When browsing, you have probably seen your favorite website tell you that it uses cookies and caching. As a website owner, you can ensure that your website is more accessible and user-friendly by having the right caching mechanisms in place. With the right caching mechanisms, information and data is usually stored closer to the user making websites easier to access.
Memcached is one of the caching systems that you can use to speed up web applications by reducing the entire load of a database. When a computer user requests for information or data from a database, more information is usually added to what is already is existing in the server. To much information in the server can lead to delays in the relaying of data.
Memcached usually reduces the stress on a server by storing and adding data into a short-term memory used for applications. This short-term memory is commonly known as dynamic memory.
How Does Memcached Work?
This caching system is made up of four key critical components. These components are integrated in such a way that the client and the data server operate in a complimentary manner so that data that is cached is delivered as efficiently as possible.
These components include:
1. A Hashing Algorithm That Is Client Based
This is the algorithm that chooses a server based on the input key.
2. The Least Recently Used (LRU) Algorithm
This is a paging algorithm that relies on the observation that data and pages that have been heavily used in the recent past have a high probability of being keyed in and used again by a client.
3. Client Software
This is the software that receives a list of data that is available on servers that have been Memcached.
4. Server Software
This is used to store cached data values and associated keys internally in a hash table.
The components listed above allow Memcached to store data and retrieve it. Cached data usually has raw data, a key and an expiration time.
In a normal setup, there are usually many Memcached servers and clients. Clients use the hashing algorithm to determine if the data they require is stored in a server and if it is stored, which particular server has the data.
The search with the hashing algorithm is critical in distributing the data load in the server. After a server has been identified, the server then usually produces another hash key to determine where the other value should be stored in the internal hash table.
Memcached data is usually stored in the RAM of a computer. After the RAM is full, the oldest data is usually removed from the computer to create way for new data.
After a client has requested for data, it can either be found stored in Memcached or it can be absent. If it is present, the data is usually returned from Memcached. If it is not, a database is usually queried, the data retrieved and then it is stored in Memcached.
If Memcached data time expires or any information is changed, Memcached usually retrieves and saves fresh data with a view of ensuring that the client will get what they are looking for if they make a request for data.
