Difference between revisions of "Comparison to other CR projects"

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(Table style fix)
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{| style="border-spacing:0;"
+
{| class="wikitable sortable"
| style="border:1pt solid #000000;padding:0.176cm;"|
 
| style="border:1pt solid #000000;padding:0.176cm;"| CRIU
 
| style="border:1pt solid #000000;padding:0.176cm;"| DMTCP
 
| style="border:1pt solid #000000;padding:0.176cm;"| BLCR
 
 
 
 
|-
 
|-
| style="background-color:#dc2300;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
!
| style="background-color:#dc2300;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
! CRIU
| style="background-color:#dc2300;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
! DMTCP
| style="background-color:#dc2300;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
! BLCR
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| arch
+
| Arch
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| x86_64, ARM
+
| x86_64, ARM
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| x86, x86_64, ARM
+
| x86, x86_64, ARM
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| x86,x86_64,PPC/PPC64,ARM
+
| x86, x86_64, PPC/PPC64, ARM
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| OS
+
| OS
| colspan="3"  style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| <center>Linux</center>
+
| Linux
 
+
| Linux
|-
+
| Linux
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| modified kernel
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes, but only for some extra features.
 
 
 
All unnecessary features are already in new kernel versions
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no, module can be simply modprobed
 
 
 
 
 
problems with installation on new kernels
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| special libs
+
| Need in modified kernel
 
+
| Yes, but only for some extra features. All unnecessary features are already in new kernel versions
 
+
| No
 
+
| No, just need to load module. May be problems with installation on new kernels
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| root privileges
+
| App need to pre-load special libraries
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes, otherwise it would be unsafe,because,for example, of parasite code
+
| No
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Yes
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| need to modify programs
+
| Requires root privileges
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Yes, due to restrictions from some kernel APIs it uses
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| No
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| No
 
 
there are some difficulties with statically linked applications, and with LinuxThreads (cuz it does not support them at all)
 
 
 
 
 
 
 
 
 
|-
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| need to prepare tasks
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
It preloadsthe DMTCP library. That library runs before the routinemain(). It creates a second thread. Thecheckpoint thread then creates a socket to the DMTCP coordinator andregisters itself. The checkpoint thread also creates a signal handler.
 
 
 
 
 
 
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
CR shall notify processes when a checkpoint is to occur (before the kernel takes a checkpoint) to
 
 
 
allow the processes to prepare itself accordingly.
 
 
 
 
 
 
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Does it change behavior of the c/r-ed programs?
+
| Need to modify programs to C/R
 
+
| No
 +
| No
 +
| Yes. There are some difficulties with statically linked applications, and with LinuxThreads (it does not support them at all)
  
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
 
because of wrappers on system calls
 
 
 
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
 
because of wrappers on system calls
 
  
 
|-
 
|-
| style="background-color:#008000;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| Need to prepare tasks
| style="background-color:#008000;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| No
| style="background-color:#008000;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| Yes. It preloadsthe DMTCP library. That library runs before the routinemain(). It creates a second thread. Thecheckpoint thread then creates a socket to the DMTCP coordinator andregisters itself. The checkpoint thread also creates a signal handler.
| style="background-color:#008000;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| Yes. CR shall notify processes when a checkpoint is to occur (before the kernel takes a checkpoint) to allow the processes to prepare itself accordingly.
 
 
|-
 
| style="border:1pt solid #000000;padding:0.176cm;"| migration
 
| style="border:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
even if kernel ,libs, etc are newer
 
 
 
 
 
Can use Memory Changes Tracking to decrease time for dumping
 
| style="border:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
if both kernels are recent
 
| style="border:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
but if all is the same!
 
