1. LibreOffice Online Debugging Collabora Productivity
Andras Timar
Collabora Productivity
@CollaboraOffice

2. Rendering issues Tiled rendering 256 × 256 px PNG tiles
OK in desktop Libreoffice, not OK in LibreOffice Online
gtktiledviewer
bin/run gtktiledviewer <absolute-path-to- libreoffice-install's-program-directory> <path-to- document> [<options> ... ]

3. Connectivity issues Browser, Web Developers Tool (F12)
Webserver, load balancer etc. logs
Loolwsd logs
Wireshark
1. plain HTTP, port 9980
2. reverse proxy 80 ↔ 9980
3. SSL (certs, self signed certs)
4. Load balancer
5. SSL offloading
6. Websocket timeouts
File Sharing Solution
Collabora Online server

4. loolwsd logging 8 levels
fatal, critical, error, warning, notice, information, debug, trace
Set it in /etc/loolwsd/loolwsd.xml
Systemd journal or separate log file or console

5. Running LOOL locally Configure online:
--with-lokit-path=bundled/include
--enable-debug
--with-lo-path=/path/to/libreoffice- master/instdir
--disable-ssl
sudo mkdir -p /usr/local/var/cache/loolwsd
sudo chown `whoami` /usr/local/var/cache/loolwsd
make run
Click on the link presented
… or do the ‘make run’ steps manually (see README)

6. Debug loolwsd with gdb --numprespawns=1
export SLEEPFORDEBUGGER=<number of seconds>
Capabilities… run gdb as root
chroot environment… symlink LibreOffice dir
Set LOOL_DEBUG=1 to trap SIGSEGV and SEGBUS and prompt for debugger
When debugging, you want to add --numprespawns=1 to the loolwsd parameters to
limit the amount of concurrently running processes.
When the crash happens too early, you also want to
export SLEEPFORDEBUGGER=<number of seconds>
so that you have time to attach to the process.
Then run loolwsd, and attach your debugger to the process you are
interested in. Note that as the loolforkit executable file has
capabilities set, so when debugging that you need to run the debugger
with super-user privilege.
Also, note that as the child processes run in a chroot environment,
they see the LibreOffice shared libraries as being in a directory tree
/lo , but your debugger does not. So in order to be able to
effectively debug the LibreOffice code as used through LibreOfficeKit
by a child loolwsd process, you need to symlink the "lo" subdirectory
of a running child loolwsd process's chroot jail as /lo. Something like:
sudo ln -s ~/libreoffice/master/lool-child-roots/ /lo /lo
Use the ps command to find out exactly the path to use.
Set LOOL_DEBUG=1 to trap SIGSEGV and SEGBUS and prompt for debugger.
In order to run and debug one unit test, set CPPUNIT_TEST_NAME to something
non-empty:
make check CPPUNIT_TEST_NAME="unit-prefork"
make check CPPUNIT_TEST_NAME="HTTPWSTest::testCalcEditRendering"

7. trace, loolstress Record commands and notifications
Set in loolwsd.xml, <trace … >
Replay the session with loolstress tool

8. Debug mode in Browser
Ctrl + Shift + Alt + D

9. Let me show its features...
Always active
Ping times
Tile stats
Typing
Console log