1 OS_Mon Release Notes
This document describes the changes made to the OS_Mon application.
1.1 Os_Mon 2.1.3
1.1.1 Improvements and New Features
-
Extended memsup memory probing on linux to use a port
program to probe memory usage. This is faster then the
previous implementation.
Own Id: OTP-6860 Aux Id: seq10616
1.2 Os_Mon 2.1.2.1
1.2.1 Improvements and New Features
-
Minor Makefile changes.
Own Id: OTP-6689
1.3 OS_Mon 2.1.2
1.3.1 Fixed Bugs and Malfunctions
-
When the memsup_system_only flag was set to
true, a badmatch exception occurred in the
function os_mon_mib:get_load/1.
Own Id: OTP-6351 Aux Id: seq10517
1.4 OS_Mon 2.1.1
1.4.1 Fixed Bugs and Malfunctions
-
Did not build on Mac OS X.
Added support for IRIX. (Thanks to Michel Urvoy and
Daniel Solaz.)
Own Id: OTP-6136
1.4.2 Improvements and New Features
-
disksup: Now using round(T*100) instead of
trunc(T*100) when setting the threshold value
given a float T.
Own Id: OTP-6153
1.5 Os_Mon 2.1
1.5.1 Fixed Bugs and Malfunctions
-
In 2.0, a call to alarm_handler:get_alarms/0 was
introduced in memsup and disksup. This will
lead to problems if the default alarm_handler
event handler is not used, however, and the call has now
been removed. (Thanks to Serge Aleynikov for pointing
this out.)
Own Id: OTP-6029
-
A bug that in rare cases caused cpu_sup to crash
has been corrected.
Own Id: OTP-6102 Aux Id: seq10312
1.6 OS_Mon 2.0
A note on backwards compatibility: The behaviour of OS_Mon 2.0 is
backwards compatible under normal operation, but has changed
somewhat in error situations: The services do not terminate
and the API functions do not raise exceptions in all cases where
they did before. Also, in the case where a service does terminate,
the exit reason may be different. See below for details.
1.6.1 Fixed Bugs and Malfunctions
-
A call to a OS_Mon service (cpu_sup, disksup, ...) when
OS_Mon is not running, or when the service is not
available for the OS, or when the service is not started,
will no longer result in an exception. Instead a warning
is issued via error_logger and a dummy value is returned,
which one is specified in the man pages for the
respective service.
The reason is that it should not be necessary for a
service to be started on each and every node of a
distributed Erlang system for the OS-MON-MIB and other
OS_Mon users to work properly.
Own Id: OTP-4332 Aux Id: seq7358
-
References to the obsolete EVA application in
OTP-OS-MON-MIB has been removed.
Own Id: OTP-5699
-
Setting the option memsup_system_only to
true did not work, but would crash the
memsup process.
Own Id: OTP-5890 Aux Id: seq10185
-
cpu_sup:nprocs/0 returned 0 on FreeBsd.
Own Id: OTP-5901
-
If the OS_Mon service disksup or memsup was
restarted, the same alarm could be set twice. Also, set
alarms were not cleared when the application was stopped.
Own Id: OTP-5910
1.6.2 Improvements and New Features
-
Thresholds and time intervals in disksup and
memsup are now configurable in run-time.
Own Id: OTP-4246 Aux Id: Seq7230
-
memsup can now handle systems with more than 4GB
of RAM.
Own Id: OTP-5800 Aux Id: seq10130
-
The entire OS_Mon application (code and documentation)
has been reviewed and consequently updated with the goal
to make the application more robust, homogeneous and
easier to configure.
The behaviour under normal operation is backwards
compatible. However, recoverable errors now no longer
terminate the affected service (and thus possible the
entire application), instead error_logger is used
to warn the user if/when such errors occurs. Also, in the
case of unrecoverable errors, the services have been made
more homogeneous with respect to behavior and exit
reasons. See below for more information and refer to the
man pages for details.
Port handling has been unified, meaning that if a port
program sends garbage or unexpectedly dies, this is now
handled the same way by all OS_Mon services, namely
immediate process termination with the exit reason
{port_error,Garbage} or {port_died,Reason},
respectively.
Application configuration parameter handling has been
unified. Bad parameter values are no longer silently
ignored (disksup) or cause application termination
(memsup, os_sup). Instead a warning is
issued and the default value for the parameter is used.
Also, some cases where a bad parameter value accidentally
could be accepted have been corrected.
Message handling has been unified. Unknown
(gen_server-) calls cause process termination,
whereas unknown casts and messages are now ignored by all
OS_Mon services.
Own Id: OTP-5897
-
The following changes have been made to the os_sup
service:
It is now available on Windows, using nteventlog
as backend.
On Solaris, enabling the service (that is, installing a
new configuration file for syslogd etc.) can now
be done outside the os_sup process. The reason for
this is that the Erlang emulator should normally not be
run with root privileges, as is otherwise
required. The new application configuration parameter
os_sup_config must be set to false.
Also, os_sup can now be configured using a new
configuration parameter os_sup_mfa to call an
arbitrary Erlang function when a message is received from
the OS.
Own Id: OTP-5925
-
The memsup service has been rewritten, replacing
the supervised memsup_helper with a linked help
process. This gives the memsup process more
control and prevents a situation where it gets out of
synch with the received memory data and thus possibly
returns erroneous results.
Own Id: OTP-5927
1.7 OS_Mon 1.8.1
1.7.1 Fixed Bugs and Malfunctions
-
cpu_sup:util/0 failed with error reason
negative_diff when called the first time on a
machine (hw) that had been up for a very long time.
Own Id: OTP-5869 Aux Id: seq10166
1.8 OS_Mon 1.8
1.8.1 Improvements and New Features
-
The memsup part of the OS_Mon application has been made
more stable. If there are (possibly temporary) problems
collecting memory data, the interface functions
(get_memory_data/0,
get_system_memory_data/0) now do not fail, but
return the previously collected value, if any, or a dummy
value otherwise. Also, a warning message is printed.
*** POTENTIAL INCOMPATIBILITY ***
Own Id: OTP-5798
1.9 OS_Mon 1.7.4
1.9.1 Fixed Bugs and Malfunctions
-
Corrected several problems in the error handling/error
recovery (especially when OS_Mon is starting up).
Own Id: OTP-5559
1.10 OS_Mon 1.7.3
1.10.1 Improvements and New Features
-
memsup.c will now compile on OpenBSD. (Thanks to
Geoff White and Jay Nelson.)
The disksup and cpu_sup modules now work on
Mac OS X (tested on Mac OS 10.3.8).
The memsup module should now work on Linux 2.6.* as
well as on older Linuxes. (/proc/meminfo has
slightly different formats in different releases of
Linux.)
Own Id: OTP-5421
Aux Id: OTP-5194, OTP-5228, OTP-5291
1.11 OS_Mon 1.7.2
This version is identical with 1.7.
os_mon 2.1.3
Copyright © 1991-2007
Ericsson AB