Installing TortoiseHg on openSUSE 13.1

My workstation and laptops have now all, flawlessly, upgraded to openSUSE 13.1.  So now there is the small task of putting back in a few things that aren't packaged in the repositories.  The most notable of these is TortoiseHg [the excellent GUI for Mercurial DVC repositories].

Step one is to eliminate any parts of the previous installation.  With openSUSE one never has to reinstall, it is just "zypper dup", take a nap, new version!  But since Qt changes, mercurial changes, etc... the easiest approach for this unpackaged software is to rip it out and reinstall.  All the configuration is in the user's home directory, so the new version will find that and everything will work as before.

ls /usr/lib/python2.7/site-packages/tortoisehg* \
    /usr/lib64/python2.7/site-packages/tortoisehg* \
   /usr/local/lib/python2.7/site-packages/tortoisehg* \
   /usr/local/lib64/python2.7/site-packages/tortoisehg* \
   /usr/local/bin/thg \
   /usr/local/lib/python2.7/site-packages/tortoisehg* \
   /usr/local/lib64/python2.7/site-packages/tortoisehg*

If that finds anything we wipe it out.  Now we make sure we have the appropriate packages installed.

sudo zypper in python-qscintilla mercurial

Now on to installing TortoiseHg.

curl --location -o tortoisehg-2.10.tar.gz http://bitbucket.org/tortoisehg/targz/downloads/tortoisehg-2.10.tar.gz
tar xzvf tortoisehg-2.10.tar.gz
cd tortoisehg-2.10
sudo python setup.py  install

Now the "thg" application should run.  In order for the desktop environment to be aware of the application an XDG ".desktop" file needs to exist in "~/.local/share/applications/tortoise.desktop". If you previously created this file it will still be there and your DE [Gnome Shell] should keep using the application just as before.  If you are just installing TortoiseHg then you need to create the file.

#!/usr/bin/env xdg-open

[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
Exec=/usr/bin/thg
Name[en_US]=Tortoise Hg
Comment[en_US]=Mercurial Client
Name=Tortoise Hg
Comment=Mercurial Client
Icon=/usr/share/pixmaps/tortoisehg/icons/svg/thg_logo.svg

And now thg should be available in the overview, with the little turtle icon, etc...  Previously it was common to use the png icon file provided in the package;  it is more customary now to use the SVG icon [which is one tweak you may want to make to an existing tortoise.desktop file].

PostgreSQL Table Spaces

A powerful feature of PostgreSQL is the ability to create table spaces and to move database objects between them.  Each table space represents a physical storage location; so using table spaces you can tier data onto different grades of storage [SSD vs. fast disk vs. slow disk] as well as move data from storage being retired [like an iSCSI SAN] to a new storage [a Fiber-Channel SAN!].

The first step to creating a table space is to create and mount the underlying storage.  For this example I create a new logical volume in the volume group FAST [an array of SSD drives].

l# lvcreate /dev/FAST --name PGSQL1 --size 15G
Logical volume "PGSQL1" created
# mkfs -t xfs /dev/FAST/PGSQL1
# mkdir /var/lib/pgsql1
# chown postgres.postgres /var/lib/pgsql1
# mount /var/lib/pgsql1
# chown postgres.postgres /var/lib/pgsql1

Once the storage is mounted, and the postgresql user has the correct access [Important!], informing the server of the new table space is simple.

CREATE TABLESPACE FastSpace1 LOCATION '/var/lib/pgsql1';

Now in addition to the pg_default table space (whose location is provided to the server at start time - usually /var/lib/pgsql) I have a table space "FastSpace1".  I can move objects such as tables and indexes from their current table space to the new one.

ALTER TABLE obj_property SET TABLESPACE FastSpace1;
ALTER TABLE lock SET TABLESPACE FastSpace1;
ALTER INDEX doc_pk SET TABLESPACE FastSpace1;

Note that you can move tables and indexes independently.  Especially for rotating storage this can provide a significant performance improvement by separating the index [which needs to be updated along with its table] and it's table onto different spindles.  Doing so spreads the write load during updates and inserts.

As far as the application is concerned nothing changes - things just go faster.  Keep your big static tables on inexpensive 'slow' storage and spread your hot-spots around.

