Highly available architectures provide functions such as service distribution, auto scaling, and multi-zone deployment. Compared with a single ECS instance, a highly available architecture is more stable and scalable when databases and applications are deployed.

Features

Highly available architectures have the following features:
  • A multi-zone, highly available SLB instance distributes traffic to multiple ECS instances, increasing the external service capability of application systems, eliminating single point of failures, and improving the availability of application systems. SLB is used for automatic multi-zone deployment, enhancing disaster recovery capabilities of services.
  • You can use custom images to create identical ECS instances, and then add these instances to the backend server group of the SLB instance, implementing high availability for your services. SLB can be configured with Layer-4 and Layer-7 listeners at the same time, and with multiple algorithms, such as round robin, weighted round robin, and weighted least connections, properly allocating computing resources to backend ECS instances.
  • Relational Database Service (RDS) can be optimized for high concurrency scenarios, ensuring the constant stability and high throughput of the system through thread pools, parallel replication, and hidden primary keys. CloudDBA provides comprehensive performance monitoring metrics to monitor the usage of instances and hardware and slow SQL queries in real time, and gives optimization suggestions to help you locate and solve problems.

Deployment process

If you have created an ECS instance and deployed databases and applications on the instance, you can change the single-instance deployment mode to single-zone or multi-zone, highly available architecture. This topic shows you how to use ECS, EIP, SLB, and RDS to deploy a multi-zone, highly available architecture.Highly available architecture
  1. Use a custom image to create multiple identical ECS instances. For more information, see Replicate ECS instances.
  2. Create an SLB instance and add the ECS instances to the SLB backend server group to mount ECS instances from different zones, achieving the high availability of services. For more information, see Configure an SLB instance.
  3. Use DTS to migrate a user-created database from an ECS instance to an RDS instance, ensuring that the business database is not interrupted during migration and data is automatically backed up. For more information, see Migrate user-created databases to RDS instances.