Thread Dumps in WebLogic12c Server

Thread Dumps in WebLogic12c Server

Here I am going to provide information about different ways on taking java thread dumps in a WebLogic Server environment.

Thread dumps are very useful to analyze and troubleshoot performance related issues such as server hang, deadlocks, slow running, idle or stuck applications,  etc.

Different ways to take thread dumps in WebLogic Server 

Always prefer Operating system(OS) commands rather instead of Admin Console or Java Classes, because if the console is hanging, users won't be able to connect to it to issue thread dumps.

1. OS Commands for Thread Dumps

i) On Windows,

<ctrl>+<break> -- the thread dumps are generated in the server stdout

ii) On Solaris / Linux

first identify the process ID (pid) using   ps -ef | grep java, then run   kill -3 <pid> td_filename 2>&1

2. Using weblogic.WLST ( work only from WLS 9.x onwards)


First set CLASSPATH using setDomain.cmd or setDomain.sh (wlst.sh /wlst.cmd will also do in path C:\Oracle\Middleware\wlserver_12.1\common\bin ). Then run below command

java weblogic.WLST ThreadDumps.py

save below code in ThreadDumps.py file:
connect("<username>","<password>","t3://<url>:<port>")
cd(‘Servers’)
cd(‘AdminServer’)
threadDump()
disconnect()
exit()
threadDump()

The thread dumps get stored in the location from where you run it.

3. From Weblogic Administration Console

navigating to Server -> <server_name> -> Monitoring -> Dump threads stack.

4. From the JRockit Command line

jrcmd <pid> print_threads

Thread Dumps in WebLogic12c Server

Here going to provide information about different ways on taking java thread dumps in a WebLogic Server environment.

Thread dumps are very useful to analyze and troubleshoot performance related issues such as server hang, deadlocks, slow running, idle or stuck applications,  etc.

Different ways to take thread dumps in WebLogic Server

Always prefer Operating system(OS) commands rather instead of Admin Console or Java Classes, because if the console is hanging, users won’t be able to connect to it to issue thread dumps.

1. OS Commands for Thread Dumps

i) On Windows,

<ctrl>+<break> — the thread dumps are generated in the server stdout

ii) On Solaris / Linux

first identify the process ID (pid) using   ps -ef | grep java, then run   kill -3 <pid> td_filename 2>&1

2. Using weblogic.WLST ( work only from WLS 9.x onwards)

First set CLASSPATH using setDomain.cmd or setDomain.sh (wlst.sh /wlst.cmd will also do in path C:\Oracle\Middleware\wlserver_12.1\common\bin ). Then run below command

java weblogic.WLST ThreadDumps.py

save below code in ThreadDumps.py file:
connect(“<username>”,”<password>”,”t3://<url>:<port>”)
cd(‘Servers’)
cd(‘AdminServer’)
threadDump()
disconnect()
exit()
threadDump()

The thread dumps get stored in the location from where you run it.

3. From Weblogic Administration Console

navigating to Server -> <server_name> -> Monitoring -> Dump threads stack.

4. From the JRockit Command line

jrcmd <pid> print_threads

CURL Commands

Password secure:

curl –data-binary @<Filename> -k -u adminhttps://hostname:5550Admin Password

Non password secure:curl –data-binary @request.xml https://hostname:5550 -u admin:{adminPW} -k

To check weather server is up or not:curl -f http://<hostname&gt;:7400/monitor

How to install GCC in linux

Important messages about GCC:

GCC version :     $ gcc -v

gcc path  :  $which gcc

If you are using Red Hat Enterprise Linux, type the command:

# up2date gcc

If you are using CentOS/Fedora Core Linux, type the command:

# yum install gcc

Some important GCC commands :

$ which gcc
/usr/bin/gcc

$ whereis gcc
gcc: /usr/bin/gcc3.2-version /usr/bin/gcc /usr/local/bin/gcc /usr/share/man/man1/gcc.1.bz2 /usr/share/man/man1/gcc.1

$ gcc -v
Reading specs from /usr//bin/../lib/gcc-lib/i586-mandrake-linux-gnu/3.3.1/specs
Configured with: /usr/local/src/gcc-3.3.1/configure –prefix=/usr –libdir=/usr/lib –with-slibdir=/lib –mandir=/usr/share/man –infodir=/usr/share/info –enable-shared –enable-threads=posix –disable-checking –enable-long-long –enable-__cxa_atexit –enable-languages=c,c++,ada,f77,objc,java –host=i586-mandrake-linux-gnu –with-system-zlib
Thread model: posix
gcc version 3.3.1

