Monday, October 8, 2012

Clear QPid/Andes/Cassandra JMS Queues



This tutorial shows how to clear the JMS queues of Cassandra. It should be noted that this method clear all the queues; you can't clear queue of your selection. This is useful where you have sent a message, and while it's in the queue something went wrong. There could be errors in processing the message due to incorrect settings etc. Since the queues are accessed FIFO (First-In-First-Out), if a message is hanged in the queue, it'll also block all other messages in the queue because they waits until the first message is processed.

At WSO2, we use WSO2 Message Broker to connect with Cassandra via WSO2 Andes (extended version of QPid) while WSO2 ESB will utilize these to maximum use. Message Store and Message Processor mediators that comes with WSO2 ESB uses JMS queues extensively.


  • Shutdown all the servers if they are running
  • Open up Cassandra-HOME/conf/cassandra.yaml
  • Remember the log locations you have set. Typically, you would have set 
    • data_file_directories
    • commitlog_directory
    • saved_caches_directory
  • Delete all three files folders. (By default, these locations point to relevant child folder in Cassandra-HOME/logs/cassandra/)
It's all set. Now, start the cassandra and other servers. The queues will be cleaned. Actually, what  happens during this process is that it removes all the queues. When the servers start, they re-create the missing queues. That should be it! :)

Thursday, October 4, 2012

Carbon 4.0.0 - JMS Address endpoint URL format


This applies when you are using WSO2 ESB 4.5.0+ and WSO2 MB 2.0+. In WSO2 Message Broker 2.0, we use Andes as the message broker, an extended version of QPid.

The format to use when defining a JMS endpoint is like follows. Remember The configuration will be different if you are not using Andes.


jms:/MaterialMasterProxy1?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&java.naming.factory.initial=org.wso2.andes.jndi.PropertiesFileInitialContextFactory&java.naming.provider.url=repository/conf/jndi.properties&transport.jms.DestinationType=queue



If you are want to create an address endpoint with JMS in WSO2 ESB 4.5.0, then it will look following.



 <endpoint name="MaterialMasterProxyEndpoint">
     <address uri="jms:/MaterialMasterProxy1?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&amp;java.naming.factory.initial=org.wso2.andes.jndi.PropertiesFileInitialContextFactory&amp;java.naming.provider.url=repository/conf/jndi.properties&amp;transport.jms.DestinationType=queue"/>
  </endpoint>


In ESB 3.0.1, we defined the address endpoints as follows.

jms:/MaterialGroupsProxy1?transport.jms.ConnectionFactoryJNDIName=QueueConnectionFactory&amp;java.naming.factory.initial=org.wso2.andes.jndi.PropertiesFileInitialContextFactory&amp;java.naming.provider.url=tcp://10.200.3.117:5682&amp;transport.jms.DestinationType=queue&amp;java.naming.provider.url=repository/conf/server.properties




Tuesday, October 2, 2012

[Linux] Copy files faster cp command


Every Linux user is familiar with file copy command, cp (copy). As an user who uses this frequently in a day, I can't help but wonder about possible alternatives to cp. CP is terrible when copying large number of files that are small in size. So, after digging in the internet, I found the following command to be a little more faster than cp command when it comes to copying smaller files.




tar cf - dir1 | (cd dir2; tar xf -)

With this, you can move an entire directory from dir1 to dir2. Here's an example.




tar cf - images/ | (cd /media/gentoo_/images/ tar xf -)


Monday, September 17, 2012

HOW TO INSTALL VLC 2.0 IN UBUNTU 11.10


Did you know that the latest VLC player version they can get is 1.1.12?  As of today, the most recent version available is 2.0.4 which is able to install from Ubuntu 12.04. So, VLC users have to either have to upgrade Ubuntu version, or be stick with an older 1.x versions.

But there is a way to install VLC via a PPA from VLC Daily Build of master branch. It's ppa:videolan/master-daily . I first tried ppa:n-muench/vlc, but it never worked for me. This worked flawlessly. The technically savvy people may now go ahead and install VLC by using this PPA. Others or if you are just interested, follow the instructions below to get it installed.

