| Select Listener Protocol |
Select the protocol of the listener.
In this example, select TCP.
|
| Listening Port |
Set the listening port used to receive requests and forward them to backend servers.
Valid values: 1 to 65535.
Note You can set the same listening port for TCP and UDP listeners that are added to the
same SLB instance. However, you must first apply for the privilege to use the beta function of configuring the same ports in TCP/UDP listeners on the Quota Management page in the SLB console. This feature is now in public preview and is supported in
the following regions. In other cases, the listening ports must be unique.
- UAE (Dubai)
- Australia (Sydney)
- UAE (Dubai)
- UK (London)
- Germany (Frankfurt)
- US (Silicon Valley)
- US (Virginia)
- Indonesia (Jakarta)
- Japan (Tokyo)
- India (Mumbai)
- Singapore (Singapore)
- Malaysia (Kuala Lumpur)
- China (Hong Kong)
- China (Shenzhen)
- China (Hohhot)
- China (Qingdao)
- China (Chengdu)
- China (Zhangjiakou)
- China (Shanghai)
|
| Advanced Settings |
| Scheduling Algorithm |
SLB supports four scheduling algorithms: round robin (RR), weighted round robin (WRR),
weighted least connections (WLC), and consistent hashing (CH).
- Weighted Round-Robin (WRR): Backend servers with higher weights receive more requests.
- Round-Robin (RR): Requests are evenly and sequentially distributed to backend servers.
- Weighted Least Connections (WLC): Requests are distributed based on the combination of the weights and active connections
of backend servers. Requests are distributed to the backend server with the least
number of active connections. If two backend servers have the same number of active
connections, the backend server with a higher weight receives more requests.
- Consistent Hash (CH):
- Source IP: the source IP hash. Requests from the same source IP address are scheduled to the
same backend server.
- Tuple: the 4-tuple hash consisting of the source IP address, destination IP address, source
port number, and destination port number. Requests with the same 4-tuple are scheduled
to the same backend server.
|
| Enable Session Persistence |
Specify whether to enable session persistence.
After session persistence is enabled, the listener forwards all requests from the
same client to a specific backend server for the duration of a session.
For TCP listeners, session persistence is implemented based on IP addresses. Requests
from the same IP address are forwarded to the same backend server.
|
| Enable Access Control |
Specify whether to configure the listener to restrict access. |
| Access Control Method |
Select an access control method after you enable access control.
- Whitelist: Only the requests from the IP addresses or Classless Inter-domain Routing (CIDR)
blocks in the specified access control list (ACL) are forwarded. You can use the whitelist
feature when you want to allow access from specified IP addresses.
Using the whitelist feature may pose risks to your services. The whitelist allows
only the traffic from the IP addresses in the specified ACL to access the SLB listener.
If the whitelist is used while the corresponding ACL does not contain any IP addresses,
the SLB listener forwards all access requests.
- Blacklist: Requests from the IP addresses or CIDR blocks in the specified ACL are not forwarded.
You can use the blacklist feature when you want to deny access from specified IP addresses.
If the blacklist is used while the corresponding ACL does not contain any IP addresses,
the SLB listener forwards all access requests.
|
| Access Control List |
Select an ACL that functions as the whitelist or blacklist of the listener.
Note IPv6 instances can only be associated with IPv6 ACLs, and IPv4 instances can only
be associated with IPv4 ACLs. For more information, see Configure an access control list.
|
| Enable Peak Bandwidth Limit |
You can switch on this option and then set a bandwidth limit for the listener.
If an SLB instance incurs fees based on the bandwidth, you can set different peak
bandwidth values for different listeners to limit the amount of traffic that flows
in each listener. The sum of the peak bandwidth values of all listeners added to an
SLB instance cannot exceed the bandwidth of this SLB instance.
By default, this feature is disabled and all listeners share the bandwidth of the
SLB instance.
Note If an SLB instance incurs fees based on the amount of transmitted data, no peak bandwidth
limit is applied by default.
|
| Idle Timeout |
Specify the idle timeout period of TCP connections. Unit: seconds. Valid values: 10
to 900.
|
| Listener Name |
Enter a name for the listener. |
| Obtain Client Source IP Address |
For Layer-4 listeners, backend servers can directly obtain the actual IP addresses
of clients.
|
| Automatically Enable Listener After Creation |
Specify whether to start the listener after the listener is configured. By default,
the listener is started after configuration.
|
