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RunToCompletion

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Starting with version 7.1, Service Fabric supports RunToCompletion semantics for containers and guest executable applications. These semantics enable applications and services that complete a task and exit, in contrast to always running applications and services.

Before you proceed with this article, be familiar with the Service Fabric application model and the Service Fabric hosting model.

Note

RunToCompletion semantics aren't supported for services that use the Reliable Services programming model.

RunToCompletion semantics and specification

You can specify RunToCompletion semantics as an ExecutionPolicy when you import the ServiceManifest. All the CodePackages comprising the ServiceManifest inherit the specified policy. The following snippet from ApplicationManifest.xml provides an example:

<ServiceManifestImport>
  <ServiceManifestRef ServiceManifestName="RunToCompletionServicePackage" ServiceManifestVersion="1.0"/>
  <Policies>
    <ExecutionPolicy Type="RunToCompletion" Restart="OnFailure"/>
  </Policies>
</ServiceManifestImport>

ExecutionPolicy allows two attributes:

  • Type has RunToCompletion as the only allowed value.

  • Restart specifies the restart policy to apply to CodePackages in the ServicePackage on failure. A CodePackage that exits with a non-zero exit code is considered to have failed. Allowed values for this attribute are OnFailure and Never, with OnFailure as the default.

    • With restart policy set to OnFailure, any CodePackage that fails with a non-zero exit code restarts, with back-offs between repeated failures.

    • With restart policy set to Never, if any CodePackage fails, the deployment status of the DeployedServicePackage is marked Failed, but other CodePackages continue execution.

If all the CodePackages in the ServicePackage run to successful completion with exit code 0, the deployment status of the DeployedServicePackage is marked RanToCompletion.

Code example using RunToCompletion semantics

Let's look at a complete example that uses RunToCompletion semantics.

Important

The following example assumes familiarity with creating Windows container applications using Service Fabric and Docker.

Windows Server containers aren't compatible across all versions of a host OS. This example references mcr.microsoft.com/windows/nanoserver:1809. For more information, see Windows container version compatibility.

The following ServiceManifest.xml describes a ServicePackage consisting of two CodePackages, which represent containers. RunToCompletionCodePackage1 just logs a message to stdout and exits. RunToCompletionCodePackage2 pings the loopback address for a while and then exits with an exit code of either 0, 1, or 2.

<?xml version="1.0" encoding="UTF-8"?>
<ServiceManifest Name="WindowsRunToCompletionServicePackage" Version="1.0" xmlns="http://schemas.microsoft.com/2011/01/fabric" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Description>Windows RunToCompletion Service</Description>
  <ServiceTypes>
    <StatelessServiceType ServiceTypeName="WindowsRunToCompletionServiceType"  UseImplicitHost="true"/>
  </ServiceTypes>
  <CodePackage Name="RunToCompletionCodePackage1" Version="1.0">
    <EntryPoint>
      <ContainerHost>
        <ImageName>mcr.microsoft.com/windows/nanoserver:1809</ImageName>
        <Commands>/c,echo Hi from RunToCompletionCodePackage1 &amp;&amp; exit 0</Commands>
        <EntryPoint>cmd</EntryPoint>
      </ContainerHost>
    </EntryPoint>
  </CodePackage>

  <CodePackage Name="RunToCompletionCodePackage2" Version="1.0">
    <EntryPoint>
      <ContainerHost>
        <ImageName>mcr.microsoft.com/windows/nanoserver:1809</ImageName>
        <Commands>/v,/c,ping 127.0.0.1 &amp;&amp; set /a exitCode=%random% % 3 &amp;&amp; exit !exitCode!</Commands>
        <EntryPoint>cmd</EntryPoint>
      </ContainerHost>
    </EntryPoint>
  </CodePackage>
</ServiceManifest>

The following ApplicationManifest.xml describes an application based on the ServiceManifest.xml discussed above. The code specifies RunToCompletion ExecutionPolicy for WindowsRunToCompletionServicePackage with a restart policy of OnFailure.

Upon WindowsRunToCompletionServicePackage activation, its constituent CodePackages are started. RunToCompletionCodePackage1 should exit successfully on the first activation. RunToCompletionCodePackage2 can fail with a non-zero exit code, and will restart because the restart policy is OnFailure.

<?xml version="1.0" encoding="UTF-8"?>
<ApplicationManifest ApplicationTypeName="WindowsRunToCompletionApplicationType" ApplicationTypeVersion="1.0" xmlns="http://schemas.microsoft.com/2011/01/fabric" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <Description>Windows RunToCompletion Application</Description>

  <ServiceManifestImport>
    <ServiceManifestRef ServiceManifestName="WindowsRunToCompletionServicePackage" ServiceManifestVersion="1.0"/>
    <Policies>
      <ExecutionPolicy Type="RunToCompletion" Restart="OnFailure"/>
    </Policies>
  </ServiceManifestImport>

  <DefaultServices>
    <Service Name="WindowsRunToCompletionService" ServicePackageActivationMode="ExclusiveProcess">
      <StatelessService ServiceTypeName="WindowsRunToCompletionServiceType" InstanceCount="1">
        <SingletonPartition />
      </StatelessService>
    </Service>
  </DefaultServices>
</ApplicationManifest>

Query deployment status of a DeployedServicePackage

You can query deployment status of a DeployedServicePackage.

Considerations for RunToCompletion semantics

Consider the following points about RunToCompletion support:

  • RunToCompletion semantics are supported only for containers and guest executable applications.
  • Upgrade scenarios for applications with RunToCompletion semantics aren't allowed. You need to delete and recreate such applications if necessary.
  • Failover events can cause CodePackages to re-execute after successful completion, on the same node or on other nodes of the cluster. Examples of failover events are node restarts and Service Fabric runtime upgrades on a node.
  • RunToCompletion is incompatible with ServicePackageActivationMode="SharedProcess". Service Fabric runtime version 9.0 and higher fails validation for such services. SharedProcess is the default value, so you must specify ServicePackageActivationMode="ExclusiveProcess" to use RunToCompletion semantics.

Next steps