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DNS results can also be cached by your browser or OS for a certain period of time, determined by the time to live (TTL).
Latency is the time to perform some action or to produce some result.AP is a good choice if the business needs allow for eventual consistency or when the system needs to continue working despite external errors.With multiple copies of the same data, we are faced with options on how to synchronize them so clients have a consistent view of the data. This approach is seen in systems such as memcached.Recall the definition of consistency from the CAP theorem - Every read receives the most recent write or an error. Weak consistency works well in real time use cases such as Vo IP, video chat, and realtime multiplayer games.For example, if you are on a phone call and lose reception for a few seconds, when you regain connection you do not hear what was spoken during connection loss. Strong consistency works well in systems that need transactions.Serving content from CDNs can significantly improve performance in two ways: Push CDNs receive new content whenever changes occur on your server.
You take full responsibility for providing content, uploading directly to the CDN and rewriting URLs to point to the CDN.
If the heartbeat is interrupted, the passive server takes over the active's IP address and resumes service.
The length of downtime is determined by whether the passive server is already running in 'hot' standby or whether it needs to start up from 'cold' standby. Active-passive failover can also be referred to as master-slave failover.
Waiting for a response from the partitioned node might result in a timeout error.
CP is a good choice if your business needs require atomic reads and writes.
Generally, static files such as HTML/CSS/JS, photos, and videos are served from CDN, although some CDNs such as Amazon's Cloud Front support dynamic content.