Memory Leak in tomcat

To prevent this particular memory leak you should edit your tomcat/conf/server.xml and change

<Listener  lassName="org.apache.catalina.core.JreMemoryLeakPreventionListener" />

to

<Listener 
className="org.apache.catalina.core.JreMemoryLeakPreventionListener"
classesToInitialize="com.mysql.jdbc.NonRegisteringDriver" />

Error parsing HTTP request header- Invalid character found in the request target.

Http11Processor.service Error parsing HTTP request header
 Note: further occurrences of HTTP header parsing errors will be logged at DEBUG level.
 java.lang.IllegalArgumentException: Invalid character found in the request target. The valid characters are defined in RFC 7230 and RFC 3986

Solution

Edit catalina.properties add below line in end of the file.

tomcat.util.http.parser.HttpParser.requestTargetAllow=|{}

 

 

Unable to Start MySQL Linux - Please read "Security" section of the manual....

ISSUE- [ERROR] Fatal error: Please read "Security" section of the manual to find out how to run mysqld as root


Solution- Start mysql using below command.

/usr/sbin/mysqld --user=root --daemonize --pid-file=/var/run/mysqld/mysqld.pid

Grep Temp Password from MySQL

As of now for latest MySQL version there is a default password. To get this password tail mysql.log file and restart MySQL instance, and you will found MySQL temporary password.

              grep 'temporary password' /var/log/mysqld.log

Restart MySQL instance

# /etc/init.d/mysqld restart

OR

# /etc/init.d/mysql restart

Your Boot Partition is on a Disk Using GTP

1. At the partitioning screen, press Ctrl + Alt + F2 to get to a shell prompt.

2. Overwrite the GPT partition label with an MSDOS label.

[root@host ~]# parted /dev/sda -s mklabel msdos

3. Press Ctrl + Alt + F6 to return to the partitioning screen, and continue installation, it may be needed to back one step up in order for the installer to see the new changes.

Root Cause

• The GRand Unifed Bootloader (GRUB) is not compiled with the ability to utilize GPT partitions in RHEL5.
• The MSDOS partition label will allow GRUB to boot correctly, but has a physical limitation of 2 TB.
• This above error was a check added in RHEL 5.2.
• In 5.0 and 5.1, the installation would continue but the ending install will not boot.

#Source- RHEL

Install RPM From Linux CD

1- Create a directory for you local repository, e.g.

/home/user/repo

.
2- Move the RPMs into that directory.
3-Fix some ownership and file system permissions:

# chown -R root.root /home/user/repo

4- Install the createrepo package if not installed yet, and run

# createrepo /home/user/repo
# chmod -R o-w+r /home/user/repo

5- Create a repository configuration file, e.g. /etc/yum.repos.d/myrepo.repo containing

[local]
name=My Awesome Repo
baseurl=file:///home/user/repo
enabled=1
gpgcheck=0

6- Install your package using

# yum install packagename

Install Adobe Flash Player CentOS

FOR 32-bit x86

Install adobe noarch and import it.

rpm -ivh http://linuxdownload.adobe.com/adobe-release/adobe-release-i386-1.0-1.noarch.rpm

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linux

FOR 64-bit x86_64

Install adobe noarch and import it.

rpm -ivh http://linuxdownload.adobe.com/adobe-release/adobe-release-x86_64-1.0-1.noarch.rpm

rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linux

Now check for update.

yum check-update

Now install flash plugin and supported libraries using yum.

yum install flash-plugin nspluginwrapper alsa-plugins-pulseaudio libcurl