User manual MACROMEDIA FLASH MEDIA SERVER 2-USING FLASH MEDIA SERVER EDGE SERVERS

[. . . ] Using Flash Media Server Edge Servers Trademarks 1 Step RoboPDF, ActiveEdit, ActiveTest, Authorware, Blue Sky Software, Blue Sky, Breeze, Breezo, Captivate, Central, ColdFusion, Contribute, Database Explorer, Director, Dreamweaver, Fireworks, Flash, FlashCast, FlashHelp, Flash Lite, FlashPaper, Flash Video Encoder, Flex, Flex Builder, Fontographer, FreeHand, Generator, HomeSite, JRun, MacRecorder, Macromedia, MXML, RoboEngine, RoboHelp, RoboInfo, RoboPDF, Roundtrip, Roundtrip HTML, Shockwave, SoundEdit, Studio MX, UltraDev, and WebHelp are either registered trademarks or trademarks of Macromedia, Inc. and may be registered in the United States or in other jurisdictions including internationally. Other product names, logos, designs, titles, words, or phrases mentioned within this publication may be trademarks, service marks, or trade names of Macromedia, Inc. or other entities and may be registered in certain jurisdictions including internationally. [. . . ] You use a URI in a wrapped format to make the connection to an explicit proxy: rtmp://edge/?rtmp://origin/app You can also connect to a chain of proxies by forming a string that routes the outgoing connection requests through a sequence of explicitly identified proxies: rtmp://edge1/?rtmp://edge2/?rtmp?://edge3/?rtmp://edge4/?rtmp://origin/app As the connection moves through each edge in the chain, Flash Media Server drops the first token in the string. After making the connection to edge1, the connection string changes to: rtmp://edge2/?rtmp?://edge3/?rtmp://edge4/?rtmp://origin/app 12 Using Edge and Origin Servers Detecting the presence of proxy servers Flash Player 8 automatically detects any edge servers in its proximity. When an edge server is available, Flash Player automatically routes the connection from the client to the origin server through the proxy server. These edge servers are defined as implicit proxies since the client is generally unaware that its communication with Flash Media Server is being routed through a proxy. This use of an implicit proxy allows your current applications to continue working without any changes. Flash Player exposes the proxy information to the client only through the read-only properties on the NetConnection object. For more information on the NetConnection class, see the Client-Side Media ActionScript Language Reference. Earlier versions of Flash Player cannot automatically detect edge servers in their proximity. NO TE Chaining edge servers You can chain together any number of edges when you make connections to the origin server. The following URI shows how two explicit proxies are chained together to direct connection requests to the origin server: rtmp://proxy1/?rtmp://proxy2/?rtmp://origin/app/inst When you use URL decoration to chain proxies, Flash Player 7 and earlier versions may have problems with shared objects because of the embedded question mark (?) character in the URL. A workaround is available for clients who use earlier versions of Flash Player. You can resolve the problem by using the following function to escape the question marks from the URI before passing the URI 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); } You call this function on the URI you are about to pass into the shared object, then use the result of the function instead of the original URI. Flash Player 8 resolves this problem for Flash Media Server. Introducing edge servers 13 A second problem surfaces when RTMPT is specified in the URI. The following are valid URIs: rtmpt://foo/?rtmp://bar/app/inst rtmpt://foo:443/?rtmp://bar/app/inst The following are invalid URIs: rtmpt://foo/?rtmpt://bar/app/inst rtmp://foo/?rtmpt://bar/app/inst Configuring edge servers All Flash Media Server functionalities--live streaming, on-demand streaming, messaging, shared object handling, scripting--take place as application instances. Application developers write scripts to create Flash Media Server applications, instances of which are then distributed by the Flash Media Server. A minimal application runs on the edge to perform connection aggregation, stream splitting, stream caching, and smart state management. This separation of tasks off loads to the edge server a large portion of the processing from the main application that runs on the origin server. Flash Media Server and network administrators can configure edge servers to function in different ways. The XML configuration files define how the edge servers connect clients to the origin server. These settings determine how the incoming URLs are routed between the edges and the origin server. You can have a computer run Flash Media Server in a mixed mode, in which certain virtual hosts on this system run applications locally, while others run applications remotely. To configure Flash Media Server, you edit or modify the XML tags in its configuration files. Following are some representative examples: The Anonymous tag in the Vhost. xml file configures the edge server as either an implicit (transparent) or explicit proxy. For more information, see "Anonymous" in Managing Flash Media Server. [. . . ] This edge server sends the required information back to the client: <?xml version=\"1. 0\" encoding=\"utf-8\" ?> <fpad> <proxy>10. 133. 192. 85:1935</proxy> <timestamp>627539012</timestamp> <userdata></userdata> </fpad> where the <proxy> tag contains the host:ip address of the edge server to connect to. Introducing edge servers 17 7. The client then uses the information to make an explicit connection: first to the edge, then to the origin server using a wrapped URI: nc = new NetConnection(); nc. onStatus = function(info) { trace(info. code); } uri = "rtmp://yourcompany. com/app/inst"; myXML = new XML(); myXML. onLoad = function(success) { if (success) { var proxy = this. childNodes[1]. childNodes[1]. firstChild. nodeValue; uri = "rtmp://" + proxy + "/?" + uri; } nc. connect(uri); } myXML. load("http://yourcompany. com/fcs/fpad?uri=" + uri); The /fcs/fpad?code in the XML. load() URI tells the edge server that it needs to broadcast an FPAD message using the URI named uri, as specified. Setting up origin and proxy servers Use the following guidelines as you install and configure the origin and proxy servers. Using these guidelines helps ensure satisfactory performance and results: Make sure your Macromedia license permits you to use proxy servers or a proxy cluster. Use the same operating system (Linux or Windows) on all computers to avoid conflicts with filenames. [. . . ]