http://www.randombugs.com Just another Bastard Operator From Hell. Everything from *nix to programming Thu, 06 May 2010 14:21:46 +0000 en hourly 1 http://wordpress.org/?v=3.0 http://www.randombugs.com/linux/crash-innodb-table.html http://www.randombugs.com/linux/crash-innodb-table.html#comments Thu, 06 May 2010 14:16:10 +0000 admin http://www.randombugs.com/?p=658
I searched over internet, on several tens of posts, to find how to delete a crashed Innodb table. Short story: I tried to import a big table but it crashed in the middle of the process (power failure). The table was not very important so I didn’t care about the table, I just want to delete it and start from the scratch, but surprise! The table cannot be deleted! I use the latest MySQL Innodb plugin from Debian backports repository (is coming with Debian 5.1.xx) with file per table ...]]> http://www.randombugs.com/linux/crash-innodb-table.html/feed 0 http://www.randombugs.com/java/dbappender-log4j-12.html http://www.randombugs.com/java/dbappender-log4j-12.html#comments Thu, 24 Sep 2009 20:19:46 +0000 admin http://www.randombugs.com/?p=595
Initially, DBAppender for Log4j was introduced in version 1.3 of Log4j, but this version was ABANDONED by Apache team. DBAppender is very useful when we want to send our log on a JNDI resource and not on standard JDBC or file. If you need just logging in a database for your application, then you should use JDBCAppender. If you want to log on a JNDI or Database Connection Pool the DBAppender is for you. In this post I will show you how to get, compile and quick test the DBAppender. 1. ...]]> http://www.randombugs.com/java/dbappender-log4j-12.html/feed 5 http://www.randombugs.com/linux/tuning-linux-system-database.html http://www.randombugs.com/linux/tuning-linux-system-database.html#comments Thu, 16 Jul 2009 17:24:13 +0000 admin http://www.randombugs.com/?p=567
In my experiments with databases I was constrained to tune the system together with the databases. A system what will run a database is quite different from any other server system, because databases put a lot of stress on the IO and especially on the disks (probably the file servers too). Hardware is not all you should tune your system as much as possible. In this post I will talk about Linux with Ext3 (is what I have right now), but on future I will test OpenSolaris with ZFS. 1. ...]]> http://www.randombugs.com/linux/tuning-linux-system-database.html/feed 2 http://www.randombugs.com/linux/mysql-postgresql-benchmarks.html http://www.randombugs.com/linux/mysql-postgresql-benchmarks.html#comments Thu, 18 Jun 2009 14:25:25 +0000 admin http://www.randombugs.com/?p=458
We are living interesting times ... MySQL was first purchased by SUN and now SUN was purchased by ORACLE. I don't know what future will reserve for MySQL, but in this moment it seems MySQL is coming very very close to PostgreSQL. We are NOT talking about MySQL with MyISAM, we are talking about MySQL with InnoDB, because I'm directly interested in a set of properties what PostgreSQL already have them built-in and MySQL achieve them through InnoDB (and the new Maria Data plugin). This properties are Atomicity, Consistency, Isolation, Durability = ACID, in other words, very stable, good integrity and crash proof database. Why an ACID database? Sometimes we are more interested in ACID for our data than raw speed. For example do you keep your savings to a bank who is running a NON ACID database? I think you understand my concern. ]]> http://www.randombugs.com/linux/mysql-postgresql-benchmarks.html/feed 45 http://www.randombugs.com/linux/migrating-fromto-mysql-tofrom-postgresql.html http://www.randombugs.com/linux/migrating-fromto-mysql-tofrom-postgresql.html#comments Thu, 19 Mar 2009 08:41:35 +0000 admin http://www.randombugs.com/?p=322
We will not discuss who is better or who is not, we just try to provide you a simple how-to to migrate from MySQL to Postgres or from Postgres to Mysql. On internet are several documents about that, but I will try to add new fresh informations from my experience with that. The differences between this Postgres and MySQL are starting from the concept of this two platforms. For example Postgres follow more closer the ANSI SQL standard than MySQL, the method of administration is totally different between them, Mysql ...]]> http://www.randombugs.com/linux/migrating-fromto-mysql-tofrom-postgresql.html/feed 1 http://www.randombugs.com/linux/mysql-root-password-recovery.html http://www.randombugs.com/linux/mysql-root-password-recovery.html#comments Fri, 27 Feb 2009 10:15:16 +0000 admin http://www.randombugs.com/?p=187
