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Description

The Sitecore Messaging library can be configured to retry connecting to the SQL database in case a connection error occurs. The Sitecore.Framework.TransientFaultHandling library is used to provide the retry functionality. The following steps are required to configure Messaging to use the connection retrying behavior.

Defining A Retryer

The following example defines an Exponential Retryer that will fail after retrying to connect to the database 10 times.

The DefaultSqlPolicyRetryerFactory creates a retryer that, by default, can handle SQL Always On and SQL Azure transient errors. Additional error codes can be added under the CustomErrorCodes section:

For xConnect instances, change the \App_Data\Config\Sitecore\Messaging\sc.XConnect.TransientFaultHandling.xml and \App_Data\jobs\continuous\AutomationEngine\App_Data\Config\sitecore\Messaging\sc.XConnect.TransientFaultHandling.xml files (if they exist) as follows:

<Settings>
  <Sitecore>
    <XConnect>
      <Services>
        <TransientFaultHandling>
          <Type>Sitecore.Framework.TransientFaultHandling.RetryerRegistry, Sitecore.Framework.TransientFaultHandling</Type>
          <As>Sitecore.Framework.TransientFaultHandling.IRetryerRegistry, Sitecore.Framework.TransientFaultHandling.Abstractions</As>
          <Options>
            <Retryers>
              <Messaging.ExponentialRetryer>
                <Type>Sitecore.Framework.TransientFaultHandling.Sql.DefaultSqlPolicyRetryerFactory, Sitecore.Framework.TransientFaultHandling.Sql</Type>
                <Options>
                  <CustomErrorCodes>
                    <ConnectionError>19</ConnectionError>
                  </CustomErrorCodes>
                  <ExponentialRetry>
                    <MaxAttempts>10</MaxAttempts>
                    <MinBackoff>00:00:01</MinBackoff>
                    <MaxBackoff>00:00:30</MaxBackoff>
                    <DeltaBackoff>00:00:10</DeltaBackoff>
                  </ExponentialRetry>
                </Options>
              </Messaging.ExponentialRetryer>
            </Retryers>
          </Options>
        </TransientFaultHandling>
      </Services>
    </XConnect>
  </Sitecore>
</Settings>

Create a new configuration file in the \App_Config\Include folder of your Sitecore XP instance containing the following:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <TransientFaultHandling>
      <Retryers>
        <Messaging.ExponentialRetryer>
          <Type>Sitecore.Framework.TransientFaultHandling.Sql.DefaultSqlPolicyRetryerFactory, Sitecore.Framework.TransientFaultHandling.Sql</Type>
          <Options>
            <CustomErrorCodes>
              <ConnectionError>19</ConnectionError>
            </CustomErrorCodes>
            <ExponentialRetry>
              <MaxAttempts>10</MaxAttempts>
              <MinBackoff>00:00:01</MinBackoff>
              <MaxBackoff>00:00:30</MaxBackoff>
              <DeltaBackoff>00:00:10</DeltaBackoff>
	    </ExponentialRetry>
          </Options>
        </Messaging.ExponentialRetryer>
      </Retryers>
    </TransientFaultHandling>
  </sitecore>
</configuration>

For the Sitecore Cortex™ Processing Engine Role:

Create a new configuration file in the \App_Data\jobs\continuous\ProcessingEngine\App_Data\Config\Sitecore\Messaging folder (for example, sc.Messaging.Retry.xml) with the following content:

<Settings>
  <Sitecore>
    <Processing>
      <Services>
        <RetryerRegistry>
          <Options>
            <Retryers>
              <ExponentialRetryer>
                <Type>Sitecore.Framework.TransientFaultHandling.Sql.DefaultSqlPolicyRetryerFactory, Sitecore.Framework.TransientFaultHandling.Sql</Type>
                <Options>
                  <CustomErrorCodes>
                    <ConnectionError>19</ConnectionError>
                  </CustomErrorCodes>
                  <ExponentialRetry>
                    <MaxAttempts>10</MaxAttempts>
                    <MinBackoff>00:00:01</MinBackoff>
                    <MaxBackoff>00:00:30</MaxBackoff>
                    <DeltaBackoff>00:00:10</DeltaBackoff>
                  </ExponentialRetry>
                </Options>
              </ExponentialRetryer>
            </Retryers>
          </Options>
        </RetryerRegistry>
      </Services>
    </Processing>
  </Sitecore>
</Settings>

For the On-premise setup, restart the Processing Engine Windows service.

