MonALISA Grid Monitoring
Optical Switches
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Dec 03, 2015

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MonALISA Agents used to monitor and control optical switches
Creating on demand an optical path/tree for end user applications

In the MonALISA framework we developed dedicated modules and agents to monitor and control Optical Switches. These modules are used now for the CALIENT  switch at CALTECH and the GLIMMERGLASS switch at CERN.  The monitoring modules use the TL1 language to communicate with the switch and they are used to collect specific monitoring information. The state of each link and any change in the system is reported to dedicated MonALISA agents which are in fact dynamically loadable  modules running inside MonALISA services.

The distributed set of these MonALISA agents is used to control the system. They use the discovery mechanism to find each other and they communicate between them using the Proxy Services. Each proxy service can handle ~1000 messages /s and the architecture is using more than one such service to achieve a reliable communication between agents. The agent system is used to create a global path or tree as it  knows the state of each link,  inter-site  connections and the cross connections.  The routing algorithm provides global optimization and can be extended to handle priorities and pre reservations.

The system is integrated in a reliable and secure way with the  end  user applications and provides  simple shell-like commands to map global connections and to create an optical path / tree on demand for any data transfer application.

A schematic view of how the entire system works is shown in the figure below:


Each station having an optical network card runs a MonALISA demon. This demon does the discovery of MonALISA services and the optical control agents and at the same time is used to provide user authentication ( using X509 certificates) and secure connection  with  at least one agent. The demon can use any of the agents running on different MonALISA services. The demon takes the user commands and transfer them to the agent system as well as the answers using the authenticated and encrypted channel.

The system also provides a shell like command, ml_path, which creates an on demand optical path for any user defined application which then can use it .

Details to configure the monitoring modules, Optical Switch Agent and Optical Switch Daemon  :

When an optical path is required by an user or application the agent system establish it in less than 1 second,  independent of  how many switches are involved and were they are located.  In the case when all the system involved  are on the same LAN, the time to create the path is ~ 150 ms.

The entire system is monitored in  real-time and it presents the state  and transitions for  each port and link .
We partitioned both switches ( CALIENT and GLIMMERGLASS) in 4  units , with physical cross connects to simulate 8 independent switches.
Each such unit is monitored and controlled by one MonALISA service.