# Spot Instance interruptions You can launch Spot Instances on spare EC2 capacity for steep discounts in exchange for returning them when Amazon EC2 needs the capacity back. When Amazon EC2 reclaims a Spot Instance, we call this event a *Spot Instance interruption*. Demand for Spot Instances can vary significantly from moment to moment, and the availability of Spot Instances can also vary significantly depending on how many unused EC2 instances are available. It is always possible that your Spot Instance might be interrupted. The following are the possible reasons that Amazon EC2 might interrupt your Spot Instances: **Capacity** Amazon EC2 can interrupt your Spot Instance when it needs it back. EC2 reclaims your instance mainly to repurpose capacity, but it can also occur for other reasons such as host maintenance or hardware decommission. **Price** The Spot price is higher than your maximum price. You can specify the maximum price in your Spot request. However, if you specify a maximum price, your instances will be interrupted more frequently than if you do not specify it. **Constraints** If your Spot request includes a constraint such as a launch group or an Availability Zone group, the Spot Instances are terminated as a group when the constraint can no longer be met. When Amazon EC2 interrupts a Spot Instance, it either terminates, stops, or hibernates the instance, depending on the interruption behavior that you specified when you created the Spot request. **Topics** + [Interruption behavior](interruption-behavior.md) + [Prepare for interruptions](prepare-for-interruptions.md) + [Initiate an interruption](initiate-a-spot-instance-interruption.md) + [ # Spot Instance interruption notices ](spot-instance-termination-notices.md) + [ # Find interrupted Spot Instances ](finding-an-interrupted-Spot-Instance.md) + [ # Determine whether Amazon EC2 terminated a Spot Instance ](BidEvictedEvent.md) + [Billing](billing-for-interrupted-spot-instances.md) # Behavior of Spot Instance interruptions Interruption behavior When you create a Spot request, you can specify the interruption behavior. The following are the possible interruption behaviors: + [Stop](#stop-spot-instances) + [Hibernate](#hibernate-spot-instances) + [Terminate](#terminate-interrupted-spot-instances) The default behavior is that Amazon EC2 terminates Spot Instances when they are interrupted. ## Stop interrupted Spot Instances Stop You can specify that Amazon EC2 stops your Spot Instances when they are interrupted. The Spot Instance request type must be `persistent`. You can't specify a launch group in the Spot Instance request. For EC2 Fleet or Spot Fleet, the request type must be `maintain`. **Considerations** + Only Amazon EC2 can restart an interrupted stopped Spot Instance. + For a Spot Instance launched by a `persistent` Spot Instance request: Amazon EC2 restarts the stopped instance when capacity is available in the same Availability Zone and for the same instance type as the stopped instance (the same launch specification must be used). + While a Spot Instance is stopped, you can modify some of its instance attributes, but not the instance type. If you detach or delete an EBS volume, it is not attached when the Spot Instance is started. If you detach the root volume and Amazon EC2 attempts to start the Spot Instance, the instance will fail to start and Amazon EC2 will terminate the stopped instance. + You can terminate a Spot Instance while it is stopped. + If you cancel a Spot Instance request, an EC2 Fleet, or a Spot Fleet, Amazon EC2 terminates any associated Spot Instances that are stopped. + While an interrupted Spot Instance is stopped, you are charged only for the EBS volumes, which are preserved. With EC2 Fleet and Spot Fleet, if you have many stopped instances, you can exceed the limit on the number of EBS volumes for your account. For more information about how you're charged when a Spot Instance is interrupted, see [Billing for interrupted Spot Instances](billing-for-interrupted-spot-instances.md). + Make sure that you are familiar with the implications of stopping an instance. For information about what happens when an instance is stopped, see [Differences between instance states](ec2-instance-lifecycle.md#lifecycle-differences). ## Hibernate interrupted Spot Instances Hibernate You can specify that Amazon EC2 hibernates your Spot Instances when they are interrupted. For more information, see [Hibernate your Amazon EC2 instance](Hibernate.md). Amazon EC2 now offers the same hibernation experience for Spot Instances as is currently available for On-Demand Instances. It offers more extensive support, where the following is now supported for Spot Instance hibernation: + [More supported AMIs](hibernating-prerequisites.md#hibernation-prereqs-supported-amis) + [More supported instance families](hibernating-prerequisites.md#hibernation-prereqs-supported-instance-families) + [User-initiated hibernation](hibernating-instances.md) ## Terminate interrupted Spot Instances Terminate When Amazon EC2 interrupts a Spot Instance, it terminates the instance by default, unless you specify a different interruption behavior, such as stop or hibernate. For more information, see [Terminate Amazon EC2 instances](terminating-instances.md). # Prepare for Spot Instance interruptions Prepare for interruptions Demand for Spot Instances can vary significantly from moment to moment, and the availability of Spot Instances can also vary significantly depending on how many unused EC2 instances are available. It is always possible that your Spot Instance might be interrupted. Therefore, you must ensure that your application is prepared for a Spot Instance interruption. We recommend that you follow these best practices so that you're prepared for a Spot Instance interruption. + Create your Spot request using an Auto Scaling group. If your Spot Instances are interrupted, the Auto Scaling group will automatically launch replacement instances. For more information, see [Auto Scaling groups with multiple instance types and purchase options](https://docs.aws.amazon.com/autoscaling/ec2/userguide/ec2-auto-scaling-mixed-instances-groups.html) in the *Amazon EC2 Auto Scaling User Guide*. + Ensure that your instance is ready to go as soon as the request is fulfilled by using an Amazon Machine Image (AMI) that contains the required software configuration. You can also use user data to run commands at startup. + Data on instance store volumes is lost when the instance is stopped or terminated. Back up any important data on instance store volumes to a more persistent storage, such as Amazon S3, Amazon EBS, or Amazon DynamoDB. + Store important data regularly in a place that isn't affected if the Spot Instance terminates. For example, you can use Amazon S3, Amazon EBS, or DynamoDB. + Divide the work into small tasks (using a Grid, Hadoop, or queue-based architecture) or use checkpoints so that you can save your work frequently. + Amazon EC2 emits a rebalance recommendation signal to the Spot Instance when the instance is at an elevated risk of interruption. You can rely on the rebalance recommendation to proactively manage Spot Instance interruptions without having to wait for the two-minute Spot Instance interruption notice. For more information, see [EC2 instance rebalance recommendations](rebalance-recommendations.md). + Use the two-minute Spot Instance interruption notices to monitor the status of your Spot Instances. For more information, see [Spot Instance interruption notices](spot-instance-termination-notices.md). + While we make every effort to provide these warnings as soon as possible, it is possible that your Spot Instance is interrupted before the warnings can be made available. Test your application to ensure that it handles an unexpected instance interruption gracefully, even if you are monitoring for rebalance recommendation signals and interruption notices. You can do this by running the application using an On-Demand Instance and then terminating the On-Demand Instance yourself. + Run a controlled fault injection experiment with AWS Fault Injection Service to test how your application responds when your Spot Instance is interrupted. For more information, see the [Tutorial: Test Spot Instance interruptions using AWS FIS](https://docs.aws.amazon.com/fis/latest/userguide/fis-tutorial-spot-interruptions.html) in the *AWS Fault Injection Service User Guide*. # Initiate a Spot Instance interruption Initiate an interruption You can select a Spot Instance request or a Spot Fleet request in the Amazon EC2 console and initiate a Spot Instance interruption so that you can test how the applications on your Spot Instances handle being interrupted. When you initiate a Spot Instance interruption, Amazon EC2 notifies you that your Spot Instance will be interrupted in two minutes, and then, after two minutes, the