Drag-N-Drop Message Format

A little recognized feature in GNOME is the that e-mail messages can be drag-n-dropped from GNOME's Evolution to other applications.  When a message from Evolution is dropped into Nautilus the message will be saved to the corresponding folder as an mbox file.  This is useful, but probably not optimal, for a desktop environment. 
To optimize this behavior the gsettings command can be used to change the default format as a PDF.

gsettings set org.gnome.evolution.mail drag-and-drop-save-file-format 'pdf'

PDF is a much better format for archiving messages to projects, linking to tasks, uploading to bug reports, or just use as documents.
In combination with GVFS PDFs of messages can be easily drag-n-dropped to a server application, a WebDAV folderfor example.  Simply navigate to that target in Nautilus and drag the messages over.
This drag-n-drop is an effortless way to turn messages into documents which can be filed, sorted, archived, etc... beyond the confines of an e-mail account. 

Advanced Streaming Format (ASF) Demuxer

You go to open a WMV video file in Nautilus on a new GNOME install, GNOME Video opens, and you are immediately greeted with: "Advanced Streaming Format (ASF) demuxer".  A message that is terribly helpfully, but at least it offers to "Search" for a solution. The auto-find-the-solution button works sometimes, but not always.  An easier solution is to preemptively install the required packages. 

zypper ar http://ftp.gwdg.de/pub/linux/packman/suse/openSUSE_12.3 packman
zypper in gstreamer-plugins-bad-orig-addon gstreamer-plugins-libav
gstreamer-plugins-ugly-orig-addon w32codec-all
Add the Packman repository and install the required packages.

The package install may prompt you to allow a vendor change (from the 'official' openSUSE repository to the Packman repository).  This vendor change is desired so it should be allowed.  Once the packages are installed GNOME Video player should play WMV files which use ASF multiplexing without further complaint.

Aside:  If you don't want to be pestered about package vendor changes in the future you can edit  /etc/zypp/zypp.conf and set "solver.allowVendorChange = true".  But don't do that unless you know what that means.

Getting a native connection from the ORM

The SQLAlchemy ORM provides a powerful abstraction from the database allowing operations to be performed on objects and queries to be constructed based on object attributes rather than dealing with attribute-to-field correspondence.  But there are still some operations for which you need to talk directly to the underlying database. 
In 'normal' mode SQLAlchemy maintains a connection pool and releases connections from the pool to the application as needed, tracks them, and tries to keep everything tidy.  When the need arises for a 'native' DBAPI connection [for this example I'm using PostgreSQL] it is possible to explicitly check a connection out from the pool - after which it is yours to deal with, to track the isolation, close, etc..
Assuming the database connection has already been created and bound to the session factory with something like:

from sqlalchemy import create_engine, Session
...
engine = create_engine( orm_dsn, **{ 'echo': orm_logging } )
Session.configure( bind=engine )

 - then sessions can be taken from the connection pool simply by calling "db = Session( )".  When the "db.close( )" is performed that session goes back into the pool.
If a connection is to be used outside of all the mechanics that SQLAlchemy provides it can be checked out, as mentioned before, using a rather verbose call:

conn = Session( ).connection( ).connection.checkout( ).connection

Now "conn" is a 'native' DBAPI connection.  You can perform low level operations such as setting the isolation level and creating cursors:

conn.set_isolation_level( psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT )
curs = conn.cursor( )
curs.execute( .... )

This is not a frequent need, but for very database backend specific it is the simplest approach [otherwise you can extend SQLAlchemy...]. One use case is using PostreSQL's asyncronous notify channels to capture database events; for this purpose an application needs to select on the DBAPI connection, there's no need for an ORM in the mix when you are just capturing events.

Windows "Uptime"

Windows XP and its brethren lack an "uptime" command.  Yeah, the reason the probably obvious, but sometimes it would be nice to know.  A user says they restarted their workstation... but most user's [including recent college graduates] don't know the difference between logging out and restarting.  So how to know how long a workstation has been running?
On the command line just execute "net statistics server", the line that starts with "Statistics since" provides the time the server component of the operating system has been up.  In the case of a workstation this is almost certainly since the last boot. 
And nope, the user had not restarted their workstation for almost three weeks.

First openSUSE 12.3 Upgrade

Last night I upgraded one of my spare laptops (an HP DV7-3165DX) to the new openSUSE 12.3.  In a word: flawless.  It updated, rebooted, and was ready to go.  Everything just works and all my work-a-day applications resumed operation with their expected configuration.  Defined VPN connections all remained operational as well.

Now running the 3.7.10-1.1-desktop kernel and some shiny new versions.  No separate repository is required to get to the excellent GNOME Shell 3.6.x (the version where GNOME Shell got all grow'd up).

