Posts Tagged ‘opinion’

Automatic restart Tomcat on Windows script via TaskScheduler daily – A command line to add / remove new Windows “Cron” like job

Thursday, January 22nd, 2015

Reading Time: 4 minutes

automatic-restart-Tomcat-on-Windows-via-TaskShcheduler-daily-weekly-monthly-a-command-line-to-add-remove-new-windows-cron-job
I'm responsbile for a project environment made up of 3 components which is occasionally dying. Here is a short raw overview of environment

  • Apache Reverse Proxy (entry door to app server)
  • Tomcat Server with an Application enabling web access
  • A Java Standalone application using SQLite database

 The Tomcat and Java Standalone application is running on top of Windows 2008 RC2 Standard, the overall environment is becoming inacessible periodically and in order to solve that the customer decided to implement a daily Windows server reboot in my opinion this is very bad approach as it is much better to just set an auto reboot of each of components using few tiny batch scripts and Windows Taskmgr, however as the customer is king and decided to implement the reboot its their own thing. 
However even fter the daily server reboot was set once a week or so the application was becoming inaccessible and a Tomcat server restart was necessery as a fix.

Finally as a work-around to the issue, I've proposed the logical thing to automatically restart Tomcat once a day early in morning, here is how Tomcat auto Restart was implemented on the Win server:

1. Check out the name of running Tomcat service

First thing is to use the sc command to find out the Tomcat application name:

 

how-to-show-tomcat-service-name-command-windows-screenshot

C:UsersGeorgi>sc query state= all| findstr "Tomcat"
SERVICE_NAME: Tomcat7_r2c
DISPLAY_NAME: Apache Tomcat Tomcat7_r2c

C:UsersGeorgi>

 

2. Create bat script to stop and start Tomcat service

Press keyboard Win-button + R, start notepad type inside:
 

@echo off
sc stop Tomcat7_r2c && sc start Tomcat7_r2c

(MyApp-Tomact-Restart-bat-file-ms-windows-screenshot

Don't be confused from screenshot that I have Tomcat7_MyApp instead of Tomcat7_r2c, but I made screenshot in hurry for another app.
Save the file, somewhere (preferrably) in application folder/bin/  it is best to save it once with bat extension MyApp-Tomcat_Restart.bat and once as MyApp-Tomcat_Restart.xml (XML format file is later needed for import to Task Scheduler which understands .XMLs). The .bat file is good to have because it is useful to somtimes restart Tomcat manually by running it (in case of some sudden Tomcat Appserver occurs even though the auto-restart script).
 

3. Create new Task using command line (cmd.exe)


Task can be created also from command line using following syntax:
 

schtasks /Create [/S [/U [/P [  ]]]]
/XML <xmlfile> /TN <taskname>

Simple way to create a new Windows task is shown in below command, it will set my Tomcat Restart script to run everyday in 05:00 early morning when no employees are using the system:

schTasks /Create /SC DAILY /TN "My Task" /TR "C:UsersGeorgiDesktopmyApp-Tomcat_Restart.bat" /ST 05:00
SUCCESS: The scheduled task "Tomcat Restart Task" has successfully been created.

 

import-new-windows-task-scheduler-task-from-command-line-windows-add-new-cronjob-command-screenshot


4. Create / Import new Windows "Cron" job 

Alternative way is to use Task Scheduler GUI frontend and create new (Basic Task) or  import just created script

To run Windows Task Scheduler from comamnd line :
 

Taskschd.msc

taskschd_windows-run-from-command-line-screenshot

To import already existing .XML formatted file for Task scheduler, right click on the Task Scheduler (Local) and select Import task

task-scheduler-local-task-import-microsoft-2008-r2-windows-screenshot

Import the myApp-Tomcat_Restart.XML previously created file

task-scheduler-import-tomcat-restart-xml-file-windows-server-2008-r2-screenshot

Adjust settings to suit your needs, but what change atleast:

  •         the path to the myApp-Tomcat_Restart.bat file in Actions tab
  •         the Local User account with which script will be running (administrator) in General tab

Task-Scheduler-windows-general-local-user-account-with-which-task-will-be-running

After making all changes you will be prompted for server Administrator account password 

5. check existing Win Cron job from command line

To see the configured (Scheduled Tasks) in command line mode with a command:

Schtasks.exe

schtasks-windows-equivalent-command-to-linux-unix-crontab-screenshot

The command is Windows equivalent to UNIX / Linux's crontab, e.g.:

crontab -u root -l


6. Delete existing Windows Task Job from Command line

If you happen to need to delete just created task or any other task from command line (Assuming that you know the previously created task name), use cmd:

C:>schtasks /Delete /TN "Tomcat Restart Task"
WARNING: Are you sure you want to remove the task "Tomcat Restart Task" (Y/N)? y

SUCCESS: The scheduled task "Tomcat Restart Task" was successfully deleted.


Task completed, Tomcat will auto-restart on Windows host at your scheduled time. Feedback is mostly welcome 🙂
Enjoy  

 

Installing Linux on old hardware PC. Few thoughs on Puppy and Xubuntu Linux

Tuesday, January 24th, 2012

Reading Time: 2 minutes

I needed a G/Linux distribution that will work fine on an old PC with hardware configuration:

guest@xubuntu-desktop:~$ grep -i cpu /proc/cpuinfo; free -m; df -h
cpu family : 6
cpu MHz : 797.613cpuid level : 2
total used free shared buffers cachedMem: 497 470 26 0 35 259-/+ buffers/cache: 176 321Swap: 1454 10 1444File System Size Used Free % Mounted on
/dev/sda1 37G 4,3G 31G 13% /

I've read a lot on the internet and come to the conclusion I have basicly two popular Linux distros as option to install on archaic x86 hardware:

1. Puppy Linux
2. Xubuntu Linux

I first give Puppy Linux a try. It worked quite nice, but the interface was too old school and the desktop felt like a bit out-dated.
Besides that many of the Puppy Linux shipped programs were not a mainstream programs available across most of the other Linux distributions.

