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* Targeted release: [[Releases/11|Fedora 11]]  
* Targeted release: [[Releases/11|Fedora 11]]  
* Last updated: January 28, 2009
* Last updated: January 28, 2009
* Percentage of completion: 30%
* Percentage of completion: 80%


== Detailed Description ==
== Detailed Description ==
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#* Configuration files to specify the location of the server
#* Configuration files to specify the location of the server


We should also provide a public debuginfofs server for Fedora users, and pre-configure the service to use that.
If possible, we should also provide a public debuginfofs server for Fedora users, and pre-configure the service to use that.
 
The debuginfofs package has been submitted for review: https://bugzilla.redhat.com/show_bug.cgi?id=487587


== How To Test ==
== How To Test ==


1. Prepare a debuginfo server
1. Prepare a debuginfo server
* ''public instance coming soon''
* ''public instance coming soon (?)''
  git clone git://fedorapeople.org/~wwoods/debuginfofs.git
  curl -O http://wwoods.fedorapeople.org/review/debuginfofs-server-0.1-0.fc11.noarch.rpm
  cd debuginfofs
  yum localinstall --nogpgcheck debuginfofs-server-0.1-0.fc11.noarch.rpm
vi rsync-fedora-debuginfo.sh ''# pick an rsync mirror near you''
  debuginfofs-mirror --releasever=YOURDISTROVERSION --basearch=CLIENTARCH
  ./rsync-fedora-debuginfo.sh ''# will require 50-100GB in /var!''
service httpd start


2. Install / configure debuginfofs on the client
2. Install / configure debuginfofs on the client
* ''packages coming soon''
  curl -O http://wwoods.fedorapeople.org/review/debuginfofs-0.1-0.fc11.noarch.rpm
  git clone git://fedorapeople.org/~wwoods/debuginfofs.git
  yum localinstall --nogpgcheck debuginfofs-0.1-0.fc11.noarch.rpm
  cd debuginfofs
  vi /etc/sysconfig/debuginfofs ''# change DEBUGINFOFS_SERVER''
cp debuginfofs.init /etc/init.d
cp debuginfofs.sysconfig /etc/sysconfig/debuginfofs
  vi /etc/sysconfig/debuginfofs ''# Set DEBUGINFOFS_HOST to the right hostname''


3. Mount debuginfofs
3. Mount debuginfofs
  sudo service debuginfofs start
  service debuginfofs start


4. Crash a program in gdb
4. Crash a program in gdb
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If everything is working as expected, you will see the function/file names, as above.
If everything is working as expected, you will see the function/file names, as above.
<!-- This does not need to be a full-fledged document.  Describe the dimensions of tests that this feature is expected to pass when it is done.  If it needs to be tested with different hardware or software configurations, indicate them.  The more specific you can be, the better the community testing can be.
Remember that you are writing this how to for interested testers to use to check out your feature - documenting what you do for testing is OK, but it's much better to document what *I* can do to test your feature.
A good "how to test" should answer these four questions:
0. What special hardware / data / etc. is needed (if any)?
1. How do I prepare my system to test this feature? What packages
need to be installed, config files edited, etc.?
2. What specific actions do I perform to check that the feature is
working like it's supposed to?
3. What are the expected results of those actions?
-->


== User Experience ==
== User Experience ==
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== Dependencies ==
== Dependencies ==
<!-- What other packages (RPMs) depend on this package?  Are there changes outside the developers' control on which completion of this feature depends?  In other words, completion of another feature owned by someone else and might cause you to not be able to finish on time or that you would need to coordinate?  Other upstream projects like the kernel (if this is not a kernel feature)? -->


* We've chosen WebDAV as the network filesystem for this project, so:
* We've chosen WebDAV as the network filesystem for this project, so:
** The server-side requires {{package|httpd}}'s Dav module.
** The server-side requires {{package|httpd}}'s Dav module.
** Client-side requires a FUSE implementation of WebDAV. {{package|wdfs}} is the only one packaged at the moment, but [http://sourceforge.net/projects/dav/ davfs2] could be considered as well.
** Client-side requires a FUSE implementation of WebDAV. {{package|wdfs}} is the only one packaged at the moment, but [http://sourceforge.net/projects/dav/ davfs2] could be considered as well.
* A public debuginfofs server will require somewhere around 40GB of disk per Fedora version/arch - a total of 500GB for Fedora (8,9,10) * (i386,x86_64,ppc).  
* A public debuginfofs server will require somewhere around 30GB of disk per Fedora version/arch - a total of ~300GB for Fedora (9,10,11) * (i386,x86_64,ppc).  
** Some further work could be done to drastically reduce the amount of disk space needed by only unpacking debuginfo ''when it is needed'' - this may be required if the Fedora infrastructure can't spare that much disk space.
** Some further work could be done to drastically reduce the amount of disk space needed by only unpacking debuginfo ''when it is needed'' - this may be required if the Fedora infrastructure can't spare that much disk space.
** This would also reduce setup time to near-zero, since we don't have the overhead of unpacking all the RPMs.
** This would also reduce setup time to near-zero, since we don't have the overhead of unpacking all the RPMs.
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== Contingency Plan ==
== Contingency Plan ==
<!-- If you cannot complete your feature by the final development freeze, what is the backup plan?  This might be as simple as "None necessary, revert to previous release behaviour."  Or it might not.  If you feature is not completed in time we want to assure others that other parts of Fedora will not be in jeopardy.  -->


None needed - things stay as they are.
None needed - things stay as they are.


== Documentation ==
== Documentation ==
<!-- Is there upstream documentation on this feature, or notes you have written yourself?  Link to that material here so other interested developers can get involved. -->


The gdb info pages and [[Releases/FeatureBuildId]] give some background on the Build-Id feature that makes this possible.
The gdb info pages and [[Releases/FeatureBuildId]] give some background on the Build-Id feature that makes this possible.


