Redmine

Hi all,
I got a problem with MySql connection using Redmine.

I saw an HowTo into the Redmine Documentation about it and I followed the provided instruction: I inserted this row into the config/environment.rb

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ActiveRecord::Base.verification_timeout = 6048000 ==================================================================================================

but every day Redmine looses connection with MySql. This a piece of log file about it:

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ActiveRecord::StatementInvalid (Mysql::Error: Lost connection to MySQL server during query: SELECT max(updated_on) AS max_updated_on FROM `settings` ): ==================================================================================================

I noticed that when I restart the Mongrel application server, the production.log file traces this rows:

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WARNING: You're using the Ruby-based MySQL library that ships with Rails. This library is not suited for production. Please install the C-based MySQL library instead (gem install mysql) ==================================================================================================

I tried to install the mysql library and this is the output:

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Building native extensions. This could take a while...
ERROR: Error installing mysql:
ERROR: Failed to build gem native extension.

/usr/bin/ruby1.8 extconf.rb install mysql
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lm... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lz... yes
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lsocket... no
checking for mysql_query() in -lmysqlclient... no
checking for main() in -lnsl... yes
checking for mysql_query() in -lmysqlclient... no

• extconf.rb failed ***
  Could not create Makefile due to some reason, probably lack of
  necessary libraries and/or headers. Check the mkmf.log file for more
  details. You may need configuration options.

Provided configuration options:
--with-opt-dir
--without-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/usr/bin/ruby1.8
--with-mysql-config
--without-mysql-config
--with-mysql-dir
--without-mysql-dir
--with-mysql-include
--without-mysql-include=${mysql-dir}/include
--with-mysql-lib
--without-mysql-lib=${mysql-dir}/lib
--with-mysqlclientlib
--without-mysqlclientlib
--with-mlib
--without-mlib
--with-mysqlclientlib
--without-mysqlclientlib
--with-zlib
--without-zlib
--with-mysqlclientlib
--without-mysqlclientlib
--with-socketlib
--without-socketlib
--with-mysqlclientlib
--without-mysqlclientlib
--with-nsllib
--without-nsllib
--with-mysqlclientlib
--without-mysqlclientlib

Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/mysql-2.7 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/mysql-2.7/gem_make.out

==================================================================================================

Any suggestions?
Thanks
-- Marco