Add activity_stats method that mimics the SQL Server Activity Monitor.

Author: jrafanie

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -358,6 +358,51 @@ def cs_equality_operator
         @@cs_equality_operator || 'COLLATE Latin1_General_CS_AS_WS'
       end
 
+      def activity_stats
+        self.select(<<-EOSQL)
+          SELECT
+             [session_id]    = s.session_id,
+             [user_process]  = CONVERT(CHAR(1), s.is_user_process),
+             [login]         = s.login_name,
+             [database]      = ISNULL(db_name(r.database_id), N''),
+             [task_state]    = ISNULL(t.task_state, N''),
+             [command]       = ISNULL(r.command, N''),
+             [application]   = ISNULL(s.program_name, N''),
+             [wait_time_ms]  = ISNULL(w.wait_duration_ms, 0),
+             [wait_type]     = ISNULL(w.wait_type, N''),
+             [wait_resource] = ISNULL(w.resource_description, N''),
+             [blocked_by]    = ISNULL(CONVERT (varchar, w.blocking_session_id), ''),
+             [head_blocker]  =
+                  CASE
+                      -- session has an active request, is blocked, but is blocking others
+                      WHEN r2.session_id IS NOT NULL AND r.blocking_session_id = 0 THEN '1'
+                      -- session is idle but has an open tran and is blocking others
+                      WHEN r.session_id IS NULL THEN '1'
+                      ELSE ''
+                  END,
+             [total_cpu_ms]   = s.cpu_time,
+             [total_physical_io_mb]   = (s.reads + s.writes) * 8 / 1024,
+             [memory_use_kb]  = s.memory_usage * 8192 / 1024,
+             [open_transactions] = ISNULL(r.open_transaction_count,0),
+             [login_time]     = s.login_time,
+             [last_request_start_time] = s.last_request_start_time,
+             [host_name]      = ISNULL(s.host_name, N''),
+             [net_address]    = ISNULL(c.client_net_address, N''),
+             [execution_context_id] = ISNULL(t.exec_context_id, 0),
+             [request_id]     = ISNULL(r.request_id, 0),
+             [workload_group] = N''
+          FROM sys.dm_exec_sessions s LEFT OUTER JOIN sys.dm_exec_connections c ON (s.session_id = c.session_id)
+          LEFT OUTER JOIN sys.dm_exec_requests r ON (s.session_id = r.session_id)
+          LEFT OUTER JOIN sys.dm_os_tasks t ON (r.session_id = t.session_id AND r.request_id = t.request_id)
+          LEFT OUTER JOIN
+          (SELECT *, ROW_NUMBER() OVER (PARTITION BY waiting_task_address ORDER BY wait_duration_ms DESC) AS row_num
+              FROM sys.dm_os_waiting_tasks
+          ) w ON (t.task_address = w.waiting_task_address) AND w.row_num = 1
+          LEFT OUTER JOIN sys.dm_exec_requests r2 ON (r.session_id = r2.blocking_session_id)
+          WHERE db_name(r.database_id) = '#{current_database}'
+          ORDER BY s.session_id
+        EOSQL
+      end
 
       protected
 

test/cases/connection_test_sqlserver.rb

@@ -117,6 +117,16 @@ def setup
 
   end
 
+  context 'Diagnostics' do
+    should 'testing #activity_stats' do
+      stats = @connection.activity_stats
+      assert stats.length > 0
+      
+      assert stats.all? { |s| s.has_key?("session_id") }
+      assert stats.all? { |s| s["database"] == @connection.current_database }
+    end
+  end
+  
 
 
   private