.if false
==================================================================================
- Copyright (c) 2019 Nokia
+ Copyright (c) 2019 Nokia
Copyright (c) 2018-2019 AT&T Intellectual Property.
Licensed under the Apache License, Version 2.0 (the "License");
Date 29 January 2019
.fi
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+.im &{lib}/man/setup.im
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RMr -- Ric Message Router Library
&h2(DESCRIPTION)
-RMr is a library which provides a user application with the ability
+RMr is a library which provides a user application with the ability
to send and receive messages to/from other RMr based applications
without having to understand the underlying messaging transport environment (e.g. Nanomsg)
and without needing to know which other endpoint applications are currently
available and accepting messages.
To do this, RMr depends on a routing table generated by an external source.
-This table is used to determine the destination endpoint of each message sent by mapping the
+This table is used to determine the destination endpoint of each message sent by mapping the
message type T (supplied by the user application) to an endpoint entry.
Once determined, the message is sent directly to the endpoint.
The user application is unaware of which endpoint actually receives the
&space
RMr functions do provide for the ability to respond to the specific source
-instance of a message allowing for either a request response, or call
-response relationship when needed.
+instance of a message allowing for either a request response, or call
+response relationship when needed.
&h3(The Route Table)
-The library is supplied with a route table which maps message numbers to
+The library must be given a route table which maps message numbers to
endpoint groups such that each time a message of type T is sent, the message
-is delivered to one member of each group associated with T.
+is delivered to one member of each group associated with T.
For example, message type 2 might route to two different groups where
group A consists of worker1 and worker2, while group B consists only of
logger1.
&space
It is the responsibility of the route table generator to know which endpoints
-belong to which groups, and which groups accept which message types.
+belong to which groups, and which groups accept which message types.
Once understood, the route table generator publishes a table that is ingested
by RMr and used for mapping messages to end points.
-&h3(Environment)
-To enable configuration of the library behaviour outside of direct user application
-control, RMr supports a number of environment variables which provide information
-to the library.
-The following is a list of the various environment variables, what they control
-and the defaults which RMr uses if undefined.
+.sp
+The following is a simple route table which causes message types 0 through 9 to
+be routed to specific applications:
+
+&ex_start
+newrt|start
+ mse|0|-1| %meid
+ mse|1|-1|app10:4560,app11:4560
+ mse|2|-1|app12:4560
+ mse|3|-1|app14:4560
+ mse|4|-1|app18:4560
+ mse|5|-1|app01:4560
+ mse|6|-1|app02:4560
+ mse|7|-1|app03:4560
+ mse|8|-1|app04:4560
+ mse|9|-1|app05:4560
+newrt|end
+&ex_end
+&space
+The special endpoint "%meid" indicates that the message type (0 in this case) is
+to be routed to the endpoint which has been listed as the "owner" for the meid
+appearing in the message.
+MEID ownership is communicated to RMR using the same Route Table Manager interface
+and by supplying a "table" such as the one below:
+
+&ex_start
+meid_map | start
+ mme_ar | control1 | meid000 meid001 meid002 meid003 meid004 meid005
+ mme_ar | control2 | meid100 meid101 meid102 meid103
+meid_map | end | 2
+&ex_end
+
+This table indicates that the application (endpoint) &ital(control1) "owns" 6 MEIDs
+and &ital(control2) owns 4.
+When message type 0 is sent, the MEID in the message will be used to select the
+endpoint via this table.
+
+&space
+The MEID table will update the existing owner relationships, and add new ones; it
+is necessary to send only the changes with the add/replace (mme_ar) entries in
+the table.
+When necessary, MEIDs can be deleted by adding an &cw(mme_del) record to the table.
+The following example illustrates how this might look:
+
+&ex_start
+meid_map | start
+ mme_ar | control1 | meid000 meid001 meid002 meid003 meid004 meid005
+ mme_ar | control2 | meid100 meid101 meid102 meid103
+ mme_del| meid200 meid401
+meid_map | end | 1
+&ex_end
+
+&h3(Route Table Syntax)
+The following illustrates the syntax for both the route table.
+
+&space
+&ex_start
+newrt | start
+mse | <message-type>[,<sender-endpoint>] | <sub-id> <roud-robin-grp>[;<round-robin-grp>]...
+newrt | end
+&ex_end
+&space
+A round robin group is one or more endpoints from which one will be selected to receive
+the message.
+When multiple endpoints are given in a group, they must be separated with a comma.
+An endpoint is the IP address and port (e.g. 192.158.4.30:8219) or DNS name and port of the
+application that should receive the message type.
+If multiple round-robin groups are given, they must be separated by a semicolon, and
+
+&h3(MEID Map Syntax)
+The MEID map is similar to the route table.
+Entries are used to add or replace the ownership of one or more MEIDs (mme_ar) or to
+delete one or more MEIDs (mme_del).
+The following is the syntax for the MEID map.
-&beg_dlist(.75i : ^&bold_font )
-&di(RMR_BIND_IF) This provides the interface that RMr will bind listen ports to allowing
- for a single interface to be used rather than listening across all interfaces.
- This should be the IP address assigned to the interface that RMr should listen
- on, and if not defined RMr will listen on all interfaces.
+&space
+&ex_start
+meid_map | start
+mme_ar | <owner-endpoint> | <meid> [<meid>...]
+mme_del | <meid> [<meid>...]
+meid_map | end | <count>
+&ex_end
-&di(RMR_RTG_SVC) RMr opens a TCP listen socket using the port defined by this
- environment variable and expects that the route table generator process
- will connect to this port.
- If not supplied the port 4561 is used.
+&space
+The <count> on the end record indicates the number of mme_ar and mme_del records
+which were sent; if the count does not match the whole map is refused and dropped.
+The <owner-endpoint> is the endpoint which should receive the message when a message
+is routed based on the MEID it contains.
+A MEID may be "owned" by only one endpoint, and if supplied multiple times, the last
+observed relationship is used.
+Each of the lists of MEIDs are blank separated.
-&di(RMR_RTG_ISRAW) Is set to 1 if the route table generator is sending "plain" messages
- (not using RMr to send messages, 0 if the rtg is using RMr to send. The default
- is 1 as we don't expect the rtg to use RMr.
-&di(RMR_SEED_RT) This is used to supply a static route table which can be used for
- debugging, testing, or if no route table generator process is being used to
- supply the route table.
- If not defined, no static table is used and RMr will not report &ital(ready)
- until a table is received.
-&end_dlist
+&h3(Environment)
+To enable configuration of the library behaviour outside of direct user application
+control, RMr supports a number of environment variables which provide information
+to the library.
+The following is a list of the various environment variables, what they control
+and the defaults which RMr uses if undefined.
+
+&space
+.** the list of environment vars supported
+.im &{lib}/man/env_var_list.im
&h2(SEE ALSO )
rmr_free_msg(3),
rmr_init(3),
rmr_init_trace(3),
+rmr_get_meid(3),
+rmr_get_src(3),
+rmr_get_srcip(3),
rmr_get_trace(3),
rmr_get_trlen(3),
+rmr_get_xact(3),
rmr_payload_size(3),
rmr_rcv_msg(3),
rmr_rcv_specific(3),
rmr_has_str(3),
rmr_tokenise(3),
rmr_mk_ring(3),
+rmr_realloc_payload(3),
rmr_ring_free(3),
rmr_set_trace(3),
rmr_torcv_msg(3),
.ju on
-.qu
Code Review / ric-plt / lib / rmr.git / blobdiff