<p>This article describes how to create a server resource pool for a classic ELB instance.</p> <p>Classic ELB supports using ECS and BMS hosts to build resource pools.</p> <p><strong><span style="font-size:18px">Prerequisites</span></strong></p> <p>&bull;&nbsp;You have created a classic ELB instance.</p> <p>&bull;&nbsp;For a classic ELB instance that needs to provide services to the Internet through the Internet gateway (IGW) in East China, make sure you have created an ECS or other virtualized computing resources in any subnet under the DMZ network in the VPC where the ELB instance is located.</p> <p>&bull;&nbsp;For a classic ELB instance that needs to carry call requests between VPC internal systems, make sure you have created an ECS or other virtualized computing resources in the VPC subnet where the ELB instance is located.</p> <p><strong><span style="font-size:18px">Procedures</span></strong></p> <p>1.&nbsp;Log in to the <a href="https://pinganyun.com/console/loadBalance/overview" target="_blank">ELB Console</a>.</p> <p>2.&nbsp;In the left navigation pane, click <strong>Instance Management</strong> <strong>(Classic)</strong> and enter the <strong>Instance Management</strong> <strong>(Classic)</strong> page.</p> <p>3.&nbsp;Click the instance name of the target ELB instance and enter the<strong> Instance Information</strong> page.</p> <p>4.&nbsp;Click the <strong>Pool</strong> tab.</p> <p>5.&nbsp;In the upper-right corner of the tab, click <strong>Create </strong>and enter the <strong>Create Pool</strong> page.</p> <p>6.&nbsp;Create a server resource pool based on the following information.</p> <p><img src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20201607144428-1385ccd6935c.png" style="height:628px; width:830px" /></p> <p><strong>Basic Information</strong></p> <table border="1" cellpadding="0" cellspacing="0" style="width:0px"> <tbody> <tr> <td style="background-color:#ededed; width:220px"> <p><strong>Configuration item</strong></p> </td> <td style="background-color:#ededed; vertical-align:top; width:561px"> <p><strong>Description</strong></p> </td> </tr> <tr> <td style="width:220px"> <p>Description</p> </td> <td style="vertical-align:top; width:561px"> <p>Customize the display name of the Server Resource Pool.</p> </td> </tr> <tr> <td style="width:220px"> <p>Port</p> </td> <td style="vertical-align:top; width:561px"> <p>Enter the back-end protocol port number that is open on the back-end server to receive requests, which is the port for health check detection.</p> </td> </tr> <tr> <td style="width:220px"> <p>Schedule Algorithm</p> </td> <td style="vertical-align:top; width:561px"> <p>Select a Schedule algorithm. <strong>Weighted Round Robin (WRR)</strong> and <strong>Weighted Least Connections</strong> two algorithms are supported.</p> <p>&bull;&nbsp;In WRR mode, the access requests will be assigned to the hosts in the server resource pool according to the weight value. The higher the host weight, the greater the probability of being distributed. If the weight values are the same, the round robin mode is implemented.</p> <p>&bull;&nbsp;In the Weighted Least Connections mode, in addition to round robin according to the weight, the actual load of the hosts in the server resource pool (the connections) is also considered, so as to realize that the server with higher weight value bears a larger proportion of the active connection load. For hosts with the same weight, the less the active connections, the greater the probability of being polled.</p> </td> </tr> </tbody> </table> <p><strong>Health Check</strong></p> <table border="1" cellpadding="0" cellspacing="0" style="width:0px"> <tbody> <tr> <td style="background-color:#ededed; width:213px"> <p><strong>Configuration item</strong></p> </td> <td style="background-color:#ededed; vertical-align:top; width:568px"> <p><strong>Description</strong></p> </td> </tr> <tr> <td style="width:213px"> <p>Protocol</p> </td> <td style="vertical-align:top; width:568px"> <p>Select the protocol for health check. TCP and HTTP are supported.</p> </td> </tr> <tr> <td style="width:213px"> <p>Path</p> </td> <td style="vertical-align:top; width:568px"> <p>For HTTP protocol, you need to enter the URL path for health check. Make sure that the path can be accessed normally.</p> </td> </tr> <tr> <td style="width:213px"> <p>Interval</p> </td> <td style="vertical-align:top; width:568px"> <p>Set the time interval between two health checks. Value range is [1, 50] seconds.</p> </td> </tr> <tr> <td style="width:213px"> <p>Timeout</p> </td> <td style="vertical-align:top; width:568px"> <p>Set the maximum timeout period of each health check response. The value range is [1, 300] seconds. During the health check, if the hosts in the server resource pool do not respond correctly within this period of time, the health check has will fail.</p> </td> </tr> </tbody> </table> <p><strong>Add Instance</strong></p> <p>Check the instances you want to add to the resource pool, click the right arrow to select, and configure the weights.</p> <table border="1" cellpadding="0" cellspacing="0" style="width:0px"> <tbody> <tr> <td style="background-color:#ededed; width:221px"> <p><strong>Configuration item</strong></p> </td> <td style="background-color:#ededed; vertical-align:top; width:560px"> <p><strong>Description</strong></p> </td> </tr> <tr> <td style="width:221px"> <p>Weight</p> </td> <td style="vertical-align:top; width:560px"> <p>Set the weight of the host. The higher the back-end server weight, the more forwarding requests it receives. The value range is 1 to 256.</p> </td> </tr> </tbody> </table> <p>7.&nbsp;Click<strong> Create</strong>, and you will see an<strong> </strong><strong>Operation succeeded</strong> message at the bottom of the page.</p>