First enter the following command to add this PPA to your software sources


sudo add-apt-repository ppa:videolan/stable-daily


Now, you can update your software indexes, and install VLC.


sudo apt-get update && sudo apt-get install vlc


Now, you have a nice looking VLC at your hand. They say the performance is improved too among other new features. But I'm yet to test those! :-)


Wednesday, September 12, 2012

Linux commands I can not afford to lose



HTTP Requests -
GET - wget blog.kasunbg.org


GET request - curl --request GET http://localhost:9763/services/StudentService.StudentServiceHttpEndpoint/student/kasun




POST request - curl -d "age=01&name=kasun&subjects=unix" http://localhost:9763/services/StudentService.StudentServiceHttpEndpoint/student/kasun


SOAP POST request to a SOAP 1.2 endpoint -
curl -d '<soapenv:Envelope xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope"><soapenv:Body><p:echoString xmlns:p="http://echo.services.core.carbon.wso2.org"><in>kasun</in></p:echoString></soapenv:Body></soapenv:Envelope>'   -H "Content-Type: application/soap+xml"    http://localhost:9443/services/echo


Other commands - PUT, DELETE


SCP - 
scp -r -P 2200 /home/kasun/docbook-webhelp/  kasun@example.com:/home/kasun/public_html/
rsync


grep -ri "example" ../../ --include "*xml" -A5 -B5
find ../.. -iname "*xml"
tail -f target/carbontmp/wso2as-4.1.0-SNAPSHOT/repository/logs/wso2carbon.log


Replace a given word with a new one from a set of files - Here, I'm replacing the word 'oldWord' with 'newWord' of a set of files that ends with .xml in the current folder.

find . -name "*.xml" -exec sed -i "s/oldWord/newWord/g" '{}' \;


to replace the word "<webXml>${basedir}/../../web.xml</webXml>" with newWord. Note the escape charater (\) before $ and /. Used : for easy writing.

find . -name "pom.xml" -exec sed -i "s:<webXml>\${basedir}/../../web.xml<\/webXml>:newWord:g" '{}' \;


Find running Java processes - ps ax | grep java
Kill a process - kill -9 <process-id>

Subversion
Get only the modified files - svn status | egrep  "^M"
Create patch - svn diff > my-contribution.patch
Apply patch - patch -p0 < my-contribution.patch

Extract files -
tar -xjf my-archive.tar.bz2
tar -xzf my-archive.tar.gz
unzip my-archive.zip

Get the disk usage of a directory, sorted - du -s ./* | sort -g
Shutdown - sudo shutdown -h now
Reboot - reboot

The archive reader - file-roller
PDF reader - evince
Partition editor - gparted

Find the VGA driver in the machine - lspci -v | grep -i vga
Find attached USB devices - lsusb

Only copy a set of symbolic links in the current directory, and copy those to a separate folder. I did this in Ubuntu.
cp `l -1 | grep -ri @ | grep -ri "[^@]*" -o` ../my-symlinks/ -P

l -1 | grep -ri @ | grep -ri "[^@]*" -o - Selects outputs the file names of the symlinks. Then we copy it using cp with the parameter -P. -P means that cp won't follow the symlinks.

Bash for loop - in one line

for file in `fn pom.xml`; do echo $file; done

iPhone

Mount in Linux/Ubuntu

ifuse <mount_point> --root   - Only add --root if the phone is jail broken. Only jail broken phones can access the root / location.
ifuse /mnt/iPhone --root



Wednesday, July 25, 2012

Install Wireless / USB HP Printer in Ubuntu



Installing/Verifying the Drivers

The HPLIP software

HPLIP is an interface developed by HP to give Linux printing, scanning and fax functionalities.
The last version available at the moment (2.8.9) supports 1.445 models of HP printers and most probably the printer you're going to install is listed there.
To be sure of this, you just need to check the page that contains the entire list of the supported printers.
After having identified your model of printer in the list, pay attention to the first parameter, Min. HPLIP Version, which represents the minimum version of HPLIP that you need.
Every Ubuntu system contains a version of HPLIP (i.e. mine is the 2.8.2) by default. To verify this, type the following command on terminal:

dpkg -l hplip


You shall get a message similar to this:


Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                                 Version                              Description
+++-====================================-====================================-========================================================================================
ii  hplip                                3.11.7-1ubuntu3.1                    HP Linux Printing and Imaging System (HPLIP)


If in the first column you read the "ii" characters, it means that the version showed in the third column is currently installed on your computer.
If the installed version of HPLIP is lower that the minimum version that you require, keep reading, or skip to the next paragraph about the installation of a printer.


