The database
Now that we are aware of the benefits and disadvantages of a monolith application and we have decided to break our app into multiple pieces, it is time to move the first resource outside of the monolith.Â
As we anticipated in the first section of this chapter, it is necessary to move the data (also called state) outside of the EC2 machine. In some web applications, the database is the only data source. However, in others, there are also files uploaded from the users saved directly on the disk or index files if you use an index engine such as Apache Solr. For more information on this, refer to http://lucene.apache.org/solr/.
When possible, it is always convenient to use a cloud service instead to install a program in a virtual machine. For a database, the RDS  service (https://aws.amazon.com/rds/)provides a large set of open or closed source(AmazonAurora, PostgreSQL, MySQL, MariaDB, Oracle, and Microsoft SQL Server), so if you need an IBM Db2https://www.ibm.com/products/db2-database...
