Please note that the following notes apply to the MySQL database version of telemetry collection.
This page does not apply to any telemetry data collected since the end of January-2013.

Current Configuration

This is an incomplete and brief description of the current configuration of telemetry as it is in the process of being migrated to the SAN and the clustered data store.

Overview

Logically, telemetry consists of five components: the data store, the collection library, the extraction services, the exporter, and the monitor.

The data store is responsible for organizing the telemetry data and storing it. It consists of two dependent relational databases hosted by a MySQL DBMS on a 64-bit linux.

The collection library is responsible for registering telemeters with the data store and writing samples to the data store. It is implemented as a shared library with a C++ API.

The extraction services provide scriptable access to the data in the data store. These are implemented as a collection of Java servlets.

The exporter provides a user interface for accessing data in the data store. This is implemented as a GWT application.

The monitor plots live feeds of data pulled from the data store. This is implemented as a GWT application, using SVG to render the plots.

Telemetry needs to know about the UTC leap seconds. It knows how to parse the leap-seconds.list file provided by NIST. A current version of this file needs to be available to the collection library, extraction services, exporter and monitor.

Deployment

Data Store

The data store hosted by a single MySQL 5.0 DBMS. The DBMS runs on the server tel-collect.mountain.lbto.org that lives on the mountain.

The data store has a 2 TB limit on the amount of data it can hold. This allows for at least the last three weeks of data to be accessible. The rest is archived to tape. To handle the archiving of telemetry data to tape, there is a replica of the data store in Tucson on the machine tel-store-mtn.tucson.lbto.org. It uses MySQL's replication to synchronize itself with the mountain. Once a week a backup job is run that archives the binary logs to tape. This machine runs MySQL 5.1.

Collection Library

The collection library is currently deployed in three places on the mountain. In all three places, it can be reached through the directory /lbt/telemetry/. The primary place of deployment is the telemetry/ directory on the mountain NFS mount /exports/lbt. The machines jet.mountain.lbto.org and tcs5.mountain.lbto.org aren't allowed to have NFS mountains. On these machines, the directory /lbt/telemetry exists on local disk.

The directory /lbt/telemetry/ contains a configuration file and several directories, one per release. The current release is in r16/. The configuration file, mountain-my.cnf, contains the connection parameters for connecting to the data store's DBMS.

The collection library needs access to a current version of the leap-seconds.list file. This should be located on the same machines as the collection library in the directory /lbt/UT/.

The collection library depends on the MySQL 5.0 client shared library.

Extraction Services, Exporter and Monitor

The extraction services, exporter and monitor are all deployed in a single web application hosted by a Tomcat servlet container behind an Apache web server. The Tomcat and Apache services run on the machine telemetry.tucson.lbto.org that lives in Tucson. The web server provides the website through the URL http://telemetry.lbto.org.

All three of these components use the MySQL Connector/J implementation of JDBC to connect to the data store's DBMS. This is already installed on telemetry.lbto.org.

All three of these components need access to a current version of the leap-seconds.list file. This should be located in the root directory of the telemetry web application. N.B. This is a hack that resulted from a recent oversight. If I would have had enough time before I left, I would have resolved this.

-- TonyEdgin - 18 May 2012
Topic revision: r6 - 07 Mar 2013, KelleeSummers
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