How to monitor tempdb in MS SQL

Error: tempdb is full due to active_transaction.

 select
 ss.[host_name],
 ss.login_name,
 ss.original_login_name,
 ss.[status],
 R.*
 from(
     SELECT  COALESCE(T1.session_id, T2.session_id) [session_id] ,
             T1.request_id ,
             COALESCE(T1.database_id, T2.database_id) [database_id],
             DB_NAME(COALESCE(T1.database_id, T2.database_id)) as Database_Name,
             COALESCE(T1.[Total Allocation User Objects], 0) + T2.[Total Allocation User Objects] [Total Allocation User Objects (MB)] ,
             COALESCE(T1.[Net Allocation User Objects], 0) + T2.[Net Allocation User Objects] [Net Allocation User Objects] ,
             COALESCE(T1.[Total Allocation Internal Objects], 0) + T2.[Total Allocation Internal Objects] [Total Allocation Internal Objects (MB)] ,
             COALESCE(T1.[Net Allocation Internal Objects], 0) + T2.[Net Allocation Internal Objects] [Net Allocation Internal Objects (MB)] ,
             COALESCE(T1.[Total Allocation], 0) + T2.[Total Allocation] [Total Allocation (MB)] ,
             COALESCE(T1.[Net Allocation], 0) + T2.[Net Allocation] [Net Allocation (MB)] ,
             COALESCE(T1.[Query Text], T2.[Query Text]) [Query Text]
     FROM    (( SELECT   TS.session_id,
               TS.request_id,
               TS.database_id,
               CAST(TS.user_objects_alloc_page_count / 128. AS DECIMAL(15,2)) [Total Allocation User Objects] ,
               CAST((TS.user_objects_alloc_page_count - TS.user_objects_dealloc_page_count) / 128. AS DECIMAL(15,2)) [Net Allocation User Objects] ,
               CAST(TS.internal_objects_alloc_page_count / 128. AS DECIMAL(15,2)) [Total Allocation Internal Objects] ,
               CAST((TS.internal_objects_alloc_page_count - TS.internal_objects_dealloc_page_count) / 128. AS DECIMAL(15,2)) [Net Allocation Internal Objects] ,
               CAST((TS.user_objects_alloc_page_count + internal_objects_alloc_page_count) / 128. AS DECIMAL(15,2)) [Total Allocation] ,
               CAST((TS.user_objects_alloc_page_count + TS.internal_objects_alloc_page_count - TS.internal_objects_dealloc_page_count - TS.user_objects_dealloc_page_count) / 128. AS DECIMAL(15,2)) [Net Allocation] ,
               T.text [Query Text]
               FROM  sys.dm_db_task_space_usage TS
                     INNER JOIN sys.dm_exec_requests ER ON ER.request_id = TS.request_id AND ER.session_id = TS.session_id
                     OUTER APPLY sys.dm_exec_sql_text(ER.sql_handle) T
             ) T1
             RIGHT JOIN
             ( SELECT  SS.session_id,
                           SS.database_id,
                           CAST(SS.user_objects_alloc_page_count / 128. AS DECIMAL(15,2)) [Total Allocation User Objects] ,
                           CAST((SS.user_objects_alloc_page_count - SS.user_objects_dealloc_page_count)/ 128. AS DECIMAL(15, 2)) [Net Allocation User Objects] ,
                           CAST(SS.internal_objects_alloc_page_count / 128. AS DECIMAL(15,2)) [Total Allocation Internal Objects] ,
                           CAST((SS.internal_objects_alloc_page_count - SS.internal_objects_dealloc_page_count) / 128. AS DECIMAL(15, 2)) [Net Allocation Internal Objects] ,
                           CAST((SS.user_objects_alloc_page_count + internal_objects_alloc_page_count) / 128. AS DECIMAL(15, 2)) [Total Allocation] ,
                           CAST((SS.user_objects_alloc_page_count + SS.internal_objects_alloc_page_count - SS.internal_objects_dealloc_page_count - SS.user_objects_dealloc_page_count) / 128. AS DECIMAL(15, 2)) [Net Allocation] ,
                           T.text [Query Text]
                FROM   sys.dm_db_session_space_usage SS
                       LEFT JOIN sys.dm_exec_connections CN ON CN.session_id = SS.session_id
                       OUTER APPLY sys.dm_exec_sql_text(CN.most_recent_sql_handle) T
              ) T2 ON T1.session_id = T2.session_id)
 ) R
 left join sys.dm_exec_sessions ss on R.session_id=ss.session_id
 order by ss.status, [Total Allocation User Objects (MB)] desc

参考链接：https://www.mssqltips.com/sqlservertip/4356/track-sql-server-tempdb-space-usage/