The high availability (HA) deployment manager function
can be configured to eliminate single point of failure for administrative
functions in a WebSphere® Application Server
Network Deployment cell.
Before you begin
This feature is supported only on distributed
platforms and is not available on z/OS®.Privileges
for the high availability (HA) deployment manager differ, depending
on the various roles. Roles include monitor, operator, configurator,
and administrator. If you are a user with either a monitor or a configurator
role, you can only view the HA deployment manager information. If
you have the role of operator or administrator, you have all the privileges
for the HA deployment manager.
Before you follow these steps
ensure that the system environment has a suitable shared file system
available, such as IBM® SAN FS or NFS Version 4. The
shared file system requirements are the same for both the failover
of transaction logs and for the high availability deployment manager.
See the
File store high availability topic in the
WebSphere Application Server Information Center
for more information.
Note: You must stop all deployment
managers that are running in your environment before you can perform
maintenance on the NFS drive. Use the extended repository service
in conjunction with the HA deployment manager feature. In the event
of a NFS failure, you can recover the latest configuration changes
by using the extended repository service.
Each
deployment manager must share the same master configuration repository
and workspace area, which must be on the shared file system. Each
deployment manager must also have read and write permissions to the
shared master configuration repository and workspace area. The master
configuration repository and workspace area default locations are install_root/profiles/deployment_manager/config and install_root/profiles/deployment_manager/wstemp/ directories.
File sharing is typically accomplished by installing the deployment
manager on the shared file system. Sharing the entire installation
is not mandatory, and an alternative is to locate only the deployment
manager profiles on the shared file system. In the scenarios that
are described in this topic, WebSphere Virtual Enterprise is
installed on the shared file system. For scenarios in which only the
deployment manager configuration repository and workspace reside on
the Network Attached Storage (NAS), see the xd_hadmgrAdd command.
About this task
Set up a high availability deployment manager environment
to eliminate the deployment manager as a single point of failure.
When one deployment manager fails, a configured deployment manager
can resume the work. See The high availability deployment manager for more
information.
Procedure
- Choose a topology. The HA deployment manager
function can be configured in a variety of topologies. In a production
environment, it is recommended that each deployment manager runs on
its own computer to increase availability. If a single on demand router
(ODR) is in the topology, it must run on its own computer. To eliminate
the ODR as a single point of failure, you can use multiple on demand
routers in conjunction with an IP sprayer. A typical
HA deployment manager environment requires at least three computers:
Computer name |
Processes |
A |
Deployment manager |
B |
Standby deployment manager |
C |
Node agent and on demand router |
- You can either create a new cell with an HA deployment
manager configuration, or convert an existing cell to an HA deployment
manager configuration.
To create a new cell with an
HA deployment manager configuration:
- Install WebSphere Application Server on
the shared file system.
- Install WebSphere Virtual Enterprise on
the shared file system.
- Create a deployment manager profile using the IP address
for computer A.
- Start the deployment manager on computer A.
- Create a custom profile using the IP address for computer
C. Federate computer C with the deployment manager.
- Create an ODR on the federated custom profile.
- Create a deployment manager profile using the IP address
for computer B.
- Run the xd_hadmgrAdd command within the deployment manager
profile for computer B to convert it into a standby deployment manager. For more information, see xd_hadmgrAdd command.
To convert an existing cell to an HA deployment manager configuration: - Install WebSphere Application Server on
the shared file system.
- Install WebSphere Virtual Enterprise on
the shared file system.
- Create a deployment manager profile using the IP address
for computer A and with the same cell and node name as the existing
deployment manager.
- Use the backupConfig and restoreConfig command line
utilities to relocate the existing cell configuration to the shared
file system.
- Copy the tmsStorage folder
and its contents from the existing deployment manager profile to the
new deployment manager profile on the shared file system.
- Ensure that the existing cell configuration contains
an ODR. Create an ODR if an ODR does not exist.
- Create a deployment manager profile using the IP address
for computer B.
- Run the xd_hadmgrAdd command within
the deployment manager profile for computer B to convert it into a
standby deployment manager. For more information, see xd_hadmgrAdd command.
- Restart the deployment managers and on demand routers. To avoid errors, use the following start sequence:
- Start the node agent for the on demand router node.
- Start the on demand router.
- Start the deployment managers. The first deployment
manager that starts is the active deployment manager, and the other
is the standby deployment manager.
If you do not follow this start sequence, you might encounter
an error:XHAD0005E: A Deployment Manager process running in active mode cannot be found.
This
error indicates that the deployment manager started before the on
demand router, so the environment does not know which deployment manager
is active. When the on demand router is started, the primary deployment
manager can be assigned.
Results
Multiple deployment managers are configured. The deployment
manager is eliminated as a single point of failure because a primary
deployment manager hosts the administrative function for the cell,
and has backup deployment managers that are in standby node. If the
primary deployment manager fails, the standby deployment managers
can resume without losing work.
What to do next
After your high availability deployment manager
environment is set up, you can manage the deployment managers in the
administrative console. Click System administration > Deployment
manager > All deployment managers to view and manage the configured
deployment managers in your environment.
If you need to remove
a high availability deployment manager from the cell, use the command
line utility to remove the function. See xd_hadmgrRemove command for more information.