When ZooKeeper engine updates are available, you can upgrade your Microservices Engine (MSE) Microservices Registry instance to get the latest fixes and improvements. MSE supports two types of upgrades:
Engine version upgrade: Update the ZooKeeper engine to a newer version within the same edition.
Edition upgrade: Migrate a Basic Edition instance to Developer Edition or Professional Edition.
Basic Edition reached end of sale and all instances were released at 12:00 on March 3, 2025 (UTC+8). Basic Edition instances are no longer accessible through the console or client. Technical support and ticket services for Basic Edition instances remained available until 12:00 on March 3, 2025 (UTC+8). For details, see Notice on the discontinuation of MSE Microservices Registry Basic Edition instances.
Upgrade impact
An engine version upgrade takes approximately 10 minutes. During this period, engine operations in the MSE console are unavailable.
The impact on your workloads depends on the number of nodes in the cluster:
| Node count | Upgrade behavior | Business impact |
|---|---|---|
| 3 or more | Rolling upgrade: nodes upgrade one at a time, data syncs automatically | No interruption |
| 1 or 2 | All nodes restart during the upgrade | Possible interruption |
ZooKeeper requires a majority of nodes (quorum) to remain available. During a rolling upgrade, only one node restarts at a time, so a 3-node cluster always maintains quorum. Clusters with 1 or 2 nodes cannot maintain quorum during a restart, which may cause brief service interruptions.
Regardless of node count, expect the following during a rolling upgrade:
Connections may close and sessions may time out as each node restarts. Make sure your client supports a retry mechanism.
Connection re-establishment logs are generated and monitoring metrics may briefly fluctuate due to instance restarts.
Schedule upgrades during off-peak hours to minimize impact on your workloads. We recommend testing the upgrade on a non-production instance first if possible.
Upgrade the ZooKeeper engine version
Prerequisites
Before you begin, ensure that you have:
An MSE Microservices Registry instance that is not already on the latest engine version
Client applications configured with a retry mechanism for connection re-establishment
Procedure
Log on to the MSE console and select a region in the top navigation bar.
In the left-side navigation pane, choose Microservices Registry > Instances.
Start the upgrade using either method:
From the instance list: Find the target instance and click Upgradeable in the Engine version column.
From instance details: Click the instance name to open the Basic Information page, then click Manual Upgrade next to Engine version.
NoteIf the instance already runs the latest version, Upgradeable does not appear in the Engine version column.
In the Cluster Upgrade dialog, click OK.
Upgrade from Basic Edition to Developer Edition or Professional Edition
Edition compatibility
Not all edition transitions are supported. The following table lists valid upgrade paths:
| Source edition | Target edition | Supported |
|---|---|---|
| Basic Edition | Developer Edition | Yes |
| Basic Edition | Professional Edition | Yes |
| Developer Edition | Developer Edition (later version) | Yes |
| Developer Edition | Professional Edition | No |
| Professional Edition | Professional Edition (later version) | Yes |
| Professional Edition | Developer Edition | No |
Prerequisites
Before you begin, ensure that you have:
A Basic Edition ZooKeeper instance
Dubbo version 2.7.4 or later (versions earlier than 2.7.4 may cause registration failures after the upgrade)
A target edition selected based on your requirements -- see Select an instance type and an instance edition and Billing overview of common instances
Procedure
Log on to the MSE console and select a region in the top navigation bar.
On the Instances page, find the ZooKeeper Basic Edition instance and click More in the Actions column.
For a subscription instance, select Upgrade or Downgrade.
For a pay-as-you-go instance, select Upgrade/Downgrade.
On the Upgrade/Downgrade page, configure the following parameters:
Parameter Guidance Product edition Developer Edition for single-node instances (no high availability) or Professional Edition for multi-node instances (high availability) Engine Specifications Match specifications to your workload requirements Number of Cluster Nodes Set based on your availability needs ImportantDo not reduce specifications (including node count) during the upgrade. Downsizing during an upgrade may cause failures due to insufficient instance capacity.
Confirm the engine specifications, node count, and price in the lower-right corner, then click Buy Now.