Distributed transaction tracing allows you to trace the performance of a business transaction across multiple tiers. It provides metrics for the time spent in all the tiers through which the business transaction passes and the ability to get call graphs displaying activity for all the tiers. See Organizing Traffic as Business Transactions and Measure Distributed Transaction Performance for general information.
The tiers in a distributed transaction can be heterogeneous. All combinations of PHP, Java, .NET, and Node.js tiers are supported, whether they are an originating, continuing, or terminating tier in the transaction.