<Insert Picture Here> Exadata MAA Best Practices Series Session #4: Exadata and OLTP Applications Hector Pujol Hector Pujol Consulting Member of Technical Staff, Oracle X and MAA Teams
Exadata MAA Best Practices Series 1. E-Business Suite on Exadata 2. Siebel on Exadata 3. PeopleSoft on Exadata 4. Exadata and OLTP Applications 5. Using Resource Manager on Exadata 6. Migrating to Exadata 7. Using DBFS on Exadata 8. Exadata Monitoring 9. Exadata Backup & Recovery 10. Exadata MAA 11. Troubleshooting Exadata 12. Exadata Patching & Upgrades 13. Exadata Health Check <Insert Picture Here> 2
Agenda Key Points and Customer Takeaways Business Takeaways Best Practices Takeaways 3
<Insert Picture Here> Key Points and Customer Takeaways 4
Exadata leverages your OLTP tuning knowledge Exadata smart flash cache and Infiniband network boosts OLTP application performance Exadata reduces risk to OLTP applications by managing mixed workloads 5
Key Point #1 Exadata Leverages your OLTP Tuning Knowledge Business Value Add Employ your existing OLTP tuning experience 6
Tuning Methods SQL Tuning Understand Execution Plans Generate statistics Use bind variables 7
Configuration Tuning Linux HugePages Normal page size is 4 KB HugePage size is 2 MB Memory savings for mulitiple and/or large SGAs, and large numbers of processes See Support Note 744769.1 - How to Configure HugePages for Oracle Database on 64-bit Linux Platforms 8
Configuration Tuning FAST_START_MTTR_TARGETSTART TARGET Bounds instance recovery time Larger values => lazier DBWR, more I/O for LGWR Good initial starting point is 300 (seconds) Consider increasing the time if you still see: Outliers for long times of log file sync and log file parallel write Majority of physical writes are due to checkpoints See physical writes and physical writes noncheckpoint 9
Configuration Tuning Connection Management Managing connections with pooling Avoiding excessive logon/logoffs 10
Key Point #2 Exadata Smart Flash Cache and Infiniband ib Network Boosts I/O Performance Business Value Add Enable significant reductions in I/O response times enabling greater throughput 11
Smart Flash Cache Exadata Smart Flash Cache is fast Exadata Smart Flash Cache is efficient i Exadata Smart Flash Cache is flexible 12
Smart Flash Cache: Monitoring Statistics are available to monitor the effectiveness of the Smart Flash Cache (AWR example below) Wait event to look for: cell single block physical reads 13
Smart Flash Cache: Monitoring Additional Metrics: Database-level V$SYSSTAT (from AWR) Statistic Total -------------------------------- ------------------ cell flash cache read hits 459,038... physical read total IO requests 471,394 97% of reads from flash cache In AWR, Optimized and UnOptimized reads for Segment Statistics and Top SQL show are shown next 14
Smart Flash Cache: Monitoring Additional Metrics: Database-level Segment Statistics (shown in AWR) Segments by UnOptimized Reads Snaps: 856-859 Tablespace Subobject Obj. UnOptimized Owner Name Object Name Name Type Reads %Total ---------- ---------- -------------------- ---------- ----- ------------ ------- APPS APPS_TS_TX SGT_FIXED_REVENUE_DI TABLE 732 43.94 PA APPS_TS_TX TX PA_EVENTS_N1 N1 INDEX 43 2.58 Segments by Optimized Reads Snaps: 856-859 Tablespace Subobject Obj. Optimized Owner Name Object Name Name Type Reads %Total ---------- ---------- -------------------- ---------- ----- ------------ ------- PA APPS_TS_TX PA_EXPENDITURE_ITEMS TABLE 69,086 20.88... HXC APPS_TS_TX TX HXC_TIME_ATTRIBUTE_U U INDEX 24,494494 7.40 15
Is the EMP Table Currently Cached? Cell-level caching statistics for a DB object SQL> SELECT data_object_id FROM DBA_OBJECTS WHERE object_name='emp'; OBJECT_ID --------- 57435 CellCLI> LIST FLASHCACHECONTENT WHERE objectnumber=57435 DETAIL cachedsize: 495438874 dbid: 70052 hitcount: 415483 misscount: 2059 objectnumber: 57435 tablespacenumber: 1 16
Leverage the Infiniband Network Low latency = fast communication RDS bcopy (db->db) and zcopy (db->cell) Minimal CPU overhead Alert.log log shows RDS configured for the interconnect Cluster communication is configured to use the following interface(s) for this instance 192.168.20.21 cluster interconnect IPC version:oracle RDS/IP (generic) 17
Leverage the Infiniband Network Interface configuration, network configuration, etc all preconfigured for performance and HA Extending the IB fabric with IPoIB IB with no application changes Media servers, batch servers 18
Leverage the Infiniband Network AWR excerpt from a customer s OLTP production database Global Cache and Enqueue Services - Workload Characteristics ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Avg global enqueue get time (ms): 0.1 Avg global cache cr block receive time (ms): 0.3 Avg global cache current block receive time (ms): 0.2 Avg global cache cr block build time (ms): 0.0 Avg global cache cr block send time (ms): 0.0 Avg global cache current block pin time (ms): 0.1 Avg global l cache current block send time (ms): 0.00 19
Key Point #3 Exadata Reduces Risk to OLTPA Applications by Managing Mixed Workloads Business Value Add OLTP Workloads Continue to Meet Business Objectives Even When Mixed Workloads Must Run Together 20
Managing Mixed Workloads Most systems use hybrid workloads OLTP Batch Reporting Reports and Batch jobs are commonly CPU and I/O intensive OLTP workloads require predictable response times, often tied to SLAs that must be met 21
Workload Consolidation: Resource Management Resource Manager manages mixed workloads CPU resource management using instance caging IO Resource Management Resource Management will be discussed in more detail in part 4 of the Exadata Best Practice Series. 22
Business Takeaways 23
Business Takeaways Leverage your DBA s performance tuning experience with Exadata Improve your application performance and increase your user capacity with Exadata Improve batch throughput and reduce risk by completing batch runs faster 24
Best Practice Takeaways 25
Best Practice Takeaways Tune OLTP applications as usual Utilize Exadata smart flash cache Leverage Exadata s features to consolidate workloads 26
<Insert Picture Here> Appendix 27
Best Practices Additional Resources sponsored by MAA and X-Team Oracle Exadata Best Practices (Doc ID 757552.1) Links to various best practice notes Specifically, see OLTP Best Practices Note 1269706.11 (available soon) Database Machine and Exadata Storage Server 11g Release 2 (11.2) Supported Versions (Doc ID 888828.1) Latest recommended patches 28
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