If a preemptible instance is forcibly recycled due to a market price change or insufficient resources, an interruption event is triggered. Before the preemptible instance is recycled, it enters the locked state and you are prompted that the instance will be recycled. This topic describes how to query interruption events of preemptible instances. You can automate the instance interruption and recycle processes based on the recycle status of instances.

Query interruption events of preemptible instances by using Cloud Monitor SDK

This section describes how to query interruption events of preemptible instances by using Cloud Monitor SDK for Java.

  1. Access Cloud Monitor SDK for Java. For more information, see Java SDK.
  2. Query interruption events of preemptible instances by using the SDK. 
    import com.aliyuncs.DefaultAcsClient;
import com.aliyuncs.IAcsClient;
import com.aliyuncs.exceptions.ClientException;
import com.aliyuncs.exceptions.ServerException;
import com.aliyuncs.profile.DefaultProfile;
import com.google.gson.Gson;
import java.util.*;
import com.aliyuncs.cms.model.v20190101.*;

public class DescribeSystemEventAttribute {
    public static void main(String[] args) {

        DefaultProfile profile = DefaultProfile.getProfile("cn-hangzhou", "<accessKeyId>", "<accessSecret>");
        IAcsClient client = new DefaultAcsClient(profile);

        DescribeSystemEventAttributeRequest request = new DescribeSystemEventAttributeRequest();
        request.setRegionId("cn-hangzhou");
        request.setProduct("ECS");
        request.setEventType("StatusNotification");
        request.setName("Instance:PreemptibleInstanceInterruption");
        try {
            DescribeSystemEventAttributeResponse response = client.getAcsResponse(request);
            System.out.println(new Gson().toJson(response));
        } catch (ServerException e) {
            e.printStackTrace();
        } catch (ClientException e) {
            System.out.println("ErrCode:" + e.getErrCode());
            System.out.println("ErrMsg:" + e.getErrMsg());
            System.out.println("RequestId:" + e.getRequestId());
        }
    }
}
  3. Check interruption events of preemptible instances based on the responses.

    The following code shows the event notification in the JSON format:

    {
  "ver": "1.0",
  "id": "2256A988-0B26-4E2B-820A-8A********E5",
  "product": "ECS",
  "resourceId": "acs:ecs:cn-hangzhou:169070********30:instance/i-bp1ecr********5go2go",
  "level": "INFO",
  "name": "Instance:PreemptibleInstanceInterruption",
  "userId": "169070********30",
  "eventTime": "20190409T121826.922+0800",
  "regionId": "cn-hangzhou",
  "content": {
    "instanceId": "i-bp1ecr********5go2go",  
    "action": "delete"                       
  }
}
    The following table describes parameters in the content field.
    Parameter Description Example
    instanceId The ID of the preemptible instance. i-bp1ecr********5go2go
    action The operation on the preemptible instance. If the parameter is set to delete, the interrupted preemptible instance will be forcibly recycled. delete

Query interruption events of preemptible instances by using instance metadata

  1. Remotely connect to an ECS instance. For more information, see Overview.
  2. Run the following command to query instance metadata: 
    curl 'http://100.100.100.200/latest/meta-data/instance/spot/termination-time'
    • If the response is empty, the instance can still be used.
    • If information in the 2015-01-05T18:02:00Z (UTC+0) format is returned, the preemptible instance will be recycled at that point in time.

Query interruption events of preemptible instances by calling an API operation

This section describes how to call the DescribeInstances operation to determine whether the instance has entered the to be recycled state based on the returned OperationLocks parameter.

The following content shows sample code of DescribeInstancesSample.java: 
public class DescribeInstancesSample {
  public static void main(String[] args) throws InterruptedException {
      OpenApiCaller caller = new OpenApiCaller();
      JSONArray allInstances = new JSONArray();
      allInstances.addAll(Arrays.asList("i-bp18hgfai8ekoqwo0***", "i-bp1ecbyds24ij63w1***"));
      while (! allInstances.isEmpty()) {
          DescribeInstancesRequest request = new DescribeInstancesRequest();
          request.setRegionId("cn-hangzhou");
          request.setInstanceIds(allInstances.toJSONString());// Specify the ID of the instance and query only the instance whose ID has been specified.
          DescribeInstancesResponse response = caller.doAction(request);
          List<DescribeInstancesResponse.Instance> instanceList = response.getInstances();
          if (instanceList ! = null && ! instanceList.isEmpty()) {
              for (DescribeInstancesResponse.Instance instance : instanceList) {
                  System.out.println("result:instance:" + instance.getInstanceId() + ",az:" + instance.getZoneId());
                  if (instance.getOperationLocks() ! = null) {
                      for (DescribeInstancesResponse.Instance.LockReason lockReason : instance.getOperationLocks()) {
                          System.out.println("instance:" + instance.getInstanceId() + "-->lockReason:" + lockReason.getLockReason() + ",vmStatus:" + instance.getStatus());
                          if ("Recycling".equals(lockReason.getLockReason())) {
                              //do your action
                              System.out.println("spot instance will be recycled immediately, instance id:" + instance.getInstanceId());
                              allInstances.remove(instance.getInstanceId());
                          }
                      }
                  }
              }
              System.out.print("try describeInstances again later ...") ;
              Thread.sleep(2 * 60 * 1000);
          } else {
              break;
          }
      }
  }
}
The following result is returned if the recycle is triggered:
instance:i-bp1ecbyds24ij63w****-->lockReason:Recycling,vmStatus:Stopped
spot instance will be recycled immediately, instance id:i-bp1ecbyds24ij63w****