- What is this?
This software package includes
the Intelligent HTTP Gateway. This package
is referred to as the "Eddie base package" elsewhere.
It is only meaningful to install the Eddie base package on a set of hosts. Never the less it is possible to simulate advanced clusters on a single host. Read the tutorial included in this package to do this.
The other Eddie component is the Load-balancing DNS Server.
The Intelligent HTTP Gateway is a peer which sits on top of back-end HTTP servers such as the Apache Web server. The gateway schedules requests to the least loaded back-ends on the LAN using adaptable load-balancing algorithms. It also analyzes incoming requests directing certain types of traffic to certain types of hosts using configurable scheduling patterns, e.g. CGI-script requests can be directed to host A and requests for static HTML pages to host B.
The gateway also features advanced admission control mechanisms, it handles a session for each client and during server overload only clients with active sessions are granted access. A new client is put on hold (queued) during overload but is given a queue number and a rough estimate on when access is granted. The client is frequently and automatically reconnected as he/she advances in the queue. This behavior is fully configurable, e.g. customized put on hold HTML pages and CGI-scripts can be specified (commercials?).
If the Load-balancing DNS Server, or indeed a simple round-robin DNS server, and the IP Migration Application are used together several gateways can be used in parallel. This guarantees a solution with high throughput, high availability and a high degree of scalability. A single host can even harbor several gateways and back-ends at the same time if necessary. The gateways take this into account and the load-balancing algorithms adapt.
The GAteway Application includes an IP Migration feature making it possible to set up overlapping take-over and fail-over sets using any type of servers. The goal is to be in service as long as at least one host is running. All aspects of the clustering are configurable and call-back scripts can be written to customize start, stop, monitoring and alarm handling.
2) Installation
Read the installation and configuration manual at www.eddieware.org.
3) Support
If you have problems report this to talk@eddieware.org.
Attach the following information:
- A description of the problem.
- Eddie package version and OS revision.
- The log files, e.g. /var/tmp/eddie_eddie@zaphod.{1-5} and the /var/tmp/eddie_log.eddie@zaphod directory.