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Function Compute:Instance types and usage modes

Last Updated:Oct 31, 2024

Function Compute provides elastic instances and GPU-accelerated instances. Both types of instances can be used in on-demand and provisioned modes. On-demand instances are billed based on actual execution durations. You can use on-demand instances together with the instance concurrency feature to improve resource utilization. Billing of a provisioned instance starts when Function Compute starts the provisioned instance and ends when you release the instance. Provisioned instances can effectively mitigate cold starts. This topic describes the types, usage modes, billing methods, and specifications of function instances in Function Compute.

Instance type

  • Elastic instance: the basic instance type of Function Compute. Elastic instances are suitable for scenarios with bursty traffic or compute-intensive workloads.

  • GPU-accelerated instance: Instances that use the Ampere and Turing architectures for GPU acceleration. GPU-accelerated instances are mainly used in audio and video processing, Artificial Intelligence (AI), and image processing scenarios. Instances of this type accelerate business by offloading workloads to GPU hardware.

    The following topics describe best practices for GPU-accelerated instances in different scenarios:

    Important
    • GPU-accelerated instances can be deployed only by using container images.

    • When you use GPU-accelerated instances, join the DingTalk user group 64970014484 and provide the following information so that technical support can be provided in a timely manner:

      • Your organization name, such as your company name.

      • The ID of your Alibaba Cloud account.

      • The region in which you want to use GPU-accelerated instances. Example: China (Shenzhen).

      • Your contact information, such as your mobile number, email address, or DingTalk account.

Usage modes

GPU-accelerated instances and elastic instances support on-demand and provisioned mode. This section describes the two usage modes.

On-demand mode

Introduction

On-demand instances are allocated and released by Function Compute. Function Compute automatically scales instances based on the number of function invocations. Function Compute creates instances when the number of function invocations increases, and destroys excess instances when the number of function invocations decreases. On-demand instances are automatically created upon requests. On-demand instances are destroyed if no requests are submitted for a period of time (usually 3 to 5 minutes). The first time you invoke an on-demand instance, a cold start occurs.

By default, a maximum of 300 instances can be created in on-demand mode for an Alibaba Cloud account in each region. If you need to increase this limit, join the DingTalk group 64970014484 for technical support.

Billing method

Billing of an on-demand instance starts when requests are sent to the instance for processing and ends when the requests are processed. Each on-demand instance can process one or more requests at a time. For more information, see Configure instance concurrency.

No instance is allocated if no request is submitted for processing, and therefore no fees are generated. In on-demand mode, you are charged only when your function is invoked. For more information about pricing and billing, see Billing overview.

Note

You can use the instance concurrency feature based on your business requirements to improve resource utilization. In this case, multiple tasks preemptively share CPU and memory resources on your instance to improve resource utilization.

Instance concurrency = 1

Measurement of execution duration starts when a request arrives at an instance and ends when the request is completely executed.

image

Instance concurrency > 1

Measurement of the execution duration of an on-demand instance starts when the first request is received and ends when the last request is completely executed. You can reuse resources to concurrently process multiple requests. This way, resource costs can be reduced.

image

Provisioned mode

Introduction

In provisioned mode, you can manage the allocation and release of function instances. Provisioned instances are retained unless you release them. Invocation requests are preferentially distributed to provisioned instances. If provisioned instances are not enough to process the requests, Function Compute allocates on-demand instances to process excess requests. For more information about how to delete a provisioned instance, see Modify or delete a provisioned instance policy.

Note

If cold starts are an issue for you, we recommend that you use provisioned instances. You can specify a fixed number of provisioned instances or configure a scheduled auto scaling policy or water-level based auto scaling policy based on factors such as your resource budget, traffic fluctuations of your business, and resource usage thresholds. The average cold start latency of instances is significantly reduced when provisioned instances are used.

Idle mode

Elastic instances

States of elastic instances are classified into the active state and the idle state based on whether vCPU resources are allocated. By default, the idle mode is enabled.

  • Active state

    Instances are considered active if they are processing requests or if the idle mode feature is disabled for them. If you disable Idle Mode, vCPUs are always allocated to provisioned instances regardless of whether the instances are processing requests or not. Running of background tasks is not affected.

  • Idle state

    If you enable Idle Mode, Function Compute freezes vCPUs of provisioned instances when the instances are not processing requests and the provisioned instances enter the idle state. You are not charged for vCPU resources when the instances are in the idle state, which helps you save costs. For more information about instance states, see Configure instance lifecycles.

You can choose whether to enable the idle mode feature based on your business requirements.

  • Costs

    If you want to use provisioned instances to mitigate cold starts and hope to save costs, we recommend that you enable the idle mode feature. This feature allows you to pay only for memory and disk resources of provisioned instances if provisioned instances are in the idle state, and requests can be responded without cold starts.

  • Background tasks

    If your function needs to run background tasks, we recommend that you do not enable the idle mode feature. The following items provide example scenarios:

    • Some application frameworks rely on the built-in scheduler or background features. Some dependent middleware needs to regularly report heartbeats.

    • Some asynchronous operations are performed by using Goroutine lightweight threads that use Go, the async functions that use Node.js, or the asynchronous threads that use Java.

GPU-accelerated instance

GPU-accelerated instances can be classified into active and idle states based on whether they are allocated GPU resources. By default, the idle mode is turned on for GPU-accelerated instances.

  • Active state

    Instances are considered active if they are processing requests or if Idle Mode is disabled for them. After the idle mode is enabled, Function Compute freezes the GPU cards of the provisioned instances and the instances enter the idle state.

  • Idle state

    Provisioned instances for which the idle mode is enabled are idle instances when they are not processing requests .

Billing method

  • Active state

    The billing of provisioned instances starts when the provisioned instances are created and ends when the provisioned instances are released. Provisioned instances are requested and released by yourself. Therefore, you are charged for the provisioned instances based on active mode prices even if they are not processing any requests if the instances are not released and the idle mode is not enabled.

    image
  • Idle state

    After the idle mode is enabled, the provisioned instances enter the idle state when they are not processing requests. The prices of idle instances are much lower than prices of active instances. For more information, see Conversion factors.

Instance specifications

  • Elastic instances

    The following table describes specifications of elastic instances. You can configure instance specifications based on your business requirements.

    vCPU

    Memory size (MB)

    Maximum code package size (GB)

    Maximum function execution duration (seconds)

    Maximum disk size (GB)

    Maximum bandwidth (Gbit/s)

    0.05–16

    Note: The value must be a multiple of 0.05.

    128–32768

    Note: The value must be a multiple of 64.

    10

    86,400

    10

    Valid values:

    • 512 MB. This is the default value.

    • 10 GB.

    5

    Note

    The ratio of vCPU to memory capacity (in GB) is 1: N. N must be a value that ranges from 1 to 4.

  • GPU-accelerated instance

    The following table describes specifications of GPU-accelerated instances. You can configure instance specifications based on your business requirements.

    Note
    • fc.gpu.tesla.1 GPU instances provide essentially the same GPU performance as physical NVIDIA T4 cards.

    • fc.gpu.ampere.1 GPU instances provide essentially the same GPU performance as physical NVIDIA A10 cards.

    Instance specifications

    Full GPU size (GB)

    Computing power of full GPU card (TFLOPS)

    Available specifications

    On-demand mode

    Regular provisioned mode

    Idle provisioned mode

    FP16

    FP32

    vGPU memory (MB)

    vGPU computing power (card)

    vCPUs

    Memory size (MB)

    fc.gpu.tesla.1

    16

    65

    8

    Valid values: 1024 to 16384 (1 GB to 16 GB).

    Note: The value must be a multiple of 1,024.

    The value is calculated based on the following formula: vGPU computing power = vGPU memory (GB)/16. For example, if you set the vGPU memory to 5 GB, the maximum vGPU computing power is 5/16 memory cards.

    The computing power is automatically allocated by Function Compute and does not need to be manually allocated.

    Valid values: 0.05 to the value of [vGPU memory (GB)/2].

    Note: The value must be a multiple of 0.05. For more information, see GPU specifications.

    Valid values: 128 to the value of [vGPU memory (GB) x 2048].

    Note: The value must be a multiple of 64. For more information, see GPU specifications.

    Y

    Y

    Y

    fc.gpu.ampere.1

    24

    125

    30

    Valid values: 1024 to 24576 (1 GB to 24 GB).

    Note: The value must be a multiple of 1,024.

    The value is calculated based on the following formula: vGPU computing power = vGPU memory (GB)/24. For example, if you set the vGPU memory to 5 GB, the maximum vGPU computing power is 5/24 memory cards.

    The computing power is automatically allocated by Function Compute and does not need to be manually allocated.

