# 1 OS_Mon Release Notes

This document describes the changes made to the OS_Mon application.

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1.1 Os_Mon 2.9

####
Fixed Bugs and Malfunctions

- Fix internal os_mon_sysinfo:get_disk_info/1 function to not crash when run on Windows with multiple drives.

  Own Id: OTP-18246 Aux Id: PR-6284 GH-6156

- Fixed a memory leak when calling cpu_sup:util/0,1 on FreeBSD.

  Own Id: OTP-18546 Aux Id: GH-7070, PR-7071

####
Improvements and New Features

- The disksup:get_disk_info/0 and disksup:get_disk_info/1 functions have been introduced. These can be used in order to immediately fetch information about current disk usage.

  Own Id: OTP-18303 Aux Id: PR-6384

- Runtime dependencies have been updated.

  Own Id: OTP-18350

- Support for cpu_sup:util() on OpenBSD.

  Own Id: OTP-18566 Aux Id: PR-7080

###
1.2 Os_Mon 2.8.2

####
Fixed Bugs and Malfunctions

- Avoid error report from failing erlang:port_close at shutdown of cpu_sup and memsup. Bug exists since OTP 25.3 (os_mon-2.8.1).

  Own Id: OTP-18559 Aux Id: ERIERL-942

###
1.3 Os_Mon 2.8.1

####
Fixed Bugs and Malfunctions

- The port programs used by cpu_sup and memsup are now gracefully shut down when cpu_sup and memsup are shut down.

  Own Id: OTP-18469 Aux Id: PR-6689

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1.4 Os_Mon 2.8

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Improvements and New Features

- The disk_space_check_interval configuration parameter of disksup can now be set to values smaller than a minute.

  Own Id: OTP-18304 Aux Id: PR-6385

###
1.5 Os_Mon 2.7.1

####
Fixed Bugs and Malfunctions

- On a Mac with Apple Silicon, memsup:get_os_wordsize/0 would return 32 instead of 64.

  Own Id: OTP-17441

###
1.6 Os_Mon 2.7

####
Improvements and New Features

- The temporarily introduced configuration parameter memsup_improved_system_memory_data has been removed.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-16943 Aux Id: OTP-16906

- Fix disk_sup to also search the system PATH on linux when looking for the df program.

  Own Id: OTP-16944 Aux Id: PR-2787

###
1.7 Os_Mon 2.6.1

####
Improvements and New Features

- The configuration parameter memsup_improved_system_memory_data has been introduced. It can be used to modify the result returned by memsup:get_system_memory_data(). For more information see the memsup documentation.

  Note that the configuration parameter is intended to be removed in OTP 24 and the modified result is intended to be used as of OTP 24.

  Own Id: OTP-16906 Aux Id: ERIERL-532

###
1.8 Os_Mon 2.6

####
Fixed Bugs and Malfunctions

- memsup now returns the correct amount of system memory on macOS.

  Own Id: OTP-16798 Aux Id: ERL-1327

####
Improvements and New Features

- Fix memsup:get_os_wordsize/0 to return the current size on aarch64.

  Own Id: OTP-16742

###
1.9 Os_Mon 2.5.2

####
Fixed Bugs and Malfunctions

- Fix various compiler warnings on 64-bit Windows.

  Own Id: OTP-15800

####
Improvements and New Features

- Refactored the internal handling of deprecated and removed functions.

  Own Id: OTP-16469

###
1.10 Os_Mon 2.5.1.1

####
Improvements and New Features

- The configuration parameter memsup_improved_system_memory_data has been introduced. It can be used to modify the result returned by memsup:get_system_memory_data(). For more information see the memsup documentation.

  Note that the configuration parameter is intended to be removed in OTP 24 and the modified result is intended to be used as of OTP 24.

  Own Id: OTP-16906 Aux Id: ERIERL-532

###
1.11 Os_Mon 2.5.1

####
Fixed Bugs and Malfunctions

- Fix disk_sup to ignore squashfs on Linux when determining if a mounted filesystem is full or not.

