Failover is the process of switching a service from a failed or unhealthy component to a standby or backup component so that users experience little or no interruption.
Why it matters
Failover turns a hardware or software failure into a short blip rather than a long outage. It can happen at many levels: a load balancer removing a bad server, a database promoting a replica, or DNS pointing traffic to a secondary site.
It works only if the standby is current, tested and able to handle the load. Detection also matters, because the system has to decide a failure has happened without reacting to short glitches.
Example
A primary database fails health checks three times in a row. The orchestrator promotes a replica to primary within about 30 seconds and the application reconnects through the same hostname.
Common mistakes
- Never testing failover, so the first real failure is also the first test.
- A standby that is out of date or too small to carry production load.
- Relying on DNS failover with a long TTL, which delays the switch.
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यह पेज सामान्य जानकारी है, जिसे हमारी संपादकीय टीम ने लिखा है और दस्तावेज़ीकरण बदलने पर अपडेट किया जाता है। सर्वर और प्रदाता अलग-अलग होते हैं, इसलिए बदलाव पहले सुरक्षित तरीके से जाँचें। देखें: संपादकीय नीति और अस्वीकरण.