<h2>Agents Sharing the Same Agent ID</h2><br/><div style="overflow-x:auto"><style type="text/css"><!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: #000000; } span { font-size: 12pt; font-family: Lato; color: #000000; } h2 { font-size: 24pt; font-family: Lato; color: black; } h3 { font-size: 18pt; font-family: Lato; color: black; } h4 { font-size: 14pt; font-family: Lato; color: black; } a { font-size: 12pt; font-family: Lato; color: #00718F; } a:hover { font-size: 12pt; color: #024F69; } a:target { font-size: 12pt; color: #032D42; } a:visited { font-size: 12pt; color: #00718f; } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: block; max-width: ; width: auto; height: auto; } } </style> <div class="ns-kb-css-body-editor-container"> <h3>Symptoms:</h3> <ul style="list-style-position: inside;"><li>Agent does not appear on the instance.</li><li>IP address is flipping on the agent record.</li><li>Agent name is flipping on the agent record.</li><li>The "Host" field on the Agent record is blank, but data collection appears successful.</li><li>The Agent Issues table shows multiple <code>ACC-4004</code> errors.</li><li>When viewing the Agent form, the "ACC Error Messages" related list shows <code>ACC-4004</code>errors in "Active Error" state.</li></ul> <div><hr /> <h3>Root Cause:</h3> <div>This issue is caused by copying the agent cache folder (specifically the <code>agent_now_id</code> file) as part of a golden image used during host deployment. <div><hr /> <h3>Why This Happens:</h3> <ul style="list-style-position: inside;"><li>The <code>agent_now_id</code> file uniquely identifies an agent on the instance. </li><li>When this file is duplicated across multiple hosts, all agents report using the same agent ID. </li><li>As a result, only one record appears in the agent table, and all agents with the same agent ID update this shared record — causing data inconsistencies like hostname/IP flipping and missing agents. </li></ul> <h3>Deployment Best Practice:</h3> <ul style="list-style-position: inside;"><li>The <code>agent_now_id</code> file should not be included as part of the golden image. The file should be deleted before making the image of the VM. </li><li>This way, when the new agents are deployed, the agents will generate a new agent ID instead of using the same agent ID.</li></ul> <div><hr /> <h3>Resolution:</h3> <ol style="list-style-position: inside;"><li>Identify Impacted Hosts: <ul style="list-style-position: inside;"><li>The system logs duplicate agent detection as <code>ACC-4004</code> errors. </li><li>Check the Agent Issues table for these errors. </li><li>The <code>key</code> column lists the agent IDs that are being detected as being shared across different agents. </li><li>The <code>key_extension</code> column lists all affected agents using the format <code>Agent_<hostname></code>. </li></ul> </li><li>Fix Steps: <ul style="list-style-position: inside;"><li>Delete the<code>agent_now_id</code>file on each affected host. </li><li>Restart the agent service on each affected host.</li></ul> </li></ol> <div>This will cause each agent to generate a new unique ID and register correctly.</div> <div>Auto resolution of this issue is available starting agent installer v5.0.0.</div> <h3>Update Set:</h3> <div>For agents that are on a version lower than v5.0.0, an Update Set can be applied to the Instance to support Duplicate Agent ID Auto Remediation.</div> <div>DISCLAIMER: This Update Set should ONLY be applied in environments where there are only Windows agents. If deployed on an Instance with Linux agents, there is a chance that the Linux agents will not come back online after the auto-remediation is executed on the agents.</div> <div><a href="/kb?id=kb_article_view&sys_kb_id=94045a35979be25085e13bbe2153af60" target="_blank" rel="noopener noreferrer">KB2200106: Duplicate Agent ID Detection and Remediation Update Set</a></div> <div><hr /></div> <h3>Detection False Positives:</h3> <ul style="list-style-position: inside;"><li>The duplicate agent detection is based on hostnames.</li><li>If a hostname changes, it may trigger an <code>ACC-4004</code>error.</li><li>However, if the issue is not seen again within 24 hours, it is auto-resolved by the system.</li></ul> <div><hr /></div> <div>Know Issues with Duplicate Agent ID detection/resolution:</div> <ul style="list-style-position: inside;"><li><a href="/problem.do?sys_id=28177071c342ee10757171dc7a013178">PRB1902306</a> : Duplicate Agent ID Error will not resolve if agents are down when job runs</li></ul> </div> </div> </div> </div> </div></div>