Coyote Point Systems Equalizer, Installation And Administration Manual

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Chapter 5: Administering Virtual Clusters
64 Equalizer Installation and Administration Guide
7. Click the Add button to add the virtual cluster.
An Add Cluster command can be refused for several reasons, including:
■
Attempting to add a cluster address that is already configured or is configured as a
server address
■
Specifying an invalid IP address or port number
■
Attempting to add more clusters than are supported by Equalizer
Configuring a Cluster’s Load-Balancing Options
Load balancing policy and responsiveness settings are configured for each cluster
independently. If you have multiple clusters, they do not need to use the same load
balancing configuration even if they are hosted on the same physical server machines. For
example, if you have one cluster on port 80 for handling HTML traffic and one on port
8000 for serving images, they can use different load balancing policies.
When you are using adaptive load balancing (the cluster’s load balancing policy is not set
to round robin or static weight), you can fine-tune the static weights of the cluster’s servers
to optimize cluster performance. For more information, see “Adjusting a Server’s Static
Weight” on page 76.
Options Set for Layer 7 Clusters
Enable Spoofing Enable this option if you want Equalizer to spoof the client IP address when
routing a request to a server in a virtual cluster. If this option is not enabled, the
server receiving the request will see the Equalizer’s address as the client address
because the TCP connection to the client is terminated when the request is
routed.
Enable Persistence Enable this option to use cookies to maintain a persistent session between a
client and a particular server.
Always Use Cookie Enable this option to include a cookie in the response whether or not the server
actually set a cookie.
Cookie Lifetime The length of time that the cookie should be maintained by the client browser.
The browser can delete the cookie after the specified number of seconds have
elapsed.
Cookie Path Limits the cookie to being presented only when the path component of the
request URI has a prefix in common with the specified path. For example, if the
cookie path is set to /store/, the browser will only present the cookie if the request
URI includes the specified path, such as /store/mypage.html.
Cookie Domain Limits the cookie to being presented only to servers whose host name is within
the specified domain. For example, if the cookie domain is set to
coyotepoint.com, the browser will only present the cookie to servers in the
coyotepoint.com domain, such as www.coyotepoint.com or my.coyotepoint.com.
Options Set for Layer 4 Clusters
Sticky Time The number of seconds that Equalizer should “remember” connections from
clients. If you don't need sticky connections, leave this option set to 0. See
“Enabling Sticky Connections” on page 70 for more information.
Enable Inter-Cluster
Sticky When enabled, Equalizer ensures that requests from a particular user are
directed to the same server, even if the connection is to a different virtual cluster.
For more information, see “Enabling Sticky Connections” on page 70.