Failover MID server for LDAP Integrations

[nicholasmayo]

Hey there folks,

I couldn't find anything on the documentation so I was wondering if anyone could help me. We're moving over to a MID server integration with our LDAP server to populate our user base, and I was wondering what the best practice is for redundancy?

I don't want to set up two entries that simultaneously run, but I would like to have an automatic failover in case the MID server goes down. Ideally, if the MID server goes down and the integration is severed, another MID -> LDAP integration becomes active in it's place.

Any idea if this is possible OOB? Or would I have to set up some event queuing and scripts to set a different MID -> LDAP entry to active?

Thanks!

[rlatorre]

Here's an example of the onAfter update Business Rule on the MID Server [ecc_agent] table although I recommend looking into setting up Clusters per the comment by @Admin Pro.

Condition: Status changes from "Up" && Name is one of <names of MID Servers to monitor>

Advanced script:

function onAfter(current, previous) {
	// Create Incident
	var inc = new GlideRecord('incident');
	inc.initialize();
	inc.applyTemplate('MID Server BCP Switchover');
	var incDesc = '';
	
	// Identify BCP MID Server
	var midBCP = '';
	if (current.name == 'mid_01'){
		midBCP = 'mids_bcp_01';
	} else if (current.name == 'mid_02'){
		midBCP = 'mid_bcp_02';
	}
	
	// Switch to BCP MID Server
	var mid = new GlideRecord('ecc_agent');
	mid.addQuery('name', midBCP);
	mid.addQuery('status', 'Up');
	mid.query();
	if (!mid.next()){
		// If alternate server is not available
		incDesc = 'BCP switchover for downed MID server ' + current.name + ' to ' + midBCP + ' failed. BCP MID Server was not available or is Down.\n\n';
	} else {
		incDesc = 'BCP switchover for downed MID server ' + current.name + ' to ' + mid.name + '.\n\n';
		
		// =============================================================
		// Update Data Sources
		var ds = new GlideRecord('sys_data_source');
		ds.addQuery('mid_server', current.sys_id);
		ds.query();
		
		// If no data sources found to switchover
		if (!ds.next()){
			incDesc = incDesc + 'Found no Data Sources using downed MID Server.\n';
		}
		
		// Switch to BCP MID Server
		while (ds.next()){
			ds.mid_server = mid.sys_id;
			ds.update();
			incDesc = incDesc + 'Switchewd Data Source ' + ds.name + ' to BCP MID Server.\n';
		}
		
		// =============================================================
		// Update SOAP Messages
		var soap = new GlideRecord('sys_soap_message_function');
		soap.addQuery('use_mid_server', current.sys_id);
		soap.query();
		
		// If no SOAP Messages found to switchover
		if (!soap.next()){
			incDesc = incDesc + 'Found no SOAP Messages using downed MID Server.\n';
		}
		
		// Switch to BCP MID Server
		while (soap.next()){
			soap.use_mid_server = mid.sys_id;
			soap.update();
			incDesc = incDesc + 'Switchewd SOAP Message ' + soap.soap_message.getDisplayValue() + ' to BCP MID Server.\n';
		}
	}
	inc.description = incDesc + '\nCheck status of downed MID server (https://[your_instance].service-now.com/ecc_agent_list.do?sysparm_query=) and on <name of MID Server VM>. <We have monitoring configured on our MID Server VMs> If the MID server service is not running ensure we received an alert from MONITORING ENGINEERING.';
	inc.insert();
}