Configure Messaging Bus To Use Retryers

In order to configure a Messaging Bus to use TransientFaultHandling retryers, the Messaging transport needs to explicitly specify the retryer in its configuration. This can be done via the following configuration:

Define a retryer for Sitecore Cortex Processing Engine role:

In the \xconnect\App_Data\jobs\continuous\ProcessingEngine\App_Data\Config\Sitecore\Messaging\sc.Processing.Engine.TaskProgress.xml file, add a new child node <RetryerName> with the retryer name defined in the sc.Messaging.Retry.xml file into the <SqlServer> section:

<Sitecore.Processing.Engine.Buses.TaskProgressConsumer>
  <Transport>
    <SqlServer>
      <OneWay>false</OneWay>
      <ConnectionStringOrName>messaging</ConnectionStringOrName>
      <TableName>Sitecore_Transport</TableName>
      <InputQueueName>SitecoreProcessingTaskProgressConsumer</InputQueueName>
      <RetryerName>ExponentialRetryer</RetryerName>
    </SqlServer>
  </Transport>
  <Logging Type="Sitecore.Framework.Messaging.Rebus.DotNetLoggerFactory, Sitecore.Framework.Messaging.Rebus" />
</Sitecore.Processing.Engine.Buses.TaskProgressConsumer>

In the \xconnect\App_Data\jobs\continuous\ProcessingEngine\App_Data\Config\Sitecore\Messaging\sc.Processing.Engine.TaskRegistration.xml file, add a new child node <RetryerName> with the retryer name defined in the sc.Messaging.Retry.xml file into the <SqlServer> section:

<Sitecore.Processing.Engine.Buses.TaskRegistrationConsumer>
  <Transport>
    <SqlServer>
      <OneWay>false</OneWay>
      <ConnectionStringOrName>messaging</ConnectionStringOrName>
      <TableName>Sitecore_Transport</TableName>
      <InputQueueName>SitecoreProcessingTaskRegistrationConsumer</InputQueueName>
      <RetryerName>ExponentialRetryer</RetryerName>
    </SqlServer>
  </Transport>
  <Logging Type="Sitecore.Framework.Messaging.Rebus.DotNetLoggerFactory, Sitecore.Framework.Messaging.Rebus" />
</Sitecore.Processing.Engine.Buses.TaskRegistrationConsumer>

In the \xconnect\App_Data\jobs\continuous\ProcessingEngine\App_Data\Config\Sitecore\Messaging\sc.Processing.Engine.TaskStatusBus.xml file, add a new child node <RetryerName> with retryer name defined in sc.Messaging.Retry.xml file into the <SqlServer> sections of the <Transport> and <Subscriptions> nodes:

<Sitecore.Processing.Engine.Abstractions.Buses.TaskStatusBus>
  <Transport>
    <SqlServer>
      <OneWay>false</OneWay>
      <!--Set of credentials for proper connection to database-->
      <ConnectionStringOrName>messaging</ConnectionStringOrName>
      <!--The name of the table which holds messages until they are handled-->
      <TableName>Sitecore_Transport</TableName>
      <!--The name of MSMQ queue which publisher uses for publishing message to the bus-->
      <InputQueueName>TaskStatus</InputQueueName>
      <RetryerName>ExponentialRetryer</RetryerName>
    </SqlServer>
  </Transport>
  <Subscriptions>
    <SqlServer>
      <!--Set of credentials for proper connection to database-->
      <ConnectionStringOrName>messaging</ConnectionStringOrName>
      <!--The name of the table which saves the information about the relationships between queues and messages-->
      <TableName>Sitecore_Subscriptions</TableName>
      <!--Means that both subscribers and publishers have access to the same central subscription storage-->
      <IsCentralized>true</IsCentralized>
      <RetryerName>ExponentialRetryer</RetryerName>
    </SqlServer>
  </Subscriptions>
  <Logging Type="Sitecore.Framework.Messaging.Rebus.DotNetLoggerFactory, Sitecore.Framework.Messaging.Rebus" />
</Sitecore.Processing.Engine.Abstractions.Buses.TaskStatusBus>

Restart the Processing Engine windows service in case of on-premise deployment (Azure will handle configuration file changes automatically).

Define a retryer for the proper working of the Sitecore Cortex Processing Engine on Sitecore XP CM or Standalone roles (depending on your setup). In the \App_Config\Sitecore\Processing.Tasks.Messaging.Xmgmt\Sitecore.Processing.Tasks.Messaging.config file, add a new child node <RetryerName> with the retryer name defined in the sc.Messaging.Retry.xml file into the <SqlServer> section of the following nodes: <Sitecore.Processing.Tasks.Messaging.Buses.TaskRegistrationProducer> and <Sitecore.Processing.Tasks.Messaging.Buses.TaskProgressProducer>. The following is an example for the <Sitecore.Processing.Tasks.Messaging.Buses.TaskRegistrationProducer> node:

<Sitecore.Processing.Tasks.Messaging.Buses.TaskRegistrationProducer>
  <Transport>
    <SqlServer>
      <OneWay>false</OneWay>
      <ConnectionStringOrName>messaging</ConnectionStringOrName>
      <TableName>Sitecore_Transport</TableName>
      <!-- InputQueueName should be unique for CM/CD instance to handle response messages on the correct instance. -->
      <InputQueueName>SitecoreProcessingTaskRegistrationProducer_${MachineName}_${ProcessId}</InputQueueName>
      <RetryerName>ExponentialRetryer</RetryerName>
    </SqlServer>
  </Transport>
  <Routing>
    <TypeBasedMappings>
      <TypeMappings>
        <RegisterDistributedTaskMap>
          <Type>Sitecore.Processing.Engine.Abstractions.Messages.RegisterDistributedTask, Sitecore.Processing.Engine.Abstractions</Type>
          <DestinationQueue>SitecoreProcessingTaskRegistrationConsumer</DestinationQueue>
        </RegisterDistributedTaskMap>
        <RegisterDeferredTaskMap>
          <Type>Sitecore.Processing.Engine.Abstractions.Messages.RegisterDeferredTask, Sitecore.Processing.Engine.Abstractions</Type>
          <DestinationQueue>SitecoreProcessingTaskRegistrationConsumer</DestinationQueue>
        </RegisterDeferredTaskMap>
      </TypeMappings>
    </TypeBasedMappings>
  </Routing>
  <Logging Type="Sitecore.Messaging.SitecoreLoggerFactory,Sitecore.Messaging"/>
</Sitecore.Processing.Tasks.Messaging.Buses.TaskRegistrationProducer>

