Configuration and Deployment

OVERVIEW

The RIC Message Router (RMR) is a library for peer-to-peer communication. Applications use the library to send and receive messages where the message routing and endpoint selection is based on the message type rather than DNS host name-IP port combinations.

This document contains information regarding the configuration of RMR when it is embedded by a user application . RMR itself is a library, not a deployable entity.

Configuration

Many aspects of RMR behavior are controlled via environment variables. These values are read when a user application invokes the RMR initialization function. This allows these variables to be set before the application is started as a function of the true environment, or set by the application as a means for the application to influence RMR’s behaviour. The following is a list of environment variables which RMR recognizes. Also see the main RMR manual page in the development package for more details.

RMR_ASYNC_CONN	Allows the async connection mode to be turned off (by setting the value to 0). When set to 1, or missing from the environment, RMR will invoke the connection interface in the transport mechanism using the non-blocking (async) mode. This will likely result in many “soft failures” (retry) until the connection is established, but allows the application to continue unimpeded should the connection be slow to set up.
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.
RMR_CTL_PORT	This variable defines the port that RMR should open for communications with Route Manager, and other RMR control applications. If not defined, the port 4561 is assumed. Previously, the RMR_RTG_SVC (route table generator service port) was used to define this port. However, a future version of Route Manager will require RMR to connect and request tables, thus that variable is now used to supply the Route Manager’s well-known address and port. To maintain backwards compatibility with the older Route Manager versions, the presence of this variable in the environment will shift RMR’s behaviour with respect to the default value used when RMR_RTG_SVC is not defined. When RMR_CTL_PORT is defined: RMR assumes that Route Manager requires RMR to connect and request table updates is made, and the default well-known address for Route manager is used (routemgr:4561). When RMR_CTL_PORT is undefined: RMR assumes that Route Manager will connect and push table updates, thus the default listen port (4561) is used. To avoid any possible misinterpretation and/or incorrect assumptions on the part of RMR, it is recommended that both the RMR_CTL_PORT and RMR_RTG_SVC be defined. In the case where both variables are defined, RMR will behave exactly as is communicated with the variable’s values.
RMR_RTREQ_FREQ	When RMR needs a new route table it will send a request once every n seconds. The default value for n is 5, but can be changed if this variable is set prior to invoking the process. Accepted values are between 1 and 300 inclusive.
RMR_RTG_SVC	The value of this variable depends on the Route Manager in use. When the Route Manager is expecting to connect to an xAPP and push route tables, this variable must indicate the port which RMR should use to listen for these connections. When the Route Manager is expecting RMR to connect and request a table update during initialisation, the variable should be the host of the Route Manager process. The RMR_CTL_PORT variable (added with the support of sending table update requests to Route manager), controls the behaviour if this variable is not set. See the description of that variable for details.
RMR_HR_LOG	By default RMR writes messages to standard error (incorrectly referred to as log messages) in human readable format. If this environment variable is set to 0, the format of standard error messages might be written in some format not easily read by humans. If missing, a value of 1 is assumed.
RMR_LOG_VLEVEL	This is a numeric value which corresponds to the verbosity level used to limit messages written to standard error. The lower the number the less chatty RMR functions are during execution. The following is the current relationship between the value set on this variable and the messages written: 0 Off; no messages of any sort are written. 1 Only critical messages are written (default if this variable does not exist) 2 Errors and all messages written with a lower value. 3 Warnings and all messages written with a lower value. 4 Informational and all messages written with a lower value. 5 Debugging mode – all messages written, however this requires RMR to have been compiled with debugging support enabled.
RMR_RTG_ISRAW	Deprecated. Should be 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. This variable is only recognised when using the NNG transport library as it is not possible to support NNG “raw” communications with other transport libraries. It is also necessary to match the value of this variable with the capabilities of the Route Manager; at some point in the future RMR will assume that all Route Manager messages will arrive via an RMR connection and will ignore this variable.
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 ready until a table is received. The static route table may contain both the route table (between newrt start and end records), and the MEID map (between meid_map start and end records).
RMR_SRC_ID	This is either the name or IP address which is placed into outbound messages as the message source. This will used when an RMR based application uses the rmr_rts_msg() function to return a response to the sender. If not supplied RMR will use the hostname which in some container environments might not be routable. The value of this variable is also used for Route Manager messages which are sent via an RMR connection.
RMR_STASH_RT	Names the file where RMR should write the latest update it receives from the source of route tables (generally Route Manager). This is meant to assist with debugging and/or troubleshooting when it is suspected that route information isn’t being sent and/or received correctly. If this variable is not given, RMR will save the last update using the RMR_SEED_RT variable value and adding a .stash suffix to the filename so as not to overwrite the static table.
RMR_VCTL_FILE	This supplies the name of a verbosity control file. The core RMR functions do not produce messages unless there is a critical failure. However, the route table collection thread, not a part of the main message processing component, can write additional messages to standard error. If this variable is set, RMR will extract the verbosity level for these messages (0 is silent) from the first line of the file. Changes to the file are detected and thus the level can be changed dynamically, however RMR will only suss out this variable during initialisation, so it is impossible to enable verbosity after startup.
RMR_WARNINGS	If set to 1, RMR will write some warnings which are non-performance impacting. If the variable is not defined, or set to 0, RMR will not write these additional warnings.