-- VladimirGligorov - 2009-08-24

How to attach a debugger to a process when running online

Use case

If MOORE is crashing, attaching a debugger can help track down the problem. The tricky part is attaching the debugger before the code is actually executed, so that the process can be monitored right from the beginning; this is important e.g. in cases where MOORE crashes during configuration.

Loading a process without executing it (aka start Gaucho but not configure yet)

  • First allocate on the main control panel on the main button on the top.
  • Then on the main control panel (the one with the subsystems and their states listed) left click on the HLT subsystem. This will open a window that will show a list of the participating Hosts. And on the left side you'll see something like FEST_partAlloc and PART06 (depending on your settings).
  • Now left click on PART06 (or somthing similar like PART02). This will open another submenu showing all the subfarms as seperate subsystems and their respective state. Now most of them should be greyed out, but at least one should be coloured (most likely orange), click on that one (for example HLTA06).
  • This will open yet another screen showing the participating Hosts as individual Subsytems with their respective states. Choose one (for Example HLTA0601) and click on it's state (the coloured field) and change it to LOAD.

The whole point of this excercise is that now you know that on this machine their will be Gaucho jobs started but still not configured. This is essential if you want to attach a debugger to the job before the configuration step in order to debug the configuration itself. After you did so Configure the farm partion as normal by selecting CONFIGURE on the main panels main state button.

Attaching the debugger to a loaded process

Useful commands when in the debugger

Edit | Attach | Watch | Print version | History: r3 < r2 < r1 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r3 - 2009-08-24 - VladimirGligorov
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    LHCb All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2020 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding TWiki? Send feedback