From IBM z/OS Connect V3.0.57, if the preferred CICS region is on the same LPAR as the IBM z/OS Connect server, you can specify