View Source SASL Application
Description
The SASL application provides the following services:
- alarm_handler
- release_handler
- systools
Note
The SASL application in OTP has nothing to do with "Simple Authentication and Security Layer" (RFC 4422).
Configuration
The following configuration parameters are defined for the SASL application. For
more information about configuration parameters, see
app(4) in Kernel.
All configuration parameters are optional.
- start_prg = string()- Specifies the program to be used when restarting the system during release installation. Default is- $OTPROOT/bin/start.
- masters = [atom()]- Specifies the nodes used by this node to read/write release information. This parameter is ignored if parameter- client_directoryis not set.
- client_directory = string()- This parameter specifies the client directory at the master nodes. For details, see Release Handling in OTP Design Principles. This parameter is ignored if parameter- mastersis not set.
- static_emulator = true | false- Indicates if the Erlang emulator is statically installed. A node with a static emulator cannot switch dynamically to a new emulator, as the executable files are written into memory statically. This parameter is ignored if parameters- mastersand- client_directoryare not set.
- releases_dir = string()- Indicates where the- releasesdirectory is located. The release handler writes all its files to this directory. If this parameter is not set, the OS environment parameter- RELDIRis used. By default, this is- $OTPROOT/releases.
Deprecated Error Logger Event Handlers and Configuration
In Erlang/OTP 21.0, a new API for logging was added. The old error_logger
event manager, and event handlers running on this manager, still work, but they
are not used by default.
The error logger event handlers sasl_report_tty_h and sasl_report_file_h,
were earlier used for printing the so called SASL reports, that is, supervisor
reports, crash reports, and progress reports. These reports are now also
printed by the default logger handler started by the Kernel application.
Progress reports are by default stopped by the primary log level, but can be
enabled by setting this level to info, for example by using the Kernel
configuration parameter logger_level.
If the old error logger event handlers are still desired, they must be added by
calling error_logger:add_report_handler/1,2.
- sasl_report_tty_h- Formats and writes supervisor reports, crash reports, and progress reports to- stdio. This error logger event handler uses- error_logger_format_depthin the Kernel application to limit how much detail is printed in crash and supervisor reports.
- sasl_report_file_h- Formats and writes supervisor reports, crash report, and progress report to a single file. This error logger event handler uses- error_logger_format_depthin the Kernel application to limit the details printed in crash and supervisor reports.
A similar behaviour, but still using the new logger API, can be obtained by
setting the Kernel application environment variable
logger_sasl_compatible to
true. This adds a second instance of the standard Logger handler, named
sasl, which only prints the SASL reports. No SASL reports are then printed by
the Kernel logger handler.
The sasl handler is configured according to the values of the following SASL
application environment variables.
- sasl_error_logger = Value-- Valueis one of the following:- tty- Installs- sasl_report_tty_hin the error logger. This is the default option.
- {file,FileName}- Installs- sasl_report_file_hin the error logger. All reports go to file- FileName, which is a string. The file is opened in- writemode with encoding- utf8.
- {file,FileName,Modes}- Same as- {file,FileName}, except that- Modesallows you to specify the modes used for opening the- FileNamegiven to the- file:open/2call. By default, the file is opened in- writemode with encoding- utf8. Use- [append]to have the- FileNameopen in append mode. A different encoding can also be specified.- FileNameis a string.
- false- No SASL error logger handler is installed.
 
- errlog_type = error | progress | all- Restricts the error logging performed by the specified- sasl_error_loggerto error reports or progress reports, or both. Default is- all.
- utc_log = true | false- If set to- true, all dates in textual log outputs are displayed in Universal Coordinated Time with the string- UTCappended.
The error logger event handler log_mf_h can also still be used. This event
handler writes all events sent to the error logger to disk. Multiple files and
log rotation are used. For efficiency reasons, each event is written as a
binary. For more information about this handler, see
the STDLIB Reference Manual.
To activate this event handler, three SASL configuration parameters must be set:
- error_logger_mf_dir = string() | false- Specifies in which directory- log_mf_his to store its files. If this parameter is undefined or- false, the- log_mf_hhandler is not installed.
- error_logger_mf_maxbytes = integer()- Specifies the maximum size of each individual file written by- log_mf_h. If this parameter is undefined, the- log_mf_hhandler is not installed.
- error_logger_mf_maxfiles = 0<integer()<256- Specifies the number of files used by- log_mf_h. If this parameter is undefined, the- log_mf_hhandler is not installed.
The new logger_disk_log_h might be an alternative to log_mf_h if log
rotation is desired. This does, however, write the log events in clear text and
not as binaries.
See Also
alarm_handler, error_logger, logger, log_mf_h, rb,
release_handler, systools