 
 
  
if even prelinked addresses are different,it will not restore
 
 
 
But it can save the whole used libs and localization files to restore program on the different machine
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Containers
+
| Does it change behavior of the c/r-ed programs?
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| No
 
+
| Yes, because of wrappers on system calls
LXC and OpenVZ containers
+
| Yes, because of wrappers on system calls
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| looks like no
 
 
 
It doesn't support namespaces, so it probably can’t dump containers
 
 
 
 
 
 
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| looks like no
 
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| parallel/distributed computations
+
| Live migration
| style="border:1pt solid #000000;padding:0.176cm;"| no
+
| Yes, even if kernel, libs, etc are newer. Can use Memory Changes Tracking to decrease freeze time
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes, if both kernels are recent
 
+
| Yes, but if all components are the same. Even if prelinked addresses are different,it will not restore, but it can save the whole used libs and localization files to restore program on the different machine
OpenMPI, MPICH2, OpenMP, Cilk are alredy supported and Infiniband is in progress.
 
| style="border:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
Cray MPI, Intel MPI, LAM/MPI, MPICH-V, MPICH2, MVAPICH, Open MPI, SGI MPT
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| c\r gdb with debugging app
+
| Containers
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no, because they are using the same interface
+
| Yes, LXC and OpenVZ containers
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| No. It doesn't support namespaces, so it probably can’t dump containers
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Looks like no
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| X-Windows graphics programs (KDE, GNOME, etc)
+
| Parallel/distributed computations libraries
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes, by using vnc
+
| No (in plans)
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes, by using vnc
+
| Yes. OpenMPI, MPICH2, OpenMP, Cilk are alredy supported and Infiniband is in progress
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| seems like no
+
| Yes. Cray MPI, Intel MPI, LAM/MPI, MPICH-V, MPICH2, MVAPICH, Open MPI, SGI MPT
 
 
 
 
 
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Solutions for invocation in the custom software
+
| C/R gdb with debugging app
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
+
| No, because they are using the same interface
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
 
+
| No
Plugins and API
 
 
 
 
 
 
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
 
  
 
|-
 
|-
| colspan="4"  style="background-color:#800080;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|  
+
| X-Windows apps (KDE, GNOME, etc)
 +
| Yes, by using vnc
 +
| Yes, by using vnc
 +
| Looks like no
  
|-
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| unix sockets
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes,all kinds
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| udp sockets
+
| Solutions for invocation in the custom software
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes, both ipv4 and ipv6
+
| No, only fork + daemonize + exec
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
+
| Yes. Plugins and API
 
+
| Not yet
developers of dmtcp had no request for this
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| tcp sockets
+
| colspan="4" |
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| remote tcp connection
+
| Unix sockets
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
+
| Yes
 
+
| No
but you can write a simple DMTCP plugin that tells DMTCP how you want to reconnect on restart
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Infiniband
+
| UDP sockets
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Yes, both ipv4 and ipv6
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
+
| Not yet. Developers of dmtcp had no request for this
 
+
| Not yet
developing is on the half-way
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
  
 
|-
 
|-
| style="background-color:#008080;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| TCP sockets
| style="background-color:#008080;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| Yes
| style="background-color:#008080;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| Yes
| style="background-color:#008080;border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"|
+
| Not yet
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| multithread support
+
| Established tcp connection
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No, but you can write a simple DMTCP plugin that tells DMTCP how you want to reconnect on restart
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| multiprocess
+
| Infiniband
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Not yet, developing is on the half-way
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| process groups
+
| Multithread support
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
+
| Yes
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| zombies
+
| Multiprocess
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| Yes
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| namespaces
+
| Process groups and sessions
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| no
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| no
+
| Not yet
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| sessions
+
| Zombies
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No
| style="border:1pt solid #000000;padding:0.176cm;"| not yet
+
| No
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| Ptraced programs
+
| Namespaces
| style="border:1pt solid #000000;padding:0.176cm;"| no
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No
| style="border:1pt solid #000000;padding:0.176cm;"| no
+
| No
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| System V IPC
+
| Ptraced programs
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| No
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| no
+
| No
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| memory mappings
+
| System V IPC
| style="border:1pt solid #000000;padding:0.176cm;"| yes, all kinds
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes, partially
+
| No
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| protected memory
+
| Memory mappings
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes, all kinds
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes, partially
  
 
|-
 
|-
| style="border:1pt solid #000000;padding:0.176cm;"| pipes
+
| Pipes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border:1pt solid #000000;padding:0.176cm;"| not yet
+
| Not yet
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| terminals
+
| Terminals
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes, but only Unix98 PTYs
 
