Friday, August 22, 2008

building hypertable on Ubuntu hardy

I saw hypertable first about half a year ago, and since then I felt like giving it a try. Today I finally took the time to download it ( alpha), and tried to build it on my Ubuntu hardy. README file seemed to be precise, so I followed the instructions, and installed the packages below with apt-get as follows:

apt-get install cmake g++ libdb4.6++-dev liblog4cpp4-dev libexpat1-dev libreadline5-dev libboost-dev libboost-iostreams-dev libboost-program-options-dev libboost-python-dev libboost-thread-dev libgoogle-perftools-dev graphviz doxygen sun-java5-jdk

Then I run cmake as follows (after creating and entering build directory: mkdir -p ~/build/hypertable ; cd ~/build/hypertable):

cmake -DCMAKE_INSTALL_PREFIX=~/hypertable -DCMAKE_BUILD_TYPE="Debug" ~/src/hypertable-

Cmake checked all dependencies and created the appropriate makefiles to the build dir:
-- Use thread library: -lpthread
-- Looking for required boost libraries...
-- Boost include dir: /usr/include
-- Boost thread lib: /usr/lib/
-- Boost program options lib: /usr/lib/
-- Boost iostreams lib: /usr/lib/
-- Boost python lib: /usr/lib/
-- Boost lib dir: /usr/lib
-- Boost version: 1_34_1
-- gcc version: 4.2.3
-- Looking for doxygen...
-- Looking for doxygen... - found /usr/bin/doxygen
-- Looking for dot tool...
-- Looking for dot tool... - found /usr/bin/dot
-- Found BerkeleyDB: /usr/lib/
-- Berkeley DB version: 4.6.21
-- Found Readline libraries: /usr/lib/;/usr/lib/
-- Java headers found at: /usr/lib/jvm/java-1.5.0-sun/include
-- Hadoop includes not found. Please set HADOOP_INCLUDE_PATH variable
-- Hadoop libraries not found. Please set HADOOP_LIB_PATH variable
-- You decided not to build shared libraries. MapReduce will be disabled
-- Got boost 1.34.x, prepend fix directory
-- MapReduce support disabled.
-- Configuring done
-- Generating done
-- Build files have been written to: /home/qzy/build/hypertable

So all I had to do now is to start the build process by issueing make. All seemed to be compiling fine, but at 82% when building AccessGroup.o, it died with the following error message:

/usr/include/boost/multi_index/detail/index_node_base.hpp:22:42: error: boost/serialization/access.hpp: No such file or directory

Well, after some minutes I figured out this is beacuse boost serialization module was not there, so I installed it:
apt-get install libboost-serialization-dev
After this, the build procedure succesfully finished, so the only remaining step was to issue the make install command.

And voila... now I have a working hypertable on my Ubuntu hardy. Even though the stuff is still alpha, the build process is fairly painless. The only bug I found is the lack of the boost serialization module check in cmake (however README suggests to install libboost-.*-dev, I don't like unnecessary packages hanging around, so this cmake issue is still a bug).
Now it's time to take a deeper breath in the hyperspace...

Wednesday, August 13, 2008

log4net: hostname in logfile's name

I recently came across the problem that while using the excellent log4net tool with fileappender I needed to programatically include the machine name in the logfile's name (the application's config is on a shared disk area, so hard-wiring the nodename was not an option). Thanks to the log4net team, since version 1.2.9 this can be achieved via the PatternString and the ConversionPattern classes. Let's see a working c# example.

This is what you should put into your application's config (Web.config in my case) to the <log4net> section:

<appender name="SomeLogFileAppender" type="log4net.Appender.FileAppender">
<file type="log4net.Util.PatternString" >
<name value="hostname" />
value="MyNamespace.MySubNamespace.HostnamePatternConverter,MyNamespace" />
value="debuglog-%hostname{LocalApplicationData}.txt" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<datePattern value="yyyyMMdd" />
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level - %message%newline" />

And then the code snippet which implements HostnamePatternConverter:

using log4net;
using System;

namespace MyNamespace.MySubNamespace {


public class HostnamePatternConverter : log4net.Util.PatternConverter
protected override void Convert(TextWriter writer, object state)