Definition database cluster There are two key points: 1. Two or more database servers: If only one database server can not be called a cluster. 2. Transparent Services: Services and stand-alone systems in the cluster to clients to clients, maintaining binary compatibility from the protocol. II. Related Glossary 1. Synchronization database client sends a request to update the data, after each cluster node to wait for all the updates, only to return results to the client. 2. asynchronous database client sends a request to update the data, accept the request of the node (where often the primary database) immediately returns the results to the client, the data will be updated in the next transfer of a time to be copied to the cluster on the other nodes. 3. Based on this load balancing connection load balancing technology is relatively simple to achieve foreign server rental, is in the client initiates landing, according to some load balancing algorithm to select a landing station to the cluster database, then all client requests will all sent to the database. 4. Based on the request of such load balancing to achieve load balancing technology is more complex, but powerful, that is initiated by the client when landing two-server rental, Clustered Gateway will also log on to the database cluster nodes, then all client requests After the analysis is divided into two categories Clustered Gateway, query load balancing algorithm to pick a node to perform according to the data update requests and there are a host to perform real-time synchronization of data to each node in the cluster. (5) filtering unnecessary services and port filtering unnecessary services and ports that fake IP filtering on the router ...... only open port services become popular practice of many servers, such as WWW server then only 80 and will be open to all other ports close or do to stop the policy on the firewall. Whether the source (6) Check the visitor's use of Unicast Reverse Path Forwarding and other methods to check the visitor through a reverse IP address of the router query is true, if it is false, it will be shielded. Many hackers often use fake IP addresses ways to confuse the user, it is difficult to find out where it comes from. Therefore, the use of Unicast Reverse Path Forwarding can reduce the appearance of fake IP address to help improve network security. (7) All RFC1918 IP address filtering RFC1918 IP address is the IP address of the internal network, like 10.0.0.0,192.168.0.0 and 172.16.0.0, they are not fixed IP address of a network segment, but inside an area reserved for Internet of IP addresses, they should be filtered out. This method does not filter access to internal staff, but the large number of false forged internal IP filtering attack, so you can reduce the DdoS attacks. Server hosting, server rental, hosting, dedicated hosting, free overseas host game server rental, free record server, free cloud hosting, free web hosting for the record, the free space to find clothes Ltd. Shenzhen Huaxin Yun Cloud Server Hosting | China Letter cloud service (certified) | Bao'an District server rental service provided by the Shenzhen Municipal Science and Technology Co., Ltd. 华信云. Shenzhen Huaxin Yun clothes Ltd. (www.idc80.cn) (www.idc80.cn) Guangdong Shenzhen, servers, workstations leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Huaxin Yun served in the leadership of the staff warmly welcome all inquiries negotiations to create a better future Huaxin Yun clothing. You can also access (www.idc80.cn/supply_details_45508135.html), for more information about the company.