$ gcc –version
gcc (GCC) 3.3.1
Copyright (C) 2003 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Install GCC in linux:

su -
passwrd:

mkdir /usr/local/src
cd /usr/local/src

gunzip /tmp/gcc-3.3.1.tar.gz #where I downloaded the file
tar xvf /tmp/gcc-3.3.1.tar

cd /opt/build
/usr/local/src/gcc-3.3.1/configure
–prefix=/usr –libdir=/usr/lib –with-slibdir=/lib –mandir=/usr/share/man –infodir=/usr/share/info –enable-shared –enable-threads=posix –disable-checking –enable-long-long –enable-__cxa_atexit –enable-languages=c,c++,ada,f77,objc,java –host=i586-mandrake-linux-gnu –with-system-zlib

make
make install

copy file from one linux to another linux box using SCP

sending a file from one linux box to another linux box.

scp stands for secure cp (copy), which means that you can copy files across an ssh connection that will be encrypted, and therefore secured.

You can this way copy files from or to a remote server, you can even copy files from one remote server to another remote server, without passing through your PC.

Usage

scp [[user@]from-host:]source-file [[user@]to-host:][destination-file]

Description of options

from-host

Is the name or IP of the host where the source file is, this can be omitted if the from-host is the host where you are actually issuing the command

user

Is the user which have the right to access the file and directory that is supposed to be copied in the cas of the from-host and the user who has the rights to write in the to-host

source-file

Is the file or files that are going to be copied to the destination host, it can be a directory but in that case you need to specify the -r option to copy the contents of the directory

destination-file

Is the name that the copied file is going to take in the to-host, if none is given all copied files are going to maintain its names

Options

-p

Preserves the modification and access times, as well as the permissions of the source-file in the destination-file

-q

Do not display the progress bar

-r

Recursive, so it copies the contents of the source-file (directory in this case) recursively

-v

Displays debugging messages

Examples

scp *.txt user@remote.server.com:/home/user/

This will copy all files with .txt extension to the directory /home/user in the remote.server.com host

scp -r subha@10.1.2.2:/home/subha/ subha@10.1.2.3:/home/subha/

This is going to recursively copy all files from miguel’s Home directory on 10.1.2.2 host to his Home directory in 10.1.2.3 host.

list of UNIX/Linux or Bash commands (Snapshot)

UNIX OR BASH COMMANDS
adduser      Add a user to the system
  addgroup     Add a group to the system
  alias        Create an alias •
  apropos      Search Help manual pages (man -k)
  apt-get      Search for and install software packages (Debian)
  aspell       Spell Checker
  awk          Find and Replace text, database sort/validate/index

  basename    Strip directory and suffix from filenames
  bash        GNU Bourne-Again SHell
  bc          Arbitrary precision calculator language
  bg          Send to background
  break       Exit from a loop •
  builtin     Run a shell builtin
  bzip2       Compress or decompress named file(s)

  cal         Display a calendar
  case        Conditionally perform a command
  cat         Display the contents of a file
  cd          Change Directory
  cfdisk      Partition table manipulator for Linux
  chgrp       Change group ownership
  chmod       Change access permissions
  chown       Change file owner and group
  chroot      Run a command with a different root directory
  chkconfig   System services (runlevel)
  cksum       Print CRC checksum and byte counts
  clear       Clear terminal screen
  cmp         Compare two files
  comm        Compare two sorted files line by line
  command     Run a command - ignoring shell functions •
  continue    Resume the next iteration of a loop •
  cp          Copy one or more files to another location
  cron        Daemon to execute scheduled commands
  crontab     Schedule a command to run at a later time
  csplit      Split a file into context-determined pieces
  cut         Divide a file into several parts

  date        Display or change the date & time
  dc          Desk Calculator
  dd          Convert and copy a file, write disk headers, boot records
  ddrescue    Data recovery tool
  declare     Declare variables and give them attributes •
  df          Display free disk space
  diff        Display the differences between two files
  diff3       Show differences among three files
  dig         DNS lookup
  dir         Briefly list directory contents
  dircolors   Colour setup for `ls'
  dirname     Convert a full pathname to just a path
  dirs        Display list of remembered directories
  dmesg       Print kernel & driver messages
  du          Estimate file space usage

  echo        Display message on screen •
  egrep       Search file(s) for lines that match an extended expression
  eject       Eject removable media
  enable      Enable and disable builtin shell commands •
  env         Environment variables
  ethtool     Ethernet card settings
  eval        Evaluate several commands/arguments
  exec        Execute a command
  exit        Exit the shell
  expect      Automate arbitrary applications accessed over a terminal
  expand      Convert tabs to spaces
  export      Set an environment variable
  expr        Evaluate expressions

