Now it is cool to monitor your application on a regular basis.
Because I’m used to shell scripting in LINUX I present you here a scripting solution within a bash shell. But I’m sure you can do the same in Windows.
The idea is to set up a cron job ( for windows use the scheduler) and get the statuspage from your tomcat every – lets say – five minutes.
Get some of the interesting values out of this page and save them in a csv – File.
Create a new file every day. Perhaps you want to use this files as input for a spreadsheet program to create some nice charts.

But to be honest – this is a very special script – you have to adopt it to your needs.
This are the basic prerequisites:

• you need linux to run it (this script is developed on a SUSE – Distribution)
• eventually you need to install some tools (I think the w3m tool is not bundled with every linux distribution)
• this script only! works correct with a tomcat 6.0 version

#!/bin/bash
# -configure below-
HTTPPORT="8080"    # The http Port of your tomcat
JKPORT="8709"      # The Modjk Port of your tomcat (if your tomcat should be reachable from a apache webserver)
SERVER="localhost:$HTTPPORT" # you can even monitor a tomcat on another server!
USER="tomcat-oper" # the account and
PW="IwantItAll"    # password you have defined in tomcat-users.xml
APPL="CoolAppl"    # The name of your application
# -configure above-
TODAY=`date ‘+%m-%d-%y’`
TIME=`date ‘+%H:%M:%S’`
OUTFILE="tomcat-stats-${TODAY}.csv"
#
#set -x   # uncomment if you want to improve the script or if you are searching for a bug
#
# # If there is no csv-file create one and put a headerline in
if !(test -e $OUTFILE) then
  echo "Time,FreeMemory,UsedMemory,MaxMemory,HttpThreadsMax,
  HttpThreadsBusy,ModJKThreads,ModJKThreadsBusy,Sessions" > $OUTFILE
fi
# # get the statuspage from tomcat – filter it for the wanted informations – and create a temporary file
  w3m -dump http://${USER}:${PW}@${SERVER}/manager/status/all| \
  egrep "(memory|thread|Active sessions|
  ^JVM|$HTTPPORT|$JKPORT|${APPL})" >/tmp/tomcat-status
#
# # put the values in variables / uncomment to get a better understanding of the process
#
while read line
   do
      case $line in
           JVM) read line
                JVM_VALUE=`echo $line | awk ‘{print($3 "," $7 "," $11)}’`
#               uncomment below if you want to debug
#               echo "JVM_VALUE: <$JVM_VALUE>"
                ;;
            *${HTTPPORT}) read line
                HTTP_MAX_THREADS=`echo $line |awk ‘{print("," $3)}’`
#               uncomment if you want to debug
#               echo "HTTP_MAX_THREADS: <$HTTP_MAX_THREADS>"
                HTTP_BSY_THREADS=`echo $line |awk ‘{print("," $11)}’`
#               uncomment below if you want to debug
#               echo "HTTP_BSY_THREADS: <$HTTP_BSY_THREADS>"
                ;;
            *${JKPORT}) read line
                MODJK_MAX_THREADS=`echo $line |awk ‘{print("," $3)}’`
#               uncomment below if you want to debug
#               echo "MODJK_MAX_THREADS: <$MODJK_MAX_THREADS>"
                MODJK_BSY_THREADS=`echo $line |awk ‘{print("," $11)}’`
#               uncomment below if you want to debug
#               echo "MODJK_BSY_THREADS: <$MODJK_BSY_THREADS>"
                ;;
            *${APPL}) read line
                SESSION_CNT=`echo $line |awk ‘{print("," $3)}’`
#               uncomment below if you want to debug
#               echo "SESSION_CNT: <$SESSION_CNT>"
                ;;
            *) ;;
      esac
    done < /tmp/tomcat-status
# # Now is the time to write the data to the csv-file
  echo "${TIME},${JVM_VALUE}${HTTP_MAX_THREADS}${HTTP_BSY_THREADS}
  ${MODJK_MAX_THREADS}${MODJK_BSY_THREADS}${SESSION_CNT}" >>$OUTFILE
exit

*) be aware that based on word wrapping this script might not work instantly

Create a scriptfile (e.g. tomcat-check.sh) and apply the script to your tomcat. Then edit your crontab.

There should be a line like:
"*/5 * * * * cd ~/statistics; ./tomcat-check.sh 1>tomcat-check.log 2>&1"

And then the script should create the csv-files. I’m not used to excel – but even I managed to create a more or less interesting diagram from this data. Note how regular the memory behaves while there is no user session.

A basic security can be established by a password restricted folder access, enforced by the Apache Webserver itself.

This can be done by some simple instructions added to our .htaccess file:
(In case you haven’t already a .htaccess file, just create a new file calling it .htaccess and locating it in the folder you want to protect.)

AuthType Basic
AuthName "Protected Area"
AuthUserFile FILE
require valid-user

These commands will tell the Apache webserver that the folder in question (and all below) are now protected and it needs a valid combination of username/password to access it.

• AuthName is some free form text you can specify, telling the visitor what you are asking for and Apache Webserver will show in it’s dialog box.

• AuthUserFile is the reference to the stored .htpasswd file containing all valid username/password combinations to access the folder in question (ususally and best located out of the protected directory tree).

Having that done we now need to create the necessary .htpasswd file which we can do interactive on our server with the command:

htpasswd2 -c FILE USER

Assuming html is your webroot, a valid example, for protecting a folder called images below our webroot and using demouser/demopassword as user credentials, would be:

.htaccess:
(Locate this file within the folder images and be aware to use an absolute path for AuthUserFile, as for www.domain.com would be wrong!)

