Tracing the Path of Related Messages (Visual Trace)

Accessing the Visual Trace

To display the Visual Trace:

1. Access the Message Viewer.

2. Click the Session ID column for the message you want to examine.

The system displays the Visual Trace in a new area at the bottom of the page. You can resize this area.

Basics

The Visual Trace displays a visual representation of message activity, with one column for each business host that handles the message. The business hosts are grouped into inbound hosts (business services), process hosts (business processes), and outbound hosts (business operations). The host names are displayed at the top of the columns.

Each rounded box corresponds to a message. The date and time indicate the message creation time stamp. See Invocation Style and Message Time Stamps. The text below that is the name of the message class. Within the box, the arrow starts at the business host that sent the message and ends at the business host that received the message. For convenience, each box is labeled with a number, starting with 1 for the earliest message in the sequence. Additional connectors in the diagram add information about the overall flow of data.

The previous example diagram indicates the following overall sequence of events:

1. Sample.FileService sent a message to Sample.Process. The message type was Sample.Message and it was sent at 18:22:00:57.

2. Sample.Process received a message and then sent a new message to Sample.FileOperation. The new message type was Sample.NewMessage and it was sent at 18:22:00.571.

3. Sample.FileOperation received this message and then generated a response message, which it sent to Sample.Process. The response message type was Sample.OKResponse and it was sent at 18:22:00.573.

4. Sample.Process received the response message and then sent it to Sample.FileService at 18:22:00:573.

When using the Visual Trace, note the following special cases:

• If a message is sent from an outbound HTTP adapter to another interoperability-enabled namespace, the incoming message is assigned a new SessionID. If you want to associate the related messages across namespaces, you can use the SendSuperSession setting. If this setting is specified on an outbound HTTP adapter, the adapter sets the SuperSession property in the HTTP header. This header property is preserved through the incoming HTTP adapter and preserved throughout the production. For details, see SendSuperSession.

• With this tool, synchronous calls from long-running business processes are portrayed as if they were asynchronous. This does not change the fact that the calls are actually synchronous. It is a side effect of the internal tracking mechanism that InterSystems IRIS uses to free system resources while it is waiting for a synchronous call to return.

Showing or Hiding Message Details

To display message details, click a message within the Visual Trace or click the Display Message Details button on the right. The Visual Trace then displays a new area on the right. This area provides the same details as the Message Viewer (with Header, Body, and Contents sections).

To hide the message details, click the Hide Message Details button.

Filtering the Display

If there are many messages shown in the Visual Trace, it can be useful to limit the messages displayed by using a filter. To do so, use the Filter Hosts option and select a business host. This filters the display to show only messages sent or received by that business host.

Visual Trace Legend

If you select Legend, the system displays a popup guide with additional information, as follows:

See Also

• Viewing Messages

• Managing Messages

• Using the Enterprise Message Viewer

• Concepts