Patching and Updating WebLogic servers just got a whole lot easier! The release of Zero Downtime Patching marks a
huge step forward in Oracle's commitment both to simplifying the maintenance of
WebLogic servers, and to our ability to provide continuous availability.
Zero Downtime Patching allows you to rollout distributed patches to
multiple clusters or to your entire domain with a single command. All without causing any service outages or
loss of session data for the end-user. It takes what was once a tedious and time-consuming task and replaces it
with a consistent, efficient, and resilient automated process.
By automating this process, we're able to drastically reduce the amount of
human input required (errors), and we're able to verify the input that is given
before making any changes. This will
have a huge impact on the consistency and reliability of the process, and it
will also greatly improve the effiency of the process.
The process is resilient in that it can retry steps when there are errors,
it can pause for problem resolution and resume where it left off, or if desired,
it can revert the entire environment back to its original state.
As an administrator, you create and verify a patched OracleHome archive
with existing and familiar tools, and place the archive on each node that you
want to upgrade. Then, a simple command
like the one below will handle the rest.
rolloutOracleHome("Cluster1, Cluster2", "/pathTo/patchedOracleHome.jar", "/pathTo/backupOfUnpatchedOracleHome")
The way the process works is that we take advantage of existing clustering
technology combined with an Oracle Traffic Director (OTD) load balancer, to
allow us to take individual nodes offline one at a time to be updated. We communicate with the load balancer and
instruct it to redirect requests to active nodes. We also created some advanced techiques for
preserving active sessions so the end-user will never even know the patching is
We can leverage this same process for updating the Java version used by
servers, and even for doing some upgrades to running applications, all without
service downtime for the end-user.
There's a lot of exciting aspects to Zero Downtime (ZDT) Patching that we
will be discussing here, so check back often!
For more information about Zero Downtime Patching, view the documentation.