instance is interrupted. The underlying service that performs the Spot Instance interruption is AWS Fault Injection Service (AWS FIS). For information about AWS FIS, see [AWS Fault Injection Service](https://aws.amazon.com/fis/). **Note** Interruption behaviors are `terminate`, `stop`, and `hibernate`. If you set the interruption behavior to `hibernate`, when you initiate a Spot Instance interruption, the hibernation process will begin immediately. Initiating a Spot Instance interruption is supported in all AWS Regions except Asia Pacific (Jakarta), Asia Pacific (Osaka), China (Beijing), China (Ningxia), and Middle East (UAE). **Topics** + [ ## Initiate a Spot Instance interruption ](#initiate-interruption) + [ ## Verify the Spot Instance interruption ](#spot-interruptions-verify-result) + [ ## Quotas ](#fis-quota-for-spot-instance-interruption) ## Initiate a Spot Instance interruption You can use the EC2 console to quickly initiate a Spot Instance interruption. When you select a Spot Instance request, you can initiate the interruption of one Spot Instance. When you select a Spot Fleet request, you can initiate the interruption of multiple Spot Instances at once. For more advanced experiments to test Spot Instance interruptions, you can create your own experiments using the AWS FIS console. **To initiate the interruption of one Spot Instance in a Spot Instance request using the EC2 console** 1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/). 1. From the navigation pane, choose **Spot Requests**. 1. Select a Spot Instance request, and then choose **Actions**, **Initiate interruption**. You can’t select multiple Spot Instance requests to initiate an interruption. 1. In the **Initiate Spot Instance interruption** dialog box, under **Service access**, either use the default role, or choose an existing role. To choose an existing role, choose **Use an existing service role**, and then, for **IAM role**, select the role to use. 1. When you're ready to initiate the Spot Instance interruption, choose **Initiate interruption.** **To initiate the interruption of one or more Spot Instances in a Spot Fleet request using the EC2 console** 1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/). 1. From the navigation pane, choose **Spot Requests**. 1. Select a Spot Fleet request, and then choose **Actions**, **Initiate interruption**. You can’t select multiple Spot Fleet requests to initiate an interruption. 1. In the **Specify number of Spot Instances** dialog box, for **Number of instances to interrupt**, enter the number of Spot Instances to interrupt, and then choose **Confirm**. **Note** The number can't exceed the number of Spot Instances in the fleet or your [quota](#fis-quota-for-spot-instance-interruption) for the number of Spot Instances that AWS FIS can interrupt per experiment. 1. In the **Initiate Spot Instance interruption** dialog box, under **Service access**, either use the default role, or choose an existing role. To choose an existing role, choose **Use an existing service role**, and then, for **IAM role**, select the role to use. 1. When you're ready to initiate the Spot Instance interruption, choose **Initiate interruption.** **To create more advanced experiments to test Spot Instance interruptions using the AWS FIS console** 1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/). 1. From the navigation pane, choose **Spot Requests**. 1. Choose **Actions**, **Create advanced experiments**. The AWS FIS console opens. For more information, see [Tutorial: Test Spot Instance interruptions using AWS FIS](https://docs.aws.amazon.com/fis/latest/userguide/fis-tutorial-spot-interruptions.html) in the *AWS Fault Injection Service User Guide*. ## Verify the Spot Instance interruption After you initiate the interruption, the following occurs: + The Spot Instance receives an [instance rebalance recommendation](rebalance-recommendations.md). + A [Spot Instance interruption notice](spot-instance-termination-notices.md) is issued two minutes before AWS FIS interrupts your instance. + After two minutes, the Spot Instance is interrupted. + A Spot Instance that was stopped by AWS FIS remains stopped until you restart it. **To verify that the instance was interrupted after you initiated the interruption** 1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/). 1. From the navigation pane, open **Spot Requests** and **Instances** in separate browser tabs or windows. 