Manage service chain load balancers

Task

Description

Create health monitors

Health monitors are used for detecting the operating status of real servers. Multiple monitor methods are supported.

Create virtual servers

Virtual servers are virtual carriers of user services. A virtual server can be used by multiple listeners. Service requests (with different protocols and port numbers) matching different listeners can be processed by one virtual server.

Create listeners

Listeners listen to service requests received by the LB device. When a request matches the protocol, port number, and virtual server IP address configured for a listener, the LB device distributes the request to the associated virtual server.

Create real server groups

Multiple real servers with the same or similar functions can form a real server group. You can specify the common attributes for real server group members, such as LB method, health monitor method, and session persistence method.

Create load balancers

In this procedure, you can associate load balancers with listeners.

Operation

Parameter

Description

Create a load balancer

Resource

Specify the resource where the load balancer resides.

Listener

Select listeners from the available listener list, and then click  to add them to the selected listener list. You can also move listeners from the selected listener list to the available listener list.

If no available listeners exit, click Create to create a listener.

Create a virtual server

IP Version

Select an IP version. Options are IPv4 and IPv6.

Subnet

Specify the subnet or VPN to which the virtual server belongs.

Server IP

Specify the virtual service IP address, which must belong to the specified subnet or VPN.

Floating IP

Optional.

Specify an elastic IP address. To access the external network, you can configure this parameter.

Create a listener

IP Version

Select an IP version. Options are IPv4 and IPv6.

Virtual Servers

Select one or more existing virtual servers. When a request matches the protocol, port number, and virtual server IP address configured for a listener, the LB device distributes the request to the associated virtual server.

If no available virtual servers exist, click Add Virtual Server to add a virtual server.

Protocol

Select a protocol. Options are:

·          HTTP—An application layer protocol that supports cookie-based session persistence. This protocol is used for applications that recognize data contents, such as web applications and mobile games.

·          TCP—A protocol that supports source address-based session persistence. This protocol applies to scenarios that require high data accuracy, such as file transmission, email sending, and email receiving.

·          HTTPS—A protocol that encrypts and transmits data.

SSL Key

Specify the SSL key file. This field is required when the protocol is HTTPS. For more information about this parameter, see Creating a certificate.

SSL Certificate

Specify the SSL certificate file. This field is required when the protocol is HTTPS. For more information about this parameter, see Creating a certificate.

Port Number

Specify the monitored port by its number.

Connection Limit

Specify the maximum number of connections. The default setting 0 means not limited.

Idle Timeout (Seconds)

Specify the idle timeout time for TCP connections. If a client does not send a TCP packet to the server before the time expires, the TCP session ages.

 CAUTION:

For F5 LB devices, you must configure this parameter.

User Source Network Address Translation

Specify whether to allow the virtual server to translate the source IP addresses of packets.

X-Forwarded-For

Specify whether to allow the virtual server to insert real source IP addresses of packets to the HTTP extended fields.

State

Specify whether to enable the listener.

Default Real Server Farm

Specify the monitored real server group. If no available real server groups exist, click Create Real Server Group to create a real server group. To edit a real server group, click Edit in the Actions column for it.

Create a real server group

LB Mode

Select an LB mode. Options are ROUND_ROBIN, LEAST_CONNECTIONS, RANDOM, and SOURCE_IP. For more information about this parameter, see "Create a listener."

Session Persistence

Select a session persistence method. Options are APP_COOKIE, HTTP_COOKIE, and SOURCE_IP. For more information about this parameter, see "Create a listener."

Cookie Name

Specify the cookie name. This field is required when the session persistence method is APP_COOKIE. Make sure the cookie name matches that configured for the application on the back-end real server.

Health Monitors

Select health monitors from the available health monitor list, and then click  to add them to the selected health monitor list. You can also move health monitors from the selected health monitor list to the available health monitor list.

If no available health monitors exit, click Create to create a health monitor.

Create a health monitor

Monitor Method

Specify the health monitor protocol. Options are PING, TCP, HTTP, and HTTPS.

Delay (Seconds)

Specify the probe interval.

Timeout (Seconds)

Specify the timeout time for the health monitor. If a health check is not completed before the timer expires, the check is considered timed out.

Max Probes

Specify the maximum number of consecutive probe failures. If this number is reached, the real server is excluded from load balancing services.

Monitor Port

Specify the port used by the listener to monitor back-end real servers. This field is required when the monitor method is TCP.

HTTP

Specify the HTTP method. In the current software version, only the GET option is available. This field is required when the monitor method is HTTP or HTTPS.

URL

Specify the URL for the health monitor to access the real server. You can configure this parameter when the monitor method is HTTP or HTTPS.

Expected Status Codes

Specify the expected status codes received upon access to the real server resources based on the specified URL. The status codes contain information about server status. You can configure this parameter when the monitor method is HTTP or HTTPS.

Expected Response

Specify the expected response content. If the response packet contains the expected response content, the member is valid. If the response packet does not contain the expected response content, the member is invalid.

You can configure this parameter when the monitor method is HTTP or HTTPS.

Response Packet Offset (Bytes)

Specify the offset of the expected content in the response packets.

If this parameter is 0, LB device performs content matching from the first byte of the response packets. If no match is found, the next byte is looked up.

If this parameter is not 0, LB device performs content matching from the first byte after the offset. If no match is found, the LB device performs content matching from the first byte of the response packets. If no match is found again, the second byte is looked up.

You can configure this parameter when the monitor method is HTTP or HTTPS.