Why use a load balancer?
Deploying a load balancer helps
achieve constant server availability as well as simple scalability.
It allows administrators to easily perform server maintenance, and a painless
way to add systems to the Load Balanced server farm.
How easy is the Barracuda Load Balancer to configure?
The
Barracuda Load Balancer provides the industry's easiest configuration via an
intuitive Web interface. Normal setup can be performed in a few simple steps.
Most customers are able to set up their load balancing configurations within 10
minutes.
Does the Barracuda Load Balancer have any security
features?
The Barracuda Load Balancer has a built-in Intrusion
Prevention System (IPS), as well as Access Control Lists (ACL) and a SSL-secured
Web user interface.
How does the Barracuda Load Balancer's internal IPS
work?
The Barracuda Load Balancer's integrated Intrusion Prevention
System uses a refined set of constantly updated vulnerability definitions to
automatically block malicious attacks as they happen. When an attack is
detected, the Barracuda Load Balancer simply sends a TCP RESET in both
directions (server and client).
What protocols does the Barracuda Load Balancer
support?
The Barracuda Load Balancer supports any TCP or UDP
service.
How many real servers does the Barracuda Load Balancer
support?
The entry-level Load Balancer (model 240) supports up to 25
real servers, while a higher-end system (model 440) can support up to 250 real
servers.
Do I need any additional hardware to be able to load
balance?
You may need additional switches depending on your
deployment configuration. The Barracuda Load Balancer includes two ports:
a WAN and LAN interface.
When should I use Layer 4 IP persistence?
Client IP
persistence is useful in applications which require session persistence. For
example, Web-based shopping carts or any service which requires a login and/or
uses multiple requests would be a good candidate for IP persistence.
Is it easy to add new servers to the server farm?
Real
servers can be added to the configuration with one step using the Barracuda Load
Balancer's Web interface.
What can I use the Barracuda API for?
Available on the
Barracuda Load Balancer 440, the Application Programming Interface (API)
facilitates scripted implementation of any setting available in the Web
interface. Most often used by ISPs and MSPs, this allows for load balanced
services (including intrusion prevention) to be integrated into existing
customer build scripts.
What is the Service Monitor?
The Service Monitor actively
watches all real servers, their connections, and performance.
How does the Barracuda Load Balancer handle failed
servers?
When the Service Monitor detects a downed real server, the
Barracuda Load Balancer automatically removes the server from the load-balanced
cluster. If the real server again becomes available, it will automatically place
the server back in the distribution queue.
Real servers may also be
placed in “maintenance mode,” which gracefully removes them from any bound
services in order to facilitate server maintenance or upgrades. When the real
server is again available, administrators simply enable the server through the
Barracuda Load Balancer's Web interface.
What protocols and applications are supported by the Barracuda Load
Balancer?
The Barracuda Load Balancer works with any TCP/UDP service
or application.
What sort of configuration flexibility does the Barracuda Load
Balancer offer?
The Barracuda Load Balancer supports route-path,
bridge-path, and direct server return configurations. Server weights are fully
configurable along with flexible scheduling options such as round-robin and
least connections.
What is Direct Server Return?
Ideal for high bandwidth
and content delivery networks, Direct Server Return is a load balancing
configuration which facilitates responses to server requests being delivered
directly to the network rather than being routed back through the load balancer.
This configuration can be used to deliver 10x bandwidth throughput versus
route-path or bridge-path modes.
Configuration of Direct Server Return is
easy, and uses the built-in non-ARPing loopback adapter which is included in
allWindows and Linux servers.
What is a VIP (Virtual IP)?
The VIP, or Virtual IP
Address, is the IP address that is used to access load-balanced services.
What is a Real Server?
A “Real Server” is the actual
physical server which holds the content or runs the application that is
delivered to the client via the Barracuda Load Balancer.
What is a Service?
A “Service” is the combination, or
binding, of a Virtual IP address, ports, and real server IP addresses.