Philippe Makowski's blog

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Wednesday 18 March 2015

Mageia 5 Cinnamon with Fedora chroot

I moved my main home computer to Mageia 5 (it was under Fedora before).

I choose Cinnamon because I have it on my laptop and I like it.

Since I have to maintain my Fedora packages (Firebird related), I choosed to create a Fedora 21 chroot.

Here what I did under Mageia 5 :

# urpmi yum python-lzma
# mkdir -p /var/local/chroot/fedora/var/lib/rpm
# rpm --root /var/local/chroot/fedora --initdb
# cd /tmp/
# wget ftp://195.220.108.108/linux/fedora/linux/releases/21/Everything/x86_64/os/Packages/f/fedora-release-21-2.noarch.rpm
# wget ftp://195.220.108.108/linux/fedora/linux/releases/21/Everything/x86_64/os/Packages/f/fedora-repos-21-2.noarch.rpm
# rpm -ivh --nodeps --root /var/local/chroot/fedora fedora*rpm
# for f in /var/local/chroot/fedora/etc/yum.repos.d/*; do  sed -i 's/$basearch/x86_64/g;' $f; done
# ln -s /var/local/chroot/fedora/etc/pki/rpm-gpg/ /etc/pki/rpm-gpg
# yum --installroot=/var/local/chroot/fedora repolist all
# yum --installroot=/var/local/chroot/fedora groupinstall Core
# urpmi schroot
Configure the chroot in schroot :
$ cat /etc/schroot/chroot.d/fedora
[fedora]
description=Fedora 21
type=directory
directory=/var/local/chroot/fedora
users=philippe
groups=wheel
root-groups=root,wheel
aliases=default
preserve-environment=true
Finally, we do some customizations to make the Fedora system schroot friendly
# echo fedora21 > /var/local/chroot/fedora/etc/debian_chroot
# cat << 'EOF' > /var/local/chroot/fedora/etc/profile.d/debian_chroot.sh
# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
debian_chroot=$(cat /etc/debian_chroot)
fi
# set a fancy prompt (non-color, overwrite the one in /etc/profile)
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
EOF
Test :
philippe@callandor ~$ schroot -c fedora
(fedora)philippe@callandor:~$ cat /etc/fedora-release
Fedora release 21 (Twenty One)
All is ok, I can now set up the Fedora packager tools with a yum install fedora-packager and fedora-packager-setup

Sunday 2 February 2014

Mageia 4 on time for Fosdem and …

Anne has announced that Mageia 4 is now available just on time for Fosdem !

I updated all the computers at home without any trouble (two under Gnome Shell, one under KDE, and the last one now under Cinnamon).

We did a full review of the Python stack, now Mageia provide byte compiled Python modules, and as you can see in the Mageia Applications Database, here there are a lot of new Python and Python 3 modules.

I'm also really happy that Bruno packaged Ansible my favorite IT automation tool, with a urpmi module.

Mageia have also new scientific, engineering softwares like OpenFoam, Su2, Paraview, ...

For the next months, I will try to give more time to the Security team to help them for security updates, and also the Sysadmin team to work on an Mageia version of the Fedora tool fedmsg, because it seems we need somthting like that for our infrastructure.

Thanks again, all Mageia's contributors !

Tuesday 28 February 2012

Firebird transactions settings

From the support list, by Ann Harrison, as a reminder :

  • isc_tpb_consistency can cause performance problems due the fact that it's locking tables and possibly excluding concurrent access.
  • isc_tpb_concurrency is the design center for Firebird. Readers don't block writers, writers don't block readers, and both get a consistent view of the database.
  • iisc_tpb_read_committed + isc_tpb_rec_version + isc_tbp_read_only give inconsistent results and occasionally produces an error on a blob read*, but unlike other modes, it does not block garbage collection so it's a good mode for long running read transactions that don't have to get the "right" answer.
  • isc_tpb_read_committeed + isc_tpb_rec_version has the same performance as isc_tpb_concurrency, but gets inconsistent results - the same query run twice in the same transaction may return different rows.
  • isc_tpb_read_committed + isc_tpb_no_rec_version + isc_tpb_wait is slower than other modes because it will wait for a change to be commited rather than reading the newest committed version. Like all variants of isc_tpb_read_committed, it does not produce consistent results.
  • isc_tpb_read_committed + isc_tpb_no_rec_version + isc_tpb_no_wait gives lots and lots of deadlock errors because every time a reader encounters a record that's being changed, it returns an error.


Good luck, Ann

* If you have the bad luck to read a record version which includes a blob and someone else changes the record version and the blob, and that transaction commits, and somebody else comes by and garbage collects the record version and blob before you get around to reading the blob, you'll get an error. Doesn't happen in other modes.

Tuesday 7 June 2011

Mageia 1 a Firebird friendly new distribution

Mageia 1 is there : http://blog.mageia.org/en/

It is a community driven project and a Firebird friendly distribution with Firebird 2.5.0, PHP, PHP-pdo, Perl, Ruby drivers, Rails adapter, Flamerobin, and Python drivers (kinterbasdb and firebirdsql).

I'm really happy to have now Mageia on my computer, and being one of the packagers.

For people wanting to use Firebird under Gnu/Linux, Mageia can be a really good choice.

The community is active, and in next months will decide what will be the future. Like Firebird, Mageia organisation is community-driven; no commercial management can dictate the path Mageia will take.

Download it, try it !



PS

Some friends of mine created  Hupstream  a company providing commercial services (like IBphoenix for Firebird) with or around Mageia software, tools or project .

So you can imagine Firebird under Mageia with professional support with IBPhoenix and Hupstream if you want !

Friday 29 April 2011

Windows Firebird Classic and cache

From the Firebird support list, posted by Sean Leyne :

We have over 60 production Firebird servers running Windows, some servers with 100s of database connections.

What you need to remember is:

- Each database connection starts a new server process, so more RAM memory is needed/used

- Each database page cache setting should be kept low, improve performance by reduce the amount of synchronization which occurs between the Firebird processes

- 64 bit versions of Windows (very true with 2008) have a poor algorithm for managing OS page cache, which can result in an excessive amount of cache paging, which severely impacts performance. There are some utilities available (SET_CACHE.EXE) which can set the cache size to definable level (we usually set it to 70% of available RAM).

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