SUMMARY
IPC::Locker provides a server for locks and a Perl package for clients to access that server. The result is that clients can access named locks on a Internet wide basis, solving critical section problems without the mess of NFS or other file locking techniques.
The latest version is available from CPAN and from https://www.veripool.org/ipc-locker.
EXAMPLE
use IPC::Locker;
# ...
my $lock = IPC::Locker->lock(host=>'example.std.com');
# ... Critical section ...
$lock->unlock;
INSTALLATION
Build and Install the Package
Install from CPAN:
cpan install IPC::Locker
Or, build from sources:
# Obtain distribution kit
git clone git@github.com:veripool/IPC-Locker.git
# Build
cd IPC-Locker
git pull
perl Makefile.PL
make
make test
make install
Install the Daemons
You may wish to install lockerd
and pidstatd
in a init.rc file so that it is run at system startup. Depending on your distribution, you may be able to just:
cp init.d/lockerd /etc/init.d/lockerd # On one server only
cp init.d/pidstatd /etc/init.d/pidstatd # On all machines
Edit paths in above to point to /usr/bin instead of /usr/local/bin, if needed.
service lockerd start # On one server only
service pidstatd start # On all machines
chkconfig lockerd on # On one server only
chkconfig pidstatd on # On all machines
If you get "This account is currently not available." you need to change the daemon account from a shell of /sbin/nologin to /sbin/bash.
Nagios
If you are using Nagios http://www.nagios.org, sample scripts to check the daemons are included in the nagios subdirectory.
DOCUMENTATION
IPC::Locker provides the following programs/packages:
lockerd
lockerd
is the daemon that supports IPC::Locker. See man lockerd
after installation.
IPC::PidStat
IPC::PidStat
is a Perl package which answers the question, "is pid X running on host Y?". See man IPC::PidStat
after installation.
pidstat
pidstat
is a program which answers the question, "is pid X running on host Y?". See man pidstat
after installation.
pidstatd
pidstat
is the daemon that supports IPC::PidStat
and pidstat
. See man pidstatd
after installation.
pidwatch
pidwatch
is a program which starts other programs, and kill that program when another job exists. See man pidwatch
after installation.
uriexec
uriexec
is a simple wrapper which allows executing a command which is quoted using URI escapes. This prevents layered shells from interpreting special characters. See man uriexec
after installation.
check_lockerd and check_pidstatd
check_lockerd
and check_pidstatd
are Nagios plugins to check lockerd
and pidstatd
. See the Nagios documentation at https://www.nagios.org for information on installing plugins.
LICENSE
This package is Copyright 1999-2022 by Wilson Snyder <wsnyder@wsnyder.org>.
This program is free software; you can redistribute it and/or modify it under the terms of either the GNU Lesser General Public License Version 3 or the Perl Artistic License Version 2.0. This code is provided with no warranty of any kind, and is used entirely at your own risk.