We used to have cases where our customers reported a performance issue that is causing delay in their business. Working on this issue we saw that the LOG_RATE_GOVERNOR was the most wait time. In this video below we going to provide us some insights about it,.
Why this issue happened?
How?
- Azure Portal
- Select * from sys.dm_db_resource_stats
select top 5 * from sys.dm_db_resource_stats
- Select * from sys.dm_exec_requests in combinations with other DMVs.
SELECT
req.session_id
, req.start_time
, cpu_time 'cpu_time_ms'
, status
, wait_time
, last_wait_type
, total_elapsed_time
, transaction_id
, wait_resource
, task_address
, object_name(st.objectid,st.dbid) 'ObjectName'
, substring
(REPLACE
(REPLACE
(SUBSTRING
(ST.text
, (req.statement_start_offset/2) + 1
, (
(CASE statement_end_offset
WHEN -1
THEN DATALENGTH(ST.text)
ELSE req.statement_end_offset
END
- req.statement_start_offset)/2) + 1)
, CHAR(10), ' '), CHAR(13), ' '), 1, 512) AS statement_text,*
FROM sys.dm_exec_requests AS req
CROSS APPLY sys.dm_exec_sql_text(req.sql_handle) as ST
where session_id <> @@SPID
Best Practices
- Use Business Critical, Premium or Hyperscale if possible.
- Use smaller batches.
- Review if all indexes are needed
- Avoid huge amount like text.
- Implement a more robust retry logic execution.
- Move Historical data to another DB.
Enjoy!
