Newer flags for configure:
* Rename --enable-debug to --enable-logging
* Add --enable-debug: "-Wall -g3 -O0" (for debugging DMTCP)
Newer flags for dmtcp_restart:
* Add --debug-restart-pause flag to dmtcp_restart
Bug fixes and enhancements:
* Fixes for glibc versions greater than or equal to 2.24
* Fix deadlock in system() wrapper when the child crashes
* Fix deadlock when a process is forked in the resume phase (issue #691)
* jsocket: Warn user if peer closes socket while draining (issue #701)
* Fix epoll1 test (initialize addrlen for accept()) (#705)
* Fix to correctly calculate Coordinator/Host IP:
Affects some distributed applications
* Allow restored stack to grow if needed.
* Fix bug in POSIX timer: race condition manifested in test/timer.c/Ubuntu-18.04
* Modified InfiniBand plugin for more robust support
(primarily of interest for MPI)
* The floating point environment (fegetenv()) is now restored on restart.
(Formerly, only the rounding mode (fegetround()) was restored.)
* The current resource limits (rlim_cur) for RLIMIT_NOFILE and RLIMIT_STACK
are restored if possible.
* Mutex ownership and robust mutexes are now supported if DMTCP is configured
with --enable-mutex-wrappers. (However, this configuration can also add runtime overhead
if mutex operations are called very frequently.)
[Thanks to Johannes Stoelp, Laurent Buchard, Pankaj Mehta of Synopsys, Inc.]
* Fix bug if stack grows a lot after a restart.
* Improved support for pty's
* util/gdbinit-example added for those who wish to debug DMTCP internals.
* Many bug fixes
This release mostly provides added robustness. Two notable items of
added functionality are:
i. DMTCP_RESTART_PAUSE and DMTCP_RESTART_PAUSE0 environment variables
for easier debugging upon initial restart
ii. The --debug-logs flag was added to dmtcp_launch/dmtcp_restart.
One can now turn on logging individually for separate plugins,
instead of only turning it on globally.
An incompatibility of DMTCP with Open MPI 1.10 when using orterun (mpirun)
was discovered. This may also affect some other versions of Open MPI 1.10.
This bug will be fixed in a future release.... read more
This release includes a few new plugins and several bug fixes for robustness.
Some of the highlights include:
process_vm_readv
and process_vm_writev
--enable-fast-restart
.--with-plugin-32
for dmtcp_launch to specify--enable-pthread-mutex-wrappers
configure flag to enablepthread_mutex_{lock,unlock}
wrappers needed for Open MPI.modify-env
plugin.dmtcp_restart
to be invoked by root.pathvirt
: to virtualize filesystem paths.delayresume
: for finer-grained control over resuming of user threadsdmtcp_dlsym()
extended to provide more robust wrapper functions.Several important enhancements were added:
Several important enhancements were added:
__poll_chk
process_vm_readv
/process_vm_writev
dmtcp_checkpoint()
API call for DMTCP-aware applicationsSeveral important changes and enhancements were added:
dmtcp_launch/restart/command/coordinator
now take the flags-h, -p, --coord-host/port
and environment variablesDMTCP_COORD_HOST/PORT
. The older --host, --port, DMTCP_HOST/PORT
plugin/batch-queue/job_examples/
for SLURM/DMTCP submission scripts.cat /proc/self/maps | grep '\[vvar]'
ls -l /lib*/libc.so.6 /lib/*/libc.so.6
DMTCP_GDB_ATTACH_ON_RESTART
was added. SettingSeveral important enancements were added to this 2.4 release candidate:
This is primarily a bug fix release. However, if you are using DMTCP
for the ARM v7 CPU, or if you are using DMTCP either with the InfiniBand
network or with the SLURM batch system, then it is strongly recommended
to upgrade.
The primary changes for this release are:
This is a bug fix release. The previous release had a bug when configured
with --enable-unique-checkpoint-filenames configure flag. This has been fixed
now. Users relying on this flag are highly recommended to upgrade to 2.2.1.
DMTCP version 2.2. has now been released.
In this release, the lowest layers have been re-organized and partially
re-written for greater clarity of code and greater maintainability.
These changes should be transparent to end users.
Users relying on the use of DMTCP with MPI, InfiniBand or the Toruqe or
SLURM batch queues are strongly advised to upgrade.
Other changes are:
DMTCP version 2.1. has now been released.
As before, it runs on most Linux distros, and supports both x86 and x86_64
(Intel/AMD for 32- and 64-bits), and 32-bit ARM (ARMv7). In addition, the
older DMTCP version 1.2.x (currently 1.2.8) continues to be maintained, but on
a bug-fix basis only.
