<p>This article describes main features of Ping An Cloud ELB.</p> <table border="1" cellpadding="0" cellspacing="0" style="width:0px"> <tbody> <tr> <td style="vertical-align:top; width:239px"> <p><strong>Function</strong></p> </td> <td style="vertical-align:top; width:544px"> <p><strong>Description</strong></p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Schedule algorithm</p> </td> <td style="vertical-align:top; width:544px"> <p>External and Internal ELB support Weighted Round Robin (WRR) scheduling algorithm. When the weight values are identical, then Round Robin (RR) scheduling algorithm is adopted.</p> <p>Classical ELB supports WRR and Weighted Least Connections (WLC) algorithm. When the weight values are identical, then RR scheduling algorithm is adopted.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Health check</p> </td> <td style="vertical-align:top; width:544px"> <p>After you turn on the health check function, ELB service will check the health status of the hosts in the service resource pool. If ELB service finds that there is a problem with a host, it will forward the request to other normal hosts. When the host returns to normal, ELB service will resend the request to the host.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Session persistence</p> </td> <td style="vertical-align:top; width:544px"> <p>ELB provides the function of session persistence. After you turn on the session persistence function, requests from the same client can be forwarded to the same back-end server for processing during the life cycle of the session. If the front-end protocol is HTTP/HTTPS, the session persistence supports the source address Hash and Cookie. If the front-end protocol is TCP/UDP, the session persistence supports the source address Hash.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Access control</p> </td> <td style="vertical-align:top; width:544px"> <p>After you turn on the access control function, you can control the access permission of the specified IP address. ELB supports creating access control policy groups and editing address information in policy groups, and performing access control by blacklisting or whitelisting to flexibly control client access.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Multi-availability zone</p> </td> <td style="vertical-align:top; width:544px"> <p>Most regions support multi-availability zone deployment for External ELB. When the main availability zone fails, ELB can automatically switch to the standby availability zone to provide services.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Cross-availability zone citywide disaster recovery</p> </td> <td style="vertical-align:top; width:544px"> <p>External ELB can distribute access requests and traffic to back-end servers in multi-availability zones to respond, and establish a real-time cross-availability zone citywide disaster recovery mechanism to meet the requirements of different enterprises for high availability of business systems.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Anti-DDoS protection</p> </td> <td style="vertical-align:top; width:544px"> <p>Ping An Cloud DDoS Protection provides 1G free basic protection for each External ELB service IP. The default cleaning threshold are100 Mbps for traffic threshold and 20,000 pps for DDoS message threshold.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Supported network types</p> </td> <td style="vertical-align:top; width:544px"> <p>ELB provides services for both External ELB and Internal ELB. You can create an Internal ELB instance to load balance network traffic in a VPC, or you can create an External ELB instance to load balance flow from the Internet.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Monitor</p> </td> <td style="vertical-align:top; width:544px"> <p>Combined with Ping An Cloud Argus, you can view information such as the number of connections and traffic for ELB.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>View operation logs</p> </td> <td style="vertical-align:top; width:544px"> <p>Combined with the operation audit function provided by Ping An Cloud, you can understand the tenant&#39;s operation behavior by analyzing the ELB access log, which is convenient for troubleshooting.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Certificate management</p> </td> <td style="vertical-align:top; width:544px"> <p>ELB provides unified certificate management service for HTTPS protocol. You do not need to upload the certificate to the back-end server. You need to decrypt the certificate through ELB service to reduce the CPU consumption of the back-end server.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Multi-certificate mount</p> </td> <td style="vertical-align:top; width:544px"> <p>An ELB instance supports multiple SSL certificate mounts. It can mount different SSL certificates to different listeners, and implement different SSL certificates for ELB services for different HTTPS service ports.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>WS/WSS support</p> </td> <td style="vertical-align:top; width:544px"> <p>WebSocket support. ELB supports two-way communication channel between client and server, which is mainly used to save bandwidth resources and realize two-way and real-time communication.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>HTTP/2 support</p> </td> <td style="vertical-align:top; width:544px"> <p>ELB supports HTTP/2 (Hypertext Transfer Protocol Version 2), backward compatible with HTTP1.X protocol version, and can greatly improve its performance.</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Gzip compression</p> </td> <td style="vertical-align:top; width:544px"> <p>You can choose to turn on the Gzip compression function, which can be used to save traffic resources. When the requested back-end resource is greater than 1 K, the resource will be compressed by ELB before being passed back to the client.</p> <p>Compressed file type: text/xml text/plain text/css application/javascript application/x-javascript application/rss+xml application/atom+xml application/xml</p> </td> </tr> <tr> <td style="vertical-align:top; width:239px"> <p>Get the authentic client IP</p> </td> <td style="vertical-align:top; width:544px"> <p>In the HTTP/HTTPS protocol listener configurations, you can get the client IP address through the X-Forwarded-For header field.</p> </td> </tr> </tbody> </table>