Pandora Monitoring Platform - Summary

This group is not part of the GNU Project.

Pandora is a general purpose monitoring platform.  It offers a high level of flexibility while still achieving good performance. In this section we present briefly the architecture of Pandora and its main characteristics.

Each monitoring task executed by Pandora is split into basic and self-contained building blocks called ``components''. These components are chained inside ``stacks'' to constitute high level tasks. Stack execution consists of components exchanging messages (data structures called ``events'') from the beginning of the stack, to the end.

Pandora provides a framework dealing with (among others) event demultiplexing, timers, threads and communication. This allows programmers to concentrate on the precise functionalities they want to implement and promotes code reuse. During stack execution, components are created as necessary and the resources they use are collected after some -- user-specified -- time of inactivity.

Pandora may be configured in two different (and complementary) ways. First, at run time, Pandora reads static configuration files either from disk or from the network. Second, if told so, Pandora opens a control socket to which commands can be sent. Pandora provides an API with C++, C and Guile bindings to ease the construction of clients. These commands allow queries of the actual configuration of the platform and to perform arbitrary modifications on it. These modifications impact also the stacks being executed. Configuration itself includes stack definitions and component library localisation. A stack definition specifies the exact chaining of components while the localization of a component tells Pandora which library to load in order to create the component.

A single Pandora process is able to execute several stacks concurrently. Furthermore, a logical stack may be split into several substacks. These substacks may be run either within distinct threads inside the same process or within different processes, possibly on distinct hosts. Indeed, Pandora provides communication components that allow such stack connections.

Concerning performance, experiments show that the overhead related to component chaining is limited to 75 ns per component and per event, on a 1 GHz Pentium III processor.

Registration Date: Tue 12 Feb 2002 08:42:26 AM UTC
License: GNU General Public License v2 or later
Development Status: 4 - Beta