• Any latest Ubuntu server ( I’m using Ubuntu 10.10 Server )
• ddclient installed (use “aptitude install ddclient”)
• net connection, I have set up my linux server as a firewall/gateway

After installing ddclient, go to /etc and edit ddclient.conf, below is the format that I used, modify it to suite your configuration.

ssl=yes
use=web, web=whatismyip.org
server=updates.opendns.com
protocol=dyndns2
login=<openDNS_username_here>
password='<openDNS_password_here>'
<openDNS_network_label_here> #this can be found under settings, just the label, nothing else should be added here

Save the new configuration file and restart the client /etc/init.d/ddclient restart
Also make sure that the network that your going to update the IP address has set its Dynamic IP Update option enabled. This can be found under the advance setting of the network.

FLUSH LOGS;

Bring in a fresh copy of the database from the master-server and update the slave-server database. THIS IS IMPORTANT! Since if you don’t update the slave database, you will not have the data from the time you were disconnected until you reset the relay logs. So UPDATE YOUR SLAVE WITH THE LATEST DATABASE FROM THE MASTER!

Now when the logs are flushed,all the relay-bin logs will be deleted when the slave is started again. Usually, this fixes the problem, but when you start the slave and the failed relay log error is still there, now you have to do some more desperate measures… reset the slave. This is what I had to do to fully restore my MySQL slave server. Reseting the slaves restores all the settings to default… password, username, relay-log, port, table to replicate, etc… So better to have a copy of your settings first before actually do a slave reset. When your ready to rest the slave, do the command…

RESET SLAVE;

after which you should restore all your setting with a command something like…

CHANGE MASTER TO MASTER_HOST=.....

now start your server with…

SLAVE START;

check your slave server with…

SHOW SLAVE STATUS\G

look for …

Slave_IO_Running: Yes
Slave_SQL_Running: Yes

both should be YES, if not, check your syslog if there are other errors encountered. I’ll leave this until here since this is what I encountered and I was able to fix it.

Edit 5/14/11:

There is a possible change that after executing the CHANGE MASTER command that you’ll receive this error below…

ERROR 1201 (HY000): Could not initialize master info structure; more error messages can be found in the MySQL error log

This can occur when the relay logs under /var/lib/mysql were not properly cleaned and are still there. The next thing is to delete them manually, log back in to mysql, refresh logs, reset slave then execute the CHANGE MASTER command again. The file to delete would be relay-log.info .This should work now. Sometimes I don’t know why mysql can’t reset the slave logs.

1. Login as root, you can also use “su” though I prefer to login as root.
2. apt-get install sun-java5-jdk
• This will install Java 2 SDK (1.5), ubuntu will start downloading packages that are not found in your system.
3. apt-get install tomcat5.5 tomcat5.5-admin tomcat5.5-webapps
• Of course jakarta-tomcat 5.5, I’m using 5.5 since this supports java 1.5
4. Now here’s the tricky part, location for Java and jakarta-tomcat
• Java’s location is in /usr/lib/jvm/java-1.5.0-sun
• Jakarta-Tomcat’s location is in /usr/share/tomcat5.5
• We will need these location for the export configurations to be written in the .bashrc
5. Now, open .bashrc in your favorite text editor, I used vim
6. At the end of the file add these:
   
export JAVA_HOME=/usr/lib/jvm/java-1.5.0-sun
export CLASSPATH="/usr/share/tomcat5.5/common/lib/jsp-api.jar;/usr/share/tomcat5.5/common/lib/servlet-api.jar"
export CATALINA_HOME=/usr/share/tomcat5.5

7. Now save the file and exit, then log back in. This is required for the export script to be set.
8. Before starting the server, the default port the installer set is 8180 instead of the 8080 port that Tomcat uses. To change this, go to /usr/share/tomcat5.5/conf/ and open the file server.xml. Locate the line:
   
...Connector port="8180" maxHttpHeaderSize="8192"...

   and change 8180 to 8080. Save and exit. Now your ready to test the server.
9. Now try the server if it starts, /usr/share/tomcat5.5/bin/startup.sh You should see something like this:
   
