yrShutdown

Note

Constraints:

• When users define their own yrShutdown, the function signature must match the interface prototype. Otherwise, the cloud will not be able to find the corresponding function to execute graceful shutdown.

• If the execution time of yrShutdown exceeds gracePeriodSeconds seconds, the cloud instance will not wait for the function to complete and will be immediately reclaimed.

Interface description

public void yrShutdown(int gracePeriodSeconds)

Users can use this interface to perform data cleanup or data persistence operations.

In actors executed in the cloud, add a graceful shutdown function named yrShutdown. The function supports calling the openYuanrong interface. The yrShutdown function will be executed in the following scenarios:

1. When the runtime receives a shutdown request (for example, when a user on-premises calls the terminate interface).

2. When the runtime captures a Sigterm signal (for example, when the cluster executes a scaling-down policy and the runtime-manager captures the Sigterm signal and forwards it to the runtime).

// Define `yrShutdown` in the stateful function.
public class Counter {
    private int cnt = 0;

    public int add() {
        this.cnt += 1;
        return this.cnt;
    }

    public void yrShutdown(int gracePeriodSeconds) throws YRException {
        SetParam setParam = new SetParam.Builder().writeMode(WriteMode.NONE_L2_CACHE_EVICT).build();
        YR.kv().set("myKey", "myValue".getBytes(StandardCharsets.UTF_8), setParam);
    }
}

public void main(String[] args) throws Exception {
    // Use Case 1: GRACEFUL_SHUTDOWN_TIME is not configured, using the system-configured graceful shutdown time.
    YR.kv().del("myKey");
    InstanceHandler ins = YR.instance(Counter::new).invoke();
    ObjectRef ref = ins.function(Counter::add).invoke();
    YR.get(ref, 10);
    ins.terminate();
    // On-premises, using the `kv` interface to retrieve the value mapped by `my_key` will return `'my_value'`.
    byte[] byteArray = YR.kv().get("myKey", 30);
    String shutdownValue = new String(byteArray, StandardCharsets.UTF_8);
    Assert.assertEquals(shutdownValue, "myValue");

    // Use Case 2: Configure GRACEFUL_SHUTDOWN_TIME.
    YR.kv().del("myKey");
    InvokeOptions option = new InvokeOptions();
    option.getCustomExtensions().put("GRACEFUL_SHUTDOWN_TIME","10");
    InstanceHandler ins2 = YR.instance(Counter::new).options(option).invoke();
    ObjectRef ref2 = ins2.function(Counter::add).invoke();
    YR.get(ref2, 10);
    ins2.terminate();
    // On-premises, using the kv interface to retrieve the value mapped by my_key will return 'my_value'.
    byte[] byteArray2 = YR.kv().get("myKey", 30);
    String shutdownValue2 = new String(byteArray2, StandardCharsets.UTF_8);
    Assert.assertEquals(shutdownValue2, "myValue");

    YR.Finalize();
}

• Parameters:

  • gracePeriodSecond (int) – Function execution timeout, in seconds. Default value: 60.