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HTTP(S) health check

Last Updated: Nov 06, 2019

You can create health check for an address pool to monitor each IP address in the pool separately and obtain the running status of the application services corresponding to the IP addresses. When a monitored IP address encounters an exception, the address will be blocked until it is restored.

Health check name

Set a health check name that is easy to recognize. It can contain both Chinese and English characters.

HTTP(S) monitoring

Target IP addresses are monitored over HTTP(S). The metrics include web server network accessibility, service availability, and first packet latency.

Port checking

The system monitors the operation of a port of the web server corresponding to the target IP address. The default monitored port is Port 80 for HTTP and Port 443 for HTTP(S). You can select another web server port to be monitored as needed.

Time-out period

The time of responding to sent HTTP(S) data packets is calculated during HTTP(S) monitoring. Health check is deemed to have timed out when no response packet is returned within the time-out period.The time-out period can be set to 2, 3, 5, or 10, in seconds.

Continuous failed attempts

During HTTP(S) monitoring, the system determines that an application service is abnormal only after consecutive exceptions have occurred. This prevents transient jitters and other causes from affecting monitoring accuracy.Continuous Failed Attempts can be set to 1, 2, or 3 times.

  • 1 times: An application service is deemed abnormal when health check detects one alarm.
  • 2 times: An application service is deemed abnormal when health check detects two alarms.
  • 3 times: An application service is deemed abnormal when health check detects three alarms.

Failure Rate

The failure rate is the proportion of abnormal metrics to the total metrics of health check during HTTP(S) monitoring. When the failure rate exceeds the configured threshold, the system determines that the application service is abnormal.Failure Rate can be set to 20%, 50%, 80%, or 100%.

Monitored node

A monitored node is the geographic location of the node that executes HTTP(S) monitoring. The default monitored nodes are:

Nodes geographic location
BGP Nodes Zhangjiakou、 Qingdao、Hangzhou、Shanghai、Hohhot、Shenzhen、Beijing
Overseas Nodes Hong Kong、Germany、Singapore、Silicon Valley、Australia、Malaysia、Japan
ISP Nodes ChinaUnicomWuhan、ChinaUnicomDalian、ChinaUnicomNanjing、ChinaUnicomTianjin、 ChinaTelecomQingdao、ChinaTelecomChangsha、ChinaTelecomXian、ChinaTelecomZhengzhou、ChinaMobileWuhan、ChinaMobileGuangzhou、ChinaMobileDalian、ChinaMobileNanjing

Response code greater than

During HTTP(S) monitoring, the system checks whether a web server operates properly based on the response code returned by the server. If the response code is greater than the alarm threshold, the system determines that the web server is abnormal.

  • Greater than 400: Bad Request. If an HTTP(S) request carries an incorrect request parameter, the web server returns a response code greater than 400. If the alarm threshold is greater than 400, you must enter the precise URL path parameter in a URL path.
  • Greater than 500: Server Error. If a web server encounters an exception, it returns a response code greater than 500. Set the alarm threshold to be greater than 500 unless otherwise specified.

Host configuration

During HTTP(S) monitoring, set the Host field carried in the HTTP(S) request header to identify the accessed HTTP website. Set this field to the primary domain name on the Global Settings page unless otherwise specified.