Configure EXM To Use Retryers

In order to configure EXM to use retryers, Sitecore.EmailExperience.Messaging.config files on corresponding servers should be updated.

Define retryers on all CM instances. Navigate to \App_Config\Sitecore\Messaging and create a new configuration file as shown in the Defining a retryer section.
On all CM instances, update the \App_Config\Sitecore\EmailExperience \Sitecore.EmailExperience.Messaging.config file by adding a new child node <RetryerName> with a retryer name after <InputQueueName> under the /configuration/Sitecore/Messaging/Rebus/[name of messaging bus]/Transport/SqlServer node for all messages buses:
- Sitecore.EmailCampaign.Model.Messaging.Buses.AutomatedMessagesBus
- Sitecore.EmailCampaign.Model.Messaging.Buses.UpdateListSubscriptionMessagesBus
- Sitecore.EmailCampaign.Model.Messaging.Buses.ConfirmSubscriptionMessagesBus
- Sitecore.EmailCampaign.Model.Messaging.Buses.EmailOpenMessagesBus
- Sitecore.EmailCampaign.Model.Messaging.Buses.ClearSuppressionListMessagesBus
- Sitecore.EmailCampaign.Model.Messaging.Buses.EmailAddressHistoryBus
- Sitecore.EmailCampaign.Model.Messaging.Buses.SentMessagesBus
For example:
```
<Sitecore.EmailCampaign.Model.Messaging.Buses.UpdateListSubscriptionMessagesBus role:require="!DedicatedDispatch">
<Transport>
  <SqlServer>
    <OneWay role:require="(Standalone or ContentManagement) and !ContentDelivery">false</OneWay>
    <OneWay role:require="ContentDelivery">true</OneWay>
    <ConnectionStringOrName>messaging</ConnectionStringOrName>
    <TableName>Sitecore_Transport</TableName>
    <InputQueueName>UpdateListSubscriptionMessagesQueue</InputQueueName>
    <RetryerName>ExponentialRetryer</RetryerName> 
  </SqlServer>
</Transport>
</Sitecore.EmailCampaign.Model.Messaging.Buses.UpdateListSubscriptionMessagesBus>
```
Define retryers on all DDS instances. Navigate to \App_Config\Sitecore\Messaging and create a new configuration file as shown in the Defining a retryer section.
Repeat the second step for the \App_Config\Sitecore\EmailExperience\Sitecore.EmailExperience.Messaging.config files on all DDS instances.
Define retryers on all CD instances. Navigate to \App_Config\Sitecore\Messaging and create a new configuration file as shown in the Defining a retryer section.
Repeat the second step for the \App_Config\Sitecore\EmailExperience\Sitecore.EmailExperience.Messaging.config files on all CD instances.
Define retryers on the XConnect instance. Navigate to \yourInstance_collection\App_Data\Config\Messaging and create a new configuration file as shown in the Defining a retryer section.
On the XConnnect instance update the \yourInstance_collection\App_Data\Config\Sitecore\Messaging\ sc.EXM.Messaging.xml file by adding a new child node <RetryerName> with a retryer name after the <InputQueueName> under the /Settings/Sitecore/XConnect/Services/Messaging/Options/Rebus/name of messaging bus/Transport/SqlServer node for all messages buses:

Sitecore.EmailCampaign.Model.Messaging.Buses.AutomatedMessagesBus
Sitecore.EmailCampaign.Model.Messaging.Buses.ClearSuppressionListMessagesBus

For example:

<Sitecore.EmailCampaign.Model.Messaging.Buses.AutomatedMessagesBus>
<Transport>
  <SqlServer>
    <OneWay>true</OneWay>
      <ConnectionStringOrName>messaging</ConnectionStringOrName>
      <TableName>Sitecore_Transport</TableName>
      <InputQueueName>AutomatedMessagesQueue</InputQueueName>
      <RetryerName>ExponentialRetryer</RetryerName>
  </SqlServer>
</Transport>
<Sitecore.EmailCampaign.Model.Messaging.Buses.AutomatedMessagesBus>

Repeat the previous step for the \App_Data\jobs\continuous\AutomationEngine\App_Data\Config\sitecore\Messaging\sc.EXM.Messaging.xml file.

Messaging SQL high availability configurations

Description

Defining A Retryer

Configure Messaging Bus To Use Retryers

Configure EXM To Use Retryers