To deploy Zowe high availability, you must set up the Parallel Sysplex® environment. A Parallel Sysplex is a collection of z/OS® systems that cooperatively use certain hardware and software components to achieve a high-availability workload processing environment.
Zowe high availability instances require a Sysplex environment that consists of the following:
One or more central processor complexes (CPCs) that can attach to a coupling facility
At least one coupling facility
At least one Sysplex timer
Connection to shared DASD
Shared SAF database, see Sharing a database with sysplex communication in data sharing mode
Sysplex Distributor with configured Dynamic VIPA TCP/IP address, see Configuring Sysplex Distributor for instructions
VSAM record-level sharing (RLS), see Preparing for VSAM record-level sharing
USS Shared file system, see How to share file systems in a Sysplex
JESPlex/JES2 Multi-Access Spool (MAS) environment
z/OSMF high availability, see Configuring z/OSMF high availability in Sysplex
Node.js v12.x, v14.x (except v14.17.2), or v16.x
Note: It is highly recommended that Node.js installed on a shared file system.
The following example DVIPA configuration ensures the availability of Zowe in Hot-Standby mode. For example, suppose that you have a Sysplex of two z/OS systems: A, B.
Enable dynamic XCF on each host by adding the following TCP/IP definitions:
IPCONFIG SYSPLEXROUTING DYNAMICXCF x.x.x.A 255.255.255.0 1for SYSA
IPCONFIG SYSPLEXROUTING DYNAMICXCF x.x.x.B 255.255.255.0 1for SYSB
Define a DVIPA for both systems:
VIPADYNAMIC VIPADEFINE 255.255.255.0 x.x.x.V VIPADISTRIBUTE DEFINE DISTM HOTSTANDBY x.x.x.V PORT 7554 DESTIP x.x.x.A PREFERRED x.x.x.B BACKUP ENDVIPADYNAMIC
- x.x.x.A is the home address for SYSA.
- x.x.x.B is the home address for SYSB.
- x.x.x.V is Dynamic VIP Address.
- 7554 is the port number of you Zowe API Mediation Layer Gateway. This should be the same port number you configured for
zowe.yaml. See Updating the zowe.yaml configuration file to learn more about
VIPADISTRIBUTE statement with
BACKUP settings is used to enable automatic dynamic VIPA takeover to occur, if needed.
All Zowe instances are bound to the DVIPA x.x.x.V. With both z/OS systems active in the Sysplex, the preferred Zowe instance, SYSA receives all new incoming requests.
If SYSA fails, new work requests to Zowe are routed to the server on SYSB. When SYSA resumes normal operations, new work requests for Zowe are routed to SYSA again. This is the default behavior because the
AUTOSWITCHBACK parameter of the
VIPADISTRIBUTE statement is in effect by default.
If you do not want the distributor to switch back to the preferred target when it becomes available, you can specify the
NOAUTOSWITCHBACK parameter for the
VIPADYNAMIC VIPADEFINE 255.255.255.0 x.x.x.V VIPADISTRIBUTE DEFINE DISTM HOTSTANDBY NOAUTOSWITCHBACK x.x.x.V PORT 7554 DESTIP x.x.x.A PREFERRED x.x.x.B BACKUP ENDVIPADYNAMIC