  Own Id: OTP-15778

- Fix bug where cpu_sup:util() always returned 100% on systems not using gnu libc, for example Alpine OS.

  Own Id: OTP-15974 Aux Id: ERL-1012

###
1.12 Os_Mon 2.5

####
Fixed Bugs and Malfunctions

- Fix typespec of cpu_sup:util().

  Own Id: OTP-15770 Aux Id: PR-2208

####
Improvements and New Features

- The application otp_mibs has been removed from OTP. Some of its components (mibs) have been moved to other apps (snmp), or removed completely (os_mon).

  Own Id: OTP-14984 Aux Id: OTP-15329

###
1.13 Os_Mon 2.4.7

####
Fixed Bugs and Malfunctions

- Due to /proc restrictions in newer Android releases enforced by SELinux, cpu_sup is fixed so that it gets some basic CPU stats using the sysinfo syscall rather than reading /proc/loadavg.

  Own Id: OTP-15387 Aux Id: PR-1966

###
1.14 Os_Mon 2.4.6

####
Fixed Bugs and Malfunctions

- Improved documentation.

  Own Id: OTP-15190

###
1.15 Os_Mon 2.4.5

####
Fixed Bugs and Malfunctions

- Fix disksup to handle mount paths with spaces in them.

  Own Id: OTP-14513

###
1.16 Os_Mon 2.4.4

####
Fixed Bugs and Malfunctions

- Removed all old unused files in the documentation.

  Own Id: OTP-14475 Aux Id: ERL-409, PR-1493

###
1.17 Os_Mon 2.4.3

####
Fixed Bugs and Malfunctions

- On macOS 10.13 (High Sierra), disksup could not grab information for any disks that used the new APFS file system. That has been corrected.

  Own Id: OTP-14560 Aux Id: ERL-461

###
1.18 Os_Mon 2.4.2

####
Improvements and New Features

- Support s390x in os_mon.

  Own Id: OTP-14161 Aux Id: PR-1309

###
1.19 Os_Mon 2.4.1

####
Fixed Bugs and Malfunctions

- Fix type specification for cpu_sup:util/1

  Own Id: OTP-13526 Aux Id: PR-1029

- Fix strict compilation on SUN/SPARC

  Own Id: OTP-13548 Aux Id: PR-1046

- Implement cpu_sup:util/0,1 on Mac OSX

  Own Id: OTP-13597 Aux Id: PR-1049

- Fix memsup:get_os_wordsize() on 64-bit FreeBSD and 64-bit Linux PPC

  Own Id: OTP-13601 Aux Id: PR-1039

###
1.20 Os_Mon 2.4

####
Improvements and New Features

- cpu_sup should use native sysctl/libkvm calls on BSD

  This avoids forking off with os:cmd every time we just want to collect the load averages. riak does this every second, which results in a lot of unnecessary load.

  Own Id: OTP-12730

- Implement native cpu_sup:util/0,1 for FreeBSD

  Own Id: OTP-12796

###
1.21 Os_Mon 2.3.1

####
Fixed Bugs and Malfunctions

- Do not crash with badmatch when integer part of loadavg has more than 2 digits.

  Own Id: OTP-12581

####
Improvements and New Features

- Fix compilation of memsup on OpenBSD.

  Own Id: OTP-12404

###
1.22 Os_Mon 2.3

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Improvements and New Features

- Adds a new application parameter 'disksup_posix_only', to make diskup use only options defined in the POSIX standard.

  Own Id: OTP-12053

###
1.23 Os_Mon 2.2.15

####
Fixed Bugs and Malfunctions

- Application upgrade (appup) files are corrected for the following applications:

  asn1, common_test, compiler, crypto, debugger, dialyzer, edoc, eldap, erl_docgen, et, eunit, gs, hipe, inets, observer, odbc, os_mon, otp_mibs, parsetools, percept, public_key, reltool, runtime_tools, ssh, syntax_tools, test_server, tools, typer, webtool, wx, xmerl

  A new test utility for testing appup files is added to test_server. This is now used by most applications in OTP.

