<p>This article describes how to create an external/internal ELB UDP listener.</p> <p><strong><span style="font-size:18px">Prerequisites</span></strong></p> <p>You have successfully created an internal ELB instance.</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> to enter the <strong>Instance Management</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>Listener</strong> tab.</p> <p>5.&nbsp;In the upper-right corner of the tab, click <strong>Create</strong> to enter the <strong>Create Listener</strong> page.</p> <p>6.&nbsp;Configure the listener as described in the following tables.</p> <p><img src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20201607115241-17c299eb9a17.png" style="height:455px; 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: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>Description</p> </td> <td style="vertical-align:top; width:568px"> <p>Customize the description of a listener.</p> </td> </tr> <tr> <td style="width:213px"> <p>Frontend protocol</p> </td> <td style="vertical-align:top; width:568px"> <p>Select UDP as the frontend protocol.</p> </td> </tr> <tr> <td style="width:213px"> <p>Port</p> </td> <td style="vertical-align:top; width:568px"> <p>Enter the port number used to receive the request and forward the request to the pool.</p> <p><img src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20201607115040-191462e69371.png" style="height:22px; margin:1px; width:50px" /><strong>:</strong> In the same ELB instance, the listener port number cannot be repeated.</p> </td> </tr> <tr> <td style="width:213px"> <p>Schedule algorithm</p> </td> <td style="vertical-align:top; width:568px"> <p>Select a schedule algorithm. Currently only <strong>Weighted Round Robin</strong> is supported. In the weighted round robin mode, the access request will be assigned to the hosts in the 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> </td> </tr> <tr> <td style="width:213px"> <p>Pool</p> </td> <td style="vertical-align:top; width:568px"> <p>Select a pool.</p> <p>You need to select a pool based on the following steps:</p> <p>1.&nbsp;Click <strong>Choose</strong> <strong>Pool</strong>, and the <strong>Choose Pool</strong> dialog box opens.</p> <p>2.&nbsp;Check the target pool, and click <strong>Confirm</strong>.</p> <p>If you have not yet created a pool, you need to create one before you can make a selection here. You can also create a server resource pool before you select one for a listener For more information about creating a pool, see Create a Pool.</p> </td> </tr> </tbody> </table> <p><strong>Advanced configuration</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>Session persistence</p> </td> <td style="vertical-align:top; width:568px"> <p>You can choose to turn on or off the session persistence function. After you turn on the session persistence function, requests belonging to the same session will be forwarded to the same host for processing.</p> <p>The way to keep the session is the source address hash SOURCE_ADDRESS.</p> </td> </tr> </tbody> </table> <p>7.&nbsp;&nbsp;&nbsp;&nbsp; Click <strong>Next</strong> and enter the health check configuration page.</p> <p><img src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20201607115040-191462e69371.png" style="height:22px; margin:1px; width:50px" /><strong>:</strong> The UDP listener of an internal ELB instance does not support the health check function, and you cannot turn on the health check function. The UDP listener of an external ELB instance supports the health check function. You need to configure the health check information as described in the following tables.</p> <p><img src="https://obs-cn-shanghai.yun.pingan.com/pcp-portal/20201607115330-10618608970f.png" style="height:744px; width:830px" /></p> <p><strong>Health check</strong></p> <table border="1" cellpadding="0" cellspacing="0" style="width:0px"> <tbody> <tr> <td style="background-color:#ededed; width:190px"> <p><strong>Configuration item</strong></p> </td> <td style="background-color:#ededed; vertical-align:top; width:591px"> <p><strong>Description</strong></p> </td> </tr> <tr> <td style="width:190px"> <p>Health check</p> </td> <td style="vertical-align:top; width:591px"> <p>You can choose to turn on or off the health check function. If you turn on the health check function, the ELB service will check the health status of the hosts in the pool. If the 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, the ELB service will resend the request to the host.</p> <p>After you turn on the health check function, you need to configure the following parameters.</p> </td> </tr> <tr> <td style="width:190px"> <p>Protocol</p> </td> <td style="vertical-align:top; width:591px"> <p>Select the protocol for health check. The check method available here includes HTTP and TCP.</p> </td> </tr> <tr> <td style="width:190px"> <p>Path</p> </td> <td style="vertical-align:top; width:591px"> <p>If the protocol is HTTP, 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:190px"> <p>Interval</p> </td> <td style="vertical-align:top; width:591px"> <p>Set the time interval between two health checks. The value range is [5, 300] seconds.</p> </td> </tr> <tr> <td style="width:190px"> <p>Timeout</p> </td> <td style="vertical-align:top; width:591px"> <p>Set the maximum timeout period for each health check response. The value range is [2, 60] seconds. During the health check, if the hosts in the pool do not respond correctly within this period of time, the health check will fail.</p> </td> </tr> <tr> <td style="width:190px"> <p>Frequency threshold</p> </td> <td style="vertical-align:top; width:591px"> <p>Set the number of consecutive health checks to determine the health status of the host. The value range is [2, 10] times. If the frequency threshold is set to 3, and if the host is determined to be healthy after three times of successive successful the health check result is received three times in succession, the host is determined to be healthy, and the host is determined to be unhealthy If the health check result is received three times in succession, the host is determined after three times of successive failed health check.</p> </td> </tr> <tr> <td style="width:190px"> <p>Custom health check request content</p> </td> <td style="vertical-align:top; width:591px"> <p>Enter the content of the user-customized health check request.</p> </td> </tr> <tr> <td style="width:190px"> <p>Custom health check return result</p> </td> <td style="vertical-align:top; width:591px"> <p>Enter the result of the user-customized health check return.</p> </td> </tr> </tbody> </table> <p>8.&nbsp;&nbsp;&nbsp;&nbsp; Click <strong>Create</strong>, and you will see an <strong>Operation succeeded</strong> message at the bottom of the page.</p>