In the customer task, Availability suddenly dropped, and the impact on Error was "The certificate of Application is invalid (page)" Error. Analyze the reasons
Certificate verification is an action during the SSL Handshake Time, so when there is a problem with the certificate, the phenomenon in Waterfall Chart is that the SSL Handshake Time fails. There are several influencing conditions: (1) Probe problem, check the physical time when Probe is doing the task, and see if it can correspond to the current time. (2) Operator problem, this is the last possible situation. When excluding client and server problems, it may be an operator problem. (3) Server-side problem, use error reporting Probe to access the same customer Host respectively, use error reporting and non-error reporting Probe to access the same Host to check the phenomenon
(1) Check whether it is a Probe problem ①Visit the page again with error report Probe to check whether the error is always reported. Instant Testing can reproduce the Error. Check debugLog and find that the physical time of Probe is the current time. ② Use this Probe to access other URLs, such as Baidu, JD.com, and Taobao. The data is normal. ③Visit the page again with the error message Probe, host other Host, and the data error message (2) Check whether it is an operator problem Checking the historical data, we found that Error reported the most errors on Xinjiang Mobile (3) Check the server, check Availability corresponding to Host, and find that Error Rate is not 100%. (4) Check the packet capture information and compare the normal and error reports. After receiving the client hello, the server did not send the server hello.