+
| Yes
only Unix98 PTYs
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
 
 
 
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| non-posix files (inotify, signalfd, eventfd, etc)
+
| Non-posix files (inotify, signalfd, eventfd, etc)
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes, inotify, fanotify, epoll, signalfd, eventfd
 
+
| Yes, epoll, eventfd, signalfd are already supported and inotify will be supported in future
inotify, epoll, etc.
+
| Looks like no
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Yes
 
 
 
epoll, eventfd, signalfd are already supported and
 
 
 
inotify will be supported in future
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| looks like no
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| timers
+
| Timers
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| No. Any counter or timer active since the beginning of a process will consider the restarted process to be a new process.
 
+
| Yes
Any counter or timer active since the beginning of a process will consider the restarted process to be a new process.  
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| Shared resources (files, mm, etc.)
+
| Shared resources (files, mm, etc.)
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes. SysVIPC, files, fd table and memory
 
+
| Yes. System V shared memory(shmget, etc.), mmap-based shared memory, shared sockets, pipes, file descriptors
files, memory, etc.
+
| No, but it is planned to suppord shared mmap regions
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
 
 
 
System V shared memory(shmget, etc.), mmap-based shared memory, shared sockets, pipes, file descriptors.
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
 
 
 
but it is planned to suppord shared mmap regions
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| block devices
+
| Block devices
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| looks like yes
+
| No
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| looks like yes
+
| Looks like yes
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| no
+
| No
 
 
 
 
  
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| character devices
+
| Character devices
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| mostly no
+
| Yes, only /dev/null, /dev/zero, etc. are supported
 
+
| Yes, looks like null and zero are supported
but /dev/null, /dev/zero, etc. are supported
+
| Yes, /dev/null and /dev/zero
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| mostly no
 
 
 
looks like null and zero are supported
 
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| mostly no
 
 
 
but /dev/null and
 
 
 
/dev/zero are supported
 
  
 
|-
 
|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| capture the contents of all open files
+
| Capture the contents of open files
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| yes
+
| Yes, if file is unlinked
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| looks like no
+
| Looks like no
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.176cm;"| not yet
+
| Not yet
  
 
|}
 
|}

Revision as of 13:58, 11 July 2013

This pages tries to explain differences between CRIU and other C/R solutions.

DMTCP

DMTCP implements checkpoint/restore of a process on a library level. This means, that if you want to C/R some application you should launch one with DMTCP library (dynamically) linked from the very beginning. When launched like this, the DMTCP library intercepts a certain amount of library calls from the application, builds a shadow data-base of information about process' internals and then forwards the request down to glibc/kernel. The information gathered is to be used to create an image of the application. With this approach, one can only dump applications known to run successfully with the DMTCP libraries, but the latter doesn't provide proxies for all kernel APIs (for example, inotify() is known to be unsupported). Another implication of this approach is potential performance issues that arise due to proxying of requests.

Restoration of process set is also tricky, as it frequently requires restoring an object with the predefined ID and kernel is known to provide no APIs for several of them. For example, kernel cannot fork a process with the desired PID. To address that, DMTCP fools a process by intercepting the getpid() library call and providing fake PID value to the application. Such behavior is very dangerous, as application might see wrong files in the /proc filesystem if it will try to access one via its PID.

CRIU, on the other hand, doesn't require any libraries to be pre-loaded. It will checkpoint and restore any arbitrary application, as long as kernel provides all needed facilities. Kernel support for some of CRIU features were added recently, essentially meaning that a recent kernel version might be required.

BLCR

Berkeley Lab Checkpoint/Restart (BLCR) is a part of the Scalable Systems Software Suite , developed by the Future Technologies Group at Lawrence Berkeley National Lab under SciDAC funding from the United States Department of Energy. It is an Open Source, system-level checkpointer designed with High Performance Computing (HPC) applications in mind: in particular CPU and memory intensive batch-scheduled MPI jobs. BLCR is implemented as a GPL-licensed loadable kernel module for Linux 2.4.x and 2.6.x kernels on the x86, x86_64, PPC/PPC64, ARM architectures, and a small LGPL-licensed library.

