There are properties on the domain resource that specify which servers should be running,
which servers should be restarted and the desired initial state. To start, stop, or restart servers, modify these properties on the domain resource
(for example, by using
kubectl or the Kubernetes REST API). The operator will notice the changes and apply them. Beginning,
with operator version 2.2, there are now properties to control server shutdown handling, such as whether the shutdown
will be graceful, the timeout, and if in-flight sessions are given the opportunity to complete.
serverStartPolicy property on the domain resource controls which servers should be running.
The operator runtime monitors this property and creates or deletes the corresponding server pods.
Do not use the WebLogic Server Administration Console to start or stop servers.
You can specify the
serverStartPolicy property at the domain, cluster, and server levels. Each level supports a different set of values.
|Level||Default Value||Supported Values|
|Domain||Admin Server||Started / Stopped|
|Domain||Standalone Server||Started / Stopped|
|Domain||Cluster||Clustered Server||Started / Stopped|
||any value||any value||Stopped|
||Started if needed to get to the cluster’s
Servers configured as
ALWAYS count toward the cluster’s
If more servers are configured as
ALWAYS than the cluster’s
replicas count, they will all be started and the
replicas count will be ignored.
For some use cases, such as an externally managed zero downtime patching (ZDP), it may be necessary to start WebLogic Server
so that at the end of its startup process, the server is in an administrative state. This can be achieved using the
property, which is available at domain, cluster, and server levels. When
serverStartState is set to
ADMIN, then servers will
progress only to the administrative state. You could then use the WebLogic console, REST API, or a WLST script to make any necessary
updates before advancing the server to the running state.
Changes to the
serverStartState property do not affect already started servers.
Normally, the Administration Server, all of the standalone Managed Servers, and enough Managed Servers in each cluster to satisfy its
replicas count, should be started.
In this case, the domain resource does not need to specify
serverStartPolicy, or list any
servers, but it does need to specify a
kind: Domain metadata: name: domain1 spec: image: ... replicas: 10
Sometimes you need to completely shut down the domain (for example, take it out of service).
kind: Domain metadata: name: domain1 spec: serverStartPolicy: "NEVER" ...
Sometimes you want to start the Administration Server only, that is, take the domain out of service but leave the Administration Server running so that you can administer the domain.
kind: Domain metadata: name: domain1 spec: serverStartPolicy: "ADMIN_ONLY" ...
To shut down a cluster (for example, take it out of service), add it to the domain resource and set its
kind: Domain metadata: name: domain1 spec: clusters: - clusterName: "cluster1" serverStartPolicy: "NEVER" ...
To shut down a specific standalone server, add it to the domain resource and set its
kind: Domain metadata: name: domain1 spec: managedServers: - serverName: "server1" serverStartPolicy: "NEVER" ...
Normally, all of the Managed Servers in a cluster are identical and it doesn’t matter which ones are running as long as the operator starts enough of them to get to the cluster’s
However, sometimes some of the Managed Servers are different (for example, support some extra services that the other servers in the cluster use) and need to always be started.
This is done by adding the server to the domain resource and setting its
kind: Domain metadata: name: domain1 spec: managedServers: - serverName: "cluster1_server1" serverStartPolicy: "ALWAYS" ...
The server will count toward the cluster’s
replicas count. Also, if you configure more than the
replicas servers count to
ALWAYS, they will all be started, even though the
replicas count will be exceeded.
The domain resource includes the element
serverPod that is available under
adminServer and each entry of
serverPod element controls many details of how pods are created for server instances.
shutdown element of
serverPod controls how servers will be shutdown. This element has three properties:
shutdownType property can be set to either
Graceful, the default,
Forced specifying the type of shutdown. The
timeoutSeconds property configures how long the server is given to
complete shutdown before the server is killed. The
ignoreSessions property, which is only applicable for graceful shutdown, when
the default, allows the shutdown process to take longer to give time for any active sessions to complete up to the configured timeout.
The operator runtime monitors this property but will not restart any server pods solely to adjust the shutdown options.
Instead, server pods created or restarted because of another property change will be configured to shutdown, at the appropriate
time, using the shutdown options set when the server pod is created.
The operator runtime configures shutdown behavior with the use of the following environment variables. Users may instead simply configure these environment variables directly. When a user-configured environment variable is present, the operator will not override the environment variable based on the shutdown configuration.
|Environment Variables||Default Value||Supported Values|
||30||Whole number in seconds where 0 means no timeout|
||Boolean indicating if active sessions should be ignored; only applicable if shutdown is graceful|
You can specify the
serverPod element, including the
shutdown element, at the domain, cluster, and server levels. If
shutdown is specified at multiple levels, such as for a cluster and for a member server that is part of that cluster,
then the shutdown configuration for a specific server is the combination of all of the relevant values with each field
having the value from the
shutdown element at the most specific scope.
