The following tables describe the error codes of each protocol that is supported by the site monitoring feature of CloudMonitor and the common HTTP status codes.
Note If a detection succeeds or fails, we recommend that you first check the predefined
error codes of CloudMonitor. If a detection fails due to DNS or network errors, the
server does not return a response and no HTTP status code is returned.
Predefined error codes of CloudMonitor
| Protocol | Error code | Description |
|---|---|---|
| HTTP | 610 | The error code returned because the detection or request has timed out. For example, the TCP or SSL connection has timed out. The default timeout period is 30 seconds. |
| 613 | The error code returned because an error occurred during DNS resolution. | |
| 615 | The error code returned because the required content is not found in the response. The content of the response is different from the custom content that you specified. | |
| 616 | The error code returned because the authentication has failed. | |
| 611 | The error code returned because the monitoring has failed. | |
| 617 |
The error code returned because the maximum number of redirections is exceeded.
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| 618 | The error code returned because the detection assertion has failed. You can view the failure cause based on the failed detection details. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. | |
| PING | 550 | The error code returned because the network connection has failed. |
| 610 | The error code returned because all packets has failed to be received within 2 seconds after the packets are sent. | |
| 613 | The error code returned because the hostname cannot be parsed to an IP address. | |
| 615 | The error code returned because more than 10% of sent packets has failed to be received. | |
| 617 | The error code returned because the IP address of the monitored object is unreachable. | |
| 618 | The error code returned because the detection assertion has failed. You can view the failure cause based on the failed detection details. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. | |
| TCP | 550 | The error code returned because the socket cannot be opened. This error occurs if all system resources are depleted. |
| 610 | The error code returned because no response is returned or the response has timed out. | |
| 611 | The error code returned because the connection has timed out or is rejected. | |
| 615 | The error code returned because the required content is not found in the response. The content of the response is different from the custom content that you specified. | |
| 618 | The error code returned because the detection assertion has failed. You can view the failure cause based on the failed detection details. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. | |
| UDP | 550 | The error code returned because the socket cannot be opened. This error occurs if all system resources are depleted. |
| 611 | The error code returned because the hostname cannot be parsed and the connection has failed. | |
| 610 | The error code returned because the request cannot be sent or the response has failed to be received. | |
| 615 | The error code returned because the required content is not found in the response. | |
| 618 | The error code returned because the detection assertion has failed. You can view the failure cause based on the failed detection details. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create a site monitoring task. | |
| DNS | 610 | The error code returned because an error has occurred in DNS resolution. |
| 613 | The error code returned because the DNS query has failed. | |
| 615 | The error code returned because the required content is not found in the response. | |
| 618 | The error code returned because the detection assertion has failed. You can view the failure cause based on the failed detection details. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. | |
| SMTP | 610 | The error code returned because the connection has timed out. |
| 611 | The error code returned because the site cannot be accessed due to failed DNS resolution, an invalid email address, or failed SMTP client initialization. | |
| 616 | The error code returned because the logon request is rejected. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. | |
| POP3 | 611 | The error code returned because the site cannot be accessed. |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. | |
| FTP | 610 | The error code returned because the FTP transmission has failed. |
| 611 | The error code returned because the DNS resolution has failed or the TCP connection has failed. | |
| 616 | The error code returned because the logon has failed. | |
| 703 | The error code returned because the server cannot be monitored over a private network. For more information about how to monitor servers over a private network, see Create an availability monitoring task. |
Common HTTP status codes
| Status code | Message | Description |
|---|---|---|
| 200 | OK | The status code returned because the request succeeds. All 2XX status codes indicate successful requests. |
| 300 | Multiple Choices | The status code returned because the server can perform multiple operations based on the request. The server selects one operation to perform based on the user agent or provides a list of operations for the user agent to choose from. |
| 301 | Moved Permanently | The status code returned because the requested web page is permanently moved to a new URL. If the server returns this status code in response to a GET or HEAD request, the server redirects the request to the new URL. You can use this status code to notify Googlebot that a web page or a website is permanently moved to a new URL. |
