The process of adding and retrieving data from Memcached involves the following steps :
Adding Data to Memcached :
* Client Interaction : A client application communicates with one or more Memcached servers over a network. The client sends a request to add data to the cache.
* Data Serialization : Before adding data to Memcached, the client serializes the data into a format that Memcached can store. This typically involves converting the data into a string or binary format.
* Key-Value Pair : The client specifies a unique key for the data being stored in Memcached. This key is used to retrieve the data later.
* Sending Request to Memcached : The client sends a "SET" request to the Memcached server(s), along with the key, serialized data, and optionally, an expiration time for the data.
* Storage in Memcached : The Memcached server receives the SET request, stores the key-value pair in its memory cache, and acknowledges the client that the data has been successfully stored.
* Optional : Data Compression: The client application can optionally compress the data before storing it in Memcached to reduce memory usage and improve performance.
Retrieving Data from Memcached :
* Client Interaction : When the client application needs to retrieve data from Memcached, it sends a request to the Memcached server(s) specifying the key of the data to be retrieved.
* Sending Request to Memcached : The client sends a "GET" request to the Memcached server(s), along with the key of the data to be retrieved.
* Data Lookup : The Memcached server(s) look up the requested key in their memory cache. If the key is found (a cache hit), the server retrieves the corresponding data and sends it back to the client.
* Cache Hit : If the requested data is found in the cache (cache hit), the Memcached server(s) return the data to the client, which can then use it as needed.
* Cache Miss : If the requested data is not found in the cache (cache miss), the Memcached server(s) return a null response to the client. The client application then fetches the data from the primary data source and stores it in Memcached for future access, optionally setting an expiration time for the data.
Error Handling and Fault Tolerance :
* Memcached clients typically handle errors such as connection failures or server timeouts gracefully, retrying requests or failing over to alternate servers if necessary.
* Additionally, Memcached servers can be configured to handle high availability and failover, ensuring uninterrupted access to cached data even in the event of server failures or network issues.
