#C# Data Caching

There are 3 types of caching in ASP.NET:

1. Output Caching
2. Fragmentation Caching
3. Data Caching

We implemented "Data Caching" in Cost and scheduling tool.

Caching takes place where frequently-used data is stored so that the application can quickly access the data rather than accessing the data from the source. Caching can improve the performance and scalability of the application dramatically and can help us to remove the unnecessary requests to the external data sources for the data that changes infrequently.

This is the simplest way of caching. In this technique, cache is stored in the memory of the local Web Server.

An in-memory cache is stored into the Server memory which is hosting the ASP.NET application. In the case of Web farm (where the application is hosted on multiple servers) or cloud hosting environments, all servers may have different values of in-memory cache. So, in-memory caching cannot be used in web farm or cloud hosting environments. For this type of environment, distributed cache is best suited.

Session vs Caching

The first main difference between session and caching is: a session is per-user based but caching is not per-user based, so what does that mean? Session data is stored at the user level but caching data is stored at the application level and shared by all the users. It means that it is simply session data that will be different for the various users for all the various users, session memory will be allocated differently on the server but for the caching only one memory will be allocated on the server and if one user modifies the data of the cache for all, the user data will be modified.

Create Cache

using System.Runtime.Caching;

MemoryCache memoryCache = MemoryCache.Default;

Assign data to cache

CacheItemPolicy cacheItemPolicy = new CacheItemPolicy();

cacheItemPolicy.AbsoluteExpiration =DateTime.UtcNow.AddMinutes(15);

memoryCache.Add(new CacheItem("AllFilterData", allTablesForFilter.Value), cacheItemPolicy);

Read data from Cache

if (memoryCache.Contains("AllFilterData"))

            {

                return (AllTablesForFilter)memoryCache.Get("AllFilterData");

            }