FlightRecorder Satellite

Name	FlightRecorder
Description	Satellite to record log messages from a Constellation
Category	Monitoring
Language	C++

Description

This satellite subscribes to Constellation log messages of a configurable level, receives them and records them to storage. Several storage options are available and can be selected via the method configuration parameter:

• FILE represents the simplest storage, all logs are recorded into a single file provided via the file_path parameter.

• ROTATE allows to use multiple, rotating log files. Every time the current log file reaches the size configured via the rotate_filesize parameter, a new file is started. After the maximum number of files set by rotate_max_files is reached, the oldest log file is overwritten. This can be useful to keep only a certain amount of history present.

• DAILY will create a new log file every 24h at the time defined with the daily_switch parameter. This method is particularly useful for very long-running Constellations which require preservation of the log history.

• RUN will switch to a new log file whenever a new run is started, i.e. when this satellite received the start command. This can be especially helpful when many runs are recorded and an easy assignment of logs is required.

The global log level to which the FlightRecorder subscribes for all satellites in the Constellation can be configured using the global_recording_level.

Caution

This level should be selected carefully. Only log messages with an active subscription are transmitted over the network and subscribing to low levels such as DEBUG or TRACE might lead to significant network traffic and sizable log files being written to storage.

Log messages are cached and flushed to storage asynchronously. The cache is flushed in regular intervals set by flush_period as well as at each run stop or interruption of operation.

Note

It should be noted that the flush_period setting also applied to the console output of the FlightRecorder satellite itself.

Parameters

The following parameters are read and interpreted by this satellite. Parameters without a default value are required.

Parameter	Type	Description	Default Value
method	String	Method to be used for logging. Valid values are FILE, ROTATE, DAILY and RUN	FILE
file_path	String	Path to the target log file	-
allow_overwriting	Boolean	Flag to allow or deny overwriting of existing log files	false
global_recording_level	String	Global log level to be recorded by this satellite	WARNING
flush_period	Integer	Period in seconds after which log messages are regularly flushed to storage	10
rotate_max_files	Integer	Maximum number of files to be user for rotating. Only used for method = "ROTATE"	10
rotate_filesize	Integer	Maximum file size Mb after which the log is rotated. Only used for method = "ROTATE"	100
daily_switching_time	Local time	Local time in the format hh:mm:ss at which the log file should be switched. Only used for method = "DAILY"	-

Configuration Example

An example configuration for this satellite which could be dropped into a Constellation configuration as a starting point

[FlightRecorder.RunLogger]
method = "RUN"
allow_overwriting = true
file_path = "/data/logs/logfile.txt"

Metrics

Metric	Description	Interval	Type
MSG_TOTAL	Total number messages received and logged since satellite startup	3s	LAST_VALUE
MSG_WARN	Number of warning messages received and logged since satellite startup	3s	LAST_VALUE
MSG_RUN	Total number messages received and logged since the last run start	3s	LAST_VALUE

Custom Commands

Command	Description	Arguments	Return Value	Allowed States
flush	Flush log sink	-	-	INIT, ORBIT, RUN, SAFE

Framework Parameters

This satellite inherits the following framework parameters from its base classes:

Parameters inherited from Satellite

Autonomous Operation

Parameter	Type	Description	Default Value
_heartbeat_interval	Unsigned integer	Interval in seconds between heartbeats to be sent to other Constellation components	10
_role	Role name	Role this satellite should take in the Constellation. Accepted values are ESSENTIAL, DYNAMIC, TRANSIENT and NONE.	DYNAMIC

Transition Orchestration

Parameters to control autonomous transition orchestration of satellites:

Parameter	Type	Description	Default Value
_conditional_transition_timeout	Unsigned integer	Timeout in seconds to wait for all conditions to be satisfied for conditional transitioning	30
_require_initializing_after	List of strings	List of canonical names of remote satellites for conditional transitioning in initializing state	-
_require_launching_after	List of strings	List of canonical names of remote satellites for conditional transitioning in launching state	-
_require_landing_after	List of strings	List of canonical names of remote satellites for conditional transitioning in landing state	-
_require_starting_after	List of strings	List of canonical names of remote satellites for conditional transitioning in starting state	-
_require_stopping_after	List of strings	List of canonical names of remote satellites for conditional transitioning in stopping state	-

Framework Metrics

This satellite inherits the following framework metrics from its base classes:

Metrics inherited from Satellite

None