Coyote Point Systems E350GX, Руководство по установке и администрированию

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Chapter 6: Administering Virtual Clusters
132 Equalizer Installation and Administration Guide
For example, let’s look at how Equalizer processes HTTPS requests. For an HTTPS cluster, Equalizer offloads SSL
processing from the servers in the cluster; that is, Equalizer does all the SSL related processing itself, and then
forwards the request in HTTP to the server. When it does this, it inserts special headers into the request to indicate
that the request was received by Equalizer in HTTPS and processed into HTTP (see “HTTPS Header Insertion” on
page 136). If
once only
is set, these special headers are only inserted into the first request in a connection; the
remainder of the requests in the connection are still processed, but no headers are inserted. Most servers that support
SSL offloading require that every request contain the special headers -- therefore, in most cases like this you need to
disable the
once only
flag for the cluster if you want to be able to parse for these headers in every request on the
server end.
Requests in a single
keep-alive connection
once only enabled once only disabled
First Request
persist enabled
If request contains a cookie and
there is no match rule hit, send
request to the server in the
cookie.
If request contains a cookie and
there is a match rule hit, send
the request to the server in the
cookie
only if it is in the list of
servers selected in the match
rule definition
. Otherwise, ignore
the cookie.
If there is no cookie, load
balance the request and send to
the server chosen.
If request contains a cookie and
there is no match rule hit, send
request to the server in the
cookie.
If request contains a cookie and
there is a match rule hit, send
the request to the server in the
cookie
only if it is in the list of
servers selected in the match
rule definition
. Otherwise,
ignore the cookie.
If there is no cookie, load
balance the request and send to
the server chosen.
persist disabled
Load balance the request and
send to the server chosen. Load balance the request and
send to the server chosen.
match rule hit
Send to the server chosen by the
match rule. Send to the server chosen by
the match rule.
Subsequent Requests
persist enabled
Send to same server as first
request (any cookie in request is
ignored).
If request contains a cookie,
send request to the server in
the cookie.
If there is no cookie, load
balance request and send to
server chosen by policy.
persist disabled
Send to same server as first
request.
Load balance the request and
send to the server chosen.
match rule hit
Send to same server as first
request.
Send to the server chosen by
the match rule.