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Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) User Manual

Page 385

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Brocade Virtual ADX Server Load Balancing Guide

369

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Displaying global Layer 4 Brocade Virtual ADX configuration

B

Table 40

lists the displayed information.

TABLE 40

Global layer 4 configuration information

Field

Description

SLB Parameters

Predictor

The load balancing metric in effect on the Brocade Virtual ADX. The
predictor can be one of the following:

least-conn (least connections)

round-robin

weighted-round-robin

weighted

enhanced-weighted

least-local-conn (least local connections)

least-local-sess (least local sessions)

The default is least-conn.
You can assign these metrics on a global basis and an individual virtual
server basis.
For more information, refer to

“Load-balancing predictor”

on page 8.

To change the predictor (globally or locally), refer to

“Changing the

Load-Balancing Predictor Method”

on page 21.

Force-deletion

The state of the force shutdown option. This option immediately shuts
down a server or service instead of waiting for existing connections to
end before shutting the server or service down. The state can be one of
the following:

0 – Disabled

1 – Enabled

Reassign-threshold

The number of contiguous inbound TCP-SYN packets sent to the server
that the server has not responded to.
The TCP SYN-ACK counter increments only when acknowledgments are
not received. Each time an expected TCP SYN-ACK is received, the
counter is cleared.
The default reassign threshold is 20 unacknowledged TCP SYN-ACKs.
The value can be from 6 through 4000. To change the reassign
threshold, refer to

“Reassign threshold”

on page 220

NOTE: You can modify this parameter to help minimize vulnerability to

TCP SYN attacks.

Reassign-limit

The number of missed TCP SYN packets the Brocade Virtual ADX will
accept before moving an inbound connection attempt to another server.

Layer 3 Health Check Parameters

Ping-interval

How often the Brocade Virtual ADX sends a Layer 3 IP ping to test the
basic health and reachability of the real servers. When enabled, this
parameter specifies the interval for the pings. To change the interval,
refer to

“Modifying the ping interval and ping retries”

on page 161.

Ping-retries

The number of times that the Brocade Virtual ADX resends a ping to a
real server that is not responding. Allowed values are from 2 through 10,
and the default is 4. To change this parameter, refer to

“Modifying the

ping interval and ping retries”

on page 161.

If the server still does not respond after the last retry, the Brocade
Virtual ADX marks the server FAILED and removes it from the load
balancing rotation.