    Valid values: 0.05 to the value of [vGPU memory (GB)/3].

    Note: The value must be a multiple of 0.05. For more information, see GPU specifications.

    Valid values: 128 to the value of [(vGPU memory (GB) x 4096)/3].

    Note: The value must be a multiple of 64. For more information, see GPU specifications.

    Y

    Y

    Y

    fc.gpu.ada.1

    48

    119

    60

    49152 (48 GB)

    Note: Only 48 GB GPU memory is supported.

    By default, computer power of full GPU cards is allocated.

    The computing power is automatically allocated by Function Compute and does not need to be manually allocated.

    Valid value: 8.

    Value description: Only 8 vCPUs are supported.

    Valid value: 65536.

    Value description: Only 64 GB memory is supported.

    N

    Y

    Y

    The GPU-accelerated instances of Function Compute also support the following resource specifications.

    Image size (GB)

    Maximum function execution duration (seconds)

    Maximum disk size (GB)

    Maximum bandwidth (Gbit/s)

    Container Registry Enterprise Edition (Standard Edition): 15

    Container Registry Enterprise Edition (Advanced Edition): 15

    Container Registry Enterprise Edition (Basic Edition): 15

    Container Registry Personal Edition (free): 15

    86,400

    10

    5

    Note
    • Specifying the instance type as g1 achieves the same effect as selecting the fc.gpu.tesla.1 instance specification.

    • GPU-accelerated instances of Tesla series GPU cards are supported in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Shenzhen), Japan (Tokyo), US (Virginia), and Singapore.

    • GPU-accelerated instances of Ampere series GPU cards are supported in the following regions: China (Hangzhou), China (Shanghai), Japan (Tokyo), and Singapore.

    • GPU-accelerated instances of Ada series GPU cards are supported in the following regions: China (Beijing), China (Hangzhou), China (Shanghai), and China (Shenzhen).

GPU specifications

Expand to view details of fc.gpu.tesla.1.

vGPU memory (MB)

vCPUs

Maximum memory size (GB)

Memory size (MB)

1024

0.05–0.5

2

128–2048

2048

0.05–1

4

128–4096

3072

0.05–1.5

6

128–6144

4096

0.05–2

8

128–8192

5120

0.05–2.5

10

128–10240

6144

0.05–3

12

128–12288

7168

0.05–3.5

14

128–14336

8192

0.05–4

16

128–16384

9216

0.05–4.5

18

128–18432

10240

0.05–5

20

128–20480

11264

0.05–5.5

22

128–22528

12288

0.05–6

24

128–24576

13312

0.05–6.5

26

128–26624

14336

0.05–7

28

128–28672

15360

0.05–7.5

30

128–30720

16384

0.05–8

32

128–32768

Expand to view details of fc.gpu.ampere.1.

vGPU memory (MB)

vCPUs

Maximum memory size (GB)

Memory size (MB)

1024

0.05–0.3

1.3125

128–1344

2048

0.05–0.65

2.625

128–2688

3072

0.05–1

4

128–4096

4096

0.05–1.3

5.3125

128–5440

5120

0.05–1.65

6.625

128–6784

6144

0.05–2

8

128–8192

7168

0.05–2.3

9.3125

128–9536

8192

0.05–2.65

10.625

128–10880

9216

0.05–3

12

128–12288

10240

0.05–3.3

13.3125

128–13632

11264

0.05–3.65

14.625

128–14976

12288

0.05–4

16

128–16384

13312

0.05–4.3

17.3125

128–17728

14336

0.05–4.65

18.625

128–19072

15360

0.05–5

20

128–20480

16384

0.05–5.3

21.3125

128–21824

17408

0.05–5.65

22.625

128–23168

18432

0.05–6

24

128–24576

19456

0.05–6.3

25.3125

128–25920

20480

0.05–6.65

26.625

128–27264

21504

0.05–7

28

128–28672

22528

0.05–7.3

29.3125

128–30016

23552

0.05–7.65

30.625

128–31360

24576

0.05–8

32

128–32768

Additional information

  • You can enable the idle mode when you configure auto scaling rules. For more information, see Configure provisioned instances.

  • For more information about the billing methods and billable items of Function Compute, see Billing overview.

  • When you call an API operation to create a function, you can use the instanceType parameter to specify an instance type. For more information, see CreateFunction.

  • For more information about how to specify the instance type and instance specifications in the Function Compute console, see Create a web function.