Multi-zone (Basic Edition) Deployment
Lindorm offers a cross-zone deployment mode (Multi-zone Basic Edition) to prevent the entire Lindorm service from becoming unavailable due to data center-level failures. This topic describes the Multi-zone Basic Edition architecture and how it differs from the Multi-zone High-availability Edition.
Background information
A single-zone Lindorm instance deploys all data and master nodes in one availability zone (AZ). In extreme cases (such as a data center-level failure), the entire AZ may become unavailable or inaccessible, causing the entire Lindorm service to go down.
A Multi-zone (Basic Edition) instance distributes master and data nodes across multiple data centers. Even if a data center-level failure occurs in one zone, data integrity and partial service availability are preserved (the level of availability depends on the computing and storage resources in the remaining zones).
The key differences between Multi-zone (Basic Edition) and Multi-zone (High-availability Edition) are as follows:
Multi-zone (Basic Edition): Storage replicas are stored across data centers, but there is only one set of computing resources. Recovery takes some time during a failure. RTO is within 1 hour, but this edition is more cost-effective.
Multi-zone (High-availability Edition): Each data center has fully independent storage and services with two sets of computing resources. In case of a failure, you can switch directly between the primary and standby clusters. RTO is within 3 minutes.
Multi-zone (Basic Edition) architecture
The Multi-zone (Basic Edition) architecture ensures high availability of data and services in the following ways:
Cross-data center deployment of master nodes: All master nodes are deployed across three data centers to ensure metadata high availability and prevent split-brain issues during network partitions.
Flexible distribution of compute nodes: For cloud disk deployments, compute nodes are distributed across two zones. For local disk deployments, they are distributed across three zones. We recommend that you reserve at least 30% redundant resources for CPU computing and storage space to prevent a single-zone failure from halving CPU and storage performance, which would affect system availability.
Upgraded OSS deployment mode: OSS is upgraded to a zone-redundant OSS deployment mode to ensure stable cold storage services and high data availability.
High availability comparison
The following table compares availability, performance, and cost across Lindorm single-zone, Multi-zone (Basic Edition), and Multi-zone (High-availability Edition) instances. Choose the deployment mode that best suits your business requirements.
Item | Single-zone | Multi-zone (Basic Edition) | Multi-zone (High-availability Edition) |
Cross-AZ count | 1 | 3 | 3 |
Supported engines | All | All | LindormTable only |
RPO and RTO during a data center failure | No data center-level disaster recovery |
|
|
Cost | 1× |
| 1.5× to 2× |
Performance | 1× |
|
|
The Multi-zone Basic Edition enables data center-level disaster recovery at minimal additional cost.
Because there is only one set of computing resources, computing and storage capacity drops significantly during a single data center failure. We recommend maintaining sufficient resource overhead to ensure capacity during disaster recovery.
Cloud disk deployment: computing and storage capacity decreases by 50% during a single data center failure.
Local disk deployment: computing and storage capacity decreases by 30% during a single data center failure.
To ensure data reliability, the Multi-zone (Basic Edition) writes data to multiple data centers by default, which causes cross-data center write operations and may increase write response time (RT). To mitigate the write RT increase, we recommend that you use batch writes, which significantly reduces the perceived latency increase.
If you upgrade from a single-zone instance to a Multi-zone (Basic Edition) instance, RT may change. Monitor your services closely during the upgrade.
Limits
The Multi-zone (Basic Edition) is currently available only in the following regions:
China: China (Ulanqab) General Industry Cloud, China (Qingdao), China (Hangzhou), China (Beijing), China (Heyuan), China (Shanghai), China (Zhangjiakou), China (Shenzhen), China (Chengdu), China (Hong Kong), China (Guangzhou), China (Ulanqab), and China (Hohhot).
Asia Pacific: South Korea (Seoul), Japan (Tokyo), Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), and Thailand (Bangkok).
Other: US (Atlanta), UAE (Dubai), Germany (Frankfurt), US (Silicon Valley), UK (London), and US (Virginia).
The cloud disk data nodes of a Multi-zone (Basic Edition) instance are evenly distributed across two data centers. Therefore, the node count must be a multiple of 2 when creating or scaling out.
The local disk data nodes of a Multi-zone (Basic Edition) instance are evenly distributed across three data centers. Therefore, the node count must be a multiple of 3 when creating or scaling out.
Purchase a Multi-zone (Basic Edition) instance
You can purchase a Multi-zone (Basic Edition) instance in the console.
Upgrade a single-zone instance to Multi-zone Basic Edition
Prerequisites
For regions with three availability zones, the three zones must be different. For regions with only two availability zones, the primary and secondary zones must be different, while the coordinator zone can be the same as the primary or secondary zone.
Node count validation: the number of nodes for cloud disk instances must be a multiple of 2, and for local disk instances must be a multiple of 3.
Version validation: LindormTable engine (2.7.5 or later), storage engine (4.5.23.4 or later), and search engine (3.9.6.1 or later) must be upgraded to the latest version.
Procedure
Log on to the Lindorm console.
In the upper-left corner of the page, select the region where the instance is deployed.
On the Instances page, click the ID of the target instance or click View Instance Details in the Actions column for the instance.
On the Instance Details page, in the Service Type section, click Upgrade to Multi-zone Basic Edition.
In the dialog box that appears, configure the Primary Zone, Secondary Zone, and Coordinator Node Zone along with their respective VSwitches, and then click OK.
Business impact
Minimal service disruption: the upgrade involves scaling and service restarts at the infrastructure level, similar to standalone changes of this type, with only slight jitter.
Write RT increases by less than 1 ms because data must be persisted across multiple data centers. Read RT may also increase.
FAQ
Why does the console show only one zone for a multi-zone instance?
For multi-zone instances, the Lindorm console currently displays only the primary zone. The secondary zone and coordinator node zone are not displayed.