SchedulerX:Gracefully shut down jobs and tasks executed in an application

# The graceful shutdown mode. WAIT_ALL: Wait for all jobs to complete. WAIT_RUNNING: Wait for running jobs to complete. 
# If you do not configure this parameter, the graceful shutdown feature is disabled. By default, the graceful shutdown feature is disabled. 
spring.schedulerx2.graceShutdownMode=WAIT_ALL
# The timeout period for graceful shutdown. Unit: seconds. By default, no timeout period for graceful shutdown is specified. 
spring.schedulerx2.graceShutdownTimeout=10

# Specifies whether to enable the port required by the HTTP service. Default value: false. 
spring.schedulerx2.httpServerEnable=true
# The port over which you can call the shutdown-purposed HTTP interface. Default port: 51886. 
spring.schedulerx2.httpServerPort=52333

Method 1: Gracefully shut down an application process by using kill -15

SchedulerX SDKs provide the hook function required by shutting down Java virtual machine (JVM) processes, which makes applications gracefully exit. If you want to shut down an application process, you can run the kill -15 Process ID command. In this case, the running process is gracefully shut down after jobs and tasks are complete based on the configured policies.

Method 2: Gracefully shut down an application process by using the SpringBoot shutdown event

If you connect an initialized SpringBoot application to SchedulerX, you can use the actuator feature provided by SpringBoot to implement graceful shutdown. The actuator feature can gracefully shut down scheduled jobs while responding to Spring container shutdown events.

To enable the SpringBoot actuator feature, perform the following steps:

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

management.endpoint.shutdown.enabled=true
management.endpoints.web.exposure.include=shutdown

curl -X GET http://NodeIP:Port/actuator/shutdown

Method 3: Gracefully shut down an application process by using the HTTP interface

Configure the following parameters to enable the port required by the HTTP service to respond to the external requests for shutting down the scheduled jobs in the current application process. Parameters:

# Specifies whether to enable the port required by the HTTP service. Default value: false. 
spring.schedulerx2.httpServerEnable=true
# The port over which you can call the shutdown-purposed HTTP interface. Default port: 51886. 
spring.schedulerx2.httpServerPort=51886

You can call the following HTTP interface to gracefully shut down scheduled jobs:

curl -X GET http://NodeIP:51886/schedulerx/worker/shutdown

Scenario 1: Integrate graceful shutdown into a self-built CD process

In most cases, a self-built continuous delivery (CD) process includes a node where you can stop the application process. You can build and execute the stop.sth script on the node to make your application process exit. You must include the processing logic of graceful shutdown in the script content. You can refer to one of the preceding methods based on your business requirements.

Sample CD process:

The following code provides a sample script that is used to shut down an application process:

# After you start the application, the process ID is written into the app.pid file.
PID="{Application deployment path}/app.pid"
FORCE=1
if [ -f ${PID} ]; then
  TARGET_PID=`cat ${PID}`
  kill -15 ${TARGET_PID}
  loop=1
  while(( $loop<=5 ))
  do
    # health: Specifies whether the current application process ends. You can configure the health field based on your business requirements.
    health
    if [ $? == 0 ]; then
      echo "check $loop times, current app has not stop yet."
      sleep 5s
      let "loop++"
    else
      FORCE=0
      break
    fi
  done
  if [ $FORCE -eq 1 ]; then
  	echo "App(pid:${TARGET_PID}) stop timeout, forced termination."
    kill -9 ${TARGET_PID}
  if
  rm -rf ${PID}
  echo "App(pid:${TARGET_PID}) stopped successful."
fi

Scenario 2: Integrate graceful shutdown into the PreStop event of the Kubernetes containerized deployment

You can use the PreStop event that is used to destroy pods in Kubernetes clusters to trigger graceful shutdown for your application. In addition, you can use exec to execute scripts or initiate HTTP requests to invoke the PreStop hook function to implement graceful shutdown.

• Exec script: Directly shut down the application process. Alternatively, you can execute the preset stop.sh script to make the application process exit.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-app-container
        image: my-app-image:latest
        lifecycle:
          preStop:
            exec:
              # command: ["/bin/sh", "-c", "kill -15 PID && sleep 30"]
              command: ["/bin/sh", "-c", "Script path /stop.sh"] 

• HTTP interface:

  • When you enable the SpringBoot actuator shutdown feature, you can set Path to /actuator/shutdown.

  • For non-Spring applications, you can set Path to /schedulerx/worker/shutdown after you enable the port over which you can call the HTTP interface by using SchedulerX SDKs to implement graceful shutdown.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-app-container
        image: my-app-image:latest
        lifecycle:
          preStop:
            httpGet:
              path: /schedulerx/worker/shutdown
              port: 51886
              scheme: HTTP

Scenario 3: Integrate graceful shutdown into an application release platform in Alibaba Cloud

If you release your application by using Alibaba Cloud Enterprise Distributed Application Service (EDAS) or by using Microservices Engine (MSE) and Container Service for Kubernetes (ACK), the graceful shutdown feature of SchedulerX is automatically integrated into the platform that you use after you enable the graceful shutdown feature on the platform. For more information, see Gracefully shut down Spring Cloud applications and Graceful shutdown.