Downloaded 12 times
![DTU Percent
(SELECT Max(v)
FROM (VALUES (avg_cpu_percent),
(avg_data_io_percent),
(avg_log_write_percent)) AS
value(v)) AS [avg_DTU_percent]](https://image.slidesharecdn.com/azuresqldatabaseperformancetuning-iderageeksync-april262017-2-170426182409/75/Geek-Sync-Azure-SQL-Database-Performance-Tuning-20-2048.jpg)
Uploaded byIDERA Software
Geek Sync - Azure SQL Database Performance Tuning
The document serves as an introduction to performance tuning for Azure SQL Database, focusing on identifying and resolving resource bottlenecks such as memory, CPU, and disk usage. It discusses the Database Transaction Unit (DTU) as a measure of database performance and provides various strategies for monitoring and improving performance, including tools like Query Store and DMVs. Additionally, it covers indexing, workload adjustments, and provides resources for further reference.
Geek Sync - Azure SQL Database Performance Tuning
- 1. Introduction to Performance Tuning withAzure SQL Database April 26, 2017
- 2.
- 3.
- 4.
- 5. Meet Resource Bottlenecks MemoryDisk CPU Network Locks Photos: http://www.flickr.com/photos/kaiban/5159888367/lightbox/ and http://www.flickr.com/photos/moodog/504456253 and http://www.flickr.com/photos/marksze/4231115464and http://www.flickr.com/photos/vvvracer/5264339383 and http://www.flickr.com/photos/iphil_photos/4962369046
- 6. What we benchmarktoday http://bit.ly/SQLPerformanceRCA
- 7. Wait Stats • PAGEIOLATCH_% •WRITELOG DISK • SOS_SCHEDULER_YIELD • CXPACKET CPU • LATCH_% • PAGELATCH_% Memory • LCK_% Locking
- 8. Waits and Queuefor I/O Running Waiting– Getting I/O Obtained I/O Suspended (Enter Queue) Top of Queue
- 9. How to monitorPerformance On-Premises DMVs Profiler Extended Events Perfmon Query Store Data Tuning Advisor
- 10. How to ImprovePerformance Increase Resources Reduce Workload Improve Design / Code
- 11.
- 12. What we benchmarktoday
- 13.
- 14. What is DTU? TheDatabase Transaction Unit (DTU) * DTU is the unit of measure in SQL Database that represents the relative power of databases based on a real- world measure: the database transaction. Reference: https://azure.microsoft.com/en-us/documentation/articles/sql-database-performance-guidance/
- 15. What the DTU…. Didanyone understand what DTU Means? What is Power of database based on real-world measure?
- 16. DTU in AzurePortal Photo Credit
- 17. What Really isDTU? Photo Credithttp://bit.ly/AzureDTU
- 18. DTU Is….. DTU =DTU Percent * DTU Limit
- 19. What Really isDTU? Photo Credithttp://bit.ly/AzureDTU
- 20. DTU Percent (SELECT Max(v) FROM(VALUES (avg_cpu_percent), (avg_data_io_percent), (avg_log_write_percent)) AS value(v)) AS [avg_DTU_percent]
- 21. Calculating DTU ISNULL(dtu_limit,0) * (SELECTMax(v) FROM (VALUES (avg_cpu_percent), (avg_data_io_percent), (avg_log_write_percent)) AS value(v)) / 100.0 AS DTU
- 22. SYS.DM_DB_RESOURCE_STATS User Database Captured EveryFifteen Seconds One Hour Historical Data Idle Database has Data
- 23. SYS.RESOURCE_STATS Master Database Every FiveMinutes 14 Days Historical Data Idle databases may not have rows
- 24.
- 25.
- 26. Azure SQL DatabaseWaits Disk Usage IO_QUEUE_LIMIT Log Usage LOG_RATE_GOVERNOR CPU SOS_SCHEDULER_YIELD bit.ly/azureSQLWaits
- 27.
- 28.
- 29.
- 30. Indexes in AzureSQL Database Index Fragmentation Missing Indexes Index Usage Queries Missing Indexes
- 31.
- 32. Azure SQL Database PerformanceTools Query Store DMVs Extended Events Azure Portal Query Performance Insight Auto-Tuning Index
- 33.
- 34.
- 35.
- 36. Improve Performance inAzure SQL Database Change Performance Tier Tune Top Offenders Chatty Database Activity Application- tier caching Sharding Data
- 37.
- 38.
- 39. Migrate 60GB Databasewith S0 39
- 40. Migrate 60gb Databaseto P1 40
- 41. Monitor Waits DuringMigration 41
- 42. • http://bit.ly/SQLPerformanceRCA • http://bit.ly/AzureDTU •http://bit.ly/azureSQLWaits • http://bit.ly/WhatIsRunning Links/QA…
Editor's Notes
- #4 Today, briefly we will cover how you monitor performance today. Next were going to talk about how we can leverage those skills to monitor performance in Azure SQL Database. Finally, we will cover new ways to monitor performance in Azure SQL DB that you cannot use in Onprem.
- #8 We are not going to focus on Locking here because we are going to focus on resource that contend for DTU.
- #10 DMVs can do so much here. You can probe the plan cache for usage statistics or specific details in execution plans that are in memory. Jason Strate and Jason Brimhall both have great blog series on these topics. Perfmon has been used since the beginning of time. You can answer basic questions like, how many request are running? How many index scans do I have vs index seeks and a lot more. Profiler or Server Side Traces can be very helpful for capturing a specific workload and doing analysis to find top offenders. You can also add perfmon data into profiler to see how statements impact specific counters.
- #13 With DaaS we have less knobs to uses. Therefore, we have less things to benchmark.
- #18 Talk about using Query Store to find DTU. DTU is calculated based on usage of CPU, read or writes.
- #20 Talk about using Query Store to find DTU. DTU is calculated based on usage of CPU, read or writes.
- #27 Want to focus on a new DMV that only exists in Azure SQL Database. Sys.dm_db_wait_stats IO_QUEUE_LIMIT -> Occurs when the asynchronous IO queue for the Azure SQL Database has too many IOs pending. Tasks trying to issue another IO are blocked on this wait type until the number of pending IOs drop below the threshold. The threshold is proportional to the DTUs assigned to the database. LOG_RATE_GOVERNOR -> Occurs when DB is waiting for quota to write to the log.
- #33 DMVs can do so much here. You can probe the plan cache for usage statistics or specific details in execution plans that are in memory. Jason Strate and Jason Brimhall both have great blog series on these topics. Perfmon has been used since the beginning of time. You can answer basic questions like, how many request are running? How many index scans do I have vs index seeks and a lot more. Profiler or Server Side Traces can be very helpful for capturing a specific workload and doing analysis to find top offenders. You can also add perfmon data into profiler to see how statements impact specific counters.
- #37 Changing Performance Tier can get you a quick hit but will not scale. You will either run out of money or performance tier options. Tuning Top Offenders by identifying top I/O and CPU consumers and adding indexes or rewriting queries to be optimizer friendly and utilize less resources. Multiple times I will see slow process occurring due to chatty database activity. Chatty database activity occurs when there are several calls between the application layer and the database. A perfect example is processing row by row instead of processing sets of data between database calls.
- #40 The end line is not the process completing. It was me giving up after looking at the difference in rows. You can actually see six hours in I change from S0 to S1 and it still didn’t help much. Lesson learned, use a premium tier for the upgrade to improve time it takes to move data. You can bring it back down once the migration is completed.
- #41 I Suggest planning and using a much higher tier to cut down the time it take to migrate data and then flip to your planned performance tier.