 |
gxPL
1.0
Tools, Application and Framework for xPL
|
|
gxPL
1.0
Tools, Application and Framework for xPL
|
Copyright (c) 2005 -- Gerry Duprey Copyright (c) 2015, epsilonRT
gxpl-hub is an implementation of the hub necessary for using xPL based applications on a linux computer. It is compatible with any xPL application needing a hub, regardless of the underlying framework the application uses.
Each computer that runs xPL based applications needs one xPL hub running. In cases where the computer has more than one network interface, you may need to run one hub per interface, but that is a moderately unusual setup.
gxpl-hub comes with an automatic supervisory function. When you start gxpl-hub, a very small, simple and well tested supervisor is what really runs. It then starts the hub and monitors it. If the hub dies for any reason, the supervisor will clean it up and start a new hub. Since hubs are so esscential to the operation of xPL applications, this sort of function is crucial.
The Hub portion of gxpl-hub has been proven in operation on a number of machines for long periods of times. It's exceedingly unlikely it would crash or cease to function in the first place. Given that reliability and the supervisory abilities to restart it in such a case, you should be able to expect nearly 100% uptime.
If the hub ever dies and needs to be restarted, gxpl-hub will make an entry in your system log file (using the syslog facility). In addition, in a worst case scenario where the hub cannot run and the supervisor keeps trying to restart it (which could consume a lot of system recources), there is a "circuit breaker" that will kick in after the supervisor attempts to start he hub more than 10,000 times. If that happens, the supervisor will log a message to the system explaining what happened (again, via syslog) and then terminate. In such a massive failure, 10,000 iterations can be completed in a few minutes, so the machine will not be crippled for long. This happening is very, very unlikely.
In all the above just means you can expect 100% uptime from gxpl-hub once it is started.
Build and install the library:
cd gxPL make sudo make install
Build and install the tools (hub, logger ...):
cd tools make sudo make install
Run the hub:
gxpl-hub -D -ddd
The installation process installs a service in /etc/init.d, then it is easy to make automatic startup hub.
In most cases, you do not need to do any configuration but the service may be configured in the /etc/gxpl-hub.conf file.
for starting the service:
sudo /etc/init.d/gxpl-hub start
The following operations are available:
On Debian for example, you can start hub service at boot time with:
sudo update-rc.d gxpl-hub enable
1.8.11 
