Set up a highly available sysplex environment
Set up a highly available sysplex environment enables you to control application rollout and workload routing.
- A highly available sysplex environment must include at least two logical partitions (LPARs). These LPARs should be on separate hardware instances to eliminate hardware single points of failure (SPOFs).
- There must be a network path redundancy leading up to the web servers and Applications Servers in the sysplex.
- If we are using HTTP sessions, session state must be shared between cluster member using the data replication service (DRS), or the session data must be stored in DB2 . If we are using stateful session Enterprise JavaBeans (EJBs), the stateful session persistent store must be configured on a shared HFS. It is not recommended that you use stateful session Enterprise JavaBeans.
Complete the following actions to set up a highly available sysplex environment.
- Configure a node on each LPAR configured in the Network Deployment cell. The deployment manager Server, which is required, must be configured on its own node. It can be configured on either LPAR or on a separate LPAR.
- Use the console to verify that a location service daemon has been defined on each LPAR that has one or more nodes in the same cell.
- Define an application server on each node, and form all of the application servers into a cluster.
See the topic Add members to a cluster for more information on how to add application servers to a cluster.
- Define the following dynamic virtual IP addresses (DVIPAs) through the z/OS Operating System's Sysplex Distributor.
- Define a dynamic virtual IP address as the IP name of the daemon for the cell. This IP address enables WLM-balanced workload routing and fail over between the LPARs for IIOP requests.
- Define a dynamic virtual IP address as the HTTP transport channel name for the cell. This IP address enables WLM-balanced routing and fail over between the LPARs for sessionless HTTP requests.
See the z/OS Communications Server IP Configuration Guide for the version of the z/OS operating system for a description of how to define IP addresses through the z/OS Sysplex Distributor. This publication is available at http://www.ibm.com/servers/eserver/zseries/zos/bkserv/v1r4books.html.
- Define a static IP address for each node as an auxiliary HTTP transport channel name for the cell. This IP address enables directed HTTP routing for sessional HTTP requests.
- Configure web server plug-ins in each of the web servers. Configure the plug-ins to use the HTTP DVIPA for sessionless requests and the static IP addresses for sessional requests.
- (zos) Sysplex Distributor
The IBM-recommended implementation, if you are running in a sysplex, is to set up the TCP/IP network with Sysplex Distributor. This makes use of dynamic virtual IP addresses (DVIPAs), which increase availability and aid in workload balancing.
- (zos) Set up the Server Runtime on multiple systems in a sysplex
If the applications require workload balance, and high availability, and you want the ability to easily add new systems to meet demand as the workload grows, you might want to migrate your Application Server runtime and associated application servers from a monoplex to a sysplex configuration.
High availability configuration Application update procedure in a high availability environment
Stopping an application server to manually update a high availability application Modify z/OS location service daemon settings Add members to a cluster Implement a web server plug-in