Example job command to implement self-monitoring for SQL Sentry monitoring service hearbeats

SQLSentry_Heartbeat_Monitoring.sql

-- Run this in the right SQL Sentry database
--USE [SentryOne];
--USE [SQLSentry];
GO
IF OBJECT_ID('[dbo].[heartbeat_log]') IS NULL
BEGIN
	CREATE TABLE [dbo].[heartbeat_log](
		[servername] [nvarchar](300) CONSTRAINT PK_Heartbeat_Log PRIMARY KEY CLUSTERED WITH(IGNORE_DUP_KEY=ON,DATA_COMPRESSION=PAGE),
		[heartbeatdate] [datetime] NULL,
		[ActualHeartbeatDate] [datetime] NULL
	);
END
GO
DECLARE
	@HeartbeatThresholdMinutes INT = 5,
	@HeartbeatRepeatAlertThresholdHours INT = 1,
	@GlobalObjID UNIQUEIDENTIFIER
	
SELECT @GlobalObjID = ObjectID FROM dbo.vwObjects_Global;
DECLARE @SubjectTitle NVARCHAR(255), @BodyText NVARCHAR(4000);
SET @SubjectTitle = N'Monitoring Service: Heartbeat Failure'

-- Delete any irrelevant heartbeat failures from log
DELETE HL
-- optionally use this output to implement an "auto-resolve" logic:
-- OUTPUT deleted.servername INTO @RestoredHeartbeats
FROM dbo.heartbeat_log AS HL
INNER JOIN dbo.ManagementEngine AS E
ON HL.servername = E.servername 
WHERE E.HeartbeatDateTime > HL.HeartbeatDate

-- Get all monitoring servers with outdated heartbeats and are not snoozed
DECLARE @site NVARCHAR(200), @servername NVARCHAR(200), @HeartbeatDateTime datetime
, @text NVARCHAR(200), @title NVARCHAR(200), @HeartbeatDateTimeLocal datetime;

DECLARE serverlist CURSOR
LOCAL FAST_FORWARD
FOR
SELECT T.[Name],E.[servername], ISNULL(E.HeartbeatDateTime, E.LastInitializationDateTime)
FROM dbo.ManagementEngine E
INNER JOIN [dbo].[Site] T ON T.ID = E.SiteID
WHERE ISNULL(E.HeartbeatDateTime, E.LastInitializationDateTime) < DATEADD(MINUTE, -@HeartbeatThresholdMinutes, GETUTCDATE())
AND NOT EXISTS (SELECT st.ObjectID FROM dbo.SnoozeStatus st WHERE st.ObjectID IN (E.ObjectID,T.ObjectID,@GlobalObjID) )

OPEN serverlist
 
WHILE 1=1
BEGIN
	FETCH NEXT FROM serverlist INTO @site, @servername, @HeartbeatDateTime
	IF @@FETCH_STATUS <> 0 BREAK;

	SET @HeartbeatDateTimeLocal = CONVERT(datetime, @HeartbeatDateTime AT TIME ZONE 'UTC' AT TIME ZONE 'Israel Standard Time' )
	SET @title = @site + ': '+ QUOTENAME(@servername) + ' ' + @SubjectTitle
	SET @text = N'Monitor server <b>' + @servername + N'</b> has lost connection to the repository.<br/>Last heartbeat was at <b>' + convert(nvarchar(200),@HeartbeatDateTimeLocal, 121) + N' (IST)</b>'
	
	SET @BodyText = N'[Message]: ' + @text
+ N'<br/><br/>[Start Time (Local)]: ' + CONVERT(nvarchar(25), @HeartbeatDateTimeLocal, 121)
+ N'<br/>[Start Time (UTC)]: ' + CONVERT(nvarchar(25), @HeartbeatDateTime, 121) 
+ N'<br/>[Duration]: ' +  ISNULL(NULLIF(CONVERT(varchar(100), DATEDIFF(dd,0, GETUTCDATE()-@HeartbeatDateTime)), 0) + ' day(s), ', '')
 + CONVERT(varchar(100), GETUTCDATE()-@HeartbeatDateTime, 114)
+ N'<br/>----------------------------------------------------------------------'
+ N'<br/>[Timestamp (Local)]: ' + CONVERT(nvarchar(25), GETDATE(), 121)
+ N'<br/>[Timestamp (UTC)]: ' + CONVERT(nvarchar(25), GETUTCDATE(), 121)
+ N'<br/>[Generated By]: ' + @@SERVERNAME
+ N'<br/>[Monitor Type]: SQLSentryHeartbeatCheck<br/>[Condition]: ' + @SubjectTitle
	;
	WITH trgt AS (SELECT * FROM dbo.heartbeat_log WHERE servername = @servername)
	MERGE INTO trgt
	USING (SELECT * FROM (VALUES(@servername, GETUTCDATE())) AS v(servername, TimeNow)) AS src
	ON trgt.servername = src.servername
	WHEN NOT MATCHED BY TARGET THEN
		INSERT (servername, heartbeatdate)
		VALUES (servername, TimeNow)
	WHEN MATCHED AND src.TimeNow > dateadd(hour, @HeartbeatRepeatAlertThresholdHours, trgt.heartbeatdate) THEN
		UPDATE SET heartbeatdate = src.TimeNow
	;

	IF @@ROWCOUNT > 0
	BEGIN
		PRINT N'Heartbeat failure for ' + QUOTENAME(@servername)

		-- Get additional metadata about the server if it's also a SQL Server
		DECLARE @SQLVersion NVARCHAR(4000), @SQLEdition NVARCHAR(4000)
		SELECT 
			@SQLVersion = CASE
					WHEN MajorVersionNumber = 10 AND MinorVersionNumber = 50 THEN '2008R2'
					WHEN EngineEdition IN (5,6) THEN 'sql_azure'
					ELSE
						CASE MajorVersionNumber
							WHEN 8 THEN '2000'
							WHEN 9 THEN '2005'
							WHEN 10 THEN '2008'
							WHEN 11 THEN '2012'
							WHEN 12 THEN '2014'
							WHEN 13 THEN '2016'
							WHEN 14 THEN '2017'
							WHEN 15 THEN '2019'
							WHEN 16 THEN '2022'
							ELSE ''
						END
				  END
		  ,@SQLEdition = CASE [EngineEdition] -- https://docs.microsoft.com/en-us/sql/t-sql/functions/serverproperty-transact-sql
							WHEN 2 THEN 'standard' -- also web and BI
							WHEN 3 THEN 'enterprise' -- also datacenter, developer and evaluation
							WHEN 4 THEN 'express'
							WHEN 5 THEN 'azure_sql_database'
							WHEN 6 THEN 'azure_sql_data_warehouse'
							WHEN 8 THEN 'azure_managed_instance'
							ELSE ''
						 END
		FROM [dbo].[vwSqlServer]
		WHERE [ObjectName] = @servername

		/* ---- TODO: Add your alert logic below this line ---- */

		/*-- Example 1: Sending an e-mail using DBMail:
		EXEC msdb..sp_send_dbmail
			@recipients = 'dba@acme.com'
		      , @subject = @title
		      , @body = @BodyText
		      , @body_format = 'HTML'
		      , @importance = 'high'
		*/


		/*-- Example 2: Throwing an error to fail the job:
		--RAISERROR(N'%s', 16, 1, @BodyText);
		*/

		/*-- Example 3: Whatever else:
		EXECUTE SendSNMPAlertCLR
					@SourceServer = @servername, 
					@Subject = @title, 
					@Body = @BodyText,
					@Severity = 3,
					@SQLVersion = @SQLVersion,
					@SQLEdition = @SQLEdition,
					@Condition = @SubjectTitle,
					@Site = @site
		*/

		/* ---- TODO: Add your alert logic above this line ---- */
	END
END

CLOSE serverlist
DEALLOCATE serverlist