| 302 | Found | The status code returned because the requested web page is temporarily moved to another URL. The user agent must continue to use the original URL for future requests. The server redirects the request to the new URL. This is similar to the operation that is performed by the server when the status code 301 is returned in response to a GET or HEAD request. |
| 303 | See Other | The status code returned because the user agent must send a GET request to a different URL. The server redirects all requests except HEAD requests to the new URL. |
| 304 | Not Modified | The status code returned because the requested web page has not been modified since the last request. If the server returns this status code, the content of the web page is not returned in the response. |
| 305 | Use Proxy | The status code returned because the requested resource must be accessed by using a proxy. If the server returns the status code, the server specifies the proxy in the response. |
| 307 | Temporary Redirect | This status code is similar to the status code 302. The status code returned because the requested resource is temporarily moved to the URL that is specified in the Location header. |
| 308 | Permanent Redirect | The status code returned because the requested resource is permanently moved to the URL that is specified in the Location header. |
| 400 | Bad Request | The status code returned because the server cannot process the request due to invalid request syntax. |
| 401 | Unauthorized | The status code returned because the user agent must pass authentication. The server may return this status code after the logon. |
| 403 | Forbidden | The status code returned because the server rejected the request. |
| 404 | Not Found | The status code returned because the server cannot find the requested web page. For example, the server returns this status code if the requested web page does not exist on the server. |
| 405 | Method Not Allowed | The status code returned because the request method is not supported. |
| 406 | Not Acceptable | The status code returned because the content of the request is not acceptable. |
| 407 | Proxy Authentication Required | The status code returned because the user agent is required to use a proxy to pass the authentication. The status code 407 is similar to the status code 401. If the server returns the status code 407, the server specifies the proxy in the response. |
| 408 | Request Timeout | The status code returned because the server did not receive a request within the timeout period. |
| 409 | Conflict | The status code returned because the request cannot be completed due to a conflict. The server returns the information about the conflict in the response. If a PUT request conflicts with the last request, the server returns this status code and the differences between the two requests. |
| 411 | Length Required | The status code returned because the length of the content is not specified in the request. This status code indicates that the server denied the request. |
| 412 | Precondition Failed | The status code returned because the server cannot meet one of the prerequisites that are specified by the user agent in the request. |
| 413 | Request Entity Too Large | The status code returned because the size of the request exceeds the processing capacity of the server. |
| 414 | Request-URL Too Long | The status code returned because the URL is too long for the server to process. |
| 415 | Unsupported Media Type | The status code returned because the request entity contains a media type that is not supported by the server. |
| 416 | Requested Range Not Satisfiable | The status code returned because the Range header of the requested web page is invalid. |
| 417 | Expectation Failed | The status code returned because the server cannot meet the requirements of the Expect request header field. |
| 499 | Client Closed Request | The status code returned because the client closed the request before the server sent a response. |
| 500 | Internal Server Error | The status code returned because the request cannot be completed due to an internal server error. Contact the system administrator to troubleshoot the error. |
| 501 | Not Implemented | The status code returned because the server does not support a feature required to complete the request. For example, the server returns this status code if the server cannot recognize the request method. |
| 502 | Bad Gateway | The status code returned because the server that acts as a gateway or proxy received an invalid response from the upstream server. For example, CloudMonitor received an invalid response from a carrier site. An ECS detection point or a carrier detection point received an invalid response from the destination site. |
| 503 | Service Unavailable | The status code returned because the server temporally cannot process requests. This issue occurs due to a temporary server overload or server maintenance. In most cases, the server remains unavailable for only a short period of time. |
| 504 | Gateway Timeout | The status code returned because the server that acts as a gateway or proxy does not receive a response from the upstream server within the timeout period. For example, an ECS detection point or a carrier detection point has failed to receive a response from the destination site within the timeout period. |
| 505 | HTTP Version Not Supported | The status code returned because the server does not support the HTTP protocol version that is used in the request. |