== Release Notes ==
== Release Notes ==
<!-- The Fedora Release Notes inform end-users about what is new in the release.  Examples of past release notes are here: http://docs.fedoraproject.org/release-notes/ -->
<!-- The release notes also help users know how to deal with platform changes such as ABIs/APIs, configuration or data file formats, or upgrade concerns.  If there are any such changes involved in this feature, indicate them here.  You can also link to upstream documentation if it satisfies this need.  This information forms the basis of the release notes edited by the documentation team and shipped with the release. -->


There is a new <code>debuginfofs</code> service, which provides debuginfo for all Fedora packages over the Internet.
There is a new <code>debuginfofs</code> service, which provides debuginfo for all Fedora packages over the Internet.

Revision as of 17:36, 2 March 2009

DebuginfoFS

Summary

A read-only, internet-mountable filesystem that provides debuginfo (for use with gdb and other debugging tools), and

a client service to mount the debuginfo filesystem when needed.

Owner

Current status

  • Targeted release: Fedora 11
  • Last updated: January 28, 2009
  • Percentage of completion: 80%

Detailed Description

When a program crashes or is otherwise misbehaving, one of the most helpful things to put in a bug report is a traceback of the offending process, gathered by using gdb. GNOME's bug-buddy does this automatically. But without debugging info, the tracebacks are incomplete.

debuginfo-install can be used to install the needed debuginfo packages, but this takes a long time (2-5 minutes) and 95% of the installed data is unused.

This Feature will provide scripts and tools to provide a WebDAV filesystem containing all the debuginfo needed for everything in Fedora, and a service to allow users (or automatic crash-reporting processes - like Features/CrashCatcher) to mount the filesystem when needed.

Benefit to Fedora

By simplifying the process of getting debugging info, we can improve the quality of bug reports, which should make it easier (and faster) to get bugs fixed.

Scope

There will be two main parts to this feature:

  1. A debuginfofs-server package, which provides
    • A debuginfofs-server service,
    • Configuration files to specify which distributions (version/arch) to support, and
    • Some documentation on setting up / maintaining the server.
  2. A debuginfofs package, which provides
    • A debuginfofs service,
    • Configuration files to specify the location of the server

If possible, we should also provide a public debuginfofs server for Fedora users, and pre-configure the service to use that.

The debuginfofs package has been submitted for review: https://bugzilla.redhat.com/show_bug.cgi?id=487587

How To Test

1. Prepare a debuginfo server

  • public instance coming soon (?)
curl -O http://wwoods.fedorapeople.org/review/debuginfofs-server-0.1-0.fc11.noarch.rpm
yum localinstall --nogpgcheck debuginfofs-server-0.1-0.fc11.noarch.rpm
debuginfofs-mirror --releasever=YOURDISTROVERSION --basearch=CLIENTARCH
service httpd start

2. Install / configure debuginfofs on the client

curl -O http://wwoods.fedorapeople.org/review/debuginfofs-0.1-0.fc11.noarch.rpm
yum localinstall --nogpgcheck debuginfofs-0.1-0.fc11.noarch.rpm
vi /etc/sysconfig/debuginfofs # change DEBUGINFOFS_SERVER

3. Mount debuginfofs

service debuginfofs start

4. Crash a program in gdb

[wwoods@metroid debuginfofs]$ gdb $(which sleep)
GNU gdb Fedora (6.8-29.fc10)
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i386-redhat-linux-gnu"...
(gdb) set args 999
(gdb) run
Starting program: /bin/sleep 999
[Hit Ctrl-C]
Program received signal SIGINT, Interrupt.
__kernel_vsyscall () at arch/x86/vdso/vdso32/int80.S:16
16	arch/x86/vdso/vdso32/int80.S: No such file or directory.
	in arch/x86/vdso/vdso32/int80.S
Current language:  auto; currently asm
(gdb) bt
#0  __kernel_vsyscall () at arch/x86/vdso/vdso32/int80.S:16
#1  0x008ac430 in __nanosleep_nocancel () from /lib/libc.so.6
#2  0x0804abd3 in xnanosleep (seconds=999) at xnanosleep.c:112
#3  0x080490f6 in main (argc=2, argv=0xbffff514) at sleep.c:150
(gdb)

If everything is working as expected, you will see the function/file names, as above.

User Experience

Getting debuginfo to get a backtrace for a bug report will become much, much easier (and faster), but the process will change slightly.

Dependencies

  • We've chosen WebDAV as the network filesystem for this project, so:
    • The server-side requires httpd's Dav module.
    • Client-side requires a FUSE implementation of WebDAV. wdfs is the only one packaged at the moment, but davfs2 could be considered as well.
  • A public debuginfofs server will require somewhere around 30GB of disk per Fedora version/arch - a total of ~300GB for Fedora (9,10,11) * (i386,x86_64,ppc).
    • Some further work could be done to drastically reduce the amount of disk space needed by only unpacking debuginfo when it is needed - this may be required if the Fedora infrastructure can't spare that much disk space.
    • This would also reduce setup time to near-zero, since we don't have the overhead of unpacking all the RPMs.
  • If we need access to the source files as well as the debugging symbols, there will need to be an additional layer on the client-side to find the source files and put them in a place where gdb can find them.

Contingency Plan

None needed - things stay as they are.

Documentation

The gdb info pages and Releases/FeatureBuildId give some background on the Build-Id feature that makes this possible.

Release Notes

There is a new debuginfofs service, which provides debuginfo for all Fedora packages over the Internet.

Comments and Discussion