Installing Message Queuing Triggers

Applies To: Windows Server 2008, Windows Vista

Message Queuing Triggers is an integral part of Message Queuing and can be installed during Message Queuing Setup by selecting the Message Queuing Triggers feature in the Add Features Wizard available in Server Manager (on Windows Server 2008 R2) or the MSMQ Triggers feature in Turn Windows feature on or off in Programs and Features (on Windows 7). Triggers and rules are defined and managed in the Computer Management snap-in. Diagnostic data generated by the Message Queuing Triggers service are recorded in the Application Log and can be viewed using Event Viewer.

Support for Message Queuing Triggers can be installed on a Message Queuing server or independent client on Windows 7 or a Windows Server 2008 R2 family computer.

To install Message Queuing Triggers, select the Message Queuing Triggers or MSMQ Triggers (on Windows 7) feature of Message Queuing during the installation of a Message Queuing server or an independent client. If the check box for this feature is selected, the Triggers service is installed automatically and started. If this check box is not selected, the Triggers service can be installed later by running Server Manager and selecting Message Queuing Triggers in the Add Features Wizard on Windows Server 2008 R2, or by running Programs and Features and selecting MSMQ Triggers from Turn Windows Features on or off on Windows 7.

An unattend file for the Windows Optional Component Setup program can contain an "MSMQ-Triggers" state="true" entry, which corresponds to selecting the Message Queuing Triggers check box on the Select Features page of the Add Features Wizard available in Server Manager (on Windows Server 2008 R2) or to selecting the MSMQ Triggers check box from Turn Windows features on or off available in Programs and Features (on Windows 7).

By default, the Message Queuing Triggers service runs under the Network Service account. Services that are running under this account interact with the network using the credentials of the computer account, and this account has the same level of access to resources and objects as members of the Users group accounts. For heightened security, you can change the default Triggers service account to a more secure setting; for example, the Local Service account, which limits access to the local computer. You can also specify a less secure account for the Triggers service; for example, the Local System account, allowing access to the entire domain. Note that the Triggers service running under the Network Service account does not interact with the desktop. If this functionality is required, you can configure the Triggers service to run under the Local System account, and enable interaction with the desktop in Computer Management.

Message Queuing Triggers installs with a set of default configuration values that are stored in the registry. These values can be changed later using the Computer Management snap-in. For more information about how to change the default configuration, see Change Default Configuration Values for Triggers.

Message Queuing Triggers is cluster-aware and supports the active/active model. When the Message Queuing service fails over to another node, the Triggers service can fail over along with it. For this to occur, you must create a Message Queuing Triggers resource with resource dependencies on the Message Queuing resource and the cluster name resource on the applicable node using Failover Cluster Management, and you must bring it online.


When Message Queuing is configured as a highly available service using the High Availability Wizard from the Failover Cluster Management console, the MSMQ Trigger service is automatically created as a clustered service in the same cluster group.

The trigger and rule definitions for the cluster resource are stored in the local Windows registry. The Message Queuing Triggers resource is checkpointed with this registry key and the subkeys under it so that when the resource is moved to a new node (during failover, for example), the required keys propagate to the local registry on the new node. After failover, the Triggers service can thus continue to process the incoming messages in each monitored queue and invoke the applicable stand-alone executable or COM component according to the rules defined. For more information about server clusters and the active/active model, see Message Queuing in Server Clusters. For more information about creating and configuring Message Queuing Triggers resources in a virtual server, see Configure Trigger Resources for Server Clusters.