  false       Do nothing, unsuccessfully
  fdformat    Low-level format a floppy disk
  fdisk       Partition table manipulator for Linux
  fg          Send job to foreground
  fgrep       Search file(s) for lines that match a fixed string
  file        Determine file type
  find        Search for files that meet a desired criteria
  fmt         Reformat paragraph text
  fold        Wrap text to fit a specified width.
  for         Expand words, and execute commands
  format      Format disks or tapes
  free        Display memory usage
  fsck        File system consistency check and repair
  ftp         File Transfer Protocol
  function    Define Function Macros
  fuser       Identify/kill the process that is accessing a file

  gawk         Find and Replace text within file(s)
  getopts      Parse positional parameters
  grep         Search file(s) for lines that match a given pattern
  groups       Print group names a user is in
  gzip         Compress or decompress named file(s)

  hash         Remember the full pathname of a name argument
  head         Output the first part of file(s)
  help         Display help for a built-in command •
  history      Command History
  hostname     Print or set system name

  id           Print user and group id's
  if           Conditionally perform a command
  ifconfig     Configure a network interface
  ifdown       Stop a network interface
  ifup         Start a network interface up
  import       Capture an X server screen and save the image to file
  install      Copy files and set attributes

  join         Join lines on a common field

  kill         Stop a process from running
  killall      Kill processes by name

  less         Display output one screen at a time
  let          Perform arithmetic on shell variables •
  ln           Make links between files
  local        Create variables •
  locate       Find files
  logname      Print current login name
  logout       Exit a login shell •
  look         Display lines beginning with a given string
  lpc          Line printer control program
  lpr          Off line print
  lprint       Print a file
  lprintd      Abort a print job
  lprintq      List the print queue
  lprm         Remove jobs from the print queue
  ls           List information about file(s)
  lsof         List open files

  make         Recompile a group of programs
  man          Help manual
  mkdir        Create new folder(s)
  mkfifo       Make FIFOs (named pipes)
  mkisofs      Create an hybrid ISO9660/JOLIET/HFS filesystem
  mknod        Make block or character special files
  more         Display output one screen at a time
  mount        Mount a file system
  mtools       Manipulate MS-DOS files
  mv           Move or rename files or directories
  mmv          Mass Move and rename (files)

  netstat      Networking information
  nice         Set the priority of a command or job
  nl           Number lines and write files
  nohup        Run a command immune to hangups
  nslookup     Query Internet name servers interactively

  open         Open a file in its default application
  op           Operator access

  passwd       Modify a user password
  paste        Merge lines of files
  pathchk      Check file name portability
  ping         Test a network connection
  pkill        Stop processes from running
  popd         Restore the previous value of the current directory
  pr           Prepare files for printing
  printcap     Printer capability database
  printenv     Print environment variables
  printf       Format and print data •
  ps           Process status
  pushd        Save and then change the current directory
  pwd          Print Working Directory

  quota        Display disk usage and limits
  quotacheck   Scan a file system for disk usage
  quotactl     Set disk quotas

  ram          ram disk device
  rcp          Copy files between two machines
  read         Read a line from standard input •
  readarray    Read from stdin into an array variable •
  readonly     Mark variables/functions as readonly
  reboot       Reboot the system
  rename       Rename files
  renice       Alter priority of running processes
  remsync      Synchronize remote files via email
  return       Exit a shell function
  rev          Reverse lines of a file
  rm           Remove files
  rmdir        Remove folder(s)
  rsync        Remote file copy (Synchronize file trees)

  screen       Multiplex terminal, run remote shells via ssh
  scp          Secure copy (remote file copy)
  sdiff        Merge two files interactively
  sed          Stream Editor
  select       Accept keyboard input
  seq          Print numeric sequences
  set          Manipulate shell variables and functions
  sftp         Secure File Transfer Program
  shift        Shift positional parameters
  shopt        Shell Options
  shutdown     Shutdown or restart linux
  sleep        Delay for a specified time
  slocate      Find files
  sort         Sort text files
  source       Run commands from a file `.'
  split        Split a file into fixed-size pieces
  ssh          Secure Shell client (remote login program)
  strace       Trace system calls and signals
  su           Substitute user identity
  sudo         Execute a command as another user
  sum          Print a checksum for a file
  symlink      Make a new name for a file
  sync         Synchronize data on disk with memory

