I was planning to answer a question in a comment on previous post and wanted to talk about the number of xPL clients that I have running. Rather than just quoting the number, I thought I’d make a post to put my response in context. Most of my xPL components support the hbeat schema. So I can identify them by sending a hbeat.request message. My perl xpl-sender command can do this:
I’ve been using the xPL Protocol since 2005, prior to that I was using Jabber (or XMPP as it is known now). As I’m thinking about changing protocol, I thought I’d write a bit about xPL and, in later posts, something about the candidates to replace it. The xPL Protocol has three types of messages: commands (xpl-cmnd), triggers (xpl-trig) and status (xpl-stat). They have the same simple format consisting of the message type, common “header” fields, the schema type and schema-specific “body” fields.