1. For **Spot Requests**, select the Spot Instance request or Spot Fleet request. The initial status is `fulfilled`. After the instance is interrupted, the status changes as follows, depending on the interruption behavior: + `terminate` – The status changes to `instance-terminated-by-experiment`. + `stop` – The status changes to `marked-for-stop-by-experiment` and then `instance-stopped-by-experiment`. 1. For **Instances**, select the Spot Instance. The initial status is `Running`. Two minutes after you receive the Spot Instance interruption notice, the status changes as follows, depending on the interruption behavior: + `stop` – The status changes to `Stopping` and then `Stopped`. + `terminate` – The status changes to `Shutting-down` and then `Terminated`. ## Quotas Your AWS account has the following default quota for the number of Spot Instances that AWS FIS can interrupt per experiment. | Name | Default | Adjustable | Description | | --- | --- | --- | --- | | Target SpotInstances for aws:ec2:send-spot-instance-interruptions | Each supported Region: 5 | Yes | The maximum number of Spot Instances that aws:ec2:send-spot-instance-interruptions can target when you identify targets using tags, per experiment. | You can request a quota increase. For more information, see [Requesting a quota increase](https://docs.aws.amazon.com/servicequotas/latest/userguide/request-quota-increase.html) in the *Service Quotas User Guide*. To view all the quotas for AWS FIS, open the [Service Quotas console](https://console.aws.amazon.com/servicequotas/home). In the navigation pane, choose **AWS services** and select **AWS Fault Injection Service**. You can also view all the [quotas for AWS Fault Injection Service](https://docs.aws.amazon.com/fis/latest/userguide/fis-quotas.html) in the *AWS Fault Injection Service User Guide*. # Spot Instance interruption notices A *Spot Instance interruption notice* is a warning that is issued two minutes before Amazon EC2 stops or terminates your Spot Instance. If you specify hibernation as the interruption behavior, you receive an interruption notice, but you do not receive a two-minute warning because the hibernation process begins immediately. The best way for you to gracefully handle Spot Instance interruptions is to architect your application to be fault-tolerant. To accomplish this, you can take advantage of Spot Instance interruption notices. We recommend that you check for these interruption notices every 5 seconds. The interruption notices are made available as an EventBridge event and as items in the [instance metadata](ec2-instance-metadata.md) on the Spot Instance. Interruption notices are emitted on a best effort basis. ## EC2 Spot Instance Interruption Warning event When Amazon EC2 is going to interrupt your Spot Instance, it emits an event two minutes prior to the actual interruption (except for hibernation, which gets the interruption notice, but not two minutes in advance, because hibernation begins immediately). This event can be detected by Amazon EventBridge. For more information about EventBridge events, see the [Amazon EventBridge User Guide](https://docs.aws.amazon.com/eventbridge/latest/userguide/). For a detailed example that walks you through how to create and use event rules, see [Taking Advantage of Amazon EC2 Spot Instance Interruption Notices](https://aws.amazon.com/blogs/compute/taking-advantage-of-amazon-ec2-spot-instance-interruption-notices/). The following is an example of the event for Spot Instance interruption. The possible values for `instance-action` are `hibernate`, `stop`, or `terminate`. ``` { "version": "0", "id": "12345678-1234-1234-1234-123456789012", "detail-type": "EC2 Spot Instance Interruption Warning", "source": "aws.ec2", "account": "123456789012", "time": "yyyy-mm-ddThh:mm:ssZ", "region": "us-east-2", "resources": ["arn:aws:ec2:us-east-2a:instance/i-1234567890abcdef0"], "detail": { "instance-id": "i-1234567890abcdef0", "instance-action": "action" } } ``` **Note** The ARN format of the Spot Instance interruption event is `arn:aws:ec2:availability-zone:instance/instance-id`. This format differs from the [EC2 resource ARN format](https://docs.aws.amazon.com/service-authorization/latest/reference/list_amazonec2.html#amazonec2-resources-for-iam-policies). ## instance-action The `instance-action` item specifies the action and the approximate time, in UTC, when the action will occur. If your Spot Instance is marked to be