Array Networks / Knowledgebase / What is slb virtual health?

SLB VIP Supports External TCP based Health Check

This is a small but useful enhancement on SLB virtual service access.
Prior to this new feature, when all the real servers correspondent to a L4 TCP-based SLB virtual service go down:

a. the status of the virtual service will NOT be marked “DOWN”.
b. any TCP connection attempt from outside will be responded normally which mistakenly convince other devices that the virtual service is good to use

With this enhancement, TM SLB module behaves differently under the same condition:

c. the status of the virtual service will be marked “DOWN”.
d. any TCP connection attempt from outside will NOT be responded so that other devices will know the unavailability of the detected virtual service.

This is useful to support external device to detect the availability of TCP-based virtual services defined in TM.

New CLI commands:

slb virtual health {on/off}

This command allows users to enable or disable virtual service health check

Other questions in this category

	What is the command syntax for http/1.1 health check?
	Sample config for script-tcp health check.
	Sample config for script-tcp health check with multiple checkers. Must use HTTP/1.1.
	Sample FTP script-tcp health check.
	Sample configuration for script-udp health check