# Creating and Modifying Destinations

Destinations are typically "static" administered objects that can be stored in a JNDI or LDAP server. Administered objects can also be stored in the EMS server and looked up using the EMS implementation of JNDI.

This section describes how to use the EMS Administration Tool to create and modify destination objects in EMS. For more information, see EMS Administration Tool.

You create a queue using the `create queue` command and a topic using the `create topic` command. For example, to create a new queue named `myQueue`, enter:

       create queue myQueue

To create a topic named `myTopic`, enter:

       create topic myTopic

The queue and topic data stored on the EMS server is located in the `queues.conf` and `topics.conf` files, respectively. You can use the `show queues` and `show topics` commands to list all of the queues and topics on your EMS server and the show queue and show topic commands to show the configuration details of specific queues and topics.

A queue or topic may include optional properties that define the specific characteristics of the destination. These properties are described in Destination Properties and they can be specified when creating the queue or topic or modified for an existing queue or topic using the `addprop queue`, `addprop topic`, `setprop queue`, `setprop topic`, `removeprop queue`, and `removeprop topic` commands.

For example, to discard messages on myQueue when the number of queued messages exceeds 1000, you can set an `overflowPolicy` by entering:

       addprop queue myQueue maxmsgs=1000,overflowPolicy=discardOld

To change the `overflowPolicy` from `discardOld` to `rejectIncoming`, enter:

       addprop queue myQueue overflowPolicy=rejectIncoming

The `setprop queue` and `setprop topic` commands remove properties that are not explicitly set by the command. For example, to change `maxmsgs` to 100 and to remove the `overflowPolicy` parameter, enter:

       setprop queue myQueue maxmsgs=100

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