iyerland-blog

[iyerland-blog]

MySQL : How to see the queries executed (log)

login to mysql

SET GLOBAL general_log = 'ON'

show variables like "%GENERAL%";

+----------------------+------------------------------------------+

| Variable_name    | Value                                            |

+----------------------+--------------- --------------------------+

| general_log          | ON                                                |

| general_log_file    | /usr/local/var/mysql/macbox.log  |

+-----------------------+------------------------------------------+

[iyerland-blog]

Mac OS X Mountain Lion JAVA_HOME

export JAVA_HOME=`/usr/libexec/java_home -v 1.6`

[iyerland-blog]

Debugging with SBT & Intellij/Eclipse

1. Set your breakpoints.

2. Within your IDE create a new REMOTE configuration.

3. Start this configuration in DEBUG mode.

4. Clone your sbt script, call it sbtd (sbt debug) and create symlinks.

5. Modify sbtd, put this before ${SBT_OPTS}:

-Xdebug -Xrunjdwp:transport=dt_socket,

server=y,suspend=n,address=127.0.0.1:5005 

6. Go to your scala project and run (This should attach sbt to 5005 port): 

sbtd 

7. Once inside sbt prompt, start your server:

run 

8. Now send requests to your scala server through postman client or web

    app client.

9. You should now hit your breakpoints! Enjoy!

[iyerland-blog]

grails run-app : error

If you get the following error when doing: grails run-app 

Configuring Tomcat Plugin for virtual directory...

2013-04-18 08:34:59,242 [main] ERROR org.codehaus.groovy.grails.web.context.GrailsContextLoader  - Error executing bootstraps: IOException parsing XML document from ServletContext resource [/WEB-INF/applicationContext.xml]; 

Solution:

grails upgrade

[iyerland-blog]

Copy MySQL tables from one host to other

On host A, do:

$ mysqldump -u 'username' -p 'password' 'table-name' > 'output-file'

Secure copy (or use FileZilla) to copy 'output-file' to host B

$ mysql -u 'username' -p 'password' 'table-name' < 'output-file'

[iyerland-blog]

Modify Xms Xmx in Tomcat 7

Create a file setenv.sh in the same directory as catalina.sh and add the following:

$ JAVA_OPTS="-Xms512m -Xmx1024m -XX:+UseConcMarkSweepGC"

or whatever value you want!

[iyerland-blog]

Kill a process by name

Unix/Linux script to automatically kill a process by name:

$ kill -9 `ps -eaf | grep | awk ‘{print $2}’` Example: Kill tomcat process: $ kill -9 `ps -eaf | grep tomcat | awk ‘{print $2}’`

Please note: In order for this to work on Linux, you may have to change to: “print $1″, basically the position of the process id, when you do a ps -eaf or ps -aux!

[iyerland-blog]

Refresh a command at some interval

Unix/Linux script to refresh a command at some interval:

$ while :; do clear; sleep ; done Example: Watch how many sockets are used up: $ while :; do clear; netstat -np tcp | grep 8080 | wc -l; sleep 3; done