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Logging

Log files

Log files are named Log_<date>_<n>.<number>.log, for example Log_2026-10-12_1.0001.log:

  • <date> is the day the application was started,
  • <n> separates files of applications started at the same time (the second instance gets 2),
  • <number> is the file sequence, starting from 0001. The file with the highest number is the current one.

When a log file reaches the configured size, the log continues in a new file with the next number. When the number of log files exceeds the configured limit, the oldest files are deleted automatically.

Settings

In the settings window, section Logging (Studio) or group Log Files (Executor), you can set:

  • Limit log file size - when checked, a log file that reaches the given size (1 to 2000 MB) is saved and the log continues in a new file. When unchecked, the log is written to a single file.
  • Limit number of log files - when checked, the oldest log files are deleted automatically once there are more of them than the given number (1 to 2000). When unchecked, no log files are deleted.
  • Show thread identifier in log files - adds the identifier of the thread to each entry.
  • Show milliseconds in log file timestamps - writes the time of each entry with millisecond precision.

Changes apply to the log file that is currently being written, without restarting the application.

Executor command line

The log of Aurora Vision Executor can also be redirected with these arguments. The other arguments of Aurora Vision Executor are described in Executor application.

  • --log-dir <path> - the directory the log files are written to. By default, the LOGS folder in the user directory is used.
  • --log-pipe <name> - creates a named pipe which receives the log entries during the lifetime of the application. It works only in console mode (--console). The application waits for a client to connect before it starts.

A client can read the pipe, e.g. in C#:


	var logPipe = new NamedPipeClientStream(".", "myProjectPipe", PipeDirection.In);
	logPipe.Connect();

	byte[] buffer = new byte[1024];
	int count = 0;
	while (logPipe.IsConnected && (count = logPipe.Read(buffer, 0, 1024)) > 0)
	{
		Console.WriteLine(Encoding.UTF8.GetString(buffer, 0, count));
	}

Environment variables

The variables below are read when the application starts. They are optional. The settings window and the variables work together like this:

  • If nothing is set in the settings window (all the Log Files options are off), the variables are used. If they are not set either, the defaults apply.
  • If any of the Log Files options is set in the settings window when the application starts, all of them are taken from the settings window and the variables are not used for the log files. If the user changes these options while the application is running, the values from the settings window are used from then on, until the application is restarted.
VariableMeaning
AVL_LOGGER_LEVELThe minimum level of the messages to log, by name (info, warning, error, fatal). Default: info.
AVL_LOGGER_MAX_SIZEThe maximum size of a single log file in bytes (not MB; in the settings window the size is entered in MB), after which the log continues in a new file. It is not the total size of all log files; use AVL_LOGGER_MAX_FILES to limit how many files are kept. 0 or unset means no size limit, when nothing is set in the settings window.
AVL_LOGGER_MAX_FILESThe number of log files to keep. The oldest are deleted. 0 or unset means that no files are deleted, when nothing is set in the settings window.
AVL_LOGGER_THREAD_ID1 - write the thread identifier to the log files. 0 or unset - do not write it.
AVL_LOGGER_TIME_MS1 - write the time with milliseconds to the log files. 0 or unset - do not write it.
AVL_LOGGER_DISABLE_CONSOLE1 - do not write messages to the console. Any other value or no value keeps the console output on.
AVL_LOGGER_DISABLE_FILE1 - do not write any log files (including the Logs folder). Any other value or no value keeps the file output on.

Invalid values

If a variable has a value that cannot be used (for example, text instead of a number), an error is written to the log and the variable is ignored.

Examples

Keep 10 log files of up to 50 MB each:

AVL_LOGGER_MAX_SIZE=52428800
AVL_LOGGER_MAX_FILES=10

Run without console output and without log files:

AVL_LOGGER_DISABLE_CONSOLE=1
AVL_LOGGER_DISABLE_FILE=1
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