This version 2.0 release represents the future of DMTCP. The older DMTCP
version 1.2.x branch will continue to be maintained for bug fixes and
back-porting of simple enhancements to DMTCP, in order to provide backward
compatibility. But DMTCP version 1.2.x will not see most new features.
DMTCP version 2.0 has been re-designed around the concept of DMTCP
plugins (similar in spirit to web browser plugins). Much of the internal
architecture of DMTCP has been moved into plugins, for greater modularity.
Further, the plugin capability has been exposed, to make it easy for end
users to write their own plugins. Among the capabilities of plugins are:... read more
DMTCP version 1.2.8 is primarily a bug fix release. It is particularly
recommended to upgrade if you are using DMTCP with the ARM CPU,
or if you will compile DMTCP with a C++11 compiler (e.g. GNU flag -std=c++11).
Important changes include:
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
Release Notes:
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
Release Notes:
- Previous release (1.2.5) introduced compilation errors for older kernels.
This release fixes them.
- Several minor bug fixes related to gcc 4.7.
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
Release Notes:
- epoll, eventfd, and signalfd are now supported
- The ARM architecture for Linux is now supported.
(Linux currently supports 32-bit ARM EABI.)
- The name "DMTCP module" is changed to "DMTCP plugin" (more common terminology).
User plugins can greatly customize the behavior of DMTCP.
- The dmtcp_checkpoint cmd was resetting the checkpoint interval even
if the user did not specify the -i/--interval flag. This is now fixed.
- Improved support for a planned Fedora package for DMTCP
- On resume from ckpt, zero pages were sometimes expanded (increasing the
memory footprint). This affected Java. This is now fixed.
- Some bug fixes were provided for programs that intensively create
and destroy threads (e.g. OpenMP, Java)
- After restart, the floating point rounding mode (fesetround) was not being
properly restored. This is now fixed.
- There have been requests for support of DMTCP for PBS/TORQUE. Some partial
support has now been added to the svn only (_not_ to this release).
Please write to us if you need this support from DMTCP.
- The FAQ at the DMTCP web site was expanded.
- 15% slowdown observed in an unusual case:
A user reports that if your program frequently does both of these:
a. is heavily multi-threaded; and
b. calls malloc/free intensively;
This has been diagnosed. It was seen too close to this 1.2.5 release,
and so the fix will be provided for the next release (and in the public svn).
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
Release Notes:
- There is now much more robust treatment of processes that rapidly create and destroy threads. This was the case for the Java JVM (both for OpenJDK and Oracle (Sun) Java). This was also the case for Cilk. Cilk++ was not tested. We believe this new DMTCP to now be highly robust -- and we would appreciate receiving a notification if you find a Java or Cilk program that is not compatible with DMTCP.
- Zero-mapped pages are no longer expanded and saved to the DMTCP checkpoint image. For Java programs (and other programs using zero-mapped pages for their allocation arena or garbage collecotr), the checkpoint image will now be much smaller. Checkpoint and restart times will also be faster.
- DMTCP_ROOT/dmtcp/doc directory added with documentation of some DMTCP internals. architecture-of-dmtcp.pdf is a good place to start reading for those who are curious.
- The directory of example modules was moved to DMTCP_ROOT/test/module. This continues to support third-part wrappers around system calls, can registering functions to be called by DMTCP at interesting times (like pre-checkpoint, post-resume, post-restart, new thread created, etc.).
- This version of MTCP (inside this package) should be compatible with the checkpoint-restart service of Open MPI. The usage will be documented soon through the Open MPI web site. As before, an alternative is to simply start Open MPI inside DMTCP, and let DMTCP treat all of Open MPI as a "black box" that happens to be a ditributed computation
- A new --prefix command line flag has been added to dmtcp_checkpoint. It operates similarly to the flag of the same name in Open MPI. For distributed computations, remote processes will use the prefix as part of the path to find the remote dmtcp_checkpoint command. This is useful when a gateway machine has a different directory structure from the remote nodes.
- configure --enable-ptrace-support now uses ptrace module (more modular code). The ptrace module should also be more robust. It now fixes some additional cases that were missing earlier
- ./configure --enable-unique-checkpoint-filenames was not respecting bin/dmtcp_checkpoint --checkpoint-open-files . This is now fixed.
- If the coordinator received a kill request in the middle of a checkpoint, the coordinator could freeze or die. This has now been fixed, with the expected behavior: Kill the old computation that is in the middle of a checkpoint, and then allow any new computations to begin.
