Overview: IBM Network Dispatcher V3.0 and V3.6
IBM Network Dispatcher is an administration and configuration tool that
provides dynamic load balancing, scalability, and high availability for
servers on the Internet or on your Intranet.
Highlights of Version 3.6 include:
- Capacity Utilization and Bandwidth rules - provides you the ability to manage the bandwidth
capacity of outbound traffic (server-to-client) for sets of servers within the configuration.
- Server Evaluation Option - allows you to choose how to evaluate a rule's condition, whether to
evaluate on all servers within the port or just the servers within the rule.
On past versions of Network Dispatcher, the only option available was to measure each rule's condition
across all servers within the port.
- GRE Support (Generic Routing Encapsulation) - allows you to configure Network Dispatcher to load
balance servers (such as OS/390, which support GRE excapsulation) located anywhere in the network or
server images that share IP address.
- Advisor Fast Fail Detection - allows you to set the advisor's timeout values at which it
detects that a server is down.
- Quiesce Enhancement for Sticky Connections - extends the quiesce function to recognize existing
connections that have the sticky feature.
- SSL Proxy to Server support - allows you to use Content Based Routing with WTE to load balance across
secure (SSL) servers.
- Enhanced ISS Load Balancing of Network Dispatchers - provides backend load status information to the
ISS DNS load balancer in order to make more appropriate load balancing decisions.
- Java 1.3 support across all platforms.
- Gigabit Ethernet supported across all platforms.
- Multi-port Ethernet card support across all platforms.
- Solaris Version 8 (32-bit mode) support.
For more information on any of the above highlights, please see the README-NewFeatures.txt file for IBM
Network Dispatcher V3.6.
Highlights of Version 3.0 include:
- Installation/Support of IBM Network Dispatcher on Windows 2000
- Mutual High Availability, allows 2 Dispatcher machines to
be both primary and backup for each other
- POP3 and IMAP CBR (content based routing) proxy support
- Cross Port Affinity, the sticky/affinity feature expanded to cover
across multiple ports
- Multiple Address Collocation, allows the customer to specify the address
of the collocated server to be different than the nonforwarding address (NFA) in
the configuration
- Rule Affinity Override, override a port designated as 'sticky' if there
is an excess of requests to a server
- Type of Service (TOS) rule, load balance based upon the content of the
TOS field in the IP header
- Manager Fixed Weights, allows a server weight to be fixed while running
the manager
The three major components of IBM Network Dispatcher are:
- Dispatcher - provides load balancing for TCP and UDP applications.
Dispatcher balances the load on servers within a local area
network or wide area network using several weights and measurements
that are dynamically set.
- Interactive Session Support (ISS) - ISS can balance the load on
servers within a local area network or wide area network using a domain
nameserver (DNS) round-robin approach, or a more advanced user-specified
approach, performed at the machine level. ISS can also provide server
load information to a Dispatcher machine.
NOTE: For Red Hat Linux, the Server Monitor Agent (SMA) replaces the ISS function
providing system-specific metrics to the Dispatcher.
- Content Based Routing (CBR) - provides load balancing for
HTTP/SSL and a proxy server for POP3 and IMAP traffic.
For HTTP and SSL, you will need Web Traffic Express
(WTE) 2.0. or higher. CBR allows WTE to proxy requests to specific servers
depending on the content of the URL request.
CBR will match URL content to a user-specified rule, and a server
set is given to IBM Network Dispatcher to determine the optimum server
for the job.
CBR without WTE can provide a single point of presence for many POP3 or IMAP servers. Each server
may have a subset of all user mailboxes serviced by the point of presence. For POP3 and IMAP, CBR is a
proxy which chooses an appropriate server based on the userid and password provided by the client.
Visit our product web site at
http://www.software.ibm.com/network/dispatcher
for the latest details on
using this product to maximize the performance of your servers.
Configuration examples and scenarios are included, as well as news,
case studies, and support information.
For information on how to perform IBM Network Dispatcher tasks, click How do I?
in the navigation area to the left; for reference information, click Reference. To find
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