  tail         Output the last part of files
  tar          Tape ARchiver
  tee          Redirect output to multiple files
  test         Evaluate a conditional expression
  time         Measure Program running time
  times        User and system times
  touch        Change file timestamps
  top          List processes running on the system
  traceroute   Trace Route to Host
  trap         Run a command when a signal is set(bourne)
  tr           Translate, squeeze, and/or delete characters
  true         Do nothing, successfully
  tsort        Topological sort
  tty          Print filename of terminal on stdin
  type         Describe a command •

  ulimit       Limit user resources •
  umask        Users file creation mask
  umount       Unmount a device
  unalias      Remove an alias •
  uname        Print system information
  unexpand     Convert spaces to tabs
  uniq         Uniquify files
  units        Convert units from one scale to another
  unset        Remove variable or function names
  unshar       Unpack shell archive scripts
  until        Execute commands (until error)
  useradd      Create new user account
  usermod      Modify user account
  users        List users currently logged in
  uuencode     Encode a binary file
  uudecode     Decode a file created by uuencode

  v            Verbosely list directory contents (`ls -l -b')
  vdir         Verbosely list directory contents (`ls -l -b')
  vi           Text Editor
  vmstat       Report virtual memory statistics

  watch        Execute/display a program periodically
  wc           Print byte, word, and line counts
  whereis      Search the user's $path, man pages and source files for a program
  which        Search the user's $path for a program file
  while        Execute commands
  who          Print all usernames currently logged in
  whoami       Print the current user id and name (`id -un')
  Wget         Retrieve web pages or files via HTTP, HTTPS or FTP
  write        Send a message to another user

  xargs        Execute utility, passing constructed argument list(s)
  yes          Print a string until interrupted
  .            Run a command script in the current shell
  ###          Comment / Remark

Switching Users: su in Linux

Switching Users: su

To switch to another user, we use su command

Running su without any parameter will automatically try to login you to root user.

You’ll be prompted for the root password and, if you enter it correctly, will drop down to a root shell.

Example:

[vih@hostname ~]$ su

It will prompt for the password, if you give the correct password you will be logged into the root shell.

If you are already in the root user(shell) and want to switch to another ID, you don’t need to enter the password when you issue this command.

If u want to login to with a particular user, then

[vih@hostname ~]$ su subha
(Or)
[vih@hostname ~]$ su – subha

The difference is,if we are using optional hyphen (-), this is tells us to switch identities and run the login scripts for that user (use the user specific environmental variables).

If there is no hyphen, the shell will take the globally set environment variables.

Linux Commands in realtime

1———->How to find  ramsize , os, os bit in Linuxarch; free -m; cat /etc/redhat-release    ( This command will tell you all these details )


2———>How to know which is 32bit and 64 bit in linuxuname -mi386 or i686 then it is 32 bit x86_64 is 64bit


3——-> How to use traceroute in windows and linux:——->in windows

> tracert <domain or IP address>Example—> tracert http://www.yahoo.com

——->in linux# traceroute <domain or IP address>Example----> traceroute www.google.com

Important commands in MIddleware Admin :

$ uname  -a                                          —————> Linux version of java.

$ java -version                               —————–> which java version it is using.

$ which java                                 —————–> where java is installed in that system.

$ ps  -ef | grep  java                  ——————> Is java is working or not.

$ps -ef  | grep httpd                ——————–> is web server is working or not.

$jboss  log-file  <path>        ———————> to see perticular log file.

$tail -f  <log file name >       ———————> to see the log file running.

$less  <log file name>         ———————- >

$tail  -200 <log file name>——————— > to see the last 200 lines of the log file.

$grep  -i  subha  <log file name >—————–> to find “subha”  in the log file .

$ find -name  subha*.*  —————————–> to find the files starting with subha.

Set Java Path in linux

SET JAVA PATH IN LINUX:

Set JAVA_HOME as follows using syntax export JAVA_HOME=<path-to-java>. If your path is set to /usr/java/jdk1.5.0_07/bin/java, set it as follows:

$ export JAVA_HOME=/usr/java/jdk1.5.0_07/bin/java

Set PATH as follows:

$export PATH=$PATH:/usr/java/jdk1.5.0_07/bin

Save and close the file. Just logout and login back to see new changes:

$ echo $JAVA_HOME
$ echo $PATH

Tip: Use the following command to find out exact path to which java executable under UNIX / Linux:

$ which java

Set JAVA_HOME / PATH for all user

You need to setup global config in /etc/profile OR /etc/bash.bashrc file for all users:

# vi /etc/profile

Next setup PATH / JAVA_PATH variables as follows:

export PATH=$PATH:/usr/java/jdk1.5.0_07/bin
export PATH=$PATH:/usr/java/jdk1.5.0_07/bin