  (Thanks to Tobias Schlager)

  Own Id: OTP-11744

####
Improvements and New Features

- Calls to erlang:open_port/2 with 'spawn' are updated to handle space in the command path.

  Own Id: OTP-10842

###
1.24 Os_Mon 2.2.14

####
Fixed Bugs and Malfunctions

- Fix incorrect reporting of memory on OS X via memsup. Thanks to Christopher Meiklejohn.

  Own Id: OTP-11454

###
1.25 Os_Mon 2.2.13

####
Fixed Bugs and Malfunctions

- Use 'df -k -l' to query FreeBSD and OpenBSD about diskspace on local disks. Previously 'df' -k -t ufs' was used but this will not handle zfs or other disks. Just use '-l' instead of listing potential filesystems.

  Own Id: OTP-11207

####
Improvements and New Features

- Fix compilation on Solaris. Thanks to Maciej Malecki.

  Own Id: OTP-11213

- Fix broken cpu_sup:nprocs and others on Solaris 64-bit. Thanks to Simon Cornish.

  Own Id: OTP-11298

###
1.26 Os_Mon 2.2.12

####
Fixed Bugs and Malfunctions

- Compilation fixes for NetBSD. Thanks to YAMAMOTO Takashi.

  Own Id: OTP-10941

####
Improvements and New Features

- Fixed disksup:get_disk_data for SUSv3, specifically OS X ML. Thanks to Sriram Melkote.

  Own Id: OTP-10945

###
1.27 Os_Mon 2.2.11

####
Fixed Bugs and Malfunctions

- Removed deprecated function calls to snmp

  Own Id: OTP-10448

###
1.28 Os_Mon 2.2.10

####
Fixed Bugs and Malfunctions

- Infinity timeout added to internal calls in disksup to allow it to work properly under very heavy load.

  Own Id: OTP-10100

- Clarify error messages from os_mon port programs

  Own Id: OTP-10161

###
1.29 Os_Mon 2.2.9

####
Fixed Bugs and Malfunctions

- Fix segmentation fault in memsup

  when /proc/meminfo does not include information about buffers/cache (for instance inside OpenVZ container) (Thanks to Anton Vorobev)

  Own Id: OTP-9913

###
1.30 Os_Mon 2.2.8

####
Improvements and New Features

- Erlang/OTP can now be built using parallel make if you limit the number of jobs, for instance using 'make -j6' or 'make -j10'. 'make -j' does not work at the moment because of some missing dependencies.

  Own Id: OTP-9451

- Tuple funs (a two-element tuple with a module name and a function) are now officially deprecated and will be removed in R16. Use 'fun M:F/A' instead. To make you aware that your system uses tuple funs, the very first time a tuple fun is applied, a warning will be sent to the error logger.

  Own Id: OTP-9649

###
1.31 Os_Mon 2.2.7

####
Fixed Bugs and Malfunctions

- Remove misc. compiler warnings

  Own Id: OTP-9542

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1.32 Os_Mon 2.2.6

####
Fixed Bugs and Malfunctions

- Add NetBSD support to memsup and disksup (Thanks to Andrew Thompson)

  Own Id: OTP-9216

- Add support for DragonFlyBSD to memsup

  DragonFly was partially supported by os_mon already but when trying to start the os_mon application it'd crash with an error about an unknown operating system in memsup. This patch changes memsup to use the FreeBSD sysctl method to get memory information when on DragonFly. (Thanks to Andrew Thompson )

  Own Id: OTP-9217

###
1.33 Os_Mon 2.2.5

####
Improvements and New Features

- Cleanups suggested by tidier and modernization of types and specs.