For instance, given the following domain resource:
kind: Domain metadata: name: domain1 spec: serverPod: shutdown: shutdownType: Graceful timeoutSeconds: 45 clusters: - clusterName: "cluster1" serverPod: shutdown: ignoreSessions: true managedServers: - serverName: "cluster1_server1" serverPod: shutdown: timeoutSeconds: 60 ignoreSessions: false ...
Graceful shutdown is used for all servers in the domain because this is specified at the domain level and is not overridden at any cluster or server level. The “cluster1” cluster defaults to ignoring sessions; however, the “cluster1_server1” server instance will not ignore sessions and will have a longer timeout.
The operator runtime automatically recreates (restarts) server pods when properties on the domain resource that affect server pods change (such as
restartVersion property on the domain resource lets you force the operator to restart a set of server pods.
The operator runtime does rolling restarts of clustered servers so that service is maintained.
The operator will restart servers when any of the follow properties on the domain resource that affect the server are changed:
If the only change detected is the addition or modification of a domain-specified label or annotation,
the operator will patch the server’s pod rather than restarting it. Removing a label or annotation from
the domain resource will cause neither a restart nor a patch. It is possible to force a restart to remove
such a label or annotation by modifying the
Prior to version 2.2, the operator incorrectly restarted servers when the
serverStartState property was changed. Now,
this property has no affect on already running servers.
Clustered servers that need to be restarted are gradually restarted (for example,
rolling restarted) so that the cluster is not taken out of service and in-flight work can be migrated to other servers in the cluster.
maxUnavailable property on the domain resource determines how many of the cluster’s servers may be taken out of service at a time when doing a rolling restart.
It can be specified at the domain and cluster levels and defaults to 1 (that is, by default, clustered servers are restarted one at a time).
When using in-memory session replication, Oracle WebLogic Server employs a primary-secondary session replication model to provide high availability of application session state (that is, HTTP and EJB sessions).
The primary server creates a primary session state on the server to which the client first connects, and a secondary replica on another WebLogic Server instance in the cluster.
maxUnavailable property value of
1 protects against inadvertent session state loss which could occur if both the primary and secondary
servers are shut down at the same time during the rolling restart process.
restartVersionto force the operator to restart servers
restartVersion property lets you force the operator to restart servers.
It’s basically a user-specified string that gets added to new server pods (as a label) so that the operator can tell which servers need to be restarted. If the value is different, then the server pod is old and needs to be restarted. If the value matches, then the server pod has already been restarted.
Each time you want to restart some servers, you need to set
restartVersion to a different string (the particular value doesn’t matter).
The operator will notice the new value and restart the affected servers (using the same mechanisms as when other properties that affect the server pods are changed, including doing rolling restarts of clustered servers).
restartVersion property can be specified at the domain, cluster, and server levels. A server will be restarted if any of these three values change.
The servers will also be restarted if
restartVersion is removed from the domain resource (for example, if you had previously specified a value to cause a restart, then you remove that value after the previous restart has completed).
restartVersion at the domain level to a new value.
kind: Domain metadata: name: domain1 spec: restartVersion: "domainV1" ...
restartVersion at the cluster level to a new value.
kind: Domain metadata: name: domain1 spec: clusters: - clusterName : "cluster1" restartVersion: "cluster1V1" maxUnavailable: 2 ...
restartVersion at the
adminServer level to a new value.
kind: Domain metadata: name: domain1 spec: adminServer: restartVersion: "adminV1" ...
restartVersion at the
managedServer level to a new value.
kind: Domain metadata: name: domain1 spec: managedServers: - serverName: "standalone_server1" restartVersion: "v1" - serverName: "cluster1_server1" restartVersion: "v1" ...
To do a full domain restart, first shut down all of the domain’s servers (Administration and Managed Servers), taking the domain out of service, then restart them. Unlike rolling restarts, the operator cannot detect and initiate a full domain restart; you must always manually initiate it.
To manually initiate a full domain restart:
serverStartPolicyon the domain resource to
kind: Domain metadata: name: domain1 spec: serverStartPolicy: "NEVER" ...
Wait for the operator to stop ALL the servers for that domain.
To restart the domain, set the domain level
serverStartPolicy back to
IF_NEEDED. Alternatively, you do not
have to specify the
serverStartPolicy as the default value is
kind: Domain metadata: name: domain1 spec: serverStartPolicy: "IF_NEEDED" ...