What is the server down?
Server downtime is the server for some reason the server can not function properly, resulting in network can not be used for web sites, server downtime caused great impact, he not only caused visitors to the site inaccessible, and even affect the site the rankings in the search engines.
In the course of the server, the server downtime can occur at any time, we need to find the cause of server downtime in order to find the corresponding solutions
Server downtime may be divided into two cases, the fake server crashes and crashes
Fake death (BSOD non) is due to a temporary hardware resources are exhausted, because there is no corresponding phenomenon of external command, usually a site visit in the peak of the run over the bandwidth and other resources, usually only need to wait for some time, wait for the server to free up more resources to return to normal
Crashes, if the ping test server, switching the keyboard number keys and function keys capital letters, no screen output display, the mouse cursor or no response, it indicates that the server hardware failure
A common cause of server failure:
1. On the operating environment problems, the most common hard disk resource is exhausted
2. On the performance problems, the most common cause of server downtime is indeed a very bad run of SQL, but not necessarily for this reason, for example, there are a lot of problems due to a server error or bug results in the behavior of
3. bad Schema and index design is the second largest issue affecting performance
4. Copy usually due standby cause data inconsistencies
The data loss is usually caused due to drop table, and always accompanied by a lack of available backup problem
How to see why the server is down?
1. whether the application is causing memory overflow or leak lead, out of memory leads?
2. whether it is too much process or continue to create, lead to resource depletion leads?
3. whether the program is a database deadlock or lead to too many connections?
4. whether it is an application exception cause?
5. Are the traffic load is too large?
6. whether it is hacked cause?
7. whether it is a mistake cause?
How to solve the server downtime?
Can prepare two web space, they keep the same content, but not the same ip address, geographical location and different room, so two hosts, while the possibility of downtime is greatly reduced. After the first time that the server downtime problem, you can quickly modify the domain records dnspod.com, point to the current normal web space,
Time dnspod resolved in force in real time, and general dns server refresh a long time, allegedly for 24 hours to take effect, but the actual experience, take effect within almost 30 minutes, or we need to check the correct binding domain