Cisco Cisco Content Switching Module Guía Para Resolver Problemas
predictor appears similar to a Domain Name System (DNS) round−robin, it is superior because no
propagation delay or caching hinders the algorithm.
propagation delay or caching hinders the algorithm.
Least Connections
The leastconns keyword directs network connections to the server with the fewest connections. Although it
may not be intuitively obvious that the leastconns predictor would provide effective load balancing, in fact, it
is quite successful. On Web sites where there is a collection of servers with similar performance, the
leastconns predictor is effective in smoothing distribution when a server becomes bogged down. On Web
sites where there are large differences in the capacity of various servers, the leastconns predictor is also very
effective. In maintaining the same number of connections to all servers, those servers that are capable of
processing (and thus terminating) connections the fastest receive more connections over time. A server
deemed to be twice as powerful as another server receives about twice as many connections per second.
may not be intuitively obvious that the leastconns predictor would provide effective load balancing, in fact, it
is quite successful. On Web sites where there is a collection of servers with similar performance, the
leastconns predictor is effective in smoothing distribution when a server becomes bogged down. On Web
sites where there are large differences in the capacity of various servers, the leastconns predictor is also very
effective. In maintaining the same number of connections to all servers, those servers that are capable of
processing (and thus terminating) connections the fastest receive more connections over time. A server
deemed to be twice as powerful as another server receives about twice as many connections per second.
Weighted Round Robin and Weighted Least Connections
The weighted keyword allows you to assign a performance weight to each server. Weighted load balancing is
similar to the function of the leastconns and round−robin keywords, however, servers with a higher weight
value receive a larger percentage of connections at any one time. CSM administrators can assign a weight to
each real server, and the CSM uses this weight to determine the percentage of the current number of
connections to give each server.
similar to the function of the leastconns and round−robin keywords, however, servers with a higher weight
value receive a larger percentage of connections at any one time. CSM administrators can assign a weight to
each real server, and the CSM uses this weight to determine the percentage of the current number of
connections to give each server.
Issue the weight command in the SLB real server configuration submode to configure the capacity of the real
servers in relation to the other real servers in the server farm. Issue the no form of this command to change the
server's weight to its default capacity.
servers in relation to the other real servers in the server farm. Issue the no form of this command to change the
server's weight to its default capacity.
weighting−value is the value to use for the server farm predictor algorithm. The range is from 1 to 100. The
default weight is 8. For example, in a configuration with five servers, the percentage of connections is
calculated as follows:
default weight is 8. For example, in a configuration with five servers, the percentage of connections is
calculated as follows:
Server Number Number of Connections
Weight of server 1 7
Weight of server 2 8
Weight of server 3 2
Weight of server 4 2
Weight of server 5 5
Total weight of all servers 24
This distribution results in server 1 getting 7/24 of the current number of connections, server 2 getting 8/24,
server 3 getting 2/24, and so on. If a new server, server 6, is added with a weight of 10, it receives 10/34, and
so on.
server 3 getting 2/24, and so on. If a new server, server 6, is added with a weight of 10, it receives 10/34, and
so on.
Source and/or Destination IP Hash (Subnet Mask Configurable)
Source or destination IP hash method maps the IP address in the request to a real in a server farm. The
configuration options are shown below.
configuration options are shown below.
predictor ip−hash netmask [source | destination] [netmask]
!−−− Source IP hash or predictor hash address.
The default (netmask) is 255.255.255.255. The hash value is produced with the following algorithm: