Containers Basic Principles

Overview

Based on the open source Apache Tomcat 8, Containers is a lightweight application container that supports standard functions of the community edition and incorporates enhancements for enterprise applications. It provides running environment resources for and manages BLUs deployed on the FusionInsight RTD platform and supports heterogeneous underlying platforms.

Tomcat Server is an open source and lightweight web application server for small- and medium-sized systems and scenarios with few concurrent access requests. It provides the following functions:

• Supports Servlet Spec 3.0 and JSP Spec 2.2.
• Prevents cross-site script attacks using random numbers.
• Prevents session attacks by changing the jessionid mechanism in security authentication.
• Records asynchronous logs.

Structure

After an event source is brought online, its BLU is deployed in a container. In FusionInsight RTD, a maximum of five containers can be installed on each host.

Principles

FusionInsight RTD manages applications in groups. Containers in a cluster can belong to only one group at a time, but different BLUs in one group can be deployed in the same container at the same time. Each BLU creates a BLU instance in a container. See Figure 1.

The Containers component monitors and manages BLUs. System administrators can deploy, start, stop, and delete BLUs on FusionInsight Manager.

The FusionInsight Manager platform provides the function of directly uploading configuration files for each BLU so that users can update BLUs based on service environments. BLUs in a group can use the same configuration file set.

Figure 1 BLU deployment

Relationship with Other Components

• Containers and RTDService

  After the event source defined by RTDService is brought online, the generated BLU application is deployed in Containers.

• Containers and ALB

  ALB is a special BLU application deployed in Containers. It is a load balancer for accessing BLUs.

• Containers and ZooKeeper

  ZooKeeper provides a service registration center for service providers in BLUs and service address lists for service consumers.