Overview
Sometimes, domain names resolution problems may lead to streams publishing/playback stopping on a server, for example, if backend server name used for REST hooks handling cannot be resolved. Since WCS build 5.2.1707 DNS may be tested periodically to detect a such problems. Also, addresses caching may be forced to decrease Java machine DNS resolver load.
DNS testing configuration
DNS testing may be enabled by the following parameters:
dns_test_enable=true dns_test_name=google.com
The settings are applied after WCS restart. The DNS name defined is resolved every 60 seconds. If the name is not set, it will not be tested. If the name cannot be resolved, Unknown host
warning will be displayed in server log.
DNS testing results displaying
DNS testing results are displayed on server statistics page
curl -s http://localhost:8081/?action=stat¶ms=dns_resolution_time
A minimum, average and maximum DNS reply times are displayed in milliseconds
-----Network Stats (Mbit/s)----- dns_resolution_time=53/59/65
Addresses cache configuration
Resolved addresses cache may be forced by the following parameter
enable_network_address_cache=true
The setting is applied after WCS restart. Cache interval is not limited in this case.