(Supporting ADX v03.1.00) Owner manual

290 Brocade Virtual ADX Server Load Balancing Guide
53-1003247-01
Miscellaneous Layer 7 switching configurations
5
The offset variable defines the distance of bytes from the offset 0. By default, offset 0 is right after
the interested string defined by matched CSW rule.
The Keyword offset or neg-offset indicates that the insertion offset starting after or before the
offset 0.
Support for large GET requests
The Brocade Virtual ADX can perform Layer 7 Content Switching on large GET requests (up to
20,000 bytes). Earlier releases supported up to 8,000-byte GET requests.
Miscellaneous Layer 7 switching configurations
Cleaning up all hash buckets
To clean up all hash buckets when a server port comes alive, enter the following command.
Virtual ADX(config)#server l7-hashing-bucket-reassign
Syntax: [no] server l7-hashing-bucket-reassign
This command also allows new connections to be forwarded to the server port that has just come
up.
Layer 7 content buffering options
In an Layer 7 switching configuration, the Brocade Virtual ADX stores client request packets in the
Layer 7 content buffer while it selects a real server to which to forward the request. The Brocade
Virtual ADX buffers the client request up to the end of the HTTP request, or up to a maximum of 20
packets.
The following two Content Buffering Options allow you to optimize the usage of the Brocade Virtual
ADX’s Layer 7 content buffer:
• Modifying the TCP window size so that the client sends fewer packets before waiting for an ACK
• Configuring the Brocade Virtual ADX not to send an ACK to the client after it has received
enough information to select a real server
Changing the TCP window size
The TCP window size in a SYN ACK or ACK packet specifies the amount of data that a client can
send before it needs to receive an ACK from a server. By reducing the TCP window size for SYN ACK
or ACK packets sent by the Brocade Virtual ADX when performing Layer 7 switching, you can
decrease the number of packets a client will send before it waits to receive an ACK from the
Brocade Virtual ADX, thus making more efficient use of the Brocade Virtual ADX’s Layer 7 content
buffer.
To change the TCP window size to 1460 bytes, enter the following command.
Virtual ADX(config)#server l7-tcp-window-size 1460
Syntax: server l7-tcp-window-size window size