Alert logs
Alibaba Cloud DNS provides alerts for status changes in addresses and address pools, such as when they become unavailable or recover. You can view the alert history to investigate the cause of anomalies.
Alert types
Health check alerts
When a health check detects an abnormal address in an address pool collection, the system records a log entry. The entry includes the time of the anomaly, the abnormal address, and an error code that identifies the cause. The following table describes common error codes.
Protocol |
Status Code |
Description |
HTTP |
610 |
Timeout. This includes connection timeouts and SSL Certificate exchange timeouts. The timeout period is 30 s. |
613 |
DNS resolution error. |
|
615 |
Content mismatch. The content returned by the request does not match the user-defined content. |
|
616 |
Authentication failed. |
|
611 |
Detection failed for other reasons. |
|
Ping |
550 |
Network is unreachable. |
610 |
The network is stable, but no response is received for any sent packets within 2 seconds. |
|
613 |
Cannot resolve the IP address from the host. |
|
TCP |
550 |
Cannot open a socket. This is usually because system resources are exhausted. |
610 |
Failed to receive a response due to a timeout or no response. |
|
611 |
Connection failed due to a timeout or rejection by the peer. |
|
615 |
Content mismatch. |
|
UDP |
550 |
Cannot open a socket. This is usually because system resources are exhausted. |
611 |
Connection failed because the host cannot be resolved. |
|
610 |
Failed to send or receive. |
|
615 |
Content mismatch. |
|
DNS |
610 |
DNS resolution failed. |
613 |
An anomaly occurred during DNS query communication. |
|
615 |
Content mismatch. |
Health check recovery
When a health check determines that an abnormal address in an address pool collection has recovered, the system records a log entry. The entry includes the recovery time and the specific address.
Address pool collection unavailable
If the number of healthy IP addresses in an address pool collection falls below the Minimum Number of Available Addresses, the system sets the collection to unavailable and records a log entry. The entry includes the time, the name of the address pool collection, the access policy name, the address pool type, and the minimum number of available addresses.
Address pool collection recovered
If the number of healthy addresses in an address pool collection meets or exceeds the Minimum Number of Available Addresses, the system sets the collection to available and records a log entry. The entry includes the time, the name of the address pool collection, the access policy name, the address pool type, and the minimum number of available addresses.
Primary/standby address pool collection switch
If the primary address pool collection for an access policy becomes unavailable, the system automatically switches to the standby address pool collection and records a log entry. The entry includes the time, the access policy name, and the switch behavior between the primary and standby address pool collections.
Procedure
Click the Alert Log tab.
Filter the logs by time range, alert type, and keyword.