--- title: Charmhub | Deploy Opensearch K8S using Charmhub - The Open Operator Collection description: Deploy the latest version of Opensearch K8S as a Kubernetes Operator on any cloud. url: https://charmhub.io/opensearch-k8s/docs/h-minor-rollback --- # Opensearch K8S [Canonical](https://charmhub.io/publisher/data-platform "View all packages from Canonical") * [Canonical](https://charmhub.io/publisher/data-platform "View all packages from Canonical") Platform: 2/edge 22 ``` juju deploy opensearch-k8s --channel 2/edge ``` [Learn to deploy on juju >](https://juju.is/docs/juju/manage-applications) --- Share your thoughts on this charm with the community on discourse. [Join the discussion](https://discourse.charmhub.io/) # How to perform a minor rollback This guide describes how to roll back a minor version of OpenSearch. This is useful when an upgrade fails and you need to roll back to the previous version. > OpenSearch does not support downgrading to a previous major version. For more information, please refer to the upstream [OpenSearch documentation about rolling upgrades](https://opensearch.org/docs/latest/install-and-configure/upgrade-opensearch/rolling-upgrade/#preparing-to-upgrade). After a `juju refresh`, if there are any version incompatibilities in charm revisions, its dependencies, or any other unexpected failure in the upgrade process, the process will be halted and enter a failure state. Even if the underlying OpenSearch cluster continues to work, it’s important to roll back the charm to a previous revision so that an update can be attempted after further inspection of the failure. ## [Summary](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#p-31610-summary) * [Summary](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#summary) * [Pre-rollback checks](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#pre-rollback-checks) * [Rollback the charm](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#rollback-the-charm) * [Check the cluster’s health](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#check-the-clusters-health) --- ## [Pre-rollback checks](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#p-31610-pre-rollback-checks) To execute a rollback we take the same procedure as the upgrade, the difference being the charm revision to upgrade to. As an example follow up [the minor upgrades guide](https://charmhub.io/opensearch-k8s/docs/h-minor-upgrade). It is important to run the `pre-upgrade-checks` action to ensure the cluster is in a healthy state before the rollback. This action will check the cluster health and the status of the upgrade. ``` juju run opensearch/leader pre-upgrade-check ``` Once the pre-upgrade checks are complete, and you get the `Charm is ready for upgrade` message, you can proceed with the rollback. For example, here is the status of the OpenSearch cluster after upgrading one unit to revision 145: ``` Model Controller Cloud/Region Version SLA Timestamp dev development localhost/localhost 3.5.3 unsupported 12:24:17Z App Version Status Scale Charm Channel Rev Exposed Message opensearch blocked 3 opensearch 2/edge 145 no Upgrading. Verify highest unit is healthy & run `resume-upgrade` action. To rollback, `juju refresh` to la st revision self-signed-certificates active 1 self-signed-certificates latest/stable 155 no Unit Workload Agent Machine Public address Ports Message opensearch/0* active idle 0 10.214.176.187 9200/tcp OpenSearch 2.15.0 running; Snap rev 56 (outdated); Charmed operator 1+e686854 opensearch/1 active idle 1 10.214.176.197 9200/tcp OpenSearch 2.15.0 running; Snap rev 56 (outdated); Charmed operator 1+e686854 opensearch/2 active idle 2 10.214.176.222 9200/tcp OpenSearch 2.16.0 running; Snap rev 57; Charmed operator 1+e686854 self-signed-certificates/0* active idle 3 10.214.176.93 Machine State Address Inst id Base AZ Message 0 started 10.214.176.187 juju-dd97d9-0 ubuntu@22.04 Running 1 started 10.214.176.197 juju-dd97d9-1 ubuntu@22.04 Running 2 started 10.214.176.222 juju-dd97d9-2 ubuntu@22.04 Running 3 started 10.214.176.93 juju-dd97d9-3 ubuntu@22.04 Running ``` Notice that the OpenSearch charm is at revision **145**. ## [Rollback the charm](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#p-31610-rollback-the-charm) **Caution**: Do not trigger rollback during the running upgrade action. It may cause an unpredictable OpenSearch state. You can initiate the rollback by running the `refresh` command with the revision of the charm you want to rollback to. For example, to rollback to revision **144**, run: ``` juju refresh opensearch --revision=144 ``` When deploying from a local charm file, you must have the previous revision’s .charm file. Then, run: ``` juju refresh opensearch --path= ``` After the refresh command, the juju controller revision for the application will be back in sync with the running OpenSearch revision. ``` Model Controller Cloud/Region Version SLA Timestamp dev development localhost/localhost 3.5.3 unsupported 12:27:02Z App Version Status Scale Charm Channel Rev Exposed Message opensearch active 3 opensearch 2/edge 144 no self-signed-certificates active 1 self-signed-certificates latest/stable 155 no Unit Workload Agent Machine Public address Ports Message opensearch/0* active idle 0 10.214.176.187 9200/tcp opensearch/1 active idle 1 10.214.176.197 9200/tcp opensearch/2 active idle 2 10.214.176.222 9200/tcp self-signed-certificates/0* active idle 3 10.214.176.93 Machine State Address Inst id Base AZ Message 0 started 10.214.176.187 juju-dd97d9-0 ubuntu@22.04 Running 1 started 10.214.176.197 juju-dd97d9-1 ubuntu@22.04 Running 2 started 10.214.176.222 juju-dd97d9-2 ubuntu@22.04 Running 3 started 10.214.176.93 juju-dd97d9-3 ubuntu@22.04 Running ``` Notice that the OpenSearch charm is now at revision **144**. ## [Check the cluster’s health](https://charmhub.io/opensearch-k8s/docs/h-minor-rollback#p-31610-check-the-clusters-health) Once the charm is rolled back, it is important to check the cluster’s health to ensure it is healthy. OpenSearch’s upstream documentation [suggests the following check](https://opensearch.org/docs/latest/install-and-configure/upgrade-opensearch/rolling-upgrade/): ``` GET "/_cluster/health?pretty" ``` The response should look similar to the following example: ``` { "cluster_name" : "opensearch-7ngj", "status" : "green", "timed_out" : false, "number_of_nodes" : 3, "number_of_data_nodes" : 3, "discovered_master" : true, "discovered_cluster_manager" : true, "active_primary_shards" : 5, "active_shards" : 15, "relocating_shards" : 0, "initializing_shards" : 0, "unassigned_shards" : 0, "delayed_unassigned_shards" : 0, "number_of_pending_tasks" : 0, "number_of_in_flight_fetch" : 0, "task_max_waiting_in_queue_millis" : 0, "active_shards_percent_as_number" : 100.0 } ``` ---