Configure TCP Health Check for Next Hop Proxy
Configure TCP Health Check for Next Hop Proxy
The address of the next hop of which the health check is to be performed must be configured under TCP Health Check.
To view the Health Check option, go to Configuration > Cluster > Health Check.
Health Check Configuration Parameters
Option | Description |
---|---|
Server Address |
|
Enabled |
Enable health check. |
Disabled-Healthy |
|
Disabled-Unhealthy |
|
Healthy Interval |
|
Number of Healthy Retries |
|
Unhealthy Interval |
|
Number of unhealthy retries |
|
Number of worker threads |
|
- A new checkbox is added in Next Hop Proxy List Synchronize this Host and Port to health check config for TCP health checks, when enabled, the host and port value is automatically pushed to Configuration > Cluster > Health Check in form Host:Port
- We can manually override the default health check settings e.g. disabling health checks, changing the frequency of health checks, etc.
Important: The auto-sync checkbox feature will be available in the upcoming release cycle.
- One must configure the entries manually in Configuration > Cluster > Health Check.
Example Illustrating Healthy/Unhealthy Retries
Assume IP1:Port1 is configured in Configuration > Cluster > Health Check.
Number of healthy retries: 3.
Number of unhealthy retries: 3.
Case 1:
- TCP 3-way handshake with IP1:Port1 is successful.
- Retry the TCP connection for ‘Number of healthy retries’ times. If it is successful for all retries (In this example for i=1, 2 and 3), this server is considered healthy.
Case 2:
- TCP 3-way handshake with IP1:Port1 fails.
- Retry the TCP connection for ‘Number of unhealthy retries’ times. If it is failed for all retries (In this example for i=1, 2 and 3), this server is considered unhealthy.
Case 3:
- TCP 3-way handshake with IP1:Port1 is successful.
- Retry the TCP connection for ‘Number of healthy retries’ times.
- For i=1, the TCP connection is successful.
- For the next retry, i=2, the TCP connection fails. Retry the TCP connection for ‘Number of unhealthy retries’ times.
- For i = 1, the TCP connection fails
- For the next retry i.e. i=2, the TCP connection is a success. The Expectation is to fail. So, SWG marks this server as Unhealthy with the reason ‘Connection Unstable’