Linked by Rahul on Tue 28th Apr 2009 14:49 UTC
Fedora Core Fedora 11 Preview Release has been announced with a large number of new features, even more so than previous general releases. This includes Presto (delta RPM updates reducing bandwidth usage over 80% typically), automatic font and mime installer via PackageKit, Nouveau as the default driver for Nvidia cards (3D support is not mature and disabled however), simplified Anaconda text mode installation and minimal installation support, automatic Bug Reporting tool, native access to Microsoft Exchange using OpenChange, Firefox 3.1 and ThunderBird 3.0, Windows Cross Compiler (MinGW and a comprehensive set of cross compiled libraries), Ext4 as the default filesystem, experimental support for the next generation Btrfs filesystem, improved I18N with the switch to IBus input system by default, much improved Kernel Mode Support, many virtualization and security improvements, RPM 4.7, GNOME 2.26, KDE 4.2, Xfce 4.6, Linux Kernel 2.6.29, Python 2.6. GCC 4.4 and several other changes.
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RE[4]: upgrades
by sbergman27 on Fri 1st May 2009 15:34 UTC in reply to "RE[3]: upgrades"
sbergman27
Member since:
2005-07-24

Sorry, but this claim should taken behind the shed and shot. In my experience apt is no faster than, say, Fedora 9 or 10. (Even w/o presto) From a -clean- state, with 4 repositories (Fedora, fedora-updates, RPMFusion, kde-*), it takes me between 1:30 to 2:20 to get a clean copy of -all- the repositories and conduct a full search. [2]. (I ran the test 3 times. Slowest run displayed; Fastest run took ~1:28)

Well, I just ran the same test, from a -clean- slate, with apt on Ubuntu Jaunty and measured an average of 14.5 seconds on 3 runs. (Range: 13.8s - 15.0s) The total number of packages was 26701. The servers are noticeably slower right now due to the recent release of 9.04. But with apt, I'm still seeing 6 to 8 times the performance than you are seeing with yum. The fact that you seem to consider 1:28 to 2:20 good is amazing to me. (Although your numbers are about what I would have guessed for Yum.) I suppose people come to accept what they are used to. Yum *is* a lot better than it used to be.

Your numbers, while pretty poor, do show another annoying characteristic of yum in the real world. See how *variable* the performance is? Not infrequently, I have to abort and try again. And not on just one machine. This is something I have noticed about yum over time. The Fedora mirror system has lots of dud and unresponsive servers. Timeout and fall back to another server is a routine occurrence.

While apt support for multiple downloads is major plus, Fedora (at least here) has better repositories which usually max-out my net connection (both @home and @work), so parallel download doesn't really change anything.

Really? On the same connection, I typically see a couple hundred KB/s, at best, using yum (yes, with the fastest-mirror plugin) and I regularly see around 1MB/s (or even more) with apt. It's interesting to watch apt "ramp up" as it finds more servers. Yum typically just staggers along, variably.

On the other hand, Fedora's mirror and repository management is far better than Debian's.

I never *worry* or think about mirrors with apt in Ubuntu. They "just work" and work well. I only have to mess with mirror configs with yum and Fedora. Relative repo management finesse, I'm not sure about.

First, I wouldn't use Fedora for an XDMP server to begin with. Being bleeding edge, Fedora should not be used for a production sever. (Especially given the 13 month support cycle)

I agree completely. The way this happened is that we were coming from, and thus were somewhat already committed to, the Red Hat world. Which means Fedora or CentOS. We were using CentOS, and it's a good OS. But by EOL the packages are moldy goo, which is not ideal for an XDMCP server. Some of the Fedora advocates around here convinced me that Fedora would be OK because of the supposedly fantastic testing that packages get as part of the release process. And one can only tell so much from a small pilot evaluation. Boy were they wrong. Boy was I wrong. And boy was the move from CentOS 4 to Fedora 8 embarrassing!

Second, people tend to forget that being bleeding edge, Fedora releases a -lot- of updates on a daily basis. At least in part, Yum's memory consumption depends on the number of packages being installed / updated.

Well, yeah, a gigabyte a month of Fedora updates is a pain.

Could you please compare apt memory consumption to Yum, when you try and install 100 packages?

No. I am not going to install and deinstall 100 packages on either my home desktop or on my customers' servers just to get numbers for you. I will reiterate and clarify that yum can cause swap storms on the XDMCP server in question when installing just *one* package. And I'm not the only one who has noticed. Just google for:

fedora yum memory

Edited 2009-05-01 15:50 UTC

Reply Parent Score: 2

RE[5]: upgrades
by gilboa on Fri 1st May 2009 16:30 in reply to "RE[4]: upgrades"
gilboa Member since:
2005-07-06

Well, I just ran the same test, from a -clean- slate, with apt on Ubuntu Jaunty and measured an average of 14.5 seconds on 3 runs. (Range: 13.8s - 15.0s) The total number of packages was 26701. The servers are noticeably slower right now due to the recent release of 9.04. But with apt, I'm still seeing 6 to 8 times the performance than you are seeing with yum. The fact that you seem to consider 1:28 to 2:20 good is amazing to me. (Although your numbers are about what I would have guessed for Yum.) I suppose people come to accept what they are used to. Yum *is* a lot better than it used to be.
Your numbers, while pretty poor, do show another annoying characteristic of yum in the real world. See how *variable* the performance is? Not infrequently, I have to abort and try again. And not on just one machine. This is something I have noticed about yum over time.


