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With speedier and more reliable access to data increasingly becoming the norm, and users trying to access information more frequently and parallelly, real-time replication continues to grow its clout. It essentially one-ups legacy storage and transfer technologies, offering a paradigm shift in optimized data availability, with a wide range of use cases, across business intelligence, disaster recovery, and more.
While the technology still remains at nascent stages, and is yet to capture the imagination of broader enterprises, it continues to improve in sophistication and possible use cases. Understanding the underlying mechanisms of real-time data replication would take extensive study and analysis.
In this article, we cover the four basic mechanisms to give you a bare-bones idea of its workings.
Built-In Data Replication
Data replication systems come in-built with most enterprise database management systems such as Oracle, MariaDB, and MySQL. These systems are often seamless, reliable, and easy to set up, but lack the sophistication of innovative new data replication solutions. Complications, however, tend to arise when trying to replicate data across databases, with different technology stacks.
Despite being built-in, the cost of these solutions are likely to be just as high, often reaching high four-figures for a 1 to 3 year license. They further require source and destination databases to be from the same vendor for support, and seamless operations. This mechanism leverages ‘Log Reading’ systems to provide such functionalities.
Trigger-Based Replication
Leading database solutions come with built-in triggers that prompt data replication, if a certain scenario or function is met. These are quite simple and straightforward, with the ability to customize triggers to suit your requirements and use cases.
Such a mechanism, however, can only support a limited number of operations, takes an additional toll on your resources, and is often far from real-time replication. Any uncertainty, or disaster could result in the loss of data, and is further unsuitable for real-time business intelligence and analytics.
Continuous Polling Method
This method requires custom code snippets to be input for the replication of your source to the destination database. Users will have to develop code snippets that identify changes and trigger the relevant action, while further specifying the format, and updating in the destination database.
The mechanism leverages the queue technique, and as such requires a field in the source database to monitor and capture changes as and when they occur. Here again, the key drawback is the heavy load on server resources, substantially hampering speed and performance.
Cloud-Based Mechanisms
Most cloud service providers allow for in-suite data replication solutions, by allowing users to combine their event streams with AWS streaming services. This is a seamless option for replication, requiring little-to-no coding, and is thus broadly preferred by the vast majority of users.
There are a few drawbacks, especially pertaining to replication between different cloud service providers for the source and destination databases. Beyond this, any functionality, or additional sophisticated features require users to develop custom code snippets to support the same.
Final Words
While real-time replication refers to the instantaneous copying, or backup of data, there are always delays in-practice. With each passing year, however, the gap continues to reduce, substantially lowering risks of data loss, fundamentally enhancing the usability of business analytics and intelligence solutions.
These are undeniably exciting times for database administrators, and related professionals in this field, with plenty of new opportunities and use-cases propping-up each passing day, with real-time server backup and recovery being only one of the many.
This article merely scratched the surface on the strategies and mechanisms used for real-time replication, and this field has already seen substantial depth in terms of relevant literature, which avid users should definitely explore.
This article was provided by José Luis Martín Cara
