protocols.md

Protocols

Message Flows in Reference Implementation

Runtime Platform to Agent Container

• message: HTTP Request to CA (in HTTP handler thread), send message via agent_ref tell
• broadcast: HTTP Request to CA (in HTTP handler thread), send message via broker.publish
• invoke: HTTP Request to CA (in HTTP handler thread), send Invoke to agent via ask invoke protocol, wait for response (in CA thread), reply in HTTP response

Agent Container to Runtime Platform

• message: agent sends HTTP Request to RP via helper method in super class
• broadcast: agent sends HTTP Request to RP via helper method in super class
• invoke: agent sends HTTP Request to RP via helper method in super class, waits for response in its own thread

Within Agent Container

• message: using regular JIAC-VI agent_ref tell
• broadcast: using regular JIAC-VI broker publish
• invoke: using regular JIAC-VI ask invoke, either with OPACA Invoke object or any other payload

Runtime Platform to Runtime Platform

• send, broadcast and invoke have optional query parameter forward with default value true
• look up connected RP that have the target agent or action
• send and broadcast: forward message to all valid platforms
• invoke: forward invoke to first valid connected platform
• forward parameter gets automatically set to false in the request to the connected platform to prevent endless forwarding

Protocol for connecting two Runtime Platforms

• platform A receives request to connect to platform B
• sends request to connect to platform A (itself) to platform B, adds B to "pending"
• platform B does the same, sending another request back to A and adding A to "pending"
• platform A recognizes the new request as already being processed and replies immediately
• platform B replies to original request, both platforms call "info" on each other

Protocol for notifying about updated Containers or connected Platforms

• container/platform calls /containers/notify or /connections/notify with own ID/URL respectively
• the idea behind "notify, then pull info" instead of "push info" is to make sure that the info does actually come from the container/platform in question and not someone else
• receiving platform calls /info for that container/platform, stores updated information
• return true if update successful, false if not reachable (see below) and 404 if unknown/not in list
• if container/platform are not reachable, their information is removed from the platform
• can be called if container's agents/actions change, if container is about to die, or at any time by the user
• update in containers (via add/remove or update) automatically triggers notification of connected platforms