<section class="section" id="architecture__section_qht_mhx_1mb"><h2 class="doc-tairway">Message Queue Kafka Application Architecture</h2> <img class="image" id="architecture__image_fkt_shx_1mb" src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20200212172810-1d2210099497.png"> <ul class="ul" id="architecture__ul_y2d_vhx_1mb"> <li class="li"><strong class="ph b">Producer</strong>—Operates in push mode and sends messages (such as website visits or server logs) to brokers.</li> <li class="li"><strong class="ph b">Kafka broker</strong>—Stores information as a server. Brokers support horizontal expansion. Generally, the more the number of the broker nodes, the higher the throughput of the cluster.</li> <li class="li"><strong class="ph b">Consumer group</strong>—Operates in pull mode and subscribes to messages from brokers.</li> <li class="li"><strong class="ph b">Zookeeper</strong>—Manages the cluster configuration, elects the leader, and balances the load when the consumer group changes.</li> </ul> </section> <section class="section" id="architecture__section_vfg_d3x_1mb"><h2 class="doc-tairway">Diagram of the Kafka Publication and Subscription Relationships</h2> <img class="image" id="architecture__image_yyz_23x_1mb" src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20200212172810-15d98b3199d6.png"> <p class="p">Message Queue Kafka uses Pub/Sub model.</p> <ul class="ul" id="architecture__ul_plt_g3x_1mb"> <li class="li">One consumer group can subscribe to multiple topics, and one topic can be subscribed to by multiple consumer groups at the same time.</li> <li class="li">One message on a topic can be consumed by only one consumer in a consumer group, but multiple consumer groups can consume this message at the same time.</li> </ul> </section> <section class="section" id="architecture__section_b24_j3x_1mb"><h2 class="doc-tairway">Kafka Deployment Architecture</h2> <img class="image" id="architecture__image_ujd_l3x_1mb" src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20200212172810-163973b197b8.png"> <ul class="ul" id="architecture__ul_alk_m3x_1mb"> <li class="li"><strong class="ph b">Kafka management platform</strong>—Uses the standard J2EE application, Tomcat deployment, and the PostgreSQL database.</li> <li class="li"><strong class="ph b">Kafka broker</strong>—The Zookeeper nodes and broker nodes are deployed on demand. The broker cluster uses the master-subordinate model. A minimum of two copies of a message are written to the disk. We recommend that you deploy nodes in different availability zones.</li> <li class="li"><strong class="ph b">Client SDK support for multiple languages</strong>—Languages such as JAVA, and C language are supported. The client accesses the broker by using the TCP protocol.</li> </ul> </section>