API Objects Reference
L4 farm
This page applies to:
- HAProxy ALOHA - all versions
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:
balanceJump to heading
Definition: Load balancing algorithm used to dispatch new connections on real servers.
Type: enum
Default value:
roundrobin
| Value | Description |
|---|---|
roundrobin | Each server is used in turn according to their weights. |
least-connections | The new connection is affected to the server with the lowest number of connections. |
hash-source | The source IP address is hashed and divided by the total weight of the running servers to designate which server will receive the request. This ensures that the same client IP address will always reach the same server as long as no server goes down or up. |
hash-destination | Assigns jobs to servers through looking up a statically assigned hash table based on destination IP addresses. |
hash-source-dest | Assigns jobs to servers through looking up a statically assigned hash table based on both source and destination IP addresses. |
shortest-expected-delay | Assign an incoming job to the server with the shortest expected delay. |
never-queue | Assign an incoming job to an idle server if there is one instead of waiting for a fast one; if all the servers are busy, it adopts the Shortest Expected Delay policy to assign the job. |
modeJump to heading
Definition: Deployment mode
Type: enum
Default value: Destination IP masquerading
| Value | Description |
|---|---|
gateway | Direct routing or direct server return (DSR) mode |
nat | Destination IP masquerading (Network Address Translation, or NAT) |
tunnel | ipip encapsulation (tunneling) |
persistenceJump to heading
Definition: If this option is enabled, multiple requests from a client (same source IP) are redirected to the same real server selected for the first request. This option may be used in conjunction with protocols such as SSL or FTP where it is important that clients consistently connect with the same real server.
Type: enum
Default value: Persistence is disabled
| Value | Description |
|---|---|
enabled | persistence is enabled |
persistence-timeoutJump to heading
Info
This attribute is ignored ifpersistence is not set toenabled.
Definition: Value in seconds specify how long sessions are kept persistence load balance table.
Type: integer
Default value: 300 seconds
persistence-netmaskJump to heading
Info
This attribute is ignored ifpersistence is not set toenabled.
Definition: Specify the granularity of persistence
Type: ip
Default value: 255.255.255.255
service-addressJump to heading
Definition: IP address on which to intercept traffic
Type: ip
Default value: no interception
service-portJump to heading
Info
This attribute is ignored unlessservice-address is configured.
Definition: network port to intercept traffic on
Type: port
Default value: all ports for the service-address are intercepted
Particular value: 0 means interception of all ports
service-protocolJump to heading
Info
This attribute is ignored unlessservice-address is configured.
Definition: layer 4 protocol (udp or tcp) to intercept
Type: enum
Default value: tcp is intercepted
| Value | Description |
|---|---|
tcp | intercept tcp |
udp | intercept udp |
check-intervalJump to heading
Definition: Interval between two consecutive server health checks in seconds
Type: integer
Default value:
10
check-portJump to heading
Definition: Destination TCP port used to perform health check
Type: integer
Default value: Server port is used
check-timeoutJump to heading
Definition: Additional health check timeout, starts after the connection has been established on the server
Type: integer
Default value:
check-interval/2
check-sourceJump to heading
Definition: Source IP address to use when performing health checks
Type: ip
Default value: First load balancer interface address is used
adv-checkJump to heading
Definition: Advanced health check method
Type: enum
Default value:
icmp
| Value | Description |
|---|---|
http | Use an http request health checks for server testing, If http status code 200 is returned, check is successful |
tcp | Perform a tcp connect. If connect accepted, check is successful |
icmp | process an icmp echo to server, if echo reply received, check is successful |
adv-check-http-uriJump to heading
Info
This attribute is ignored unlessadv-check is set tohttp.
Definition: Requested URI for HTTP health check
Type: string
Default value:
/
adv-check-http-status-codeJump to heading
Info
This attribute is ignored unlessadv-check is set tohttp.
Definition: HTTP status code value to consider check successful
Type: integer
Default value:
200
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