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Web Frontend

circonus-http is a perl web service running under Apache HTTPD on port 80. In front of this service is circonus-ssl-term, which listens on port 443 to terminate SSL connections and forward them to the backend.

Web Frontend and API are similar in their application code and logging setup, therefore debugging techniques for one typically work on the other. The default set of logs are the apache logs (rotated hourly):

  • circonus_access_log
  • circonus_error_log
  • circonus_ssl_access_log
  • circonus_ssl_error_log

By default, the web frontend does not come with any additional logs enabled. To enable additional logging, see the Additional Web Logging section.

Internal UI application errors can be found in the circonus_error_log. These errors will likely be in the form of perl stacktraces or exceptions. Some errors can be resolved by restarting the circonus-http service. For help with all other errors, contact Circonus Support (


In addition to the Apache HTTPD processes, web frontend also runs a memcached service. This service is setup in a cluster across all the web frontend nodes and services items, such as cached copies of users and accounts, as well as across security tokens.

Should users report problems with accessing the site, such as requests being rejected or incorrect security permissions, you can attempt to restart the circonus-memcached service, and then have the users reload the page and try their requests again.

Web Frontend PKI Files

  • /www/etc/ssl/ca.crt
  • /www/etc/ssl/<hostname>.crt
  • /www/etc/ssl/<hostname>.key


You will also see web.crt and web.key. These are the user facing certificates and not involved in internal SSL communication.