Daemonctrl will be the script to start/stop the process which will contain the information of list of modules and the number of instances for each module.
Which internally calls the DaemonControl.pm Module which starts the parent and then calls the start module with the module name and fork the child/children.
The info regarding the process will be in proc_tbl and also a pid file <module_name.pid>.
The config is passed from an external file start.conf <default config>.
Config Parameters:
# ------------------------------------------------
# Initialize Contfiguration Parameters
# ------------------------------------------------
$Config::config = {
'sleep_time' => 5,
'start_time' => time(),
'db_m' => 'dbi:mysql:host=mysql:database=daemon’,
'db_user_m' => ‘uname’,
'db_pass_m' => 'password',
'upload_dir' => '/home/sandeep',
};
1;
$./daemonctrl start [module_name].
$./daemonctrl stop [module_name] [-F(force exit)]
$./daemonctrl show.
LOGGING:
The error logs will be logged on to a file at a specified location (LOG_DIR/<modulename.log>).
Implementation:
Base Class
Base class for all perl classes. Includes basic methods available to all
classes. Methods may be overridden by children if neccessary.
Init Class
Init contains methods to read and write config (.ini) files.
1. Each line in a config file can contain at most one key/value pair.
2. All keys are demoted to lower case during loading.
3. Any portion of a line following a '#' and including the '#' is ignored.
ProcTbl Class
$proc_tbl->update( $count_delta ) method executes proc_ins( ..... )
inserting/updating row in prod_tbl with current process statistics
DaemonControl class
Read the daemonctrl file for list of modules and instances and forking the process.
start class
Perl Module/Process Wrapper
start initializes environment and launches a single perl process.
start.conf
Default config file for framework.
./modules/module_name.conf
Separate config file for each module.
./logs/module_name.pid
Contains the pid information for the parent and the forked children.
daemonctrl
# -------------------------------------
# Module Name, Number Of Instances
# -------------------------------------
my @module_list = (
[ 'Report', 1 ],
);
DaemonControl::exec(\@module_list, \@ARGV);
Example:
$./daemonctrl start Report.
STARTING: (./start -mReport -i0 -ls -n 1 )
$./daemonctrl show.
MODULE WHO Inst UID PID PPID START_TIME
===========================================================
Report
PARENT 0 sandeep 5000 1 06:59
CHILD 0 sandeep 5001 5000 06:59
$./daemonctrl stop Report -F
STOPPING PROC [5000]: /usr/bin/perl -w ./start -mReport -i0 -ls -n 1
STOPPING CHILD [5001]: /usr/bin/perl -w ./start -mReport -i0 -ls -n 1
$./daemonctrl show.
MODULE WHO Inst UID PID PPID START_TIME
===========================================================
Report **** NOT RUNNING ****
$cat ./logs/Report.I0.log
[sun 07dec08 06:59:02]: --- Opening new log file [Report.7.dec.08.I0] ---
[sun 07dec08 06:59:02]: Starting Process: Report.0
[sun 07dec08 06:59:02]: Starting instance [0], num_instances [1]