Now I can get back to work.  As good as this is looking I'll probably upgrade my workstation and work-a-day laptop in short order.

gnome-shell-3.6.3.1-1.1.1.x86_64
pulseaudio-3.0-1.1.1.x86_64
evolution-3.6.3-1.2.1.x86_64
banshee-2.6.0-3.2.1.x86_64
python-2.7.3-10.1.1.x86_64
libreoffice-3.6.3.2.4-2.4.1.x86_64
gnucash-2.4.11-2.1.2.x86_64
cups-1.5.4-5.2.1.x86_64
rabbitmq-server-2.8.7-2.1.3.x86_64
postgresql-server-9.2-2.1.1.noarch
glade-sharp2-2.12.10-38.2.1.x86_64.rpm
monodevelop-3.0.6-1.2.1
cadaver-0.23.3-65.1.2.x86_64
ghostscript-9.06-4.1.1.x86_64
MozillaFirefox-19.0-1.1.1.x86_64
tracker-0.14.4-2.1.2.x86_64
zeitgeist-0.9.5-2.1.1.x86_64
gnome-activity-journal-0.8.0-8.1.2.noarch
New Versions!

Only disappointment is that LibreOffice 4 didn't make the cut for the new release.

For anyone researching hardware issues, below is the low-down on the DV7-3165DX.  Probably nobody is looking, as the entire DV6 & DV7 seem to work flawlessly with LINUX,  but for the search engines...

00:00.0 Host bridge: Advanced Micro Devices [AMD] RS880 Host Bridge
00:01.0 PCI bridge: Hewlett-Packard Company Device 9602
00:04.0 PCI bridge: Advanced Micro Devices [AMD] RS780/RS880 PCI to PCI
bridge (PCIE port 0)
00:05.0 PCI bridge: Advanced Micro Devices [AMD] RS780/RS880 PCI to PCI
bridge (PCIE port 1)
00:06.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge
(PCIE port 2)
00:11.0 SATA controller: Advanced Micro Devices [AMD] nee ATI
SB7x0/SB8x0/SB9x0 SATA Controller [AHCI mode]
00:12.0 USB controller: Advanced Micro Devices [AMD] nee ATI
SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:12.1 USB controller: Advanced Micro Devices [AMD] nee ATI SB7x0 USB
OHCI1 Controller
00:12.2 USB controller: Advanced Micro Devices [AMD] nee ATI
SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:13.0 USB controller: Advanced Micro Devices [AMD] nee ATI
SB7x0/SB8x0/SB9x0 USB OHCI0 Controller
00:13.1 USB controller: Advanced Micro Devices [AMD] nee ATI SB7x0 USB
OHCI1 Controller
00:13.2 USB controller: Advanced Micro Devices [AMD] nee ATI
SB7x0/SB8x0/SB9x0 USB EHCI Controller
00:14.0 SMBus: Advanced Micro Devices [AMD] nee ATI SBx00 SMBus
Controller (rev 3c)
00:14.2 Audio device: Advanced Micro Devices [AMD] nee ATI SBx00 Azalia
(Intel HDA)
00:14.3 ISA bridge: Advanced Micro Devices [AMD] nee ATI
SB7x0/SB8x0/SB9x0 LPC host controller
00:14.4 PCI bridge: Advanced Micro Devices [AMD] nee ATI SBx00 PCI to
PCI Bridge
00:18.0 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor
HyperTransport Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor
Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor
DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor
Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices [AMD] Family 10h Processor
Link Control
01:05.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI
RS880M [Mobility Radeon HD 4200 Series]
01:05.1 Audio device: Advanced Micro Devices [AMD] nee ATI RS880 HDMI
Audio [Radeon HD 4200 Series]
08:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless
Network Adapter (PCI-Express) (rev 01)
09:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd.
RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 02)
/sbin/lscpi

processor       : 0 [and 1]
vendor_id       : AuthenticAMD
cpu family      : 16
model           : 6
model name      : AMD Turion(tm) II Ultra Dual-Core Mobile M620
stepping        : 2
microcode       : 0x10000c7
cpu MHz         : 800.000
cache size      : 1024 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 2
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 5
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt
pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc
extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic
cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt
hw_pstate npt lbrv svm_lock nrip_save
bogomips        : 4986.89
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 48 bits physical, 48 bits virtual
power management: ts ttp tm stc 100mhzsteps hwpstate
/proc/cpuinfo