sasl - The SASL application
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).
The following configuration parameters are defined for the SASL
application. For more information about configuration parameters, see
app(5) 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 $OTP_ROOT/bin/start.
- masters = [atom()]
:
- Specifies the nodes used by this node to read/write release information.
This parameter is ignored if parameter client_directory is 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 masters is 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 masters and client_directory are not
set.
- releases_dir
= string() :
- Indicates where the releases directory is located. The release
handler writes all its files to this directory. If this parameter is not
set, the OS environment parameter RELDIR is used. By default, this
is $OTP_ROOT/releases.
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, i.e. 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_depth in 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_depth in 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 :
- Value is one of the following:
- tty:
- Installs sasl_report_tty_h in the error logger. This is the default
option.
- {file,FileName}:
- Installs sasl_report_file_h in the error logger. All reports go to
file FileName, which is a string. The file is opened in
write mode with encoding utf8.
- {file,FileName,Modes}:
- Same as {file,FileName}, except that Modes allows you to
specify the modes used for opening the FileName given to the
file:open/2 call. By default, the file is opened in write mode with
encoding utf8. Use [append] to have the FileName open
in append mode. A different encoding can also be specified.
FileName is 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_logger to 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 UTC appended.
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:
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.