pdbx - IBM SP Parallel Program Debugger <author> <version> <abstract> pdbx is a front end for multiple instances of the unix debugger dbx running on multiple nodes of an IBM SP. It allows one to observe the execution of a parallel job running in the IBM parallel environment (using message passing either over the ethernet or through the high performance switch) by stepping one, a few, or all nodes through critical sections of a code. Nodes that are not being stepped can be either stalled or allowed to run freely. Likewise, breakpoints can be set on individual nodes or on groups of nodes. pdbx allows one to form process groups interactively to facilitate these functions. When a job is stopped, registers and execution stacks on single or multiple nodes can be examined. pdbx has a command line interface, but there is also an X version called xpdbx. <description><url>http://www.tc.cornell.edu:80/Parallel.Tools/tools/pdbx.html </url> <reference><url></url> <contact> <keywords>parallel debugging; parallel processing tool <category>ppt-exe <publication-date> <environment>IBM SP <method> <application> <comments> </urc>