As of version 7.2, dotConnect for PostgreSQL implements PostgreSQL Workflow Instance Store. To use PostgreSQL Workflow Instance Store you need PostgreSQL server 8 or higher.
Before using PostgreSQL Workflow Instance Store, you need to create a database that is used to persist workflow instances. dotConnect for PostgreSQL provides the scripts for creating this database. They are placed to the WF Services subfolder of the dotConnect for PostgreSQL installation folder. By default it is %ProgramFiles%\Devart\dotConnect\PostgreSQL\WF Services\. Note that there are two versions of scripts - for .NET Framework 4.5, and for previous versions of .NET Framework.
If you target .NET Framework 4.5, execute the PgSqlInstanceStoreSchema45.sql script first and then execute PgSqlInstanceStoreLogic45.sql. If you target .NET Framework 3.0, 3.5, or 4.0, execute the PgSqlInstanceStoreSchema.sql script first and then execute PgSqlInstanceStoreLogic.sql. You may use these scripts to clean up the persistence database to have a fresh database in the same way, just execute them in the same order.
To enable persistence for self-hosted workflows that use WorkflowApplication, perform the following steps:
Specify the using directive:
Create PgSqlInstanceStore and assign the following code to the InstanceStore property of WorkflowApplication:
To enable persistence using the PgSqlInstanceStoreBehavior class, perform the following steps:
Add the following statement at the top of the source file after the existing "using" statements.
Create an instance of the WorkflowServiceHost and add endpoints for the workflow service.
Construct an PgSqlInstanceStoreBehavior object and to set properties of the behavior object.
Open the workflow service host.
To configure PostgreSQL Instance Store by using the postgresqlInstanceStore behavior element in a configuration file, perform the following steps:
Add the following behavior extension element to the Machine.config file so that you can use the <postgresqlInstanceStore> service behavior element in the configuration files of your applications to configure persistence for your services:
<configuration> <system.serviceModel> <extensions> <behaviorExtensions> <add name="postgresqlInstanceStore" type="Devart.Data.PostgreSql.Activities.Configuration.PgSqlInstanceStoreElement, Devart.Data.PostgreSql.WorkflowFoundation, Version=7.1.26.0, Culture=neutral, PublicKeyToken=09af7300eec23701" /> </behaviorExtensions> </extensions> </system.serviceModel> </configuration>
Note: Replace 7.1.26.0 in the code with your actual version.
Configure PostgreSQL Instance Store by using the postgresqlInstanceStore behavior element in a configuration file of your application:
<configuration> <system.serviceModel> <behaviors> <serviceBehaviors> <behavior name=""> <postgresqlInstanceStore connectionString="host=server;database=test;user id=postgres;" instanceEncodingOption="GZip | None" instanceCompletionAction="DeleteAll | DeleteNothing" instanceLockedExceptionAction="NoRetry | BasicRetry |AggressiveRetry" hostLockRenewalPeriod="00:00:30" runnableInstancesDetectionPeriod="00:00:05" /> </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> </configuration>