If you have questions about upgrades (or need help), please feel free to reach out to us by [mailing list]({{ site.baseurl }}community/mailing-lists) or [Slack Channel]({{ site.baseurl }}community/slack).
Consider the below guidelines in preparation for upgrading.
It is wise to canary an upgraded version in one or small set of bookies before upgrading all bookies in your live cluster.
You can follow below steps on how to canary a upgraded version:
ReadOnly
mode. This can be used to verify if the Bookie of this new version can run well for read workload.ReadOnly
mode successfully for a while, restart the Bookie in Write/Read
mode.If problems occur during canarying an upgraded version, you can simply take down the problematic Bookie node. The remain bookies in the old cluster will repair this problematic bookie node by autorecovery. Nothing needs to be worried about.
Once you determined a version is safe to upgrade in a few nodes in your cluster, you can perform following steps to upgrade all bookies in your cluster.
BookKeeper client
against the new bookkeeper libraries and deploy the new versions.In a rolling upgrade scenario, upgrade one Bookie at a time. In a downtime upgrade scenario, take the entire cluster down, upgrade each Bookie, then start the cluster.
For each Bookie:
We describes the general upgrade method in Apache BookKeeper as above. We will cover the details for individual versions.
There isn't any protocol related backward compabilities changes in 4.6.x. So you can follow the general upgrade sequence to upgrade from 4.5.x to 4.6.x.
There isn't any protocol related backward compabilities changes in 4.5.0. So you can follow the general upgrade sequence to upgrade from 4.4.x to 4.5.x. However, we list a list of things that you might want to know.
multi journals
is a non-rollbackable feature. If you configure a bookie to use multiple journals on 4.5.x you can not roll the bookie back to use 4.4.x. You have to take a bookie out and recover it if you want to rollback to 4.4.x.If you are planning to upgrade a non-secured cluster to a secured cluster enabling security features in 4.5.0, please read BookKeeper Security for more details.