Deploying edge servers

Configure a virtual host to run as an edge server

1. Open the Vhost.xml file of the virtual host you want to configure and locate the following code (comments have been removed):

   <VirtualHost> 
       ... 
       <Proxy> 
           <Mode>local</Mode> 
           <Anonymous>false</Anonymous> 
           <CacheDir enabled="false" useAppName="true"></CacheDir> 
           <LocalAddress></LocalAddress> 
           <RouteTable protocol=""> 
               <RouteEntry></RouteEntry> 
           </RouteTable> 
           <EdgeAutoDiscovery> 
               <Enabled>false</Enabled> 
               <AllowOverride>true</AllowOverride> 
               <WaitTime>1000</WaitTime> 
           </EdgeAutoDiscovery>         
       </Proxy> 
   </VirtualHost>

   Note: The default VHost.xml file is located in the RootInstall/conf/_defaultRoot_/_defaultVHost_ directory.

2. Edit the following XML elements, as needed.

   Element	Required/optional	Description
   Mode	Required	Enter local to configure the server to run as an origin server. Enter remote to configure the server to run as an edge server.
   Anonymous	Optional	A Boolean value specifying whether the edge server connection is implicit (true) or explicit (false). The default value is false.
   CacheDir	Optional	Enables or disables the caching of streams to disk, in addition to caching in memory, on an edge server and allows you to specify the cache location. There are two attributes: enabled and appname. To enable caching, set the enabled attribute to "true". When enabled, the server places streams in the RootInstall/cache/appName directory by default. Use the useAppName attribute to specify whether to use the application name as the name of the cache for the application. Vod applications get significant performance gains when caching is enabled.
   LocalAddress	Optional	Specifies the local IP address to which to bind a proxy's outgoing connection (the proxy’s loopback address). This element allows the administrator to control network traffic by isolating incoming and outgoing traffic to separate network interfaces.
   RouteTable	Optional; create a routing table when it is not necessary or desirable for application developers to see the origin server URL or when you want to use implicit connections.	Specifies, in each RouteEntry element, how to route connections from the origin to the edge. There is one attribute, protocol, that indicates the protocol of the outgoing connection. Set this attribute to either "rtmp" or "rtmps". To override the RouteTable protocol for a specific RouteEntry element, add a protocol attribute to the RouteEntry element you want to change.
   RouteEntry	Optional	Each RouteEntry element maps a host/port pair to a different host/port pair. In the following example, connections to host1:port1 are routed to host2:port2: host1:port1;host2:port2 Typically, host1:port1 is your edge server and host2:port2 is your origin server. The following example routes connections destined for host "edge" on port 1935 to host "origin" on port 80: <RouteEntry>edge:1935;origin:80</RouteEntry> You can specify a wildcard character (*) for any host or port. The following example routes connections destined for any host on any port to host "origin" on port 1935: <RouteEntry>*:*;origin:1935</RouteEntry> You can also specify a wildcard for the host/port to which connections are being routed. The following example routes connections destined for any host on any port to the same host on port 80: <RouteEntry>*:*;*:80</RouteEntry> To reject connections, you can specify that a host/port combination be routed to null: <RouteEntry>edge:80;null</RouteEntry> The RouteEntry element has a protocol attribute. This attribute overrides the RouteTable protocol for a specific RouteEntry element. For example, RouteTable may have one RouteEntry element that specifies an encrypted outgoing RTMPS connection and another RouteEntry tag that specifies the regular RTMP connection. If a protocol is not specified, the outgoing connection uses the same protocol as the incoming connection.

3. Validate the XML and save the Vhost.xml file.

4. Restart the server.

Create an explicit connection

 Use the following syntax in a client-side NetConnection.connect() call to make an explicit connection to an edge server:

rtmp://edge/?rtmp://origin/app

A question mark (?) separates the edge’s prefix from the main URL. The prefix contains only the protocol, hostname, and optionally the port number. The prefix must always end with a trailing slash.

Create an implicit connection

1. In the Vhost.xml configuration file, set the Proxy/Anonymous element to true.

   Note: Restart the server after changing the Vhost.xml file.

2. In the Vhost.xml file, create a routing table in the RouteTable element; for more information, see the comments about RouteEntry tags in the Vhost.xml file installed with Flash Media Server.

3. Use the following syntax in a client-side NetConnection.connect() call to make an implicit connection to an edge server:

   rtmp://edge/app/appinstance

Connect edge servers in a chain

 You can chain together any number of edges when you make connections to the origin server. Use the following syntax to chain two explicit edges to direct connection requests to the origin server:

rtmp://edge1/?rtmp://edge2/?rtmp://origin/app/inst

As the connection moves through each edge in the chain, the server consumes the first token in the string. For example, after making the connection to edge1, the connection string changes to:

rtmp://edge2/?rtmp://origin/app/inst

Note: You can specify the RTMPT protocol only for the edges, not for the origin.

When you use URL decoration to chain edges, Flash Player 7 and earlier versions may have problems with shared objects because of the embedded question mark (?) character in the URL. Call the following function to encode or escape the question marks from the URL before passing the URL to the shared object:

function escapeURI(uri) { 
    index = uri.indexOf('?'); 
    if (index == -1) return uri; 
    prefix = uri.substring(0, index); 
    uri = uri.substring(index); 
    return prefix += escape(uri); 
}