Posts Tagged ‘proof’

how to archive with Windows default zip (compress) algorithm

Tuesday, April 1st, 2014

Reading Time: 2minutes

I'm working on a decomissioning project (for those who hear decomissioning for a first time – in corporate world this means removal of service/s or assigned resources of a server or a physical server hardware that is not to be used in future or is obsolete). The decomissioning includes removal of Apache Tomcat (Software Configuration Item CI – in HP terms) from Microsoft Windows 2007 – Service Pack 2.
Part of decomissioning is of course to create backup of Tomcat Application server and for that I needed to create compressed archive of Tomcat instances. Usually I do archives on Windows using Winrar or Winzip but this time as the server productive server has the minimum installed there was no any external vendor produced archiving software available.

My memories from past were that there is a native compressing program embedded into Windows as I've unzipped compressed archives on Win hosts with no need for external WinZip. However until so far I never did .ZIP archive with no available external uncompress software.

Using Winzip or Winrar so far to make archive from a number of files I used to select files to enter Archive press right mouse button and select Create Archive (Add To Archive) so I expected this will work whenever no Winrar, however there was no obvious button like this, so I googled a bit to find out how is that possible ending up on Article from Microsoft titled "Compress and uncompress files (zip files)", there is a dumb proof video teaching Compressing files with Microsoft default ZIP program is done by the the weird "Send To" menu 🙂 

Selecting files to enter Archive;
> (Click Right Mouse Button) -> (Send To Compressed Zipped Folder)

compress_zipped_folder_with_windows_default_archive_algorithm how to archive with windows default compress archive

Honestly If I didn't checked the net probably I will never think of looking it there.

Preserve Session IDs of Tomcat cluster behind Apache reverse proxy / Sticky sessions with mod_proxy and Tomcat

Wednesday, February 26th, 2014

Reading Time: 2minutes

Having a combination of Apache webservice Reverse Proxy to redirect invisibly traffic to a number of Tomcat server positioned in a DMZ is a classic task in big companies Corporate world.
Hence if you work for company like IBM or HP sooner or later you will need to configure Apache Webserver cluster with few running Jakarta Tomcat Application servers behind. Scenario with necessity to access a java based application via Tomcat which requires logging (authentication) relaying on establishing and keeping a session ID is probably one of the most common ones and if you do it for first time you will probably end up with Session ID issues.  Session ID issues are hard to capture at first as on first glimpse application will seem to be working but users will have to re-login all the time even though the programmers might have coded for a session to expiry in 30 minutes or so.

… I mean not having configured Session ID prevention to Tomcats will cause random authentication session expiries and users using the Tomcat app will be unable to normally access below application with authenticated credentials. The solution to these is known under term "Sticky sessions"
To configure Sticky sessions you need to already have configured Apache/s with following minimum configuration:

  • enabled mod_proxy, proxy_balancer_module, proxy_http_module and or mod_proxy_ajp (in Apache config)

  LoadModule proxy_module modules/
LoadModule proxy_balancer_module modules/
LoadModule proxy_http_module modules/

  • And configured and tested Tomcats running an Application reachable viaAJP protocol

Below example assumes there is Reverse Proxy Load Balancer Apache which has to forward all traffic to 2 tomcats. The config can easily be extended for as many as necessary by adding more BalancerMembers.

In Apache webserver (apache2.conf / httpd.conf) you need to have JSESSIONID configured. These JSESSIONID is going to be appended to each client request from Reverse Proxy to each of Tomcat servers with value opened once on authentication to first Tomcat node to each of the other ones.

<Proxy balancer://mycluster>
BalancerMember ajp:// route=delivery1
BalancerMember ajp:// route=delivery2

ProxyRequests Off
ProxyPass / balancer://mycluster/ stickysession=JSESSIONID
ProxyPassReverse / balancer://mycluster/

The two variables route=delivery1 and route=delivery2 are routed to hosts identificators that also has to be present in Tomcat server configurations
In Tomcat App server First Node (server.xml)

<Engine name="Catalina" defaultHost="localhost" jvmRoute="delivery1">

In Tomcat App server Second Node (server.xml)

<Engine name="Catalina" defaultHost="localhost" jvmRoute="delivery2">

Once Sticky Sessions are configured it is useful to be able to track they work fine this is possible through logging each of established JESSSIONIDs, to do so add in httpd.conf

LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"\"%{JSESSIONID}C\"" combined

After modifications restart Apache and Tomcat to load new configs. In Apache access.log the proof should be the proof that sessions are preserved via JSESSIONID, there should be logs like: - - [18/Sep/2013:10:02:02 +0800] "POST /examples/servlets/servlet/RequestParamExample HTTP/1.1" 200 662 "http://localhost/examples/servlets/servlet/RequestParamExample" "Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130807 Firefox/17.0""B80557A1D9B48EC1D73CF8C7482B7D46.server2" - - [18/Sep/2013:10:02:06 +0800] "GET /examples/servlets/servlet/RequestInfoExample HTTP/1.1" 200 693 "http://localhost/examples/servlets/" "Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130807 Firefox/17.0""B80557A1D9B48EC1D73CF8C7482B7D46.server2"

That should solve problems with mysterious session expiries 🙂

My Individual Strategic Human Resources Management (SHR) research paper for Arnhem Business School

Thursday, April 7th, 2011

Reading Time: 2minutes
The previous semester in Arnhem Business School, I’ve followed a module called Strategic Human Resources Management
as a part of the so called G-cluster (Grand Cluster) (the 3rd year second semester).

The Stragic HR subject (module) is a completely meaningless one and the best short way to describe it is with the word (an insanity!).
In reality there is no aim of this module, and it’s content is vague and irrelevant.

If you’re a student in Arnhem Business School (ABS) and you have as oligitory to follow this course you’re seriously in trouble.

The whole subject is a lot of bla, bla, the teachers attitude towards you is like they’re invincible and you’re a victim and you have to always obey the teacher or you’re out (fear based)

Anyways I would skip to describe how the Strategic HRM went through as it was a complete nightmare ..

As a part of the Strategic HRM course It was necessery to write the so called Strategic Paper, the paper was required as a proof to the teachers that the student has realized what Strategic HRM is.

I believe my paper became quite good and thus I decided to share it here on my blog in hope that some other students might benefit from my Strategic Human Resources and Management research paper.

Here is the strategic paper assignment document and the paper itself:

1. Assignment Strategic Paper for semester 2010-2011
2. Strategic Human Resources Research Paper in DOC format
3. Strategic Human Resources Research Paper in PDF format

As I passed the Strategic HRM and it was one of the weighting factors for the subject end mark, it appears my research paper was found to be a good one by the teachers and therefore I assume other students from HAN might like to read it as a sample if they have to write something similar.