Coyote Point Systems E350GX, Installation And Administration Manual

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Appendix B: Timeout Configuration
266 Equalizer Installation and Administration Guide
Figure 61 Probe timeout parameters
The parameters shown in the figure above determine how high level TCP and ACV server probes are handled, as
follows:
1. Equalizer begins a TCP probe by sending a TCP SYN packet to the server:
• If the server and Equalizer negotiate a three-way TCP handshake (SYN, SYN/ACK, ACK) within the
probe timeout
period, go to
Step 2
.
• If the server and Equalizer do not handshake within the
probe timeout
period, Equalizer marks the
server failing ; go to
Step 3
.
2. Equalizer then determines whether or not to send the server an ACV probe:
• If an
ACV Response
string is not defined for the cluster to which the server belongs, Equalizer marks
the server up and waits for the
probe delay
period before it starts the HLP process again at
Step 1
.
• Otherwise, if an
ACV Response
string is defined for the cluster to which the server belongs, the
ACV
Probe
string (if defined) is sent to the server on the TCP connection opened for high-level probing; if
there is no ACV probe string, nothing is sent, only the connection is opened. In either case, Equalizer