AuthUserFile /home/username/html/.htpasswd
AuthType Basic
AuthName "Login for Secure Area"
require valid-user

.htpasswd
(Create a new file called .htpasswd and locate this file within the folder you’ve specified within AuthUserFile path.)

demouser:$1$OHq3K5v3$pvFrGsHjWwYjpkZhc70T9.

SQL>  select * from v$transportable_platform;

   PLATFORM_ID PLATFORM_NAME                    ENDIAN_FORMAT
  
             1 Solaris[tm] OE (32-bit)          Big
             2 Solaris[tm] OE (64-bit)          Big
             7 Microsoft Windows NT             Little
            10 Linux IA (32-bit)                Little
             6 AIX-Based Systems (64-bit)       Big
             3 HP-UX (64-bit)                   Big
             5 HP Tru64 UNIX                    Little
             4 HP-UX IA (64-bit)                Big
            11 Linux IA (64-bit)                Little
            15 HP Open VMS                      Little
             8 Microsoft Windows IA (64-bit)    Little
             9 IBM zSeries Based Linux          Big
            13 Linux 64-bit for AMD             Little
            16 Apple Mac OS                     Big
            12 Microsoft Windows 64-bit for AMD Little

But be aware that depending on which plattforms we deal with there might be some converting necessary or not!

To help you with that, I have carried together the little cook book about "How to do" below:

1. Set the tablespace to READ ONLY

SQL> alter tablespace USERS read only;
Tablespace altered. 

2. Export metadata

exp userid=\’/ as sysdba\’ transport_tablespace=y
tablespaces=users
file=users_tts.dmp log=exp_users_tts.log
statistics=none

3. Converting tablespace if necessary

Depending on we have to convert the file between endianness Little and endianness Big (forward or backward) we can do that with RMAN:

rman target=/

Recovery Manager: Release 10.2.0.3.0 – Production on Wed Dec 10 13:10:57 2008
connected to target database: orav10 (DBID=1953618181)

RMAN> convert tablespace ‘USERS’
2>  to platform="Linux IA (32-bit)"
3>  db_file_name_convert=’/database/orav10/datafiles/users.dbf’,
4>  ‘/tmp/users.dbf’;

4. Move datafiles and export dump file

$ftp users_tts.dmp

and /database/orav10/datafiles/users.dbf (no conversion)
or /tmp/users.dbf (converted file if conversion had been required)

5. Import metadata

imp userid=\’/ as sysdba\’ TRANSPORT_TABLESPACE=Y
datafiles=/database/orav10/datafiles/users.dbf
(or /tmp/users.dbf )
file=users_tts.dmp log=imp_users_tts.log

6. Set the tablespace to READ WRITE

SQL> alter tablespace USERS read write;
Tablespace altered.

sqlplus: error while loading shared libraries: libsqlplus.so: cannot open shared object file: No such file or directory

or

Error 6 initializing SQL*Plus
Message file sp1us.msb not found
SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory

Syntax:
$ sqlplus username/password

You get this error only when you execute ‘sqlplus’ as a user outside of the dba or Oracle group, because in Oracle Database 10g Release 2 the Oracle Home was locked down by setting umask to 007 prior to installation, so that the files that sqlplus needs to execute do not have read/execute permissions for group "others" and some directories under $ORACLE_HOME have no world read nor execute permission (rwxr-x—)

Warning , don’t use the following command to lower the permissions, this may corrupt your Oracle-Installation:
chmod -R 755 $ORACLE_HOME/

The better way is to use an script which is provided by oracle:
$ORACLE_HOME/install/changePerm.sh

This script will relax the permissions on most files and directories in your Oracle Home, and allow "others" to execute them.

Now the good news is that when working in a LAMP (Linux, Apache, MySQL and PHP) environment you do not really need to have deep knowledge about relational databases to succeed.

Most tools like CMS do a full automated setup for you and the only knowledge it needs to have starting with them, is the server and database name and finally the login credentials (username/password) to access it.

Just later on the one or other maintenance work will occur and you will feel the need of having some nice and neat database interface to work with. Knowing about this need today I will recommend you a few tools and you should feel free to choose one or each of them based on your platform and taste.

The first tool I will recommend you is called phpMyAdmin. It is written in PHP and as a so called browser tool it works platform independent and flawless in all common browsers. Very often being offered by hosting providers it is mostly already part of your hosting package and easy to access and use. Coming along with all necessary options like browsing and navigating through your databases, it also offers a SQL interface and the often necessary export/import options. Personally it is my favorite tool to work with.

Once you are familiar with phpMyAdmin, phpMyBackupPro is another very similar tool you might find it worth to look at. Also browser based it is mainly written for interactive exports and imports, but can get also use for scheduled automatic backups.

For Windows platform only I would like to recommend you a tool called MyDB Studio. Coming along with a well designed interface it offers all features you need and the license it needs is given away for free in case you only use it for private and non commercial interests. It just needs you to give them a valid email address and the key is emailed to you quickly after.

And now finally and last in case you are such a Macintosh guru, I would like to recommend you CocoaMySQL. It does a similar great job like the others and can get used right away after the installation has taken place. What I like is the console view of is, showing you all command issued during the past and looking at it you might even learn some SQL (Structured Query Language).