IP Virtual Server support will let you build a high-performance virtual server based on cluster of two or more real servers. This option must be enabled for at least one of the clustered computers that will take care of intercepting incoming connections to a single IP address and scheduling them to real servers. Three request dispatching techniques are implemented, they are virtual server via NAT, virtual server via tunneling and virtual server via direct routing. The several scheduling algorithms can be used to choose which server the connection is directed to, thus load balancing can be achieved among the servers. For more information and its administration program, please visit the following URL: <http://www.linuxvirtualserver.org/>. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
Add IPv6 support to IPVS. This is incomplete and might be dangerous. See http://www.mindbasket.com/ipvs for more information. Say N if unsure.
Say Y here if you want to get additional messages useful in debugging the IP virtual server code. You can change the debug level in /proc/sys/net/ipv4/vs/debug_level
The IPVS connection hash table uses the chaining scheme to handle hash collisions. Using a big IPVS connection hash table will greatly reduce conflicts when there are hundreds of thousands of connections in the hash table. Note the table size must be power of 2. The table size will be the value of 2 to the your input number power. The number to choose is from 8 to 20, the default number is 12, which means the table size is 4096. Don't input the number too small, otherwise you will lose performance on it. You can adapt the table size yourself, according to your virtual server application. It is good to set the table size not far less than the number of connections per second multiplying average lasting time of connection in the table. For example, your virtual server gets 200 connections per second, the connection lasts for 200 seconds in average in the connection table, the table size should be not far less than 200x200, it is good to set the table size 32768 (2**15). Another note that each connection occupies 128 bytes effectively and each hash entry uses 8 bytes, so you can estimate how much memory is needed for your box. You can overwrite this number setting conn_tab_bits module parameter or by appending ip_vs.conn_tab_bits=? to the kernel command line if IP VS was compiled built-in.
This option enables support for load balancing TCP transport protocol. Say Y if unsure.
This option enables support for load balancing UDP transport protocol. Say Y if unsure.
This option enables support for load balancing ESP (Encapsulation Security Payload) transport protocol. Say Y if unsure.
This option enables support for load balancing AH (Authentication Header) transport protocol. Say Y if unsure.
This option enables support for load balancing SCTP transport protocol. Say Y if unsure.
The robin-robin scheduling algorithm simply directs network connections to different real servers in a round-robin manner. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The weighted robin-robin scheduling algorithm directs network connections to different real servers based on server weights in a round-robin manner. Servers with higher weights receive new connections first than those with less weights, and servers with higher weights get more connections than those with less weights and servers with equal weights get equal connections. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The least-connection scheduling algorithm directs network connections to the server with the least number of active connections. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The weighted least-connection scheduling algorithm directs network connections to the server with the least active connections normalized by the server weight. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The locality-based least-connection scheduling algorithm is for destination IP load balancing. It is usually used in cache cluster. This algorithm usually directs packet destined for an IP address to its server if the server is alive and under load. If the server is overloaded (its active connection numbers is larger than its weight) and there is a server in its half load, then allocate the weighted least-connection server to this IP address. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The locality-based least-connection with replication scheduling algorithm is also for destination IP load balancing. It is usually used in cache cluster. It differs from the LBLC scheduling as follows: the load balancer maintains mappings from a target to a set of server nodes that can serve the target. Requests for a target are assigned to the least-connection node in the target's server set. If all the node in the server set are over loaded, it picks up a least-connection node in the cluster and adds it in the sever set for the target. If the server set has not been modified for the specified time, the most loaded node is removed from the server set, in order to avoid high degree of replication. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The destination hashing scheduling algorithm assigns network connections to the servers through looking up a statically assigned hash table by their destination IP addresses. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The source hashing scheduling algorithm assigns network connections to the servers through looking up a statically assigned hash table by their source IP addresses. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The shortest expected delay scheduling algorithm assigns network connections to the server with the shortest expected delay. The expected delay that the job will experience is (Ci + 1) / Ui if sent to the ith server, in which Ci is the number of connections on the ith server and Ui is the fixed service rate (weight) of the ith server. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The never queue scheduling algorithm adopts a two-speed model. When there is an idle server available, the job will be sent to the idle server, instead of waiting for a fast one. When there is no idle server available, the job will be sent to the server that minimize its expected delay (The Shortest Expected Delay scheduling algorithm). If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
FTP is a protocol that transfers IP address and/or port number in the payload. In the virtual server via Network Address Translation, the IP address and port number of real servers cannot be sent to clients in ftp connections directly, so FTP protocol helper is required for tracking the connection and mangling it back to that of virtual service. If you want to compile it in kernel, say Y. To compile it as a module, choose M here. If unsure, say N.
The Netfilter connection tracking support allows the IPVS connection state to be exported to the Netfilter framework for filtering purposes.
Allow persistence based on the SIP Call-ID