The Cray parallel debuggers lgdb supports Cray's comparative debugging feature.
From Cray's release notes: lgdb is a GDB-based parallel debugger used to debug applications compiled with CCE, PGI, and GNU Fortran, C and C++ compilers. It allows programmers to either launch an application or attach to an already-running application that was launched with aprun. Additionally, preliminary comparative debugger technology has been introduced that enables programmers to compare data structures between two executing applications. Some features of lgdb include:
- Command line parallel debugger allows for launching/attaching applications via aprun.
- Utilizes process sets to operate on a subset of application ranks.
- gdb like feel, also implements a gdbmode to enable a true parallel gdb.
- Prototype of Cray Comparative Debugging Technology.
- OpenACC debugging support.
- Workload manager supported with launch command.
To use, first load the module:
% module load cray-lgdb
Then please see the man page "man lgdb" for usage information. Cray also has a web page that documents the comparative debugging feature.