System Overview

This section gives a broad overview of how the software works and all of the large scale components. Need a picture showing the layers (EW at the center, CMS and database connectivity, and RT and PP universes).

Earthworm

Earthworm 7.2 or greater is the core of the CHEETAH system for data acquisition, locating earthquakes and performing subnet triggers. The Earthworm system is connected to the CHEETAH system by a handful of modules that send messages into CMS (hyps2ps and trig2ps) or write data from Earthworm directly to the database (ewmag2cisn). It helps if a seismic network is already configured and running Earthworm. Medium term storage (days to weeks) of waveforms in Earthworm is done via a Winston waveserver or via a wave_serverV process and this is connected to CHEETAH by means of the proxy wave server (pws) module.

Database

In the CHEETAH system, the database is the central repository for all station/channel configurations and the parametric results from the processing, both automated and human driven. The database for the first edition of this system is Oracle 10g r2 (having evolved from versions 7-9). Stored procedures are used to centralize logic in the database itself and many of these are written in Java.

The main reason for using Oracle is the replication capability. Each RT host has its own self-contained database snapshot of its view of the system and it is replicated to a centralized repository for post-processing and further archiving. So, the ideal system has two RT databases (rtdb and rtdb2) that provide a redundant system and each of these is replicated to a master archive database (archdb) that is backed up on a regular basis. The archdb is thus referred to as the post processing database.

Real Time

Briefly describe the RT procs but point to the details in the RT Overview.

Monitoring of the system

describe the system_peer health scripts and the SNW configurations special to the CHEETAH system.

Post Processing

talk about how the archive database works and how Jiggle/Duty? Review waveform archiving happens...