WebSphere: Temporarily disable Global Security

Today, I got stuck at the login screen of IBM WebSphere and getting message "Invalid UserId or Password". Investigated the issue and found that due to some misconfigurations in config file, I was unable to login into WebSphere Admin console and weird thing is that to fix the issue, I have to login into admin console.

Below are the steps to temporarily disable the global security in WebSphere:
1. Open security.xml file in a text editor and locate the following text: useLocalSecurityServer="true" useDomainQualifiedUserNames="false" enabled="true" cacheTimeout="600"
Change both useLocalSecurityServer and enabled to "false".
useLocalSecurityServer="false" useDomainQualifiedUserNames="false" enabled="false" cacheTimeout="600"
2. Save the file then start/restart WebSphere services.
3. Save the file then start/restart WebSphere services.
4. Once the services are started, you will be able to access WebSphere Admin console with any username. This allows any incorrect configurations to be changed and re-tested.
5. Ensure that above parameters are reverted once the issue is resolved and restart the services.

Glassfish server - awesome open-source application server

GlassFish Server, an open-source application server project started by Sun Microsystems for the Java platform and currently sponsored by Oracle.

Glassfish server have huge list of its features. Few of them are listed here.

1. Java EE certification: Oracle GlassFish Server was the first Java EE 5–certified application server and is the first Java EE 6–certified application server, providing developers community a head start in taking advantage of the latest advancements in Java technology.

This operation has been restricted due to restrictions in effect on this computer. Please contact your system administrator.

Today when I started my day in office, I found that some applications we not working as they used to be. And when tried to start them, I got an error dialog box with a message "This operation has been restricted due to restrictions in effect on this computer. Please contact your system administrator.". It seems that IT dept has made some restrictions for applications.

Command Prompt: searching port status and killing a process

Today, while working with Glassfish server, I encounted a weird issue that I restarted Glassfish server but Glassfish failed to start and the most annoying thing was, I found nothing in it's logs. Tried to restart Glassfish from windows service several time but all in vain.
Then I tried to check all the ports used in Glassfish. Ports used by Glassfish can be checked from domain.xml file. Search "http-listner" and make a list of ports.

VMware: Prepare list of VMs with snapshots using PowerShell

VMware snapshots plays important role for VM backup. It is recommended to remove old snapshots as they consume space and may create problems if somebody revert the VM with old snapshot. If you have handsome amount of Virtual Machines, then it will be difficult and time consuming for you to manage those snapshots manually. 

Managing Old logs on server using Windows batch script

Most of the time system administrators are dealing with old log files like backing up the old logs manually and removing the original logs. To reduce their headache, here we have a small script, which provides flexibility to manage those old logs in very handy manner. Administrators just need to set the variables in the script as per there requirement and let the script do the magic.

About the script: This script takes the backup of all the log files older then specified number of days and after backup, it automatically deletes the original files and spare the disk space. 
A job can be schedules either on daily or weekly basis to execute this script and manage old log files on the server.

Linux: netstat command

netstat (network statistics) is a command used for monitoring network connections (incoming & outgoing) as well as viewing routing tables, interface statistics etc. netstat is available on all Unix-like Operating Systems and also available on Windows operating system.

Features:
a. Useful in terms of network troubleshooting (traffic, ports, network connections), networking statistics and performance measurement.
b. netstat is one of the most basic network service debugging tools, telling you what ports are open and whether any programs are listening on ports.
c. provide detailed information about how a computer is communicating with other computers or network devices.

Grant Users Access to your Outlook Calendar

Outlook Calendar -  a very powerful tool to manage your emails, appointments, meetings, calendars, notes, contacts etc. Everyone has used the Outlook product of Microsoft, which has really made our lives easy. We all know that we can schedule our appointments and send meeting invitations in Outlook calendar but today we are going to reveal another trick to grant user access to our calendar so that other person (having permission) can edit our calendar. You must open Microsoft Outlook to perform the steps below:

Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ for update!

Error: Could not open command file ‘/usr/local/nagios/var/rw/nagios.cmd’ for update!,An error that comes up from time to time and is quite annoying to deal with, I found a way to fix the problem, it is not the best way, but it is simple and fast.

Ubuntu: Segmentation fault (core dumped)

Segmentation fault: Generally such kind of errors are caused by addressing non-existent/allocated memory location. Today I encountered this error while executing "apt-get install" command.

   root@gh008:~# apt-get install binutils
   Segmentation fault (core dumped)

 

I googled around for this issue and finally got two solution for this problem. 

Nagios: Unable to check HTTPS service using check_http

Nagios is a powerful IT infrastructure monitoring solution available in market. It provides monitoring graphically. I installed Nagios Core on a server and after the completion of nagios configuration, I checked that Nagios is not able to ping the host on which https is enabled. 

Configure Gmail SMTP Relay

SMTP stands for Simple Mail Transfer Protocol, lets you send email messages through your email account using your existing email service. This email service is subject to your interest. It could be any like: Gmail Relay, Snail Mail etc.

In this post we are going to configure Gmail Relay to send emails.

Nagios HTTP WARNING: HTTP/1.1 403 Forbidden Solved

I setup a nagios server and after the setup, I encounter a warning "Nagios HTTP WARNING: HTTP/1.1 403 Forbidden".

Nagios Server Configuration for different hosts

In our previous posts, we learn how to install nagios, how to install NRPE or NSClient++. Now let's have a look on configuring hosts in nagios in best practical way Nagios Server Configuration for different hosts.

It will be good practice if we configure the client hosts in groups on Nagios Server.

Steps to Group clients servers:

1. Create locations for host configuration files:

In our configuration, we are grouping servers in 4 main categories:

Nagios NRPE Installation

In previous article, we learn how to install nagios (monitoring tool). Now we'll learn how to install nagios agent on the system, which needs to be monitored in nagios. This Agent tool is known as Nagios NRPE (for linux). To monitor system having Windows operating system, we need to install NSClient++. NSClient++ is very easy to install as it is simply a .exe file. Here are the steps to install NRPE plugin (agent) on linux machine:

Nagios Installation

NAGIOS: It's a monitoring tool used widely in server administration. When we have large no. of system like in data centers then we need some technology to monitor our data base servers, application servers, routers, other machines etc. 

Nagios provides a complete solution for this. Nagios provides graphical reports and monitoring of our network & servers. In order to setup nagios successfully, we need to install nagios on one server and different machines, servers will be configred in it. To communicate with configured hosts (servers), we need to install NRPE agents on servers, which need to be monitored. 

Setting Environment Variable in LINUX

Environment variables in LINUX are basically the shell variable used to set configuration options and customize the shell environment under Linux. 



Display Environment variables

    $ env

Here is the syntax of setting environment variables 

Organizing short folder structure Using mod_rewrite

Sometimes long folder names become annoying to type and can cause your page to result in huge loading time. Thank GOD !!! .htaccess file is there with a solution for this problem. It also leads to Search engine friendly URLS and image names (for image searches) 

Change system Password using Command Prompt

We can change the system password using command prompt. To change the password, you must be logged in as administrator and run "net user" command to change the password of a user.

    net user user_name new_password

Example:

    net user gaurav saini

Allow or Block IPs Address - .htaccess Security

Hypertext Access, commonly shortened to htaccess, is a configuration file which controls the directory it is placed in and all the subdirectories underneath it. It's an incredibly useful feature which allows webmasters to control how many aspects of their website works. You can 301 redirect pages, change the extensions of pages, rewrite urls for better keyword ranking presence, password protect directories, Error 404 Document redirect and much much more. .htaccess provide security to allowing and blocking access to a web server from a IP address. Reasons for doing this include: