Configuring Arbortext Publishing Engine > Understanding Queuing on the Arbortext PE server > Configuring Queues
  
Configuring Queues
A queue is a container of transactions that are awaiting execution. Transactions are placed on a queue by a Queue Manager evaluating incoming requests. A Queue Manager offers the request to each queue in the order they are defined in e3config.xml. After a queue accepts it, the transaction waits until the queue’s configuration allows the Queued Transaction Scheduler to select it for execution (see The Queued Transaction Scheduler). When execution is complete, a queued transaction is deleted from its queue. The transaction is placed in the active transaction directory for the client to retrieve.
Each queue can further filter a request using a TestSet parameter to accept or decline a request based on the additional test set criteria. For example, it could filter the request based on whether a Arbortext Editor client requests a PDF (see Specifying Test Sets and Queuing for Arbortext Editor Clients for information).
A queue is a Java object that implements the interface com.arbortext.e3.E3Queue. The sample implementation code for it is found in:
PE_HOME\e3\samples\java\com\arbortext\e3\ArbortextQueue.java