apt-index-watcher uses way too much system ressources

Bug #64531 reported by Marc Schiffbauer on 2006-10-07
Affects Status Importance Assigned to Milestone
libapt-front (Ubuntu)

Bug Description

Binary package hint: apt-index-watcher


I upgraded my dapper do edgy. And now I was wondering what was making so much "trouble" on the system now: On my ksysguard Graphs I can see lots of nice/user cpu power used every few seconds and memory usage going up and down every few seconds. Then I stoppen apt-index-watcher and everything was OK again...

Perhaps it would be OK to just stop it doing its job that often? I guess once an hour or twice a day would be enough... not?


Andreas Simon (andreas-w-simon) wrote :

I can confirm this with apt-index-watcher 0.3.9ubuntu4. Every couple of seconds two processes like

 6927 ? S 0:00 sh -c /usr/sbin/apt-index-watcher run --syslog
 6928 ? R 0:02 /usr/sbin/apt-index-watcher run --syslog

use all available cpu power.

Changed in libapt-front:
status: Unconfirmed → Confirmed
depp (li-sun) wrote :

i noticed if i run apt-get update once, apt-index-watcher begins to be in service and uses cpu, as soon as i run once adept, it'll stop updating

I've got a local mirror of edgy-i386 on an external HD on my laptop. apt-index-watcher runs my CPU up to 100% every 5-7 seconds for a couple seconds, even though my local mirror has not been updated.

Not very good for laptops at all, the battery use and fans, and cpu running at full throttle, etc...

Erik Meitner (e.meitner) wrote :

This just started for me today. I noticed that the fan on my laptop was running continuously. Watching a CPU graphed showed a spike every 4 seconds or so. Obviously, it is very bad for battery life on a laptop. I just noticed this today.

Currently using apt-index-watcher_0.3.9ubuntu4.

emeitner@cheren:~$ sudo time apt-index-watcher watch --syslog
Command terminated by signal 2
34.40user 1.26system 2:07.52elapsed 27%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+105823minor)pagefaults 0swaps

I downgraded to apt-index-watcher_0.3.9ubuntu3 and the CPU usage spikes ceaced to occur.

I wonder if the recent change has anything to do with it: " make sure apt-index-watcher uses a different mmapable() cache file so that it does not corrupt the main apt mmap cache (lp: #61708)"

i was wondering why wolf et runs smoothly, but constantly after about 5-8 secs DPS drops from 90 to under 5 for short period of time. then i managed, with help of top, to find that problem is apt-index-watcher.
so only solution for smooth gameplay is manually killing watcher by

ps -A | grep apt-index

and then

kill [number]

finalbeta (j-greenhouse) wrote :

Confirmed here.

Guillaume Martres (smarter) wrote :

I can confirm this (and nice -n 19 doesn't change a lot)

Jools Wills (jools) wrote :

I also have this problem. Only noticed it the last few days or so. Makes playback of videos stutter and other problems.

blackrim (blackrim) wrote :

just confirming this. really annoying. adept updating, as suggested above, doesn't seem to fix mine. i have to do the killall apt-index.

Michael Vogt (mvo) wrote :

Thanks for your bugreport.

This problem should be fixed with the upload of 0.3.9ubuntu5. Please reopen if it is still a problem for you after the update.


Changed in libapt-front:
importance: Undecided → Medium
status: Confirmed → Fix Released
Jools Wills (jools) wrote :

Noticed it again today

5557 root 19 0 17216 13m 10m R 95.8 1.3 0:00.79 apt-index-watch
3989 root 15 0 157m 20m 6076 S 4.0 2.0 0:37.68 Xorg
1 root 15 0 1632 540 448 S 0.0 0.1 0:01.03 init

Running latest version 0.3.9ubuntu5

Changed in libapt-front:
status: Fix Released → Confirmed
Leonidas Arvanitis (larvan) wrote :

It is still bugged for me too.
version 0.3.9ubuntu5

Actually a better command to close it, is:

sudo /etc/init.d/apt-index-watcher stop

Mika Wahlroos (mpw) wrote :

I've experienced this with 0.3.9ubuntu5 on stable Edgy.

I'm not sure if it uses overly much resources in total, it's just that it decides to pop in every few seconds to do something at full steam for a while that's causing problems for me. Since it isn't niced, it causes frame rates in games to drop significantly, and might actually make some high resolution videos stutter because decompressing them can take nearly all the CPU power my system can provide.

I haven't tried making it nice so I'm not sure if that'd help in this case. Possibly, but I guess that wouldn't eliminate issues regarding battery life on laptops anyway.

unggnu (unggnu) wrote :

It is very weird. On my Laptop with Pentium ULV 1,2 it seems to be fixed since some weeks but on a 386 installation with AMD64 3000+ it peaks every 5-8 seconds which results in highest CPU clock all the time without real load.

Justin Mason (jm-ubuntu) wrote :

Just to confirm, this is unpleasant behaviour: on my Dell laptop, apt-index-watcher's CPU spiking causes the fan to start up, then stop, every ~5 seconds. Killing apt-index-watcher fixes the problem and the fan has remained off since then.

Joachim Ziebs (texjoachim) wrote :

I can confirm this, too, with 0.3.9ubuntu5 on stable Edgy.

Confirmed on Thinkpad X30 with edgy apt-get upgraded from dapper. Fully updated and running apt-index-watcher 0.3.9ubuntu5.

For now I just stopped it from starting all together:
chmod -x /etc/init.d/apt-index-watcher

infopipe (infopipe) wrote :

I can confirm the regular peaks in CPU usage caused by apt-index-watcher. After starting adept and closing it again (doing nothing with it) the peaks vanish.
If I can/should provide more information, let me know.

furlan (xtreme3xxx) wrote :

I've this problem with apt-index-watcher 0.3.9ubuntu5. If i disable it the cpu usage returns ok.

moelles (moelles) wrote :

i have a fresh edgy running for a few days...
today suddenly apt-index-watcher 0.3.9ubuntu5 shows this annoying behavior

thunderstorm (rainbow1612) wrote :

I can confirm that problem, too. apt-index-watch use 35-50% CPU-Load on my Vaio-Laptop with 2,8 GHz, every 2-5 seconds.

Arthur Schiwon (blizzz) wrote :

I can confirm it as well. On my machine (1,5 GHz, Kubuntu Edgy Eft) it uses more than 80% peak.

flarp (ralf-petter) wrote :

I can confirm this too. On my Laptop Apple Powerbook Pismo it runs every couple of seconds und the Laptop is very slow. When i kill apt-index-watcher performance is ok!

Giuseppe Cardone (ippatsuman) wrote :

I can confirm this bug too. On my systems (a Pentium M 1.4 GHz and a Pentium M 745 1.80 GHz, RAM 512MiB) with a freshly installed Kubuntu Edgy Eft apt-index-watcher uses 100% cpu-load every 3-5 seconds. This bug seems to appear randoml. Killing apt-index-watcher fixes the problem (but it's not a solution).

da1l6 (da1l6) wrote :

Same thing here. I really had a hard time finding out, what was causing the frequent CPU usage spikes.
The spikes are so short that neither ksysguard nor top list apt-index-watcher with a noteable cpu load value. I killed task by task to finally find out what was going on.

What the hell "apt-index-watcher" for? Does one really need it?

I made a screenshot from ksysguard, with the update intervall set to 2 seconds. The PC was not touched during the displayed time period

Using: Edgy Eft, apt-index-watcher 0.3.9ubuntu5

Risto H. Kurppa (risto.kurppa) wrote :

Confirmed here w. 0.3.9ubuntu5


moelles (moelles) wrote :

confirmed 0.3.9ubuntu5 on a fresh kubuntu edgy installation..

starting adept stops it but on next reboot the cpu-spikes come back again.

i cant just remove it because it would also remove kubuntu-desktop, etc...

i know you are working hard, but please consider giving this bug a higher priority.

Risto H. Kurppa (risto.kurppa) wrote :

I don't have adept installed (I removed it ;) though I'm running KDE so I cannot start &close it. Synaptic doesn't do the same but ps -Af|grep index -> kill the root process does it..


Brijam (brian-opensourcery) wrote :

Confirmed here as well on an HP zd7000 notebook with 0.3.9ubuntu5.

Daniel Frein (danielfrein) wrote :

simple workaround until updated packages are available: edit /etc/init.d/apt-index-watcher and insert a line just containing "exit 0" after line 1 and apt-index-watcher won't be started any more (at least not until you update the apt-index-watcher package - an updated package would recreate this file)

Neale Pickett (neale-lanl) wrote :

I moved pkgcache.bin and srcpkgcache.bin out of /var/cache/apt-index-watcher, and the CPU spikes vanished. The files were replaced with newer copies, and the new copies had the exact same md5sum as the old ones I moved out.

So I'm thinking that one could run:

$ sudo touch /var/cache/apt-index-watcher/*

but if that doesn't work, use rm instead of touch.

I glanced at the source code and it looked complex so I gave up. My total shot in the dark based on strace output is that something's checking a timestamp. If it sees the timestamp doesn't match the apt database, it does some expensive operation with the two files to determine whether or not update scripts should be run. This is fine, but it should adjust the modified timestamp on the files after doing the expensive operation.

I too am using kubuntu 6.10, apt-index-watcher is at 0.3.9ubuntu5. I have never run adept, I use aptitude exclusively.

