Introduction As previously explained, CDC (Change Data Capture) is one of the best ways to interconnect an OLTP database system with other systems like Data Warehouse, Caches, Spark or Hadoop. Debezium is an open source project developed by Red Hat which aims to simplify this process by allowing you to extract changes from various database … Continue reading How to extract change data events from MySQL to Kafka using Debezium →
What is Change Data Capture and why do we need it?
Change Data Capture (CDC) tracks data changes (usually close to realtime). In MySQL, the easiest and probably most efficient way to track data changes is to use binary logs. However, other approaches exist. For example:
- General log or Audit Log Plugin (which logs all queries, not just the changes)
- MySQL triggers (not recommended, as it can slow down the application — more below)
One of the first implementations of CDC for …[Read more]
MySQL replication enables data to be replicated from one MySQL database server (the master) to one or more MySQL database servers (the slaves). However, imagine the number of use cases being served if the slave (to which data is replicated) isn't restricted to be a MySQL server; but it can be any other database server or platform with replication events applied in real-time!
This is what the new Hadoop Applier empowers you to do.
An example of such a slave could be a data warehouse system such as Apache Hive, which uses HDFS as a data store. If you have a Hive metastore associated with HDFS(Hadoop Distributed File System), the Hadoop Applier can populate Hive tables in real time. Data is …
This is a follow up post, describing the implementation details of Hadoop Applier, and steps to configure and install it. Hadoop Applier integrates MySQL with Hadoop providing the real-time replication of INSERTs to HDFS, and hence can be consumed by the data stores working on top of Hadoop. You can know more about the design rationale and per-requisites in the previous post.
Design and Implementation:
Hadoop Applier replicates rows inserted into a table in MySQL to the Hadoop Distributed File System(HDFS). It uses an API provided by libhdfs, a C library to manipulate files in HDFS.
The library comes pre-compiled with Hadoop distributions. It connects to the MySQL master (or read …