Adobe Flash Media Server 4.5 * Configuring performance features

Configure the size of stream chunks

Streams break into chunks as they are written to the network. You can specify the size of a chunk. Large values reduce CPU usage because there are fewer writes. However, large values can delay other content on lower bandwidth connections. The larger the content size and the higher the bandwidth of the receiving connection, the more benefit is gained from larger chunk sizes.

1. Open the Application.xml file.

   Note: You can set these values in an Application.xml file at the VHost level or at the application level. To set the value at the application level, copy an Application.xml file to the application’s folder.

2. In the Client element, set the OutChunkSize element to a value between 128 and 65536 bytes. The default value is 4096 bytes.

   For more information, see Application.xml file.

3. Restart the server.

Send aggregate messages

Important: Do not send aggregate messages and combine audio samples in the same application.

An aggregate message is a single message that contains a list of submessages. Sending aggregate messages reduces CPU usage and increases server capacity. You can configure applications to deliver aggregate messages to clients running on Flash Player 9.0.60.0 and above. When this setting is disabled, the server breaks up aggregate messages into individual messages before delivering them to clients.

Aggregate messages can be used with live and recorded streams.

An origin server can deliver aggregate messages to an edge server, and an edge server can deliver aggregate messages from the FLV data that is has cached on the disk. An edge server can deliver aggregate messages even if the origin server did not.

To ensure that aggregate messaging is enabled, be sure the following settings are enabled:

• EnableAggMsgs in the Server.xml file

• AggregateMessages in the Application.xml file

• AggregateMessages in the Vhost.xml file (if applicable)

The following table describes these settings, plus other configuration settings that are related to using aggregate messages: