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:class: borderless
- * - **RMR_BIND_IF**
+ * - **RMR_ASYNC_CONN**
-
- The interface to bind to listen ports to. If not defined
- 0.0.0.0 (all interfaces) is assumed.
+ 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_RTG_SVC**
+ * - **RMR_BIND_IF**
-
- This variabe supplies the host:port (or address:port) of the
- Route Manager (route table generator) process. RMR will
- attempt to connect to this address port combination and
- request a route table. If it is desired to prevent RMR from
- attempting to request a dynamic route table, the value of
- this variable should be set to "-1." If not set
- ``routemgr`` is assumed.
+ 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 is the port which RMR's route table collector thread
- will use to listen for RMR messages from the route manager
- (route table generator). By default this is 4561, and must be
- unique for each RMR process running on the host/container.
+ 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 a new route table is needed, the frequency that RMR
- sends a route table request to the Route Manager defaults to
- 5 seconds. This variable can be used to set the frequency to
- a value between 1 and 300 seconds inclusive.
+ 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_SEED_RT**
+ * - **RMR_RTG_SVC**
-
- Where RMR expects to find the name of the seed (static) route
- table. If not defined no static table is read.
+ 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:
+
+
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **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**
-
- If the value set to 0, RMR expects the route table manager
- messages to be messages with and RMR header. If this is not
- defined messages are assumed to be "raw" (without an RMR
- header.
+ **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**
-
- Provides a file which is used to set the verbose level of the
- route table collection thread. The first line of the file is
- read and expected to contain an integer value to set the
- verbose level. The value may be changed at any time and the
- route table thread will adjust accordingly.
+ 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_SRC_NAMEONLY**
+ * - **RMR_WARNINGS**
-
- If the value of this variable is greater than 0, RMR will not
- permit the IP address to be sent as the message source. Only
- the host name will be sent as the source in the message
- header.
+ 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.
+There are other, non-RMR, variables which may exist and are
+used by RMR. These variable names are not under the control
+of RMR, so they are subject to change without potentiallyb
+being reflected in either RMR's code, or this document. The
+following is a list of these environment variables.
+
+
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **ALARM_MANAGER_SERVICE_NAME**
+ -
+ This is the DNS name, or IP address, of the process which is
+ listening for RMR alarm messages. If this variable is
+ missing, ``service-ricplt-alarmmanager-rmr`` is assumed.
+
+ * - **ALARM_MANAGER_SERVICE_PORT**
+ -
+ This is the port that the alarm manager is using to accept
+ RMR messages. If the environment variable is missing the
+ value ``4560`` is assumed.
+
-Logging
--------
-RMR does **not** use any logging libraries; any error or
-warning messages are written to standard error. RMR messages
-are written with one of three prefix strings:
+Logging and Alarms
+------------------
+
+As with nearly all UNIX libraries, errors, warnings and
+informational messages are written in plain text to the
+standard error device (stderr). All RMR messages are prefixed
+with the current time (in milliseconds past the standard UNIX
+epoch), the process ID, and a severity indicator. RMR
+messages are written with one of three severity strings:
.. list-table::
+Log message supression
+----------------------
+
+For the most part, the *fast path* code in RMR does no
+logging; even when messages are squelched, there is a
+non-zero cosst to check for the setting each time a potential
+message is to be written. To that end, RMRM will log only
+severe errors once initialisation has completed. An exception
+to this policy exists in the route table collection thread.
+The thread of execution which collects route table updates
+does not need to be concerned with performance, and as such
+has the potential to log its actions in a very verbose
+manner. The environment variable `` RMR_VCTL_FILE `` can be
+used to define a file where the desired verbosity level (0 to
+4 where 0 is off) can be placed. If the environment variable
+is not set when the process starts, RMR will assume that the
+file ``/tmp/rmr.v`` will be used. Beginning with version
+4.6.0 this file does **not** need to exist when the process
+is started. To change the verbosity level, the desired value
+is written to the file on the first line.
+
+
+Alarms
+------
+
+The route table colleciton thread is also responsible for
+watching for situations which need to be reported as alarms
+to the platform's alarm management service. When a state
+exists RMR will create and send an alarm (via RMR message) to
+the alarm service, and will send a *clear* message when the
+state no longer exists. Currently RMR will alarm only when
+the application is not removing messages from the receive
+ring quicklye enough causing RMR to drop messages as they are
+received.
+
+
Notes
=====