Tuesday, August 31, 2010

JBoss Tuning Secrets

I know you are really pissed off with your JBoss performance, i am always having same feelings, even my Boss is always crying in his chair..."please please bring the fuc*ing App Server back!!!"

anyhow, the task is not easy, to tune JBoss you have to do research on your environment, there is no direct steps or command one can recommend you!

though i have attached a pdf here, it is the best article i could find, and ofcourse with little intelligence you can make JBoss optimum performance.

i am really thankful to the writer of this article, he did great job!


Wednesday, August 18, 2010

Saudis are busy!

I have been wondering for years to figure out, what Saudis are doing... i always thought they are doing nothing, just earning money from their tourist industry (HAJJ & UMRAH) or sleeping at canals of God gifted petroleum reserves... but i was wrong, no believe me... i was seriously wrong! they are really busy nation, exploring new era of FATWAS for rest of the muslims world... i was before completely convense that the most extreamist thoughts has been injected by saudi's to muslim world, just to keep everybody intact to their tourist industry... but NO, i was really wrong!

today i received an email from a friend, with following attachment. i have nothing to say after it!

please let me know, how far i went in my wrong perception about them?


Monday, August 16, 2010

forward dns, solved huge puzzle for me

since i joined sysadmin team at our DR site, i found SSH delay on two of our test environments, the major cause was ssh version in Solaris, that force to resolve client hostname, but at DR site the ssh client's machines have different DNS server then test environment, even both test environment has their own DNS server.

initially i was working on DNS replication, but then later due to some security policies we decided to avoid DNS replication...what happen yesterday that, our official hardware support engineer came to work on a server, that lost storage connection, during some free time, i discussed this DNS & ssh delay issue, he also gave me replication idea, but during conversation, due to his poor English he used replication as forward and here i got the idea, i suddenly started laughing that how come i miss forward dns option :) so simple and easy.

i edited /etc/named.conf of my both test environment DNS server. i.e.

options {
directory “/var/named”;
forwarders { IP ADDRESS OF SSH's CLIENTs DNS ; } ;
forward only;

just a restart of DNS service and it started working like a dream :p


Thursday, August 12, 2010

error: adduser: user exists, at samba & winbind server.

One of our colleague reported "Acess Denied" during SSH login to our fileserver i.e. configured with Samba & Winbind under Centos. During the troubleshooting process i decided to remove and add the user again, after removing, when i tried to create the same user, i was getting error "adduser: user exists"... after a research on google and reading samba official manual, i discovered i.e.

"If winbindd is not running, smbd (which calls winbindd) will fall back to using purely local information from /etc/passwd and /etc/group and no dynamic mapping will be used."

so here i got the clue and created user after stoping winbind daemom. i.e.

step 1: # service winbind stop

step 2: # useradd -u 786 -g 786 -m