Neale Pickett (neale-lanl) wrote :

Interesting. Trying to recreate the slowdown, I ran "aptitude update". A short time later (in minutes, I think) adept-notifier popped up. I needed to update GNU tar.

Rob Hasselbaum (rhasselbaum) wrote :

I just started seeing this today. This makes some time-sensitive apps suffer greatly (e.g. audio playback in a VMWare virtual machine).

Fabio Albieri (chareos) wrote :

Had same problem right now. Thankfully I found this bug report. I'm trying the "touch" thing. If it's no "solution" I'll come with more.

Jörg Menke (jhm-gmx) wrote :

I can confirm this, too.

$ sudo touch /var/cache/apt-index-watcher/*

worked fine for me. Let's see how long...

alf3 (alf3) wrote :

apt-index-watcher is adding an error message in syslog complaining of a missing file, this is what is taking up resources

Be sure to have the package debtags installed to stop this problem.

infopipe (infopipe) wrote :

for me there is no syslog message from apt-index-watcher and the debtags package is installed.
So this is no solution for me.
I run `sudo touch /var/cache/apt-index-watcher/*` every time I notice the spikes in CPU load and this stops it. Very inconvenient.

Elijah Lofgren (elijahlofgren) wrote :


I was running into this problem and running the following command solved it:
sudo apt-get install debtags

While Upgrading to Ubuntu 6.10 using the update-manager I got the following:

Could not install 'debtags'

The upgrade aborts now. Please report this bug against the 'update-manager' package and include the files in /var/log/dist-upgrade/ in the bugreport.

subprocess post-installation script returned error exit status 1

I posted that in: https://bugs.launchpad.net/distros/ubuntu/+source/debtags/+bug/26007

But since I didn't notice anything wrong, I forgot about it.

I eventually noticed apt-index-watcher taking lots of CPU and am very glad I was able to fix it by running the following command:

sudo apt-get install debtags

Hope this helps someone,

Elijah Lofgren

Elijah Lofgren (elijahlofgren) wrote :


I meant that running the following command fixed my problem (notice the --reinstall):

sudo apt-get install --reinstall debtags

Lukáš Zapletal (lzap) wrote :

I confirm. Cant find anything in my logs. I have (re)installed debtags and see. Will you release some fix for this? Very annoying...

Andreas Scherf (scherfa) wrote :

Problem still exists here installed debtags 1.5.5ubuntu2 and apt-index-watcher is at 0.3.9ubuntu5
The index watcher runs and consumes cpu time .. isn't it better to remove it completely until this
bug is fixed ??

Just reinstalling did not seem to help one of the previous posters.

I tried
dpkg --purge --force-depends debtags
apt-get -f install

This seemed to cure the problem.

infopipe (infopipe) wrote :

Does not work for me.
I still have to run `sudo touch /var/cache/apt-index-watcher/*` every time I notice the spikes in CPU load.

I confirm this

after doing

sudo apt-get --reinstall install debtags apt-index-watcher

Brian Pitts (bpitts) wrote :

Confirmed in Kubuntu 6.10 dist-upgraded from 6.06.

sergioroa (s-roa) wrote :

I confirm this bug in Kubuntu 6.10, using apt-index-watcher 0.3.9ubuntu5 and adept 2.1.1ubuntu3

Andy Bovett (abovett) wrote :

My laptop (Dell SmartStep 250N) is prone to overheating with prolonged high CPU use. This bug is enough to force a thermal shutdown at times - VERY inconvenient. Surely it should be given a higher priority?

Here's something to patch this until it's fixed upstream. This will add an hourly cron job that updates the timestamp on the two problematic files. Doing this prevents apt-index-watcher from spinning on my machine, and from the comments in this bug it works for others too.

Just paste the following into a terminal:

sudo uudecode <<'EOM'
begin 755 /etc/cron.hourly/apt-index-watcher-bug

To uninstall:

  sudo rm /etc/cron.hourly/apt-index-watcher-bug

The bug tracking system added spaces in front of each line of the previous comment (at least in Konqueror) so I've attached the patch.

You can install it with the following command:

$ sudo sh apt-index-watcher-bug.shar

Uninstall the same way as in the last comment:

$ sudo rm /etc/cron.hourly/apt-index-watcher-bug

This seems to be fixed on feisty where apt-index-watcher seems to be removed completely.

Guillaume Martres (smarter) wrote :

this bug should be marked as fixed, the problem does not exist anymore on feisty.

Brian Murray (brian-murray) wrote :

Thanks for the bug report. I'm closing it because the bug has been fixed in Feisty. It won't be fixed in 6.10 because the bug doesn't fit requirements for backporting. See https://wiki.ubuntu.com/UbuntuBackports for more information.

Changed in libapt-front:
status: Confirmed → Fix Released
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