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.
- 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.