Upgrade Milvus Standalone with Helm Chart

This guide describes how to upgrade your Milvus standalone with Milvus Helm charts.

Check the Milvus version

Run the following commands to check new Milvus versions.

$ helm repo update
$ helm search repo milvus --versions

NAME         	CHART VERSION	APP VERSION       	DESCRIPTION                                       
milvus/milvus	4.0.10       	2.2.3             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.8        	2.2.3             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.7        	2.2.3             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.6        	2.2.2             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.5        	2.2.2             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.4        	2.2.2             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.3        	2.2.2             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.2        	2.2.2             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.1        	2.2.1             	Milvus is an open-source vector database built ...
milvus/milvus	4.0.0        	2.2.1             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.6        	2.2.0             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.5        	2.2.0             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.4        	2.2.0             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.3        	2.2.0             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.2        	2.2.0             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.1        	2.2.0             	Milvus is an open-source vector database built ...
milvus/milvus	3.3.0        	2.2.0             	Milvus is an open-source vector database built ...

In normal cases, you can upgrade your Milvus instance using helm upgrade except you want to:

• Migrate the metadata
• Conduct a rolling upgrade

Migrate the metadata

Since Milvus 2.2.0, the metadata is incompatible with that in previous releases. The following example snippets assume an upgrade from Milvus 2.1.4 to Milvus 2.2.0.

1. Check the Milvus version

Run $ helm list to check your Milvus app version. You can see the APP VERSION is 2.1.4.

NAME             	NAMESPACE	REVISION	UPDATED                                	STATUS  	CHART        	APP VERSION     
my-release      	default  	1       	2022-11-21 15:41:25.51539 +0800 CST    	deployed	milvus-3.2.18	2.1.4

2. Check the running pods

Run $ kubectl get pods to check the running pods. You can see the following output.

NAME                                            READY   STATUS    RESTARTS   AGE
my-release-etcd-0                               1/1     Running   0          84s
my-release-milvus-standalone-75c599fffc-6rwlj   1/1     Running   0          84s
my-release-minio-744dd9586f-qngzv               1/1     Running   0          84s

3. Check the image tag

Check the image tag for the pod my-release-milvus-standalone-75c599fffc-6rwlj. You can see the release of your Milvus standalone is v2.1.4.

$ kubectl get pods my-release-milvus-standalone-75c599fffc-6rwlj -o=jsonpath='{$.spec.containers[0].image}'

milvusdb/milvus:v2.1.4

4. Migrate the metadata

A major change in Milvus 2.2 is the metadata structure of segment indexes. Therefore, you need to use Helm to migrate the meta while upgrading Milvus from v2.1.x to v2.2.0. Here is a script for you to safely migrate your metadata.

This script only applies to Milvus installed on a K8s cluster. Roll back to the previous version with the rollback operation first if an error occurs during the process.

The following table lists the operations you can do for meta migration.

Parameters	Description	Default value	Required
i	The Milvus instance name.	None	True
n	The namespace that Milvus is installed in.	default	False
s	The source Milvus version.	None	True
t	The target Milvus version.	None	True
r	The root path of Milvus meta.	by-dev	False
w	The new Milvus image tag.	milvusdb/milvus:v2.2.0	False
m	The meta migration image tag.	harbor.milvus.io/milvus/meta-migration:20221025-e54b6181b	False
o	The meta migration operation.	migrate	False
d	Whether to delete migration pod after the migration is completed.	false	False
c	The storage class for meta migration pvc.	default storage class	False
e	The etcd enpoint used by milvus.	etcd svc installed with milvus	False

1. Migrate meta

1. Download the migration script.
2. Stop the Milvus components. Any live session in the Milvus etcd can cause the migration to fail.
3. Create a backup for the Milvus metadata.
4. Migrate the Milvus metadata.
5. Start Milvus components with a new image.

2. Upgrade Milvus from v2.1.x to v2.2.0

1. Specify Milvus instance name, source Milvus version, and target Milvus version.

   ./migrate.sh -i my-release -s 2.1.1 -t 2.2.0
   

2. Specify the namespace with -n if your Milvus is not installed in the default K8s namespace.

   ./migrate.sh -i my-release -n milvus -s 2.1.1 -t 2.2.0
   

3. Specify the root path with -r if your Milvus is installed with the custom rootpath.

   ./migrate.sh -i my-release -n milvus -s 2.1.1 -t 2.2.0 -r by-dev
   

4. Specify the image tag with -w if your Milvus is installed with a custom image.

   ./migrate.sh -i my-release -n milvus -s 2.1.1 -t 2.2.0 -r by-dev -w milvusdb/milvus:master-20221016-15878781
   

5. Set -d true if you want to automatically remove the migration pod after the migration is completed.

   ./migrate.sh -i my-release -n milvus -s 2.1.1 -t 2.2.0 -w milvusdb/milvus:master-20221016-15878781 -d true
   

6. Rollback and migrate again if the migration fails.

   ./migrate.sh -i my-release -n milvus -s 2.1.1 -t 2.2.0 -r by-dev -o rollback -w <milvus-2-1-1-image>
   ./migrate.sh -i my-release -n milvus -s 2.1.1 -t 2.2.0 -r by-dev -o migrate -w <milvus-2-2-0-image>
   

Conduct a rolling upgrade

Since Milvus 2.2.3, you can configure Milvus coordinators to work in active-standby mode and enable the rolling upgrade feature for them, so that Milvus can respond to incoming requests during the coordinator upgrades. In previous releases, coordinators are to be removed and then created during an upgrade, which may introduce certain downtime of the service.

Rolling upgrades requires coordinators to work in active-standby mode. You can use the script we provide to configure the coordinators to work in active-standby mode and start the rolling upgrade.

Based on the rolling update capabilities provided by Kubernetes, the above script enforces an ordered update of the deployments according to their dependencies. In addition, Milvus implements a mechanism to ensure that its components remain compatible with those depending on them during the upgrade, significantly reducing potential service downtime.

The script applies only to the upgrade of Milvus installed with Helm. The following table lists the command flags available in the scripts.

Parameters	Description	Default value	Required
i	Milvus instance name	None	True
n	Namespace that Milvus is installed in	default	False
t	Target Milvus version	None	True
w	New Milvus image tag	milvusdb/milvus:v2.2.3	True
o	Operation	update	False

Once you have ensured that all deployments in your Milvus instance are in their normal status. You can run the following command to upgrade the Milvus instance to 2.2.3.

sh rollingUpdate.sh -n default -i my-release -o update -t 2.2.3 -w 'milvusdb/milvus:v2.2.3'