ltm rule namespace MR

iRule(1)						BIG-IP TMSH Manual						  iRule(1)

MR
       Namespace MR

DESCRIPTION
       The MR namespace contains iRule commands that work with the message routing framework (MRF).

       MRF routes messages between two endpoints via a message routing proxy (MR proxy) associated with each endpoint.	Certain
       application layer protocols use the MRF to route protocol-specific messages.  A received message is said to "ingress" from
       one protocol-specific endpoint to the MR proxy.	A sent message is said to "egress" from the MR proxy to the protocol-
       specific endpoint.

       Associated Events:
	   MR_INGRESS  - Triggered when an incoming message reaches the MR proxy after the protocol filter.
	   MR_EGRESS   - Triggered when an outgoing message is ready to be sent to the protocol filter.
	   MR_FAIL     - Triggered when an outgoing message is unable to be routed.
	   MR_DATA     - Triggered when an incoming message has a streaming payload.

       MR iRule commands operate within a Tcl context associated with the connection flow between the endpoint and the MR proxy.
       The ingress and egress parts of a message's journey therefore operate in separate Tcl contexts.	The Tcl context contains
       the Tcl variables and execution state of the currently executing iRule event.  Only one iRule event can execute at a time
       on a connection flow, therefore messages queue to execute their iRule events.

       In many MR protocols, messages belong to independent transactions that are carried over the same network connection flow.
       It is highly desirable for messages sharing a connection flow to execute their iRules independently of other messages.
       This provides the following advantages and behavior changes:
	   * A message does not need to wait for an unrelated message to complete an event in order to execute its own event.
	   * Messages sharing a connection flow may exit the flow in a different order than they entered.
	   * Tcl variables cannot be overwritten between events by another message.  This capability may be enabled in the
       protocol-specific router profile via the irule-scope-message attribute, only for protocols that currently support it. For
       genericmessage, it may be enabled in the MR router profile.  Before enabling irule-scope-message for a protocol, the user's
       iRules should be examined and if necessary adjusted and tested, to ensure they do not rely on sharing a Tcl context between
       messages on a connection flow.

HINTS
SEE ALSO
BIG-IP							    2022-04-12							  iRule(1)