Working on decommission of a server and installing instance on other server

Working on decommission of a server and installing instance on other server


Suppose

Server D= server to be decommissioned

Server S= server to be setup

1. Check all the sudo access present on sever D should also be allotted to admin on server S.

2. Copy all the scripts and links connecting apache.

3. Copy the apache tar from the sever D to server S.

4. Set up all the links and scripts eg. Apachectl directing to correct path.

5. Compare if both server belong to same subnet. If not, get the application configured for new subnet.

Setting up the Tomcat and apache instance on the server

Checking the perquisites

1. Check if the following user resides on the server

• (Tomcat) user name

• Group name (group that will own the tomcat)

• Any username that should be owning the application.(Application team should have a sudo excess for this particular username)

If not, raise my access request for the creating the particular group/ user.



2. Make sure that all the apache modules (needed for the tomcat setup to work properly) are already present on the server, if not get them installed on the server by the UNIX team.



3. Make sure that correct java version is present on the server. the java version can be checked by javac command or in /usr path

Installing tomcat

1. Get the set up of tomcat (probably the tar of the other tomcats on the server)

2. Get that tar transferred to the place where tomcat has to be setup.
3. Extract whole tar

4. Make the required changes in server.xml example connector port available according to the server, the application links at various places.

5. Check the scripts like start-tomcat, stop-tomcat and Catalina.sh in the present in the applicationpath/bin folder, in case any customization of tomcat startup is needed.

6. Once changes are done. Start the tomcat by going to path.. applicationpath/bin and ./start-tomcat

7. Check the path http://servername:portnumber/ , to see if tomcat is correctly installed. It should look something like this.



Installing the apache

1. Get the set up of apache (probably the tar of the other apaches on the other server)

2. Extract that tar into one folder

3. Make the changes in the ./conf.http.conf file to make it the specific to this server

Example

server root

ServerRoot "/export/apps/apache/apache-app1"



server admin

ServerAdmin apache@servername.lvst.owner.com



DocumentRoot

DocumentRoot "/project/app/apache/htdocs/app1"



4. make changes in workers.properties in conf folder

worker.tomcat1.host=servername.lvst.owner.com

ssl.conf

Listen 12.34.56.789:111
NameVirtualHost 12.34.56.789:111
SSLPassPhraseDialog builtin

SSLPassPhraseDialog exec:/export/apps/apache/apache-app1/conf/passkey.sh



ServerName  app1.lvst.owner.com

#ServerAlias app1.lvst.owner.com

DocumentRoot "/project/app1/apache/htdocs/app1"

SSLEngine on

SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL

SSLCertificateFile /export/apps/apache/apache-app1/cert/app1.crt

SSLCertificateKeyFile /export/apps/apache/apache-app1/cert/app1.key

SSLCertificateChainFile /export/apps/apache/apache-app1/cert/geotrust_intermediate.crt

NOTE- Read the document for setting up the apache for more knowledge on setting up the apache.

JOINS in SQL

Nice post

http://www.codeproject.com/KB/database/Visual_SQL_Joins/Visual_SQL_JOINS_orig.jpg

At the top level there are mainly 3 types of joins:


INNER

OUTER

CROSS



--------------------------------------------------------------------------------



INNER JOIN - fetches data if present in both the tables.



OUTER JOIN are of 3 types:



LEFT OUTER JOIN - fetches data if present in the left table.

RIGHT OUTER JOIN - fetches data if present in the right table.

FULL OUTER JOIN - fetches data if present in either of the two tables.

CROSS JOIN, as the name suggests, does [n X m] that joins everything to everything.

Similar to scenario where we simply lists the tables for joining (in the FROM clause of the SELECT statement), using commas to separate them.

  Points to be noted:

If you just mention JOIN then by default it is a INNER JOIN.

An OUTER join has to be LEFT RIGHT FULL you can not simply say OUTER JOIN.

You can drop OUTER keyword and just say LEFT JOIN or RIGHT JOIN or FULL JOIN