Compute
Elastic Cloud Server
Huawei Cloud Flexus
Bare Metal Server
Auto Scaling
Image Management Service
Dedicated Host
FunctionGraph
Cloud Phone Host
Huawei Cloud EulerOS
Networking
Virtual Private Cloud
Elastic IP
Elastic Load Balance
NAT Gateway
Direct Connect
Virtual Private Network
VPC Endpoint
Cloud Connect
Enterprise Router
Enterprise Switch
Global Accelerator
Management & Governance
Cloud Eye
Identity and Access Management
Cloud Trace Service
Resource Formation Service
Tag Management Service
Log Tank Service
Config
OneAccess
Resource Access Manager
Simple Message Notification
Application Performance Management
Application Operations Management
Organizations
Optimization Advisor
IAM Identity Center
Cloud Operations Center
Resource Governance Center
Migration
Server Migration Service
Object Storage Migration Service
Cloud Data Migration
Migration Center
Cloud Ecosystem
KooGallery
Partner Center
User Support
My Account
Billing Center
Cost Center
Resource Center
Enterprise Management
Service Tickets
HUAWEI CLOUD (International) FAQs
ICP Filing
Support Plans
My Credentials
Customer Operation Capabilities
Partner Support Plans
Professional Services
Analytics
MapReduce Service
Data Lake Insight
CloudTable Service
Cloud Search Service
Data Lake Visualization
Data Ingestion Service
GaussDB(DWS)
DataArts Studio
Data Lake Factory
DataArts Lake Formation
IoT
IoT Device Access
Others
Product Pricing Details
System Permissions
Console Quick Start
Common FAQs
Instructions for Associating with a HUAWEI CLOUD Partner
Message Center
Security & Compliance
Security Technologies and Applications
Web Application Firewall
Host Security Service
Cloud Firewall
SecMaster
Anti-DDoS Service
Data Encryption Workshop
Database Security Service
Cloud Bastion Host
Data Security Center
Cloud Certificate Manager
Edge Security
Situation Awareness
Managed Threat Detection
Blockchain
Blockchain Service
Web3 Node Engine Service
Media Services
Media Processing Center
Video On Demand
Live
SparkRTC
MetaStudio
Storage
Object Storage Service
Elastic Volume Service
Cloud Backup and Recovery
Storage Disaster Recovery Service
Scalable File Service Turbo
Scalable File Service
Volume Backup Service
Cloud Server Backup Service
Data Express Service
Dedicated Distributed Storage Service
Containers
Cloud Container Engine
SoftWare Repository for Container
Application Service Mesh
Ubiquitous Cloud Native Service
Cloud Container Instance
Databases
Relational Database Service
Document Database Service
Data Admin Service
Data Replication Service
GeminiDB
GaussDB
Distributed Database Middleware
Database and Application Migration UGO
TaurusDB
Middleware
Distributed Cache Service
API Gateway
Distributed Message Service for Kafka
Distributed Message Service for RabbitMQ
Distributed Message Service for RocketMQ
Cloud Service Engine
Multi-Site High Availability Service
EventGrid
Dedicated Cloud
Dedicated Computing Cluster
Business Applications
Workspace
ROMA Connect
Message & SMS
Domain Name Service
Edge Data Center Management
Meeting
AI
Face Recognition Service
Graph Engine Service
Content Moderation
Image Recognition
Optical Character Recognition
ModelArts
ImageSearch
Conversational Bot Service
Speech Interaction Service
Huawei HiLens
Video Intelligent Analysis Service
Developer Tools
SDK Developer Guide
API Request Signing Guide
Terraform
Koo Command Line Interface
Content Delivery & Edge Computing
Content Delivery Network
Intelligent EdgeFabric
CloudPond
Intelligent EdgeCloud
Solutions
SAP Cloud
High Performance Computing
Developer Services
ServiceStage
CodeArts
CodeArts PerfTest
CodeArts Req
CodeArts Pipeline
CodeArts Build
CodeArts Deploy
CodeArts Artifact
CodeArts TestPlan
CodeArts Check
CodeArts Repo
Cloud Application Engine
MacroVerse aPaaS
KooMessage
KooPhone
KooDrive
On this page
Help Center/ TaurusDB/ User Guide/ Read Replicas/ Promoting a Read Replica to Primary

Promoting a Read Replica to Primary

Updated on 2025-02-12 GMT+08:00

A TaurusDB instance consists of a primary node and multiple read replicas. In addition to automatic failover scenarios, you can perform a manual switchover to promote a read replica to the new primary node.

Manual Switchover

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and project.
  3. Click in the upper left corner of the page and choose Databases > TaurusDB.
  4. On the Instances page, click the instance name to go to the Basic Information page.
  5. In the Node List area, locate the read replica to be promoted and click Promote to Primary in the Operation column.

    Figure 1 Promoting a read replica to the new primary node

  6. In the displayed dialog box, click Yes.

    • During a manual switchover, there may be a brief disconnection lasting about 30 seconds. Ensure that your applications support automatic reconnection.
    • During a manual switchover, the DB instance status is Promoting to primary and this process takes several seconds or minutes.
    • After a switchover is complete, the node types of the original primary node and read replica have been exchanged, and the read replica status changes to Available.
      NOTICE:
      • A read replica whose failover priority is -1 cannot be promoted to the primary node.
      • Services may be intermittently interrupted for several seconds or minutes when a read replica is promoted to the primary node.
      • Promoting a read replica to primary will switch over the private IP addresses for read of the primary node and read replica. To ensure workloads are not interrupted, connect to your DB instance using the private IP address from the Network Information area in the Basic Information page or the proxy address from the Database Proxy page. For details about the differences between the two addresses, see Description of Each IP Address.
      • To ensure workload continuity, you first enable Application Lossless and Transparent (ALT) and then promote a read replica to primary.

Automatic Failover

TaurusDB uses an active-active HA architecture that automatically fails over to a read replica selected by the system.

Each read replica has a failover priority that determines which read replica is promoted if the primary node fails.

  • Priorities range from 1 for the highest priority to 16 for the lowest priority.
  • If two or more read replicas share the same priority, they have a same probability of being promoted to the new primary node.

TaurusDB selects a read replica and promotes it to the new primary node as follows:

  1. Read replicas available for promotion are identified.
  2. One or more read replicas with the highest priority are identified.
  3. One of the read replicas with the highest priority is selected and promoted. If the promotion fails due to network faults or abnormal replication status, TaurusDB attempts to promote another read replica by priority and repeats the process until a read replica is successfully promoted.

We use cookies to improve our site and your experience. By continuing to browse our site you accept our cookie policy. Find out more

Feedback

Feedback

Feedback

0/500

Selected Content

Submit selected content with the feedback