Installing the Printer

Enter `sudo hp-setup -i` and follow the instructions accordingly. -i is for interactive mode.
Here, I have listed how my interactive conversion with hp-setup went. :-) I needed to setup a printer via wireless. Setting up the USB connection is also pretty easy.



$ sudo hp-setup -i

HP Linux Imaging and Printing System (ver. 3.11.7)
Printer/Fax Setup Utility ver. 9.0

Copyright (c) 2001-9 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

(Note: Defaults for each question are maked with a '*'. Press <enter> to accept the default.)


--------------------------------
| SELECT CONNECTION (I/O) TYPE |
--------------------------------

  Num       Connection  Description                                            
            Type                                                                
  --------  ----------  ----------------------------------------------------------
  0*        usb         Universal Serial Bus (USB)                              
  1         net         Network/Ethernet/Wireless (direct connection or JetDirect)
  2         par         Parallel Port (LPT:)                                    

Enter number 0...2 for connection type (q=quit, enter=usb*) ? 1

Using connection type: net

Using device: hp:/net/HP_LaserJet_Professional_M1212nf_MFP?zc=NPI915B32


Setting up device: hp:/net/HP_LaserJet_Professional_M1212nf_MFP?zc=NPI915B32



------------------------
| PLUG-IN INSTALLATION |
------------------------


HP Linux Imaging and Printing System (ver. 3.11.7)
Plugin Download and Install Utility ver. 2.1

Copyright (c) 2001-9 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

(Note: Defaults for each question are maked with a '*'. Press <enter> to accept the default.)

/
-----------------------------------------
| PLUG-IN INSTALLATION FOR HPLIP 3.11.7 |
-----------------------------------------

  Option      Description                                    
  ----------  --------------------------------------------------
  d           Download plug-in from HP (recomended)          
  p           Specify a path to the plug-in (advanced)        
  q           Quit hp-plugin (skip installation)              

Enter option (d=download*, p=specify path, q=quit) ? d

--------------------------
| DOWNLOAD CONFIGURATION |
--------------------------

Checking for network connection...
Downloading configuration file from: http://hplip.sf.net/plugin.conf
Downloading configuration: [\                                                                                                                      ] 0%  

-------------------
| DOWNLOAD PLUGIN |
-------------------

Checking for network connection...
Downloading plug-in from: http://www.openprinting.org/download/printdriver/auxfiles/HP/plugins/hplip-3.11.7-plugin.run
Downloading plug-in: [****************************************************************************************************************************] 100%  8.0 KB   Receiving digital keys: /usr/bin/gpg --no-permission-warning --keyserver pgp.mit.edu --recv-keys 0xA59047B9


----------------------
| INSTALLING PLUG-IN |
----------------------

Verifying archive integrity... All good.
Uncompressing HPLIP 3.11.7 Plugin Self Extracting Archive.........................................

HP Linux Imaging and Printing System (ver. 3.11.7)
Plugin Installer ver. 3.0

Copyright (c) 2001-9 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Plug-in version: 3.11.7
Installed HPLIP version: 3.11.7
Number of files to install: 36

You must agree to the license terms before installing the plug-in:

LICENSE TERMS FOR HP Linux Imaging and Printing (HPLIP) Driver Plug-in                                                                                                


These License Terms govern your Use of the HPLIP Driver Plug-in Software (the "Software"). USE OF THE SOFTWARE INCLUDING, WITHOUT LIMITATION, ANY DOCUMENTATION, IS    
SUBJECT TO THESE LICENSE TERMS AND THE APPLICABLE AS-IS WARRANTY STATEMENT. BY DOWNLOADING AND INSTALLING THE SOFTWARE, YOU ARE AGREEING TO BE BOUND BY THESE TERMS. IF
YOU DO NOT AGREE TO ALL OF THESE TERMS, DO NOT DOWNLOAD AND INSTALL THE SOFTWARE ON YOUR SYSTEM.                                                                      


1. License Grant. HP grants you a license to Use one copy of the Software with HP printing products only. "Use" includes using, storing, loading, installing, executing,
and displaying the Software. You may not modify the Software or disable any licensing or control features of the Software.                                            


2. Ownership. The Software is owned and copyrighted by HP or its third party suppliers. Your license confers no title to, or ownership in, the Software and is not a sale
of any rights in the Software. HP's third party suppliers may protect their rights in the Software in the event of any violation of these license terms.              


