Archiver Appliance

- Overview - Getting Started - Algorithms

Overview

Archiver Appliance integrates the EPICS Archiver appliance client into CSS. The plugin connects to the appliance and retrieve the data stored on the server as it is the most convenient for the DataBrowser.

Getting Started

To use the archiver appliance client you first need to set it up. This can be done via Preferences as for any other archive reader.

The appliance protocol is called pbraw. If you have an appliance instance running on a specific IP and port you have to define the serverl url as pbraw://[server_ip]:[server_port]/retrieval. This is the default location of the archiver appliance. If your system is set up differently you may also need to change the retrieval path to something else.

Fig. 1: Archiver Appliance Setup

Algorithms

The plugin supports two different types of data loading: optimized and raw. The raw algorithm will return all the points that are available for the selected time period, while the optimized algorithm will use data reduction algorithm to avoid excessive data transfers. Data reduction used for numerical PVs is averaging. If selected via preferences, the plugin can also provide the statistical data (mean, std, min and max) when the optimized algorithm is used. To enable statistical data the property org.csstudio.archive.reader.appliance/useStatisticsForOptimizedData must be set to true (default setting); to disable this feature, set the property value to false.

Appliance provides two mechanisms to load optimized data: the original one, where it first asks for the number of points in the interval and then decide whether to make a raw or average request; and the new one, where this decision is made on the server. The setting useNewOptimizedOperator specifies whether the new mechanism will be used or not. If you know that your appliance installation supports the optimization, than set this preference to true. If you have an older installation, set the preference to false in order not to waste time and network bandwidth.