Tag: WF4

We recently had a need to list suspended Workflow Foundation 4 instances hosted in Windows Server AppFabric from code, and here’s how to do it:

SqlInstanceQueryProvider provider = new SqlInstanceQueryProvider();
var providerArgs = new NameValueCollection { { "connectionString", _instanceStoreConnectionString } };
provider.Initialize("WfInstanceProviderA", providerArgs);

InstanceQuery query = provider.CreateInstanceQuery();
var args = new InstanceQueryExecuteArgs { InstanceStatus = InstanceStatus.Suspended };

IAsyncResult asyncResult = query.BeginExecuteQuery(args, new TimeSpan(0, 0, 0, 30), null, null);
IEnumerable instances = query.EndExecuteQuery(asyncResult);

By the way, this requires a reference to Microsoft.ApplicationServer.StoreManagement.dll which is installed with AppFabric.

Resuming the workflow instances can be done like this:

SqlInstanceControlProvider provider = new SqlInstanceControlProvider();
var providerArgs = new NameValueCollection { { "connectionString", _instanceStoreConnectionString } };
provider.Initialize("WfInstanceProviderA", providerArgs);

InstanceControl control = provider.CreateInstanceControl();

foreach (InstanceInfo instanceInfo in instances)
{
    InstanceCommand cmd = new InstanceCommand
    {
        CommandType = CommandType.Resume,
        InstanceId = instanceInfo.InstanceId,
        ServiceIdentifier = instanceInfo.HostInfo.HostMetadata
    };

    // Not included in instanceInfo.HostInfo.HostMetadata...
    cmd.ServiceIdentifier["VirtualPath"] = 
         "/EducationWorkflowServices/AktivitetService.xamlx";

    IAsyncResult asyncResult = control.CommandSend.BeginSend(cmd,
        new TimeSpan(0, 0, 0, 30), null, null);
    control.CommandSend.EndSend(asyncResult);
}

AppFabric also has some great PowerShell cmdlets for administration that can be used for the same thing. Here are a few examples:

Import-Module ApplicationServer
Get-ASAppServiceInstance -status 'suspended'
Get-ASAppServiceInstance -status 'suspended' | Resume-ASAppServiceInstance
Get-ASAppServiceInstance -status 'suspended' | Stop-ASAppServiceInstance -Terminate
Get-ASAppServiceInstance -status 'suspended' | Remove-ASAppServiceInstance
Get-ASAppServiceInstance -InstanceId 95a25419-0d71-42c4-ab70-aa523ba603fc
Get-ASAppServiceInstance -InstanceId 95a25419-0d71-42c4-ab70-aa523ba603fc | Suspend-ASAppServiceInstance

Yet another alternative is to query the AppFabric persistance store database directly using SQL:

SELECT *
FROM [AppFabric_Application_Extensions].[System.Activities.DurableInstancing].[InstancesTable]
WHERE IsSuspended=1

Choose the alternative most to your liking 🙂

/Emil