stopped or terminated by Amazon EC2, the `instance-action` item is present in your [instance metadata](ec2-instance-metadata.md). Otherwise, it is not present. You can retrieve the `instance-action` using Instance Metadata Service Version 2 (IMDSv2) as follows. ------ #### [ Linux ] ``` TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` \ && curl -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/spot/instance-action ``` ------ #### [ Windows ] ``` [string]$token = Invoke-RestMethod ` -Headers @{"X-aws-ec2-metadata-token-ttl-seconds" = "21600"} ` -Method PUT -Uri http://169.254.169.254/latest/meta-data/spot/instance-action ``` ------ The following example output indicates the time at which this instance will be stopped. ``` {"action": "stop", "time": "2017-09-18T08:22:00Z"} ``` The following example output indicates the time at which this instance will be terminated. ``` {"action": "terminate", "time": "2017-09-18T08:22:00Z"} ``` If Amazon EC2 is not preparing to stop or terminate the instance, or if you terminated the instance yourself, `instance-action` is not present in the instance metadata and you receive an HTTP 404 error when you try to retrieve it. ## termination-time The `termination-time` item specifies the approximate time in UTC when the instance will receive the shutdown signal. **Note** This item is maintained for backward compatibility; you should use `instance-action` instead. If your Spot Instance is marked for termination by Amazon EC2 (either due to a Spot Instance interruption where the interruption behavior is set to `terminate`, or due to the cancellation of a persistent Spot Instance request), the `termination-time` item is present in your [instance metadata](ec2-instance-metadata.md). Otherwise, it is not present. You can retrieve the `termination-time` using IMDSv2 as follows. ------ #### [ Linux ] ``` TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` if curl -H "X-aws-ec2-metadata-token: $TOKEN" -s http://169.254.169.254/latest/meta-data/spot/termination-time | grep -q .*T.*Z; then echo termination_scheduled; fi ``` ------ #### [ Windows ] ``` [string]$token = Invoke-RestMethod -Headers @{"X-aws-ec2-metadata-token-ttl-seconds" = "21600"} -Method PUT -Uri http://169.254.169.254/latest/meta-data/spot/termination-time ``` ------ The following is example output. ``` 2015-01-05T18:02:00Z ``` If Amazon EC2 is not preparing to terminate the instance (either because there is no Spot Instance interruption or because your interruption behavior is set to `stop` or `hibernate`), or if you terminated the Spot Instance yourself, the `termination-time` item is either not present in the instance metadata (so you receive an HTTP 404 error) or contains a value that is not a time value. If Amazon EC2 fails to terminate the instance, the request status is set to `fulfilled`. The `termination-time` value remains in the instance metadata with the original approximate time, which is now in the past. # Find interrupted Spot Instances When you describe your EC2 instances, the results include your Spot Instances. The instance lifecycle of a Spot Instance is `spot`. The instance state of a Spot Instance is either `stopped` or `terminated`, depending on the interruption behavior that you configured. For a hibernated Spot Instance, the instance state is `stopped`. For additional details about the reason for the interruption, check the Spot request status code. For more information, see [Get the status of a Spot Instance request](spot-request-status.md). ------ #### [ Console ] **To find an interrupted Spot Instance** 1. Open the Amazon EC2 console at [https://console.aws.amazon.com/ec2/](https://console.aws.amazon.com/ec2/). 1. In the navigation pane, choose **Instances**. 1. Apply the following filter: **Instance lifecycle=spot**. 1. Apply the **Instance state=stopped** or **Instance state=terminated** filter depending on the interruption behavior that you configured. 1. For each Spot Instance, on the **Details** tab, under **Instance details**, find **State transition message**. The following codes indicate that the Spot Instance was interrupted. + `Server.SpotInstanceShutdown` + `Server.SpotInstanceTermination` ------ #### [ AWS CLI ] **To find interrupted Spot Instances** Use the [describe-instances](https://docs.aws.amazon.com/cli/latest/reference/ec2/describe-instances.html) command with the `--filters` option. To list only the instance IDs in the output, include the `--query` option. If the interruption behavior is to terminate the Spot Instances, use the following example: ``` aws ec2 describe-instances \ --filters Name=instance-lifecycle,Values=spot \ Name=instance-state-name,Values=terminated \ Name=state-reason-code,Values=Server.SpotInstanceTermination \ --query "Reservations[*].Instances[*].InstanceId" ``` If the interruption behavior is to stop the Spot Instances, use the following example: ``` aws ec2 describe-instances \ --filters Name=instance-lifecycle,Values=spot \ Name=instance-state-name,Values=stopped \ Name=state-reason-code,Values=Server.SpotInstanceShutdown \ --query "Reservations[*].Instances[*].InstanceId" ``` ------ #### [ PowerShell ] **To find interrupted Spot Instances** Use the [Get-EC2Instance](https://docs.aws.amazon.com/powershell/latest/reference/items/Get-EC2Instance.html) cmdlet. If the interruption behavior is to terminate the Spot Instances, use the following example: ``` (Get-EC2Instance ` -Filter @{Key="instance-lifecycle"; Values="spot"} ` @{Key="instance-state-name"; Values="terminated"} ` @{Key="state-reason-code"; Values="Server.SpotInstanceTermination"}).Instances.InstanceId ``` If the interruption behavior is to stop the Spot Instances, use the following example: ``` (Get-EC2Instance ` -Filter @{Key="instance-lifecycle"; Values="spot"} ` @{Key="instance-state-name"; Values="stopped"} ` @{Key="state-reason-code"; Values="Server.SpotInstanceTermination"}).Instances.InstanceId ``` ------ # Determine whether Amazon EC2 terminated a Spot Instance A Spot Instance runs until Amazon EC2 terminates it in response to a Spot Instance interruption, or until you terminate it yourself. For more information, see [Behavior of Spot Instance interruptions](interruption-behavior.md). After a Spot Instance is terminated, you can use AWS CloudTrail to see whether Amazon EC2 terminated it. If the CloudTrail log includes a `BidEvictedEvent`, this indicates that Amazon EC2 terminated the Spot Instance. If instead you see a `TerminateInstances` event, this indicates that a user terminated the Spot Instance. Alternatively, if you want to receive notification that Amazon EC2 is going to interrupt your Spot Instance, use Amazon EventBridge to respond to the [EC2 Spot Instance Interruption Warning event](spot-instance-termination-notices.md#ec2-spot-instance-interruption-warning-event). **To view BidEvictedEvent events in CloudTrail** 1. Open the CloudTrail console at [https://console.aws.amazon.com/cloudtrail/](https://console.aws.amazon.com/cloudtrail/). 1. In the navigation pane, choose **Event history**. 1. From the list of filters, choose **Event name**, and then in the filter field to the right, enter **BidEvictedEvent**. 1. (Optional) Select a time range. 1. If the list is not empty, choose **BidEvictedEvent** from the resulting entry to open its details page. You can find information about the Spot Instance in the **Event record** pane, including the ID of the Spot Instance. The following is an example of the event record. ``` { "eventVersion": "1.05", "userIdentity": { "accountId": "123456789012", "invokedBy": "ec2.amazonaws.com" }, "eventTime": "2016-08-16T22:30:00Z", "eventSource": "ec2.amazonaws.com", "userAgent": "ec2.amazonaws.com", "sourceIPAddress": "ec2.amazonaws.com", "eventName": "BidEvictedEvent", "awsRegion": "us-east-2", "eventID": "d27a6096-807b-4bd0-8c20-a33a83375054", "eventType": "AwsServiceEvent", "recipientAccountId": "123456789012", "RequestParameters": null, "ResponseElements": null, "serviceEventDetails": { "instanceIdSet": [ "i-1eb2ac8eEXAMPLE" ] } } ``` 1. If you did not find an entry for the `BidEvictedEvent` event, enter **TerminateInstances** as the event name. For more information about the event record for `TerminateInstances`, see [Amazon EC2 API event examples](monitor-with-cloudtrail.md#cloudtrail-event-examples). # Billing for interrupted Spot Instances Billing When a Spot Instance is interrupted, you're charged for instance and EBS volume usage, and you might incur other charges, as follows. ## Instance usage [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/billing-for-interrupted-spot-instances.html) ## EBS volume usage While an interrupted Spot Instance is stopped, you are charged only for the EBS volumes, which are preserved. With EC2 Fleet and Spot Fleet, if you have many stopped instances, you can exceed the limit on the number of EBS volumes for your account.