--- title: Health Checks analytics description: Use Health Checks analytics to debug origin availability issues. image: https://developers.cloudflare.com/core-services-preview.png --- > Documentation Index > Fetch the complete documentation index at: https://developers.cloudflare.com/smart-shield/llms.txt > Use this file to discover all available pages before exploring further. [Skip to content](#%5Ftop) ### Tags [ Analytics ](https://developers.cloudflare.com/search/?tags=Analytics) # Health Checks analytics Use Health Checks analytics to debug possible origin issues. You can evaluate origin uptime, latency, failure reason, and specific event logs: * **Health Checks By Uptime**: Shows the percentage of uptime for individual origins over time. * **Health Checks By Failure Reason**: Shows a breakdown of failures by the specific reason. Refer to [common error code causes and solutions below](#common-error-codes). * **Health Checks By Latency**: Shows average latency – measured in round trip time — for individual origins over time. * **Event Log**: Shows individual health check data. * Select each record for additional details on **Round trip time**, the **Failure Reason**, the **Average Waterfall** (showing chronological data about request stages), **Response status code**, and more. * Note that **Global** is not a configured region; it represents the aggregated data from all enabled regions. ## Common error codes ### TCP connection failed #### Cause Health Checks failed to establish a TCP connection to your origin server. #### Solution This typically occurs when there is a network failure between Cloudflare and your origin, and/or a firewall refuses to allow our connection. Ensure your network and firewall configurations are not interfering with traffic. ### HTTP timeout occurred #### Cause The origin failed to return an HTTP response within the timeout configured. This happens if you have the timeout set to a low number. For example, one to two seconds. #### Solution Cloudflare recommends increasing the HTTP response timeout to allow the origin server to respond. ### Response code mismatch error #### Cause Cloudflare receives an HTTP status code that does not match the values defined in the `expected_codes` property of your Health Check configuration. #### Solution Response codes must match the `expected_codes`. Confirm the values are correct by comparing the expected response codes and the status code received in the Event Log. #### ​​Alternate cause You may also see this issue if you have a Health Check configured to use HTTP connections and your origin server is redirecting to HTTPS. In this case, the response code will often be `301`, `302`, or `303`. #### Solution Change your Cloudflare Health Check configuration to use HTTPS or set the value of `follow_redirect` to `true` so that Cloudflare can resolve the correct status code. ### Response body mismatch error #### Cause The response body returns from your origin server and does not include the (case-insensitive) value of `expected_body` configured in your Health Check. Note We only read the first 10 KB of the response. If you return a larger response, and the `expected_body` is not in the first 10 KB, the Health Check will fail. #### Solution Ensure the `expected_body` is in the first 10 KB of the response body. ​​ ### TLS untrusted certificate error #### Cause The certificate is not trusted by a public Certificate Authority (CA). #### Solution If you’re using a self-signed certificate, Cloudflare recommends either using a publicly trusted certificate or setting the `allow_insecure` property on your Health Check to `true`. ### TLS name mismatch error #### Cause Our Health Check (client) was not able to match a name on the server certificate to the hostname of the request. #### Solution Inspect your Health Check configuration to confirm that the `header` value set in the Cloudflare Health Check is correct. ### TLS protocol error #### Cause This error can occur if you are using an older version of TLS or your origin server is not configured for HTTPS. #### Solution Ensure that your origin server supports TLS 1.2 or greater and is configured for HTTPS. ### TLS unrecognized name error #### Cause The server did not recognize the name provided by the client. When a host header is set, this is set as the ServerName in the initial TLS handshake. If it is not set, Cloudflare will not provide a ServerName, which can cause this error. #### Solution Set the host header in your Health Check object. ### ​​No route to host error #### Cause The IP address cannot be reached from Cloudflare’s network. Common causes are ISP or hosting provider network issues (e.g. BGP level), or that the IP does not exist. #### Solution Ensure IP is accurate, and check if there is an ISP or hosting provider network issue. ### TCP Timeout #### Cause Data transmission was not acknowledged and the retransmit of data did not succeed. #### Solution Confirm whether the SYN-ACK for the handshake takes place at your origin and contact [Cloudflare support](https://developers.cloudflare.com/support/contacting-cloudflare-support/). ### ​​Network Unreachable #### Cause Cloudflare cannot connect to the origin web server due to network unavailability. This is usually caused by a network issue or incorrect origin IP. #### Solution Check the IP entered for the origin in Cloudflare’s Health Checks configuration or the IP returned via DNS for the origin hostname. ### HTTP Invalid Response #### Cause Usually caused by an HTTP 502 error or bad gateway. #### Solution Ensure the origin web server responds to requests and that no applications have crashed or are under high load. ### DNS Unknown Host #### Cause The origin web server hostname does not exist. #### Solution Confirm the origin web server resolves to an IP address. ### Connection Reset by Peer #### Cause A network error occurred while the client received data from the origin web server. #### Solution Confirm whether the origin web server is experiencing a high amount of traffic or an error. ### Monitor Configuration Error #### Cause There was a configuration error in the Health Check and no checks were run against the origin. #### Solution Review your Health Check configuration to ensure it matches an expected request to your origin. ### ​​DNS Internal #### Cause The origin web server’s hostname resolves to an internal or restricted address. No checks are run against this origin. #### Solution Cloudflare does not allow use of an origin web server hostname that resolves to a Cloudflare IP. ### Other Failure #### Cause If the failure cannot be classified as any other type of failure mentioned above. #### Solution Contact [Cloudflare support](https://developers.cloudflare.com/support/contacting-cloudflare-support/). ```json {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/directory/","name":"Directory"}},{"@type":"ListItem","position":2,"item":{"@id":"/smart-shield/","name":"Smart Shield"}},{"@type":"ListItem","position":3,"item":{"@id":"/smart-shield/configuration/","name":"Configuration"}},{"@type":"ListItem","position":4,"item":{"@id":"/smart-shield/configuration/health-checks/","name":"Health Checks"}},{"@type":"ListItem","position":5,"item":{"@id":"/smart-shield/configuration/health-checks/analytics/","name":"Health Checks analytics"}}]} ```