Elastic Compute Service (ECS) is a high-performance, stable, reliable, and scalable IaaS-level service provided by Alibaba Cloud. ECS eliminates the need for upfront investments in IT hardware and allows you to scale computing resources on demand. This makes ECS instances more convenient and efficient than physical servers. ECS provides a variety of instance types that suit various business needs and helps boost business growth.

Why ECS?

ECS provides the following benefits:

  • You do not have to purchase hardware or construct data centers.
  • Instances can be delivered within minutes, which enables rapid deployment and reduces time to market.
  • You can connect ECS instances to data centers and Border Gateway Protocol (BGP) computer rooms around the world.
  • You can scale resources up or down based on your actual business needs at a transparent and clear cost.
  • x86 architecture-based ECS instances, ECS bare metal instances, and heterogeneous computing ECS instances such as GPU-accelerated and FPGA-accelerated instances are provided.
  • You can use ECS to access other Alibaba Cloud services over the internal network to reduce Internet traffic costs.
  • A host of security solutions such as virtual firewalls, role-based permission control, internal network isolation, virus protection, and traffic throttling are provided.
  • ECS comes with a performance monitoring framework and an active O&M system.
  • Industry-standard API that improves ease of use and compatibility

For more information about the benefits of ECS, see Benefits and Scenarios.


ECS comprises the following major components:

  • Instance: An ECS instance is a virtual server that includes basic components such as CPU, memory, operating system (OS), network configurations, and disks. The computing performance, memory specifications, and applicable scenarios of an instance are determined by its instance type. Each instance type has particular specifications, including the number of vCPUs, memory capacity, and network performance.
  • Image: Images provide OSs, initialization data of applications, and pre-installed software for instances. Multiple Linux distributions and Windows Server operating systems are supported.
  • Elastic Block Storage: Elastic Block Storage (EBS) devices offer high performance and reduce latency. ECS comes with distributed storage architecture-based disks, , and physical storage-based local disks.
  • Snapshot: A snapshot is a point-in-time capture of data on a disk or . Snapshots are often used to back up and restore data or to create custom images.
  • Security group: A security group is a mutually accessible group of instances located within the same region that have the same security requirements. A security group works as a virtual firewall for the ECS instances inside it.
  • Network:
    • Virtual Private Cloud (VPC): A VPC is a logically isolated private cloud network. You can configure private CIDR blocks, route tables, and gateways for VPCs.
    • Classic network: All instances of the classic network type are built on a shared infrastructure network that is planned and managed in a centralized manner by Alibaba Cloud.

For more information, visit the Elastic Compute Service page.

The following figure shows the architecture of ECS components. For more information about the functional components in the figure, see the ECS documentation. WhatIsEcs-Orange-Renminbi


An ECS instance includes computing resources (vCPUs and memory), image, EBS devices, public bandwidth, and snapshots. You are charged for these resources.

The following billing methods are supported:
  • Subscription: You pay for resources upfront and use them over a period of time.
  • Pay-as-you-go: You pay for resources after you use them. Resources can be purchased and released as needed.
  • Preemptible instance: You can bid for available computing resources to create preemptible instances. Preemptible instances offer discounts compared with pay-as-you-go instances. However, preemptible instances can be reclaimed.
  • Reserved instance: Reserved instances are discount coupons that are used together with pay-as-you-go instances. When you purchase a reserved instance, you make a commitment to use instances that have specified configurations such as instance type, region, and zone to receive discounted billing. Reserved instances are applied to offset the bills of computing resources.
  • Savings plan: Savings plans are discount plans that are used together with pay-as-you-go instances. When you purchase a savings plan, you make a commitment to use a consistent amount (measured in USD/hour) of resources to receive discounted billing. Saving plans are applied to offset the bills of computing resources and system disks.
  • Storage capacity unit (SCU): SCUs are storage resource plans provided for use with pay-as-you-go storage resources. When you purchase an SCU, you make a commitment to use storage resources of specific capacity to receive discounted billing. SCUs are applied to offset the bills of various storage resources such as EBS devices, Apsara File Storage NAS file systems, and OSS buckets.

For more information about the billing methods of ECS instances, see Billing overview and the Pricing tab of the Elastic Compute Service product page.

Management tools

After you register an Alibaba Cloud account, you can use one of the following methods provided by Alibaba Cloud to create, use, or release ECS instances in a region:

  • ECS console: a web service page used to manage ECS instances. For more information about the operations that you can perform in the ECS console, see Quick reference.
  • ECS API: a Remote Procedure Call (RPC) API that supports GET and POST requests. For more information, see API Reference. The following developer tools can be used to call ECS API operations:
    • Alibaba Cloud CLI: a flexible and scalable management tool based on Alibaba Cloud APIs. You can use CLI to encapsulate Alibaba Cloud native APIs to develop custom features.
    • OpenAPI Explorer: allows you to retrieve API operations, call API operations, and dynamically generate SDK sample code.
    • Alibaba Cloud SDK: provides SDKs for a variety of programming languages such as Java, Python, and PHP.
  • Resource Orchestration Service (ROS): automatically creates and configures Alibaba Cloud resources based on user-defined templates.
  • Operation Orchestration Service (OOS): automatically manages and executes O&M tasks. You can define items such as execution tasks, sequence, and inputs and outputs in execution templates and use the templates to automate O&M tasks.
  • Terraform: uses configuration files to call computing resources of Alibaba Cloud and other platforms that support Terraform. Terraform is an open source tool that implements version control.

Deployment suggestions

Before you purchase an ECS instance, consider the following factors:

  • Region and zone

    A region represents an Alibaba Cloud data center. The region and zone determine the physical location of an ECS instance. After an instance is created, its metadata is established and its region cannot be changed. You can obtain metadata only of the ECS instances located within VPCs. Select a region and zone based on your geographical location, availability of Alibaba Cloud services, application availability requirements, and whether internal network communication is required. For example, if you want to access both ECS and ApsaraDB RDS over the internal network of Alibaba Cloud, the RDS instance and ECS instance must be within the same region. For more information, see Regions and zones.

  • High availability

    To ensure business consistency and continuity, we recommend that you use snapshots to back up data, and use multi-zone deployment, deployment sets, and Server Load Balancer (SLB) for disaster recovery.

  • Network planning

    We recommend that you use VPC to plan your own private IP addresses. VPC supports all new features of instances and new instance types. VPC also supports business system isolation and multi-region system deployment. For more information, see What is a VPC?

  • Security solutions
    • You can use ECS security groups free of charge to control inbound and outbound access policies and the port listening status of ECS instances. For more information, see Overview.
    • For applications deployed on ECS instances, Alibaba Cloud provides Anti-DDoS Basic and basic security services for free. For more information, see Anti-DDoS Basic and Basic security services.
      • Anti-DDoS Basic provides a basic defense capacity of up to 5 Gbit/s against DDoS attacks for free. By default, Anti-DDoS Basic is enabled. If you need advanced defense capacity to safeguard your ECS business, you can purchase an Anti-DDoS Pro or Anti-DDoS Premium instance. For more information, see What are Anti-DDoS Pro and Anti-DDoS Premium?
      • Basic security services for ECS are free of charge. Alibaba Cloud Security Center Basic Edition provides basic security hardening capabilities such as suspicious logon detection, vulnerability scan, and baseline check. If you want to upgrade your Security Center to the Anti-virus, Advanced, or Enterprise edition, you can purchase the edition. For more information, see What is Security Center?