L7 farm

A farm is a container for real servers. The contained servers must have the same role and deliver the same service.

Farm attributes and options define the session behavior on the server side of the load balancer, such as how to check, dispatch connections, connect, forward data, and maintain sessions to real servers.

Farms are identified by a name; allowed characters include alpha-numeric, dot, dash, and underscore.

The available farm attributes are listed below:

balance Jump to heading #

• Definition: load balancing algorithm used to dispatch new connections on real servers

• Type: enum

• Default value: roundrobin

protocol Jump to heading #

• Definition: protocol analyzer used by load balancer. Some features of HTTP protocol require to have the analyzer on.

• Type: enum

• Default value: tcp

log Jump to heading #

• Definition: log farm events

• Type: enum

• Default value: logs are disabled

log format Jump to heading #

This attribute is ignored if log is not set to enabled.

• Definition: log format used if logs are enabled

• Type: enum

• Default value: basic log format

http-connection-mode Jump to heading #

This attribute is ignored if protocol is not set to http.

• Definition: http keepalive behavior

• Type: enum

• Default value: tunnel

http-pretend-keepalive Jump to heading #

This attribute is ignored if protocol is not set to http.

• Definition: HTTP keepalive announced to the server regardless keepalive status

• Type: enum

• Default value: disabled

http-xff-header-insert Jump to heading #

This attribute is ignored if protocol is not set to http.

• Definition: Inserts an HTTP header field X-Forwarded-For whose value is the client IPaddress

• Type: enum

• Default value: disabled

http-cookie Jump to heading #

This attribute is ignored if protocol is not set to http.

• Definition:

• Type: enum

• Default value: disabled

http-cookie-name Jump to heading #

This attribute is ignored if protocol is not set to http.

This attribute can be set and it is mandatory if http-cookie is set.

• Definition: Name of the cookie used for server affinity. On incoming connections, the request is forwarded to the server whose http-cookie-id attribute matches the current cookie value.

• Type: string

• Default value: no cookie affinity

http-cookie-mode Jump to heading #

This attribute is ignored if protocol is not set to http.

This attribute can be set and it is mandatory if http-cookie is set.

• Definition: Cookie affinity analysis / insertion behavior

• Type: enum

• Default value: No cookie affinity

http-cookie-nocache Jump to heading #

This attribute is ignored if protocol is not set to http.

This attribute can be set and it is mandatory if http-cookie is set.

• Definition: no-cache flag on inserted cookie to prevent proxy from caching the cookie.

• Type: enum

• Default value: no cookie affinity

check-interval Jump to heading #

• Definition: Interval in seconds between two consecutive server health checks.

• Type: integer

• Default value: 2

check-rise Jump to heading #

• Definition: Count of consecutive successful health checks to consider server operational.

• Type: integer

• Default value: 2

check-fall Jump to heading #

• Definition: Count of consecutive unsuccessful health checks to consider server not operational.

• Type: integer

• Default value: 3

check-port Jump to heading #

• Definition: Destination TCP port used to perform health check. Set to 0 to use server port.

• Type: integer

• Default value: server port is used

check-timeout Jump to heading #

• Definition: additional health check timeout in seconds occurring when waiting for server’s response (after the connection is established). Set to 0 for set timeout to check-interval.

• Type: integer

• Default value: check timeout is set to check-interval

adv-check Jump to heading #

• Definition: Advanced check method

• Type: enum

• Default value: No advanced check. Performs a TCP connect.

adv-check-http-uri Jump to heading #

This attribute can be set and it is mandatory if adv-check is set to http.

• Definition: Requested URI for http health check

• Type: string

• Default value: Advanced check not set to http

adv-check-http-method Jump to heading #

This attribute can be set and it is mandatory if adv-check is set to http.

• Definition: HTTP request method used during http health check. If not set, HEAD is used.

• Type: string

• Default value: advanced check not set to http

adv-check-http-version Jump to heading #

This attribute can be set and it is mandatory if adv-check is set to http.

• Definition: HTTP request protocol version. If not set, HTTP/1.0 is used. Can be used to send a Host header field.

• Type: string

• Default value: advanced check not set to http

queued-timeout Jump to heading #

This attribute can be set and it is mandatory if adv-check is set to http.

• Definition: Maximum time to wait in the queue for a server’s connection slot to be available

• Type: integer

• Default value: no timeout

• Particular value: 0 means no timeout

connect-timeout Jump to heading #

• Definition: Maximum time to wait for a server connection attempt to succeed.

• Type: integer

• Default value: no timeout

• Particular value: 0 means no timeout

connect-retries Jump to heading #

• Definition: Number of retries to perform when trying to establish a connection to a server

• Type: integer

• Default value: no retries

• Values: 0 means no retry

connect-failure-redispatch Jump to heading #

Only used when connect-retries is greater than 1

• Definition: Session redispatch to another server in case of connection failure. Last connect-retries will be performed on another server.

• Type: enum

• Default value: no redispatch

connect-source Jump to heading #

• Definition: Force source address to use when connecting to servers.

• Type: ip

• Default value: Use the first address on load balancer’s outgoing interface

• Particular value: Set to 0.0.0.0 to use first address available on load balancer’s outbound interface

connect-transparent Jump to heading #

This attribute can be set and it is mandatory if connect-source is set.

• Definition: Transparent proxy mode; the client source address is reused as the source address to connect to server.

• Type: enum

• Default value: Use the first address on load balancer’s outgoing interface

continuous-statistics Jump to heading #

• Definition: Continuous traffic statistics updates

• Type: enum

• Default value: disabled, meaning traffic counters are incremented once a session finishes.

server-inactivity-timeout Jump to heading #

• Definition:

• Type: integer

• Default value: no timeout

• Particular value: 0 for no timeout

stick-table Jump to heading #

• Definition: Create a stick table in the farm; expect type of data to be stored as an argument

• Type: enum

• Default value: none

stick-table-expire Jump to heading #

• Definition: Maximum life time of data in a stick-table if unrefreshed

• Type: integer

• Default value: 32 charaters or bytes

stick-table-keylen Jump to heading #

• Definition: Maximum size of data when storing binary or string in the table

• Type: integer

• Default value: 32 charaters or bytes

stick-table-nopurge Jump to heading #

• Definition: Maximum life time of data in a stick-table if unrefreshed

• Type: enum

• Default value: 32 charaters or bytes

stick-table-peers Jump to heading #

• Definition: HAProxy’s peers section name (must be already configured). Used to synchronize data after a reload and between two HAProxy ALOHA load balancers.

• Type: string

• Default value: none

stick-table-size Jump to heading #

• Definition: The maximum number of entries that can be stored in the table.

• Type: integer

• Default value: none

tcpreq-inspect-delay Jump to heading #

• Definition: Set the maximum allowed time to wait for data from the client during content inspection.

• Type: integer

• Default value: 0

tcprsp-inspect-delay Jump to heading #

• Definition: Set the maximum allowed time to wait for data from the server during content inspection.

• Type: integer

• Default value: 0