It happens from time to time to forget some passwords if I’m not using them very very often. Recently I forgot the root password on a MySQL database from an external client. Recovering the password was not such a big deal, but I will explain how I do that for the newbies or anybody who need to know that. To do that you will need to stop your MySQL Database so if you are in a production environment then it will be better to schedule a downtime window. The process ...]]> http://www.randombugs.com/linux/mysql-root-password-recovery.html/feed 0 http://www.randombugs.com/linux/mysql-replication-debian.html http://www.randombugs.com/linux/mysql-replication-debian.html#comments Thu, 19 Feb 2009 11:57:47 +0000 admin http://www.randombugs.com/?p=184
Always when we talk about MySQL replication we talk about high-availability (HA). Why we choose Mysql Replication and not Mysql Clustering in a high-availability environment? Because Mysql Cluster have some limitations on his NDB storage system and probably we want to use INNODB (ACID compliant storage system) and foreign keys. What is Replication ? Is a Database syncronization between two (or more) MySQLnodes. I will start explain you in this step by step tutorial how to do a master slave configuration between 2 nodes. Installing Mysql Server and Client on Debian As root ...]]> http://www.randombugs.com/linux/mysql-replication-debian.html/feed 0 http://www.randombugs.com/java/liferay-521-mysql-glassfish-21.html http://www.randombugs.com/java/liferay-521-mysql-glassfish-21.html#comments Fri, 13 Feb 2009 11:21:25 +0000 admin http://www.randombugs.com/?p=182
In the old versions of Liferay, switching from HSQL to MySQL was easy under Glassfish. Just replace the jdbc connector created for HSQL with one for MySQL and at the next restart of Liferay all was working ok. From version 5.2.1 configuration was changed and all is done from portal.properties. To switch from HSQL just create a portal-ext.properties with the following content: jdbc.default.driverClassName=com.mysql.jdbc.Driver jdbc.default.url=jdbc:mysql://localhost/lportal?useUnicode=true&characterEncoding=UTF-8&useFastDateParsing=false jdbc.default.username=lportal jdbc.default.password=lportalpassword and putit in /domain/domain1/applications/j2ee-module/liferay-portal/WEB-INF/classes/ if you are running in a single instance or if you are running in a clustered instance /nodeagents/agent1/instance1/applications/j2ee-module/liferay-portal/WEB-INF/classes . Good Luck Related Posts:How to install and configure ...]]> http://www.randombugs.com/java/liferay-521-mysql-glassfish-21.html/feed 0 http://www.randombugs.com/linux/ora-27125-unable-to-create-shared-memory-segment.html http://www.randombugs.com/linux/ora-27125-unable-to-create-shared-memory-segment.html#comments Tue, 11 Nov 2008 09:30:51 +0000 admin http://www.randombugs.com/?p=25
This post is for the users who got this error message (ORA-27125: unable to create shared memory segment) when they try to run Oracle 10g on linux. Are 2 solutions for this problem: 1. Disable Huge TLB tables export DISABLE_HUGETLBFS=1 in shell and after just restart oracle. (Take care because you will need a lot of RAM if you disable HUGETLBFS) 2. You need to recompile your linux kernel with following options enabled CONFIG_HUGETLB_PAGE=y CONFIG_HUGETLBFS=y I hope this post will be helpful. Related Posts:How to disable the display standby on a xorg xserverSpeed up Samba under LinuxInnodb table crashCore ...]]> http://www.randombugs.com/linux/ora-27125-unable-to-create-shared-memory-segment.html/feed 1 http://www.randombugs.com/linux/mysql-cluster-old.html http://www.randombugs.com/linux/mysql-cluster-old.html#comments Mon, 12 Nov 2007 12:50:43 +0000 admin http://www.randombugs.com/?p=51
I will try to exemplify as easy as possible a clustered mysql server under Debian 1. Mysql Servers For example we have 2 servers what need to be configured in clustered mode. This servers run mysql 4.1.8a (The configuration is still possible to work on other versions). Each cluster server need to have this additional conf in /etc/mysql/my.cnf: [mysqld] ndbcluster ndb-connectstring=app1.mydomain.com [mysql_cluster] ndb-connectstring=app1.mydomain.com where app1.mydomain.com is the management server for cluster. To restart a server you need to restart start ndbd server either. /etc/init.d/mysql restart killall ndbd /etc/init.d/ndbd start 2. Management server The management sever is used to provide configuration for cluster servers. ...]]> http://www.randombugs.com/linux/mysql-cluster-old.html/feed 0