3. Copies and Adaptations. You may only make copies or adaptations of the Software for archival purposes or when copying or adaptation is an essential step in the    
authorized Use of the Software. You must reproduce all copyright notices in the original Software on all copies or adaptations. You may not copy the Software onto any
public network.                                                                                                                                                        


4. No Disassembly. You may not Disassemble the Software unless HP's prior written consent is obtained. "Disassemble" includes disassembling, decompiling, decrypting, and
reverse engineering. In some jurisdictions, HP's consent may not be required for limited Disassembly. Upon request, you will provide HP with reasonably detailed      
information regarding any Disassembly.                                                                                                                                


5. No Transfer. You may not assign, sublicense or otherwise transfer all or any part of these License Terms or the Software.                                          


6. Termination. HP may terminate your license, upon notice, for failure to comply with any of these License Terms. Upon termination, you must immediately destroy the  
Software, together with all copies, adaptations and merged portions in any form.                                                                                      


7. Export Requirements. You may not export or re-export the Software or any copy or adaptation in violation of any applicable laws or regulations.                    


8. U.S. Government Restricted Rights. The Software has been developed entirely at private expense. It is delivered and licensed, as defined in any applicable DFARS,  
FARS, or other equivalent federal agency regulation or contract clause, as either "commercial computer software" or "restricted computer software", whichever is      
applicable. You have only those rights provided for such Software by the applicable clause or regulation or by these License Terms.                                    


9. DISCLAIMER OF WARRANTIES. TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, HP AND ITS SUPPLIERS PROVIDE THE SOFTWARE "AS IS" AND WITH ALL FAULTS, AND HEREBY      
DISCLAIM ALL OTHER WARRANTIES AND CONDITIONS, EITHER EXPRESS, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, WARRANTIES OF TITLE AND NON-INFRINGEMENT, ANY IMPLIED
WARRANTIES, DUTIES OR CONDITIONS OF MERCHANTABILITY, OF FITNESS FOR A PARTICULAR PURPOSE, AND OF LACK OF VIRUSES ALL WITH REGARD TO THE SOFTWARE. Some                
states/jurisdictions do not allow exclusion of implied warranties or limitations on the duration of implied warranties, so the above disclaimer may not apply to you in
its entirety.                                                                                                                                                          


10. LIMITATION OF LIABILITY. Notwithstanding any damages that you might incur, the entire liability of HP and any of its suppliers under any provision of this agreement
and your exclusive remedy for all of the foregoing shall be limited to the greater of the amount actually paid by you separately for the Software or U.S. $5.00. TO THE
MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT SHALL HP OR ITS SUPPLIERS BE LIABLE FOR ANY SPECIAL, INCIDENTAL,                                              
INDIRECT, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR LOSS OF PROFITS OR CONFIDENTIAL OR OTHER INFORMATION, FOR BUSINESS          
INTERRUPTION, FOR PERSONAL INJURY, FOR LOSS OF PRIVACY ARISING OUT OF OR IN ANY WAY RELATED TO THE USE OF OR INABILITY TO USE THE SOFTWARE, OR OTHERWISE IN CONNECTION
WITH ANY PROVISION OF THIS AGREEMENT, EVEN IF HP OR ANY SUPPLIER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES AND EVEN IF THE REMEDY FAILS OF ITS ESSENTIAL    
PURPOSE. Some states/jurisdictions do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to
you.                                                                                                                                                                  

Do you accept the license terms for the plug-in (y=yes*, n=no, q=quit) ? y

Done.

Done.

---------------------
| PRINT QUEUE SETUP |
---------------------

warning: One or more print queues already exist for this device: 59-4th-floor-HP-LaserJet-M1212nf.

Would you like to install another print queue for this device (y=yes, n=no*, q=quit) ? y

Please enter a name for this print queue (m=use model name:'HP_LaserJet_Professional_M1212nf_MFP'*, q=quit) ?
Using queue name: HP_LaserJet_Professional_M1212nf_MFP
Locating PPD file... Please wait.

