From d4bc1f467036a20defd9977dc97120e096a4dd20 Mon Sep 17 00:00:00 2001
From: denzilribeiro <denzilr@microsoft.com>
Date: Mon, 22 Jul 2019 17:04:15 -0500
Subject: [PATCH] Add support for collecting SQL Requests to identify waits and
 blocking (#6144)

---
 plugins/inputs/sqlserver/README.md    |  6 ++-
 plugins/inputs/sqlserver/sqlserver.go | 60 +++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 2 deletions(-)

diff --git a/plugins/inputs/sqlserver/README.md b/plugins/inputs/sqlserver/README.md
index 16bb353c5f93f..f04e0b6de81e9 100644
--- a/plugins/inputs/sqlserver/README.md
+++ b/plugins/inputs/sqlserver/README.md
@@ -51,7 +51,7 @@ GO
   query_version = 2
 
   ## If you are using AzureDB, setting this to true will gather resource utilization metrics
-  # azuredb = false
+  # azuredb = true 
 
   ## If you would like to exclude some of the metrics queries, list them here
   ## Possible choices:
@@ -67,7 +67,8 @@ GO
   ## - Schedulers
   ## - AzureDBResourceStats
   ## - AzureDBResourceGovernance 
-  exclude_query = [ 'Schedulers' ]
+  ## - SqlRequests
+  exclude_query = [ 'Schedulers' , 'SqlRequests']
 ```
 
 ### Metrics:
@@ -106,6 +107,7 @@ The new (version 2) metrics provide:
 - *Server properties*: Number of databases in all possible states (online, offline, suspect, etc.), cpu count, physical memory, SQL Server service uptime, and SQL Server version. In the case of Azure SQL relevent properties such as Tier, #Vcores, Memory etc.
 - *Wait stats*: Wait time in ms, number of waiting tasks, resource wait time, signal wait time, max wait time in ms, wait type, and wait category. The waits are categorized using the same categories used in Query Store.
 - *Schedulers* - This captures sys.dm_os_schedulers.
+- *SqlRequests* - This captures a snapshot of dm_exec_requests and dm_exec_sessions that gives you running requests as well as wait types and blocking sessions
 - *Azure Managed Instances*
   - Stats from `sys.server_resource_stats`:
     - cpu_count
diff --git a/plugins/inputs/sqlserver/sqlserver.go b/plugins/inputs/sqlserver/sqlserver.go
index f491954f74503..e5de5202b026f 100644
--- a/plugins/inputs/sqlserver/sqlserver.go
+++ b/plugins/inputs/sqlserver/sqlserver.go
@@ -69,6 +69,7 @@ var sampleConfig = `
   ## - Schedulers
   ## - AzureDBResourceStats
   ## - AzureDBResourceGovernance
+  ## - SqlRequests
   exclude_query = [ 'Schedulers' ]
 `
 
@@ -103,6 +104,7 @@ func initQueries(s *SQLServer) {
 		queries["ServerProperties"] = Query{Script: sqlServerPropertiesV2, ResultByRow: false}
 		queries["MemoryClerk"] = Query{Script: sqlMemoryClerkV2, ResultByRow: false}
 		queries["Schedulers"] = Query{Script: sqlServerSchedulersV2, ResultByRow: false}
+		queries["SqlRequests"] = Query{Script: sqlServerRequestsV2, ResultByRow: false}
 	} else {
 		queries["PerformanceCounters"] = Query{Script: sqlPerformanceCounters, ResultByRow: true}
 		queries["WaitStatsCategorized"] = Query{Script: sqlWaitStatsCategorized, ResultByRow: false}
@@ -1356,6 +1358,64 @@ BEGIN
   END;
 `
 
+const sqlServerRequestsV2 string = `
+SET NOCOUNT ON; 
+SELECT  blocking_session_id into #blockingSessions FROM sys.dm_exec_requests WHERE blocking_session_id != 0
+create index ix_blockingSessions_1 on #blockingSessions (blocking_session_id)
+SELECT	
+   'sqlserver_requests' AS [measurement],
+    @@servername AS [sql_instance],
+    DB_NAME() as [database_name],
+	r.session_id
+	, r.request_id
+	, DB_NAME(s.database_id) as session_db_name
+	, r.status
+	, r.cpu_time as cpu_time_ms
+	, r.total_elapsed_time as total_elasped_time_ms
+	, r.logical_reads
+	, r.writes
+	, r.command
+	, wait_time as wait_time_ms
+	, wait_type
+	, wait_resource
+	, blocking_session_id
+	, s.program_name
+	, s.host_name
+	, s.nt_user_name
+	 , r.open_transaction_count  AS open_transaction
+	 , 	LEFT (CASE COALESCE(r.transaction_isolation_level, s.transaction_isolation_level)
+		WHEN 0 THEN '0-Read Committed' 
+		WHEN 1 THEN '1-Read Uncommitted (NOLOCK)' 
+		WHEN 2 THEN '2-Read Committed' 
+		WHEN 3 THEN '3-Repeatable Read' 
+		WHEN 4 THEN '4-Serializable' 
+		WHEN 5 THEN '5-Snapshot' 
+		ELSE CONVERT (varchar(30), r.transaction_isolation_level) + '-UNKNOWN' 
+	END, 30) AS transaction_isolation_level
+	,r.granted_query_memory as granted_query_memory_pages
+	, r.percent_complete
+	, (SUBSTRING(qt.text, r.statement_start_offset / 2 + 1,
+											(CASE WHEN r.statement_end_offset = -1
+													THEN LEN(CONVERT(NVARCHAR(MAX), qt.text)) * 2
+													ELSE r.statement_end_offset
+											END - r.statement_start_offset) / 2)
+		) AS statement_text
+	, qt.objectid
+	, QUOTENAME(OBJECT_SCHEMA_NAME(qt.objectid,qt.dbid)) + '.' +  QUOTENAME(OBJECT_NAME(qt.objectid,qt.dbid)) as stmt_object_name
+	, DB_NAME(qt.dbid) stmt_db_name
+	, r.query_hash
+	, r.query_plan_hash
+	FROM	sys.dm_exec_requests r
+		LEFT OUTER JOIN sys.dm_exec_sessions s ON (s.session_id = r.session_id)
+		OUTER APPLY sys.dm_exec_sql_text(sql_handle) AS qt
+		
+	WHERE	1=1
+	 AND (r.session_id IS NOT NULL AND (s.is_user_process = 1 OR r.status COLLATE Latin1_General_BIN NOT IN ('background', 'sleeping')))
+	 OR (s.session_id IN (SELECT blocking_session_id FROM #blockingSessions))
+	 OPTION(MAXDOP 1)
+
+`
+
 // Queries V1
 const sqlPerformanceMetrics string = `SET DEADLOCK_PRIORITY -10;
 SET NOCOUNT ON;