Coyote Point Systems Equalizer GX Series, Administration Manual

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Server Health Check Probes
GUI Parameter (CLI Parameter) Location Description
Probe Port ( probe_port ) server instance
Optional. If this parameter is 0 (the default) probe
using the port set on the server definition. If non-
zero, use this parameter setting as the port number
r TCP and ACV probes.
ACV Query ( acvq ) server pool
Optional. A string sent to the server instance after
the TCP handshake completes; the server instance is
expected to respond with a string that contains the
ACV Response in the first 1024 characters. If the
ACV Response is not set, this parameter has no
effect.
ACV Response ( acvr ) server pool
Required to enable ACV probes. This is the string
Equalizerexpects to receive in the first 1024
characters of the server instance response. If this
string is not specified, ACV probes are disabled.
Probe SSL ( probe_ssl ) server pool
A flag on a server pool, disabled by default. If
enabled, the TCP and ACV probe exchange between
Equalizerand the server instance will be performed
over an encrypted SSL connection.
Once enabled, TCP and ACV probe behavior is determined by the timeouts located on the server
pool configuration screen in the GUI (and in the
srvpool
context in the CLI.
GUI Parameter (CLI Parameter) Minimum Default Maximum Units
Max Tries Per Interval ( max_tries ) >1 3 30 integer
Probe Interval ( probe_interval ) 1 15 60 seconds
Probe Global Timeout ( probe_gto ) 0 5 120 seconds
Probe Connect Timeout ( probe_cto ) 0 1 60 seconds
Probe Data Timeout ( probe_dto ) 0 2 60 seconds
By default, Equalizersends Layer 4 health check probes to a server instance at most 3 times (the
Max Tries Per Interval setting), every 15 seconds (the Probe Interval). Exactly how many probes
are sent in any given probe interval is determined by how long it takes each probe to complete
and whether any of the timeouts listed above expire while Layer 4 health checks are being sent
and received. Both TCP and ACV probes are subject to the same set of timeout values, as
summarized in the following flowchart.
676 Copyright © 2014 Coyote Point Systems, A Subsidiary of Fortinet, Inc.