Question

What’s the difference between caching and data replication?

Answer 1

Below are the differences between the Caching and data replication:

Caching :

1. Caching is the process by which the frequently accessed or used data is being temporarily transferred to cache so that it takes less time to access the data from the main memory as the data is stored in main memory for all the processes.
2. Caching speed to access the data is less as compared to replication.
3. Caching does not backup all the data that is present in the main memory . Therefore if there is any data loss happened , then only few files might be recovered and not all.
4. There is no scope of accessing the data if the connectivity is lost among the databases on different servers.
5. Cache is build over time gradually and the speed of accessing the data grows directly as more and more files are being added to the cache.
6. Caching has no space restrictions as larger caches can store considerable amount of data .
7. With Caching the network bandwidth cost will only reduce and never increase as the data is not accessed until it is actually required.

Data replication :

1. Replication copy the changes or mirror the changes of the data from one database to another database over the servers. The databases are generally present on different servers. It also helps to achieve the failover capability and load balancing. Once the data is copied to the other databases then the queries can directed to the other databases other than the primary database thereby reducing the network traffic .
2. Along with the subsequent accesses , it also increases the speed of the first data access request.
3. Replication does the data backup with double the efficiency , so in case of any loss of data the backup is available for the entire data with no loss of data .
4. In case the network connectivity is lost , then still there is a full access to the data as the main data is being replicated at different servers.
5. Building a new replica from the scratch takes a very long time and incurs high cost as well .
6. Replications take more disk space as all the replicas are of same size . This becomes a problem for the projects with very large amount of data.
7. Replication copies every change that happens to the data which overloads the network bandwidth and thereby increasing the bandwidth cost .