PUBLIC MARKS with tags network & configuration

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Step by step guide to set up a working reverse proxy

Opsview is enterprise network and application monitoring software designed for scalability, flexibility and ease of use. Opsview has been in development since 2003 and is released under the GNU GPL license. Current version is 2.12. Opsview is a fully integrated monitoring tool that incorporates popular Open Source software including Nagios, Net-SNMP and RRDtool. The Catalyst web framework provides an extensible monitoring and configuration user interface. Opsview software is supported on Linux (Debian, CentOS, RHEL and Ubuntu) and Solaris 10. It will monitor all common operating systems including Windows. Opsview extends the capabilities of Nagios in the following ways: * Distributed monitoring with high availability and fail-over * Much improved SNMP support with trap processing with rules engine * API supporting automation of Opsview configuration * Data warehouse for storage of historical performance and event data * Opsview Reports customisable reporting * Powerful configuration and management UI * Extended monitoring UI * Extensible architecture based on Catalyst Web Framework and Altinity middleware software

This guide is the first of a series in which I give you detailed step-by-step instructions on how to build a virtual cluster with Xen. The cluster thus built might not be appropriate for your case, and does reflect the author's preferences and/or needs, but if you are new to clusters or Xen, it will hopefully help you get started with both. The goal is to start it simple and then add more complexity as we progress, so in this first guide I show you how to get do the basics: * A Xen installation, the creation of 5 virtual machines (one to act as the master and four slaves), * Shared storage through NFS, * The network configuration on which to build the virtual cluster. The network structure of this first attempt will be very simple, the master having two network cards, one to the outside world and the other one connected through a switch to the slaves.

Xen is great. But installing more than one network card became a pain when I tried it the first time. There are some documents describing the principle but I was unable to find a real life example somewhere else. So this is a summary about how it works here now. Using a bridge for a Dom is generally a good idea but then all packets traversing the bridge can be intercepted by any Dom that is using the same bridge. Having a single network card in a Xen landscape also means that theoretically each Dom would be able to sniff all packets traversing this single network card including packets to and from other Doms. A solution is to have more than one network card attached to Xen using a single network card for a single dom. The scenario described here has a server with 3 network cards installed. The first card should be used to access Dom0 and some other DomNs while the second and third network card should be used to purely access Dom1 rsp. Dom2. The Dom configuration file just needs to select the appropriate bridge for each dom.

NagiosVMA is virtual machine appliance that runs Nagios, a powerful, open-source application which performs host, service and network monitoring. Additionally, the appliance was enhanced with Groundwork Monitor Architect, an open-source, web-based, configuration tool for Nagios. It is intended to offer the end-user sophisticated network monitoring in minutes, instead of hours, (or even days) as is typical with building and configuring a Linux/Nagios host. Using Nagios combined with Monarch and Monarch's automatic host discovery feature, this virtual machine appliance can be booted, configured, and ready to monitor your network in as little as 10 minutes. (in fact, as soon as it boots, its already monitoring this virtual machine appliance!)

SystemImager is software which automates Linux installs, software distribution, and production deployment. SystemImager is a part of System Installation Suite. SystemImager makes it easy to do automated installs (clones), software distribution, content or data distribution, configuration changes, and operating system updates to your network of Linux machines. You can even update from one Linux release version to another! It can also be used to ensure safe production deployments. By saving your current production image before updating to your new production image, you have a highly reliable contingency mechanism. If the new production enviroment is found to be flawed, simply roll-back to the last production image with a simple update command!

et voilà pour les conditions ...