Apache Tomcat is a prevalent, open source usage of the Java Servlet API. A servlet is "a Java class used to expand the abilities of servers." Jersey, as expressed, is a reference execution of the JAX-RS 2.0 API. Jersey is extensible and gives extra usefulness to the API.

Java Servlet technology and JavaServer Pages (JSP pages) are server-side advancements that have commanded the server-side Java technology advertise; they've turned into the standard method to create business web applications.

The JSP technology-which abstracts servlets to a more elevated amount - is an open, unreservedly accessible particular created by Sun Microsystems as a contrasting option to Microsoft's Active Server Pages (ASP) technology, and a key segment of the Java 2 Enterprise Edition (J2EE) determination.

MySQL is a mainstream open-source relational database management system (RDBMS) that is created, circulated and bolstered by Oracle Corporation. Like other relational systems, MySQL stores data in tables and uses structured query language (SQL) for database get to. In MySQL, you pre-characterize your database mapping in light of your prerequisites and set up tenets to administer the connections between fields in your tables.

MongoDB is an open-source, non-relational database created by MongoDB, Inc. MongoDB stores data as reports in a twofold portrayal called BSON (Binary JSON). Related data is put away together for quick query access through the MongoDB query language. Fields can shift from report to archive; there is no compelling reason to pronounce the structure of records to the system – reports are self-depicting. In the event that another field should be added to a report, at that point the field can be made without influencing every single other archive in the accumulation, without refreshing a central system catalog, and without taking the system offline.

ElasticSearch and Redis are powerful technologies with different strengths. They are very flexible and can be used for a variety of purposes.

ElasticSearch stores data in indexes and supports powerful searching capabilities. Logstash is an ETL pipeline to move data to and from different data sources (including Redis). Kibana helps us build rich dashboards and do adhoc searches. These tools are used not just by developers but by data analysts and devops engineers who often have different skill set.

Redis has speed and powerful data structures. It can almost function as an extension of application memory but shared across processes / servers. The downside is that records can ONLY be looked up by key. Our applications can easily store all kinds of interesting data in Redis. But if this data needs to be extracted and aggregated in different ways that requires writing code. There is no easy way to do adhoc analysis (like writing SQL queries).