Advanced Networking Services Guide

Table 5‑3. Extensions for TCP Protocol (Continued)
Monitor Extension Description
quit=STRING Sends a string to the server to cleanly close the connection.
refuse=ok|warn|crit
Accepts TCP refusals with states ok, warn, or criti. By
default, uses state crit.
mismatch=ok|warn|crit
Accepts expected string mismatches with states ok, warn,
or crit. By default, uses state warn.
jail Hides output from the TCP socket.
maxbytes=INTEGER Closes the connection when more than the specified
number of bytes are received.
delay=INTEGER Waits the specified number of seconds between sending
the string and polling for a response.
certificate=INTEGER[,INTEGER] Specifies the minimum number of days a certificate has to
be valid. The first value is #days for warning and the
second value is critical (if not specified - 0).
ssl Uses SSL for the connection.
warning=DOUBLE Specifies the response time in seconds to result in a
warning status.
critical=DOUBLE Specifies the response time in seconds to result in a critical
status.
What to do next
Add server pools for your load balancer. See “Add a Server Pool,” on page 45.
Add a Server Pool
You can add a server pool to manage and share backend servers flexibly and efficiently. A pool manages
load balancer distribution methods and has a service monitor attached to it for health check parameters.
Procedure
1 Log in to vCloud Air and navigate to the vCloud Edge Gateway Services UI.
See “Log In and Navigate to Advanced Networking Services,” on page 9 for information.
2 Click the Load Balancer tab and Pools.
3 Type a name and description for the load balancer pool.
4 Select a balancing method for the service from the Algorithm drop-down menu:
Option Description
ROUND-ROBIN
Each server is used in turn according to the weight assigned to it. This is
the smoothest and fairest algorithm when the server processing time
remains equally distributed.
IP-HASH
Selects a server based on a hash of the source and destination IP address of
each packet.
LEASTCONN
Distributes client requests to multiple servers based on the number of
connections already on the server. New connections are sent to the server
with the fewest connections.
URI
The left part of the URI (before the question mark) is hashed and divided
by the total weight of the running servers. The result designates which
server will receive the request. This option ensures that a URI is always
directed to the same server as long as no server goes up or down
Chapter 5 Load Balancing
VMware, Inc. 45