Hyrax Installation and Customization

ESIP ‘08 Summer Meeting

Best Practices in Services and Data Interoperability

Dan Holloway

James Gallagher

Outline

• Hyrax Architecture

• Example Configuration of Hyrax

• Hyrax Customization

Hyrax Architecture

• Two (or more) cooperating processes:– Front-end provides DAP interface– Back-end(s) read(s) data

• Both parts can be customized– Front-end: different network protocols– Back-end: different data formats/systems

• N-Tier design is flexible, secure

OLFS BES Data

OLFS

Java Servlet Engine

BES

Unix Daemon

BES Commands

XML- encapsulated object

File system with data files,SQL Database, …

DAP2

THREDDS

HTML

Optional THREDDScatalogs

Hyrax Architecture

Hyrax Architecture Summary

• Hyrax can be installed on one machine or several

• Installation security merits serious consideration

• Authentication & Authorization are handled by the web servers (Tomcat and Apache)

Hands on: Hyrax Configuration

• Choices:– Single or Multiple machine– Single or Multiple back-end servers– Tomcat or Apache web server– Data formats– Catalog customization– Security

• Testing– Command line tools for system administrators– Web browser

ESIP Workshop Configuration

• Run a single BES and the OLFS on one host (the virtual machine running SLAX Linux)

• Use Tomcat running on port 8080

• Data formats: NetCDF and FreeForm

• No custom THREDDS catalog

• No firewall

ESIP Hardware

• SLAX Linux VMware Virtual Appliance

• All the software needed has been built, installed and configured

• Start the virtual machine now…

Starting the Virtual Machine

• Insert the CD-ROM• Drag the opendap_vm and Wintools folders to the Windows

desktop• Copy the ISO image from the CD ROM to the harddisk (in a

command window, mkdir C:\SLAX and then use copy or dd to copy the iso to the new directory).– The dd command is in the Wintools folder– The C:\SLAX directory is coded into the virtual machine; use Vmware

Workstation/Fusion to edit

• Open the opendap_vm folder and double click on the opendap_vm.vmx virtual machine configuration file or start VMware Player/Workstation/Fusion and open opendap_vm.vmx from there.

• The virtual host will boot and the SLAX (slackware Linux with KDE) desktop will appear.

Installing the Software

• Already present on the virtual machine

• But, if it wasn’t, you’d go to the OPeNDAP web site* and download: – Binaries or source for the BES and the

data handlers needed. – Get the OLFS web archive file (which is a

compiled java servlet).– You also need the Tomcat servlet engine

* http://opendap.org/download/hyrax.html

Location of Server Files on the Virtual Machine

• On your virtual machine:– The Tomcat servlet engine is in /usr/local/javadev/apache/tomcat-5.5.12 (this is the value of $CATALINA_HOME)

– The BES, data handlers and related source files are in /usr/local/src. The BES has been built and installed in /usr/local/ ($prefix)

– The OLFS web archive file is $CATALINA_HOME/webapps/opendap.war

– BES: bes.conf, found at $prefix/etc/bes/bes.conf– OLFS: olfs.xml and catalog.xml, found at $CATALINA_HOME/content/opendap

Background: Starting the Server

• Start the BES (back-end data processing component)

• Use bescmdln to verify it’s working• Start Tomcat: This automatically starts

all installed servlets– Servlets are installed by copying the .war

file to the servlet’s webapps directory

• Verify it’s working using a web browser

Start the BES

Verify the BES is running

Start Tomcat & the OLFS

• Typical steps:– Unpack the olfs jar-file– Copy the opendap.war file to Tomcat’s

webapps directory– Start Tomcat

• Since all but the last step has been done already, start Tomcat:

– /usr/local/javadev/apache-tomcat-5.5.12/bin/startup.sh

…terminal view

Verify Tomcat is running

http://localhost:8080

…and Hyrax

http://localhost:8080/opendap

Complete the Configuration

• Steps you would typically perform:– Security: Set up a firewall! Limit access to

port 10002 to this host only – Custom catalogs: Edit the catalog.xml

configuration file. By default automatic catalogs are generated

– Logging: Edit the log4j.xml file. By default all accesses are logged

Stopping Hyrax

First, stop Tomcat using ‘shutdown.sh’

…then stop the BES using ‘besctl’

Hyrax Configuration Summary

• For our chosen configuration, we used only Tomcat, plus the Hyrax web application which consists of the BES and the OLFS

• The tools bescmdln, getdap and a web browser were used to test the installation

• There are a lot of options, but the default settings produce a working server

• Security is a must for a web application; use a firewall to isolate the BES so only the local host can connect to it.