Failover caching helps to provide necessary data whenever there are temporary failures or some glitches. The cache layer should be designed so that it can smartly decide how long the cache can be used in a normal situation or during failover situations. Setting cache standard response headers in HTTP can be used. The max-age header specifies the amount of time a resource will be considered fresh. The stale-if-error header determines how long the resource should be served from the cache. You can also use libraries such as Memcache, Redis, and so on.