CRIU, DMTCP, BLCR

“looks\seems like yes/no” - i found only unproved message(s) saying “yes”/“no”

“not yet” - it is officially planned or i found no reasons, why it can’t be done.


CRIU DMTCP BLCR
Arch x86_64, ARM x86, x86_64, ARM x86, x86_64, PPC/PPC64, ARM
OS Linux Linux Linux
Need in modified kernel Yes, but only for some extra features. All unnecessary features are already in new kernel versions No No, just need to load module. May be problems with installation on new kernels
App need to pre-load special libraries No Yes Yes
Requires root privileges Yes, due to restrictions from some kernel APIs it uses No No
Need to modify programs to C/R No No Yes. There are some difficulties with statically linked applications, and with LinuxThreads (it does not support them at all)


Need to prepare tasks No Yes. It preloadsthe DMTCP library. That library runs before the routinemain(). It creates a second thread. Thecheckpoint thread then creates a socket to the DMTCP coordinator andregisters itself. The checkpoint thread also creates a signal handler. Yes. CR shall notify processes when a checkpoint is to occur (before the kernel takes a checkpoint) to allow the processes to prepare itself accordingly.


Does it change behavior of the c/r-ed programs? No Yes, because of wrappers on system calls Yes, because of wrappers on system calls
Live migration Yes, even if kernel, libs, etc are newer. Can use Memory Changes Tracking to decrease freeze time Yes, if both kernels are recent Yes, but if all components are the same. Even if prelinked addresses are different,it will not restore, but it can save the whole used libs and localization files to restore program on the different machine
Containers Yes, LXC and OpenVZ containers No. It doesn't support namespaces, so it probably can’t dump containers Looks like no
Parallel/distributed computations libraries No (in plans) Yes. OpenMPI, MPICH2, OpenMP, Cilk are alredy supported and Infiniband is in progress Yes. Cray MPI, Intel MPI, LAM/MPI, MPICH-V, MPICH2, MVAPICH, Open MPI, SGI MPT
C/R gdb with debugging app No, because they are using the same interface Yes No
X-Windows apps (KDE, GNOME, etc) Yes, by using vnc Yes, by using vnc Looks like no


Solutions for invocation in the custom software No, only fork + daemonize + exec Yes. Plugins and API Not yet
Unix sockets Yes Yes No
UDP sockets Yes, both ipv4 and ipv6 Not yet. Developers of dmtcp had no request for this Not yet
TCP sockets Yes Yes Not yet
Established tcp connection Yes No, but you can write a simple DMTCP plugin that tells DMTCP how you want to reconnect on restart No
Infiniband No Not yet, developing is on the half-way No
Multithread support Yes Yes Yes
Multiprocess Yes Yes Yes
Process groups and sessions Yes Yes Not yet
Zombies Yes No No
Namespaces Yes No No
Ptraced programs No Yes No
System V IPC Yes Yes No
Memory mappings Yes, all kinds Yes Yes, partially
Pipes Yes Yes Not yet
Terminals Yes, but only Unix98 PTYs Yes Yes
Non-posix files (inotify, signalfd, eventfd, etc) Yes, inotify, fanotify, epoll, signalfd, eventfd Yes, epoll, eventfd, signalfd are already supported and inotify will be supported in future Looks like no
Timers Yes No. Any counter or timer active since the beginning of a process will consider the restarted process to be a new process. Yes
Shared resources (files, mm, etc.) Yes. SysVIPC, files, fd table and memory Yes. System V shared memory(shmget, etc.), mmap-based shared memory, shared sockets, pipes, file descriptors No, but it is planned to suppord shared mmap regions
Block devices No Looks like yes No


Character devices Yes, only /dev/null, /dev/zero, etc. are supported Yes, looks like null and zero are supported Yes, /dev/null and /dev/zero
Capture the contents of open files Yes, if file is unlinked Looks like no Not yet

Sources

DMTCP:

BLCR:

External links