MonALISA Grid Monitoring
Registration and Discovery
Menu mode: dynamic | fixed
Last update on:
Dec 03, 2015

Uptime: 174 days, 8h, 42m
Number of requests: 5643784
since 28 October 2005

MonALISA Registration and Discovery

MonALISA services are able to discover each other in the distributed environment and to be discovered by the interested clients. Each MonALISA service registers itself with a set of Lookup Services (LUSs) as part of one or more groups and it publishes some attributes that describe itself. In this way any interested application can request MonALISA services based on a set of matching attributes.

The registration uses a lease mechanism. If a service fails to renew its lease, it is removed from the LUSs and a notification is sent to all the services or other application that subscribed for such events. Remote event notification is used in this way to get a real overview of this dynamic system.

Lookup services have replicated information. It is important for the monitoring service to be registered in two or more distributed lookup services, because if one fails responding, interested clients can find the MonALISA services registered in the other online lookup services. Thus, the single point of failure problem can be avoided and a more reliable network for registration of services can be achieved in the distributed environment. The JINI technology used allows dinamically adding and removing Lookup Services from the system.

Securing the registration of services is important for LUSs not to be overloaded or damaged. MonALISA LUSs restrict the services' registration based on an authorized X.509 certificate.

Figure 1: MonALISA Registration and Discovery Mechanism