Using CATALINA_BASE: /usr/share/tomcat5.5
Using CATALINA_HOME: /usr/share/tomcat5.5
Using CATALINA_TMPDIR: /usr/share/tomcat5.5/temp
Using JRE_HOME: /usr/lib/jvm/java-1.5.0-sun

10. Shutting down the server is just /usr/share/tomcat5.5/bin/shutdown.sh
11. Now, during installation of tomcat, Ubuntu automatically adds a startup and shutdown script for ubuntu to use as it starts up or shutsdown in /etc/init.d/ folder. Filename is tomcat5.5. As the server finishes starting up, you will notice tomcat isn’t running at all. One possible problem is that the script didn’t use the correct path for the java 2 sdk. You can check the boot log in /var/log/. Check if during boot up, tomcat5.5 encountered problems. For the problem stated above, you can fix this by going to /etc/default/ and edit the tomcat5.5 file. Locate the line:
    
    #JAVA_HOME=/usr/lib/j2sdk1.4-sun

    remove the ‘#’ and change it to…
    
    JAVA_HOME=/usr/lib/jvm/java-1.5.0-sun

    or wherever your java directory is.After that, restart the server and see if tomcat was successfully started.
    
    /etc/init.d/tomcat5.5 status

Edit: Problem encountered:

• Tomcat does not load in Ubuntu 8.04

Found a little problem loading Tomcat 5.5 under Ubuntu 8.04, it either fails or white screen just appears. I don’t know what happened from 6.04 to 8.04 but once I compared the init.d/tomcat5.5 startup script from 6.04 and 8.04, there WERE changes to the scripts. I replaced the new tomcat5.5 script in 8.04 with the old one from 6.04 and the server started properly after a server restart. I don’t know why but this may have something to do with permissions and I have yet to trace the script.

• java.lang.ClassNotFoundException: org.apache.jasper.tagplugins.jstl.If

• The problem here is that the above name is incomplete… what it should have been is org.apache.jasper.tagplugins.jstl.core.*
• Now, to fix the problem, locate /var/lib/tomcat5.5/webapps/jsp-examples/WEB-INF/tagPlugins.xml and open it with your text editor… I used vim. Now edit each line of code that has org.apache.jasper.tagplugins.jstl in it and add “.core” after jstl. What you will see after editing the code will be…

org.apache.taglibs.standard.tag.rt.core.IfTag

org.apache.jasper.tagplugins.jstl.core.If

org.apache.taglibs.standard.tag.common.core.ChooseTag

org.apache.jasper.tagplugins.jstl.core.Choose

org.apache.taglibs.standard.tag.rt.core.WhenTag

org.apache.jasper.tagplugins.jstl.core.When

org.apache.taglibs.standard.tag.common.core.OtherwiseTag

org.apache.jasper.tagplugins.jstl.core.Otherwise

org.apache.taglibs.standard.tag.rt.core.ForEachTag

org.apache.jasper.tagplugins.jstl.core.ForEach

• SEVERE: The scratchDir you specified: [folder_path] is unusable.

• Sidenote: took me 2 days to figure out why this was happening (X_x)
• Based from the Catalina logs, the folders under webapps was not accessible by tomcat5.
• Now looking under all processes running ( ps command ), most bootup services were running under root (mysql, apache, etc ) but tomcat5 was not.
• If I start tomcat5 when I logged into the console as root, the problem disappears. This lead me to believe this might have been the Tomcat5 user was not given the correct privileges.
• Work-around 1: Elevate Tomcat5 user to root access level.
• Work-around 2: Go to /etc/init.d/ and open Tomcat5.5 under any text editor ( I used vim ). Locate the line TOMCAT5_USER=tomcat55 and change it to TOMCAT5_USER=root . Restart your server or you can also execute the restart command for Tomcat5.5 in init.d folder

sources:

• Ubuntu/Drapper Remaster
• linux journal
• Ubuntu Install Tomcat
• Net Admin Tools