2 # IP Virtual Server configuration
5 tristate "IP virtual server support (EXPERIMENTAL)"
8 IP Virtual Server support will let you build a high-performance
9 virtual server based on cluster of two or more real servers. This
10 option must be enabled for at least one of the clustered computers
11 that will take care of intercepting incoming connections to a
12 single IP address and scheduling them to real servers.
14 Three request dispatching techniques are implemented, they are
15 virtual server via NAT, virtual server via tunneling and virtual
16 server via direct routing. The several scheduling algorithms can
17 be used to choose which server the connection is directed to,
18 thus load balancing can be achieved among the servers. For more
19 information and its administration program, please visit the
20 following URL: <http://www.linuxvirtualserver.org/>.
22 If you want to compile it in kernel, say Y. To compile it as a
23 module, choose M here. If unsure, say N.
28 bool "IP virtual server debugging"
30 Say Y here if you want to get additional messages useful in
31 debugging the IP virtual server code. You can change the debug
32 level in /proc/sys/net/ipv4/vs/debug_level
35 int "IPVS connection table size (the Nth power of 2)"
38 The IPVS connection hash table uses the chaining scheme to handle
39 hash collisions. Using a big IPVS connection hash table will greatly
40 reduce conflicts when there are hundreds of thousands of connections
43 Note the table size must be power of 2. The table size will be the
44 value of 2 to the your input number power. The number to choose is
45 from 8 to 20, the default number is 12, which means the table size
46 is 4096. Don't input the number too small, otherwise you will lose
47 performance on it. You can adapt the table size yourself, according
48 to your virtual server application. It is good to set the table size
49 not far less than the number of connections per second multiplying
50 average lasting time of connection in the table. For example, your
51 virtual server gets 200 connections per second, the connection lasts
52 for 200 seconds in average in the connection table, the table size
53 should be not far less than 200x200, it is good to set the table
56 Another note that each connection occupies 128 bytes effectively and
57 each hash entry uses 8 bytes, so you can estimate how much memory is
60 comment "IPVS transport protocol load balancing support"
62 config IP_VS_PROTO_TCP
63 bool "TCP load balancing support"
65 This option enables support for load balancing TCP transport
66 protocol. Say Y if unsure.
68 config IP_VS_PROTO_UDP
69 bool "UDP load balancing support"
71 This option enables support for load balancing UDP transport
72 protocol. Say Y if unsure.
74 config IP_VS_PROTO_ESP
75 bool "ESP load balancing support"
77 This option enables support for load balancing ESP (Encapsulation
78 Security Payload) transport protocol. Say Y if unsure.
81 bool "AH load balancing support"
83 This option enables support for load balancing AH (Authentication
84 Header) transport protocol. Say Y if unsure.
86 comment "IPVS scheduler"
89 tristate "round-robin scheduling"
91 The robin-robin scheduling algorithm simply directs network
92 connections to different real servers in a round-robin manner.
94 If you want to compile it in kernel, say Y. To compile it as a
95 module, choose M here. If unsure, say N.
98 tristate "weighted round-robin scheduling"
100 The weighted robin-robin scheduling algorithm directs network
101 connections to different real servers based on server weights
102 in a round-robin manner. Servers with higher weights receive
103 new connections first than those with less weights, and servers
104 with higher weights get more connections than those with less
105 weights and servers with equal weights get equal connections.
107 If you want to compile it in kernel, say Y. To compile it as a
108 module, choose M here. If unsure, say N.
111 tristate "least-connection scheduling"
113 The least-connection scheduling algorithm directs network
114 connections to the server with the least number of active
117 If you want to compile it in kernel, say Y. To compile it as a
118 module, choose M here. If unsure, say N.
121 tristate "weighted least-connection scheduling"
123 The weighted least-connection scheduling algorithm directs network
124 connections to the server with the least active connections
125 normalized by the server weight.
127 If you want to compile it in kernel, say Y. To compile it as a
128 module, choose M here. If unsure, say N.
131 tristate "locality-based least-connection scheduling"
133 The locality-based least-connection scheduling algorithm is for
134 destination IP load balancing. It is usually used in cache cluster.
135 This algorithm usually directs packet destined for an IP address to
136 its server if the server is alive and under load. If the server is
137 overloaded (its active connection numbers is larger than its weight)
138 and there is a server in its half load, then allocate the weighted
139 least-connection server to this IP address.
141 If you want to compile it in kernel, say Y. To compile it as a
142 module, choose M here. If unsure, say N.
145 tristate "locality-based least-connection with replication scheduling"
147 The locality-based least-connection with replication scheduling
148 algorithm is also for destination IP load balancing. It is
149 usually used in cache cluster. It differs from the LBLC scheduling
150 as follows: the load balancer maintains mappings from a target
151 to a set of server nodes that can serve the target. Requests for
152 a target are assigned to the least-connection node in the target's
153 server set. If all the node in the server set are over loaded,
154 it picks up a least-connection node in the cluster and adds it
155 in the sever set for the target. If the server set has not been
156 modified for the specified time, the most loaded node is removed
157 from the server set, in order to avoid high degree of replication.
159 If you want to compile it in kernel, say Y. To compile it as a
160 module, choose M here. If unsure, say N.
163 tristate "destination hashing scheduling"
165 The destination hashing scheduling algorithm assigns network
166 connections to the servers through looking up a statically assigned
167 hash table by their destination IP addresses.
169 If you want to compile it in kernel, say Y. To compile it as a
170 module, choose M here. If unsure, say N.
173 tristate "source hashing scheduling"
175 The source hashing scheduling algorithm assigns network
176 connections to the servers through looking up a statically assigned
177 hash table by their source IP addresses.
179 If you want to compile it in kernel, say Y. To compile it as a
180 module, choose M here. If unsure, say N.
183 tristate "shortest expected delay scheduling"
185 The shortest expected delay scheduling algorithm assigns network
186 connections to the server with the shortest expected delay. The
187 expected delay that the job will experience is (Ci + 1) / Ui if
188 sent to the ith server, in which Ci is the number of connections
189 on the ith server and Ui is the fixed service rate (weight)
192 If you want to compile it in kernel, say Y. To compile it as a
193 module, choose M here. If unsure, say N.
196 tristate "never queue scheduling"
198 The never queue scheduling algorithm adopts a two-speed model.
199 When there is an idle server available, the job will be sent to
200 the idle server, instead of waiting for a fast one. When there
201 is no idle server available, the job will be sent to the server
202 that minimize its expected delay (The Shortest Expected Delay
203 scheduling algorithm).
205 If you want to compile it in kernel, say Y. To compile it as a
206 module, choose M here. If unsure, say N.
208 comment 'IPVS application helper'
211 tristate "FTP protocol helper"
212 depends on IP_VS_PROTO_TCP
214 FTP is a protocol that transfers IP address and/or port number in
215 the payload. In the virtual server via Network Address Translation,
216 the IP address and port number of real servers cannot be sent to
217 clients in ftp connections directly, so FTP protocol helper is
218 required for tracking the connection and mangling it back to that of
221 If you want to compile it in kernel, say Y. To compile it as a
222 module, choose M here. If unsure, say N.