このページは、お客様の言語ではご利用いただけません。Huawei Cloudは、より多くの言語バージョンを追加するために懸命に取り組んでいます。ご協力ありがとうございました。

Easily Switch Between Product Types

You can click the drop-down list box to switch between different product types.

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

Changing the Consistency Level of a Proxy Instance

Updated on 2024-11-06 GMT+08:00

You can configure a consistency level when creating a proxy instance or change the consistency level of an existing proxy instance.

This section describes how to change the consistency level of a proxy instance.

Introducing Consistency Levels

There are several consistency levels to meet requirements in different scenarios.

  • Eventual consistency (default)

    After a proxy instance is created, requests for SELECT operations are routed to different nodes based on their read weights. Because there is a replication latency between the primary node and each read replica and the replication latency varies for different read replicas, the result returned by each SELECT statement may be different when you repeatedly execute a SELECT statement within a session. In this case, only eventual consistency is ensured.

  • Session consistency

    To eliminate data inconsistencies caused by eventual consistency, session consistency is provided. Session consistency ensures the result returned by each SELECT statement in a session is the data that was updated after the last write request.

    Proxy instances record the log sequence number (LSN) of each node and session. When data in a session is updated, a proxy instance records the LSN of the primary node as a session LSN. When a read request arrives subsequently, the proxy instance compares the session LSN with the LSN of each node and routes the request to a node whose LSN is at least equal to the session LSN. This ensures session consistency.

    Figure 1 Principle of session consistency
    NOTE:

    In session consistency, if there is significant replication latency between the primary node and read replicas and the LSN of each read replica is smaller than the session LSN, requests for SELECT operations will be routed to the primary node. In this case, loads on the primary node are heavy and instance performance suffers.

Constraints

  • To use session consistency, the kernel versions of GaussDB(for MySQL) instances must be 2.0.28.1 or later, and the kernel versions of proxy instances must be 2.7.4.0 or later.

Procedure

  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 > GaussDB(for MySQL).
  4. On the Instances page, click the instance name to go to the Basic Information page.
  5. In the navigation pane, choose Database Proxy.
  6. Click the proxy instance name to go to the Basic Information page. In the Proxy Instance Information area, click next to Consistency Level.

    Figure 2 Changing a consistency level

  7. Select a consistency level and click .

    NOTE:

    After the consistency level is changed, you need to manually reboot the proxy instance or re-establish the connection to the proxy instance on the management console.

    For details about how to reboot a proxy instance, see Rebooting a Proxy Instance.

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