- dmtcp_inspector utility was broken in last release; now fixed
- configure --enable-forked-checkpoint was broken in the last release. It is fixed again.
- Many smaller bug fixes.
- The debian packages and rpm packages for OpenSUSE will be submitted to the distros over the next few days.
We are currently working on a new DMTCP release which would feature stability fixes for multi-threaded processes and much more. We expect to put out the release on Thursday, Jan 19, 2012.
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
This release is primarily a bug-fix release. Here are the Release Notes:
- Several bug fixes.
- Modifications added for compatibility with the checkpoint-restart service of OpenMPI (will be integrated with upcoming OpenMPI-1.6)
- Tests for emacs, vim and strace added to 'make check'
- When running emacs23 under GNU 'screen', it's not restored correctly. Currently we warn user to use emacs22. Emacs23 with 'screen' will be supported in future (and 'emacs23' continues to work fine standalone).
- Fixes a regression in which checkpointing 'gdb' with the required './configure --enable-ptrace-support' was failing. Works now.
- /proc/*/cmdline was not being restored correctly when: argc > 1 (Fixed.)
- debugging logic (primarily for DMTCP developers) was simplified so that changing CFLAGS in mtcp/Makefile to add '-DDEBUG' suffices to include MTCP debugging information. If --enable-debug is also configured, then a copy of MTCP debug information also goes into /tmp/dmtcp-USER@HOST/jassertlog.* .
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
Release Notes
- A new module system, allowing users to write their own extensions to DMTCP, including wrappers around library calls. See the module subdirectory for examples.
- ./configure --enable-m32 was not working in DMTCP 1.2.1. It works again now.
- more bug fixes and robustness testing. Tested on kernels ranging from Linux 2.6.5 to the latest kernel. Tested especially on the Linux distributions: Red Hat/Fedora, Debian/Ubuntu, SuSe/OpenSUSE; although we don't know of any Linux distributions where it fails to run.
- 'screen' did not checkpoint properly on machines using LDAP authentication. This could also affect processes using 'bash'. This has been fixed.
- Furthermore, recent versions of 'screen' began calling 'utempter' when present Support for 'utempter' and some other setuid processes has been added.
- Removed the requirement for libc.a in building DMTCP, since Red Hat does not include libc.a in its standard repository.
- ./configure --enable-ptrace now more robust. Still labelled "experimental" for this release. You will need to enable this if you want to checkpoint gdb sessions, programs running under strace, and certain other applications.
- ./configure --enable-fast-ckpt-restart can make ckpt/restart faster by using 'mmap'. You will need to set the environment variable DMTCP_GZIP to "0" if you use this. This feature is still experimental, and there are many other tricks for speeding up ckpt/restart. Please talk to the developers if this is important for your application.
- Experimental support added for HBICT ( hbict.sf.net ). This provides support for incremental and differential checkpointing. However, this is still ongoing work.
- Work has begun on improved support for process migration between different Linux kernels and distributions. Simple applications should migrate. Please talk to us if this feature is important to you.
- We do not yet support the 'epoll' and 'inotify' Linux system calls. Recently, there has been some demand for this, and we intend to raise the priority. Please talk to us if this feature is important to you.
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpoint the state of multiple simultaneous applications, including multi-threaded and distributed applications. It operates directly on the user binary executable, without any Linux kernel modules or other kernel modifications.
Release Notes
DMTCP 1.2.1 provides:
* Support for calling dmtcpaware API (dmtcpCheckpoint(), etc.) directly from inside a python session.
* The option for applications to use the dmtcpaware interface to link with a shared library (libdmtcpaware.so) instead of libdmtcpaware.a.
* Support for MPICH2 1.3.x (transparently checkpointing MPICH under DMTCP), as well as continuing the existing support for checkpointing OpenMPI.
* Support for running and checkpointing of binaries in non-privileged mode when the setuid/setgid bits of the binaries are set.
* Several bug fixes related to GNU screen.
* Experimental support for ptrace to allow checkpointing of gdb sessions, strace, and other ptrace-based aplications.
* On restart, restore original process name for 'ps' and /proc/self/cmdline.
* Additional bug fixes and enhancements.
DMTCP (Distributed MultiThreaded Checkpointing) is a tool to transparently checkpointing the state of an arbitrary group of programs spread across many machines and connected by sockets. It does not modify the user's program or the operating system.
Release Notes:
* This is a semi-major release. DMTCP now supports GNU screen.
* It also fixes some instabilities in checkpointing Matlab under certain environments.
* Numerous bug fixes were implemented as a part of review of DMTCP sub-systems.