Setting up your EntireX Environment for Sysplex

Scenario: "I want to use Sysplex for my high availability cluster."

This document covers the following topics:


Setting Broker Attributes

graphics/zos-dvipa.png

Segmenting dynamic workload from static server and management topology is critically important. Using broker TCP/IP-specific attributes, define two separate connection points:

  • One for RPC server-to-broker and admin connections. graphics/no1.gif

  • The second for client workload connections. graphics/no2.gif

See TCP/IP-specific Attributes. Sample attribute file settings:

  Sample Attribute File Settings Note
graphics/no1.gif
PORT=1972
In this example, the HOST is not defined, so the default setting will be used (localhost).
graphics/no2.gif
HOST=10.20.74.103 (or DNS)
PORT=1811
In this example, the HOST stack is the virtual IP address. The PORT will be shared by other brokers in the cluster.

Broker Cluster Considerations

Platform-independent Considerations

We recommend the following:

  • Share configurations - you will want to consolidate as many configuration parameters as possible in the attribute setting. Keep separate yet similar attribute files.

  • Isolate workload listeners from management listeners.

z/OS-specific Considerations

  • Use Started Task names that match EntireX Broker naming conventions and have logical context.

  • z/OS supports multiple TCP/IP stacks per LPAR. EntireX Broker supports up to eight separate listeners on the same or different stacks.

Configuring Redundant RPC Servers

In addition to broker redundancy, you also need to configure your RPC servers for redundant operations. We recommend the following best practices when setting up your RPC servers:

  • General Hints
    • Make sure your definitions for CLASS/SERVER/SERVICE are identical across the clustered brokers. Using identical service names will allow the broker to round-robin messages to each of the connected RPC server instances.

    • For troubleshooting purposes, and if your site allows this, you can optionally use a different user ID for each RPC server.

    • RPC servers are typically monitored using Command Central as services of a broker.

    • Establish the broker connection using the static Broker name:port definition.

  • RPC Server for CICS
    • RPC Server for CICS instances can be configured through the ERXMAIN Macro that contains default settings and naming conventions. You can use the RPC Online Maintenance Facility to control and monitor these instances online.

    • If you are using server-side mapping files (Designer files with extension .svm) at runtime in the server-side mapping container (CICS | Batch | IMS), share the server-side mapping container across RPC server instances. Use VSAM RLS or simple share options to keep a single image of the server-side mapping container across all or groups of RPC servers (for example CICS, Batch, IMS). See Job Replacement Parameters under Simplified z/OS Installation Method.

  • RPC Server for Batch
    • Make sure logging is distinguishable through each RPC Server instance for troubleshooting purposes (e.g. JES SYSOUT).

    • If you are using server-side mapping files (Designer files with extension .svm) at runtime in the server-side mapping container (CICS | Batch | IMS), share the server-side mapping container across RPC server instances. Use VSAM RLS or simple share options to keep a single image of the server-side mapping container across all or groups of RPC servers (for example CICS, Batch, IMS). See Job Replacement Parameters under Simplified z/OS Installation Method.

  • Natural RPC Server
    • Maintain separate parameter files for each Natural RPC Server instance.

  • Notes
    • For more information see Server Mapping Files for COBOL in the Designer documentation.

    • For RPC Server for CICS and Batch:
      Server mapping files with extension .svm are no longer supported at design time by the Designer. You can still use them at runtime in a server-side mapping container. All special COBOL syntax and features supported by server mapping files with extension .svm are also covered by server mapping files with extension .cvm. See When is a Server Mapping File Required? We recommend migrating .svm files to .cvm files. See Migrating Server Mapping Files under Server Mapping Files for COBOL in the Designer documentation.

Verifying your Configuration

Here are some sample commands for verifying your cluster environment:

Start of instruction setTo display the Netstat Dynamic VIPA status

  • Enter command

    D TCPIP,TCPIPEXB,N,VIPADYN

    Status must be "ACTIVE".

    EZZ2500I NETSTAT CS V1R13 TCPIPEXB 187
    DYNAMIC VIPA:
      IP ADDRESS      ADDRESSMASK     STATUS    ORIGINATION     DISTSTAT
      10.20.74.103    255.255.255.0   ACTIVE    VIPADEFINE      DIST/DEST
        ACTTIME:      11/17/2011 09:29:13

Start of instruction setTo display the Netstat Dynamic VIPA info

  • Enter command

    D TCPIP,TCPIPEXB,N,VIPADCFG

    This shows multiple static definitions to one dynamic definition:

    EZZ2500I NETSTAT CS V1R13 TCPIPEXB 190                        
    DYNAMIC VIPA INFORMATION:                                     
      VIPA DEFINE:                                                
        IP ADDRESS       ADDRESSMASK      MOVEABLE  SRVMGR FLG    
        ----------       -----------      --------  ------ ---    
        10.20.74.103     255.255.255.0    IMMEDIATE NO            
      VIPA DISTRIBUTE:                                            
        IP ADDRESS       PORT   XCF ADDRESS      SYSPT  TIMAFF  FLG
        ----------       ----   -----------      -----  ------  ---
        10.20.74.103     18000  10.20.74.104     NO     NO        
        10.20.74.103     18000  10.20.74.114     NO     NO

Start of instruction setTo display Sysplex VIPA Dynamic configuration

  • Enter command

    D TCPIP,TCPIPEXB,SYS,VIPAD

    This verifies that multiple LPARs have been defined (MVSNAMEs):

    EZZ8260I SYSPLEX CS V1R13 166                                 
    VIPA DYNAMIC DISPLAY FROM TCPIPEXB AT AHST                    
    IPADDR: 10.20.74.103  LINKNAME: VIPL0A144A67                  
      ORIGIN: VIPADEFINE                                          
      TCPNAME  MVSNAME  STATUS RANK ADDRESS MASK    NETWORK PREFIX
      -------- -------- ------ ---- --------------- ---------------
      TCPIPEXB AHST     ACTIVE      255.255.255.0   10.20.74.0    
      TCPIPEXB BHST     BACKUP 001

Managing Brokers and RPC Servers

Lifecycle Management of Brokers

An important aspect of high availability is during planned maintenance events such as lifecycle management, applying software fixes, or modifying the number of runtime instances in the cluster. Using a virtual IP networking approach for broker clustering allows high availability to the overall working system while applying these tasks.

See Starting and Stopping the Broker in the z/OS Administration documentation.

You can ping and stop a broker using the command-line utility ETBCMD.

Lifecycle Management of RPC Servers

Starting, pinging and stopping an RPC server is described in the EntireX documentation for CICS | Batch | IMS RPC servers.

See also Operating a Natural RPC Environment in the Natural documentation.