Found PPD file: drv:///hpcups.drv/hp-laserjet_professional_m1212nf_mfp.ppd
Description:

Note: The model number may vary slightly from the actual model number on the device.

Does this PPD file appear to be the correct one (y=yes*, n=no, q=quit) ?
Enter a location description for this printer (q=quit) ?
Enter additonal information or notes for this printer (q=quit) ?4th floor printer

Adding print queue to CUPS:
Device URI: hp:/net/HP_LaserJet_Professional_M1212nf_MFP?zc=NPI915B32
Queue name: HP_LaserJet_Professional_M1212nf_MFP
PPD file: drv:///hpcups.drv/hp-laserjet_professional_m1212nf_mfp.ppd
Location:
Information: 4th floor printer


-------------------
| FAX QUEUE SETUP |
-------------------


Please enter a name for this fax queue (m=use model name:'HP_LaserJet_Professional_M1212nf_MFP_fax'*, q=quit) ?q
OK, done.

Sunday, July 8, 2012

How to share 3G Internet connection on Ubuntu

I've been looking everywhere, reading tens of articles on how to share internet connection using WiFi via my 3G internet connection. I wanted connect my iPhone 3GS to Ubuntu Wifi such that I can download apps larger than 20MB easily. Finally, I found this post in ubuntu forum that fixed the my issue. Things were straight forward, so nothing big to worry. Though the post is for 9.10, it worked in Ubuntu 11.10 for me. http://ubuntuforums.org/archive/index.php/t-1384085.html

I'd like to keep things in one place for later reference, so I'm stating it here with some customizations.

I tried this with Huawei E173 3G modem, and the Wireless connection of my laptop.
Here,
3G modem -  accesses internet.
Wireless (WiFi) AdHoc network - for sharing the internet connection with other computers.

You'll need only need Firestarter. The Operating System I tested is Ubuntu 11.10 (Oneiric Ocelot).

Type in the terminal
`sudo apt-get install firestarter`


This guide assumes a basic understanding of ip addresses...gateways dns servers etc.

This solution does not provide dhcp ....but hey I don't want that anyway.

Make sure your 3G modem, and wireless card already works (may be on windows or OS X).... if not install their software and activate your card...verify it works etc...

Now plug the card into the ubuntu box and set it up with network-manager. Right click the connection and select new cdma modem (or similar) and input your details as neccesary. This is for the MODEM.

Once connected unplug any ethernet...turn off any wifi and verify you have internet access.

Then right click the network manager icon and select "Create New Wireless Network" to create an ad-hoc wifi connection. There, given a network name you prefer (say MyWifi). Set Wireless security to "WEP 40/128-bit...", and give a 5 letter key/password (0-9A-Z).

Now, go to network-manager -> "Edit Connections". In the Wireless tab, you'll find your wireless connection (MyWifi). Select it, and click on edit.

Then click ipv4 settings tab

Change from dhcp to manual and enter the following details

address = 192.168.13.1
netmask = 255.255.255.0
leave gateway blank

That's done. Now, start firestarter. 
`gksudo firestarter`

Use the wizard and select ppp0 as your internet device. You may want to set `IP Address assigned via DHCP` for this connection if that's the case. Check with your ISP for more info.

Select connection sharing and then use wlan0 as your sharing device. This is the your wifi network device. We don't need dhcp here. 

Connect to MyWifi connection, and to your 3G broadband connection.

Now, start firestarter firewall...

Now configure your iPhone/another computer to use this gateway in Static tab ..

set your ip address to be 192.168.13.101
netmask 255.255.255.0
router (or default gateway) 192.168.13.1

IMPORTANT you need to enter DNS servers... I used Google DNS. You may use openDNS if you need. The Google DNS I set was.

8.8.8.8

If you really want OpenDNS, register for their free service, and use these DNS addresses. 208.67.222.222,208.67.220.220

Thats it!

Save everything and you should have a working internet connection that is shareable! obviously everyone needs their own ip address and setup is a little cumbersome but hey it works!

if you want dhcp you can probably get this to work using ubuntu server, wvdial, and the great help by googling ubuntu easyrouter.

but hey this works for me....and I like having network manager deal with the usb modem.

Have a good day. Welcome your thoughts/questions in the comments section. :-)