Many of the programs shipped with Puppy are great, but more suitable for a computer geek than for a Windows accustomed GUI user.
Puppy Linux Screenshot

My opinion on Puppy (from what I've seen) is that its great distro for old school hardcore Linux users.
Anyways its not suitable for absolutely "uniniated" users who encounter Linux for a first time.

Secondly I installed Xubuntu. Most of the archaic hardware on the PC was detected during install time (a pleasently surprise).
Xubunto works fast and Xfce menus opens "light fast" as on the old 800Mhz pc with 512 mem of ram. Generally the GUI worked quick and responsive.
To conclude I liked Xubuntu a lot and I strongly recommend it to anyone who want to quickly roll on Linux on an old PC.
Xubuntu GNU / Linux theme

What impressed me most is the minimalistic look & feel and simplicity.

I'm sure Debian will be working great on old hardware as well, however configuring it will be hell a lot of work. Thus I think Xubuntu is a good choice for people who want save some time in obscure configurations and easily have a neat Linux ready for desktop use.

Facebook and Youtube Culture has a negative impact on people in young years development and teenagers

Tuesday, December 13th, 2011

Reading Time: 4 minutes
Facebook and Youtube helps young people get stupid

Facebook and Youtube has become for just a few years a defacto standard service for 80% of computer users in our age.
This is true and it seems there is growing tendency for people to adopt new easy to use services and a boom in the social networks.
We’ve seen that with the fast adoption of the anti-human freedom program Skype , the own privacy breaching FaceBook as well as the people interests tracking service YouTube.

We’ve seen similar high adoption rates in earlier times as well with the already dying (if not dead MySpace), with the early yahoo mail boom etc and in even earlier times with the AltaVista search engine use.
However this time it appears Youtube and FaceBook are here to stay with us and become standard online services for longer times …
Many people who work in office all day staring in a computer screen as well as growing teenagers and practically anyone in the developed and the development world is using those services heavily for (in between 5 to 10 hours a day or more). The Software as a Service users spends approximately half of their time spend on the internet in Youtube or and Facebook.

Its true Youtube can be massively educative with this global database of videos on all kind of topics and in some cases facebook can be considered helpful in keeping in touch people or keeping a catalog of pictures easily accessible from everywhere, however when few services becomes more used and influential than other provided services on the internet this makes these services harmful to the communities and destroyes cultures. The concentration of most of the human popuplation who uses high technologies around few online services creates a big electronic monopoly. In other words the tendency, we see of amalgamation of businesses in real world (building of big malls and destroyment of small and middle sized shops is being observed in the Internet space.

Besides that Facebook and Youtube and Twitter are highly contrary to the true hacker spirit and creates a big harm for intellectuals and other kind of tight and technical community culture by creating one imaginative casual disco culture without any deepness of thought or spirit.

Its observable that most of the people that are heavily using those services are turning into (if not exaggerate) a brainless consumer zombies, a crowd of pathless people who watch videos and pictures and write meaningless commentaries all day long.

You have as a result a “unified dumbness” (dumbness which unifies people).

Even if we can accept the grown and fully formed character people are aware of the threats of using Youtube or Facebook, this is definitely not the case with the growing people which are still in a process of building personality and personal likings.
The harmful resuls that the so called Social networks create can be seen almost everywhere, most of the cafeterias I visit the bar tender uses facebook or youtube all da long, most of random people I see outside in a coffee or university or any public institution where internet access is available they are again in Youtube and Facebook. The result is people almost did not use the Net but just hang around in those few services wasting network bandwidth and loading networks and computer equipment and spending energy for nothing. The wasteful computer and Internet deepens the ecologic problems as energy is spend on nonsense and not goal oriented tasks but on “empty” false entertainment.
Hence the whole original idea of internet for many is changed and comes to few words ( Skype, Youtube, Facebook etc.

Besides that youngsters instead of reading some classical valuable books, are staring in the computer screen most of their cognitive time at only this few “services” and are learned to become more a consumers than self opinion thinkers and inventors.
I have not lately met any growing real thinking man. I’ve seen already by own experience the IQ level of younger generations than mine (I’m 28) is getting downer and downer. Where I see as a main cause the constant interaction with technology built in a way to restrict, a consumers technology so to say.
Facebook and Youtube puts in young and growing man’s mind, the wrong idea that they should be limited choice people always praising what is newest and brightest (without taking in consideration any sight effects). These services lead people to the idea that one should always be with the crowds and never have a solid own opinion or solid state on lifely matters. As said own opionion is highly mitigated especially in facebook where all young people try to look not what they really are but copy / paste some trendy buzz words, modern style or just copying the today’s hearoes of the day. This as one can imagine prevents a person of getting a strong unique self identity and preference on things.

Many of the older people or computer illiterates can hardly recognize the severe problems, as they’re not aware on the technical side of things and does not realize how much security compromising as well as binding the constant exposure to those online hives are.
The purpose of this small post is hence just a small attempt to try to raise up some awareness of the potential problems, we as society might face very soon if we continue to follow the latest buzz trends instead of stop for a moment have a profound think on what is the moral consequences of giving so much power on Internet medias like Facebook and Youtube? …