A. I don't have access to my Debian machine right now, but last time I did:
$ apt-get clean
$ apt-get update
... It took far more than 15 seconds. I assume that I had a lousy mirror.

B. Regarding the 1:30 time. Please note that I'm using the fastest-mirror plugin. Once I cleaned the cache (yum clean all), yum had to:
1. Rebuild the list of the fastest mirrors. (~30seconds)
2. Download the full DB's. (~1m, depends on the type of connection and the selected mirror)

C. If you disable the fastest mirror (or select the mirror by hand, like I do in Debian), you can shave ~30 seconds of this list. [1]

D. The time variation was must likely a result of different mirror (selected by fastest mirrror. ISP load variation may lead to a different mirror each time - especially given the fact that I don't have a local Fedora mirror)

E. In 95% of all cases, yum will use the cache. As you notice, yum needs <2 seconds to read and process the contents of the cache. [2]

The Fedora mirror system has lots of dud and unresponsive servers. Timeout and fall back to another server is a routine occurrence.


I fail to what yum (as product) as to do with lousy mirrors. Mind you, as I said, I've had severe issues with the local Debian mirrors.

I never *worry* or think about mirrors with apt in Ubuntu. They "just work" and work well. I only have to mess with mirror configs with yum and Fedora. Relative repo management finesse, I'm not sure about.


Sadly enough, I can't say that I share your experience.

No. I am not going to install and deinstall 100 packages on either my home desktop or on my customers' servers just to get numbers for you. I will reiterate and clarify that yum can cause swap storms on the XDMCP server in question when installing just *one* package. And I'm not the only one who has noticed. Just google for: fedora yum memory


Being a developer myself, I tend to ignore googled results.
Real numbers, from a controlled environment, is all that I trust.

P.S. I see that you're using Fedora 8. As you well know, a -lot- of work has been done to improve yum in each release, and Fedora 10 yum's performance are far better than Fedora 8's.
With presto installed, Fedora 11's yum will run circles around F10's yum, etc.

- Gilboa
[1]
$ yum clean all
$ time yum search no-such-package
...
real 1m28.111s
user 0m2.463s
sys 0m0.315s
$ yum clean all
$ time yum search no-such-package --disableplugin=fastestmirror
...
real 1m6.075s
user 0m3.001s
sys 0m0.291s

[2]
$ time yum search no-such-package
real 0m1.088s
user 0m0.830s
sys 0m0.224s

Edited 2009-05-01 16:32 UTC

Reply Parent Score: 2

RE[6]: upgrades
by gilboa on Fri 1st May 2009 16:35 in reply to "RE[5]: upgrades"
gilboa Member since:
2005-07-06

P.S. Up until a year ago, I had Fedora on my 366Mhz, 256MB, 10 y/o laptop, and yum worked just fine. (I stopped using Fedora because I need certain patches to enable DRI on the MACH64, and having to port these [unsupported] patches once every months was rather annoying)
I now use CentOS 5.2.

- Gilboa

Reply Parent Score: 2

RE[6]: upgrades
by sbergman27 on Fri 1st May 2009 17:19 in reply to "RE[5]: upgrades"
sbergman27 Member since:
2005-07-24

I don't have access to my Debian machine right now, but last time I did ...It took far more than 15 seconds. I assume that I had a lousy mirror.

That would be extremely rare for Ubuntu. Can't comment authoritatively on Debian.

If you disable the fastest mirror (or select the mirror by hand, like I do in Debian), you can shave ~30 seconds of this list.

1:00 to 1:50 still sucks badly. Again, I just leave my mirror settings at default and have never had a need or desire to fuss with mirror optimizing band-aids on any of my Ubuntu boxes anywhere.

I fail to what yum (as product) as to do with lousy mirrors.

Note my liberal use of the qualifier "in the real world". In my rather extensive experience with both Fedora and Ubuntu, Yum on Fedora is slow and clunky compared to Apt on Ubuntu, which typically shines.

BTW, I have a long history (1997 on) with the Red Hat side of the Linux family, and was skeptical that Apt was as great as people claimed. But the difference has been so striking that I am surprised that people actually bother to argue for Yum.

I see that you're using Fedora 8. As you well know, a -lot- of work has been done to improve yum in each release, and Fedora 10 yum's performance are far better than Fedora 8's.

Well, that's the perennial Yum promise. Like a balanced budget by "Now + 8 years" or the classic old Mozilla chant "The latest nightlies are awesome!". Yum has gradually gotten better, yes. (I used FC1, when all the headers were individual, uncompressed file downloads! How could it get any worse?) But based upon experience, I take the semi-annual claims of huge improvements in yum with a large block of salt.

But yes, my Yum experience is ending with F8. The Fedora upgrades, these days, seem to be nightmarish on a server with a complex configuration, so I skipped 9 and 10 to avoid further embarrassment, and am now fielding security updates manually. And my primary focus, at this point, is upon migrating away from Fedora as quickly as practicable.

Reply Parent Score: 2