  Own Id: OTP-8455

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1.34 Os_Mon 2.2.4

####
Fixed Bugs and Malfunctions

- Memsup did not read memory correctly on macOS X Snowleopard. This has now been corrected. (Thanks to Joel Reymont)

  Own Id: OTP-8211

- Removed unused code in cpu_sup.erl.

  Own Id: OTP-8226

####
Improvements and New Features

- The documentation is now built with open source tools (xsltproc and fop) that exists on most platforms. One visible change is that the frames are removed.

  Own Id: OTP-8201

###
1.35 Os_Mon 2.2.3

####
Fixed Bugs and Malfunctions

- A missing define in memsup.c caused a build error on IRIX machines. This has now been fixed.

  Own Id: OTP-8094

###
1.36 Os_Mon 2.2.2

####
Fixed Bugs and Malfunctions

- disksup:get_disk_data/0 returned disk volume in bytes instead of kbytes as stated in the documentation. The problem occurred on Windows only and is now corrected.

  *** POTENTIAL INCOMPATIBILITY ***

  Own Id: OTP-7741

###
1.37 Os_Mon 2.2.1

####
Fixed Bugs and Malfunctions

- An error in memsup could cause os_mon to report erroneous memory values on windows for ranges of memory between 2GB and 4GB. This have now been fixed.

  Own Id: OTP-7944

####
Improvements and New Features

- Added support for dragonfly OS.

  Own Id: OTP-7938

###
1.38 Os_Mon 2.2

####
Improvements and New Features

- The copyright notices have been updated.

  Own Id: OTP-7851

###
1.39 Os_Mon 2.1.8

####
Fixed Bugs and Malfunctions

- A problem with OTP-OS-MON-MIB.mib for 64-bit environments has now been fixed. The mib has been extended with 64-bit memory retrieval counterparts.

  In addition, a new function get_os_wordsize/0 has been added in the memsup module

  Own Id: OTP-7441

- An error in memsup.c caused the compilation to crash on bsd environments. This has now been fixed.

  Own Id: OTP-7558

###
1.40 Os_Mon 2.1.7

####
Fixed Bugs and Malfunctions

- Fixed a build error that occurred on NetBSD (Thanks to Per Hedeland and Raphael Langerhorst)

  Own Id: OTP-7505

####
Improvements and New Features

- Memory information in memsup:get_system_memory_data/0 now has additional entries in its property list for Linux.

  Own Id: OTP-7409 Aux Id: seq10984

###
1.41 Os_Mon 2.1.6

####
Fixed Bugs and Malfunctions

- System information retrieval on darwin platforms with environments locales not conforming to the C locale caused an error in cpu_sup resulting in process termination.

  Own Id: OTP-7320

###
1.42 Os_Mon 2.1.5

####
Improvements and New Features

- CPU utilization, on linux, is now measured via a port program instead of os:cmd in erlang. This should enhance performance.

  Own Id: OTP-7108 Aux Id: OTP-6935

###
1.43 Os_Mon 2.1.3

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Improvements and New Features

- Extended memsup memory probing on Linux to use a port program to probe memory usage. This is faster than the previous implementation.

  Own Id: OTP-6860 Aux Id: seq10616

###
1.44 Os_Mon 2.1.2.1

####
Improvements and New Features

- Minor Makefile changes.

  Own Id: OTP-6689

###
1.45 OS_Mon 2.1.2

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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

###
1.46 OS_Mon 2.1.1

####
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

####
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

###
1.47 Os_Mon 2.1

####
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

###
1.48 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.

####
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

####
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

###
1.49 OS_Mon 1.8.1

####
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

###
1.50 OS_Mon 1.8

####
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

###
1.51 OS_Mon 1.7.4

####
Fixed Bugs and Malfunctions

- Corrected several problems in the error handling/error recovery (especially when OS_Mon is starting up).

  Own Id: OTP-5559

###
1.52 OS_Mon 1.7.3

####
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

###
1.53 OS_Mon 1.7.2

This version is identical with 1.7.