- oracle · performance tuning use the best tools sql tuning sets, database replay identify tuning...

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Top 10 Lessons Learned in Deploying the Oracle Exadata

Dan Norris

Oracle X Team, Oracle Development

Aaron Werman

Architect, Bank of America Merrill Lynch

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Agenda

Prepare

Educate yourself

Migrate

Performance tuning

Employ features in applications

Customer: Bank of America Merrill Lynch

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Prepare – System Architecture/Design

Plan for high availability and disaster recovery

Add proper test and development systems

Follow best practices from

http://www.oracle.com/goto/maa

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Prepare - Application

Investigate and test target database release (currently

11g Release 2)

Gather baseline performance data, explain plans

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Prepare - Stakeholders

Identify *all* of them

Brief them and *require* their input

Set realistic expectations

Adapt the enterprise support structure

Components are familiar

May find non-technical challenges

Assign most qualified engineers for support

Arrange training early in the project

Linux, RAC, ASM, Exadata, RMAN, Data Guard

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Migrate

Find the proper methods

SLA may dictate some choices

Opportunity to adopt best practices

Test the results and capture timing

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Performance Tuning

Use the best tools

SQL Tuning Sets, Database Replay

Identify tuning methods

Profiles

Query rewrite

Parallelism

Best practice: remove release-specific or underscore

parameters during upgrades

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Prepare - Stakeholders

Identify *all* of them

Brief them and require their input

Adapt the enterprise support structure

Arrange training early in the project

Linux, RAC, ASM, Exadata, RMAN, Data Guard

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Bank of America

Lessons Learned Migrating a Major Application to Exadata v2

Aaron Werman

Bank of America

[email protected]

Disclaimers

• All opinions are those of the author

• No endorsements are intended: this is a technical presentation intending to help others following in a similar path

Application Use Case Overview

• Complex integration of capital markets trading data

• Hundreds of ETLs, Thousands of tables

• 10K+ ETL executions per day, many highly complex

• Near real –time SLAs

• ODS with data sharing for entire line of business

• Several web applications, each with multiple hundreds of users, doing reporting and analytic queries

• Business, not traditional BI, SLAs for availability and recovery

Evaluation Considerations

• Very uncomfortable with technology risk!

• “Zero risk POC”

– Run entire production load

• Migrate full application

• Test with full production volume for a long period (1 month)

– Scale to identified 3 year growth goals

• Run a week of load in a day

– Determine how long it takes to run a day of load in a compressed period (see how overlap affects performance)

• Reporting scaling goal: 25K reports/hour

• Recovery times: RTO goal 2 hours

Alternatives Considered and Rejected

• Key Issue: mixed workload. Obvious candidates are Teradata, DB2, Netezza, Oracle for ODS and a column database for DW

• General concern: migration from Oracle entails time/cost and risk. Application is highly tuned to Oracle physical design

• Teradata concern: too small a use case for their sweet spot

• DB2 concern: migration, organizational issues, and new support issues

• Netezza: recovery model, fact/fact joins, mixed workload, tuning, LOB support

• New column database for reporting: organizational risk and current ODS I/O bottlenecks

• No other POCs were done! We chose Exadata based on migration risk avoidance

Exadata Justification for the Application

• Migrating from Oracle to another platform migration entails significant schedule risk

• Scaling Oracle ourselves is not justified by cost / risk / technology stack (but may be less painful in terms of corporate architecture)

• Potential loss of business capability and likely miss of critical SLAs if we do not scale adequately

• Current gaps in corporate SAN engineering to support VLDB (and 100TB applications)

Prep Work: Oracle 10g to 11g

Conversion/Validation

• We created a small copy of the app in Oracle 11g and tested for functional gaps

• No issues were raised

– despite some of our stack (Informatica v8.1) not being certified for 11g)

Data Migration

• Key issues are time to migrate and disk space requirements and complexity

• We rejected RMAN Oracle 10g single instance → Exadata

– Requires migration to 11g, ASM, RAC… too many steps

• We chose to use exports:

– data pump (network) for almost everything

– export classic for large LOB tables

• Be careful about considering ASM storage in FRA as a file copy target – there are limitations; review with Oracle!

Exadata Target State Architecture

X

Informatica

Cognos

Java

IIS, .NET

Oracle Physical Data

guard (TCP/IP)

Primar

y

DR

MQ, WMB EMC SRDF Synchronous Replication

file

s

file

s

file

s

file

s

file

s

X

Informatica

Cognos

Java

IIS, .NET

MQ, WMB

file

s

file

s

file

s

file

s

file

s

Bugs

Some major bugs encountered:

• 9356344 High CPU utilization of orarootagent.bin process with CRS-2409

• 9338087 ASM AND DATABASE HANG - CONNECT: OSSNET: CONNECTION FAILED TO SERVER, RESULT=5

• 9324531 ORA-00600: internal error code

These are now corrected as part of the current Exadata Oracle release

Performance Tuning

• Most due to SQL optimization differences between Oracle 10g and 11g

• ~40,000 SQL statements in app68 statements identified as substantially slower

_______________________________________

37 considered non-SLA relevant and ignored

31 important SQL statements with significant SLA impact

• 26 resolved using profiles

• 3 resolved using hints

• 2 resolved by query rewrite

• optimizer_use_sql_plan_baselines?

• Note that most statements improved in performance, and improved in proportion to how much work/time they took

RAC Tuning

• Our DBAs, based on prior RAC strategies, initially partitioned the app to segregate load and prevent potential lock/block overhead

• 8K page size only tested

• After tuning, we determined there was no gain, and all load was allowed across all nodes

– Your mileage may vary

Support Model

• Really complex to implement in our enterprise

– Disruptive technology requires change in strategy for many stakeholders, especially infrastructure support groups

• Include time in your plan to allow for the transition

• Include ALL stakeholders in your planning

• Backups:

– NAS/NFS... RMAN using a certified agent…

• Who manages the SA role?

• Monitoring (corporate standards vs. Oracle practice…)

– SNMP

Application Design Futures Based on Exadata

• Application changes, such as reducing our real time ETL SLAs by 2/3s

• Index removal

– We will experiment and remove many “for purpose” indexes

– Incremental strategy with sufficient testing required

• ILM using Hybrid Columnar Compression

• Reducing duplication of data between operational and reporting requirements

• Likely BI (read-only reporting) against disaster recovery site using Active Data Guard

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Upcoming Exadata SessionsTuesday, September 21

2:00 pm – 3:00 pm

Future of the Oracle Exadata: Developments in OLTP, Warehousing, Consolidation (S316825)

Moscone South, Room 306

3:30 pm – 4:30 pmOracle RAC on Sun Oracle Database Machine Customer Panel (S317090)


5:00 pm – 6:00 pm

Enterprise-Class Online Transaction Processing (OLTP) on the Oracle Exadata (S316823)


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Upcoming Exadata SessionsWednesday, September 22

1:00 pm – 2:00 pm

Oracle Exadata Tips, Tricks, and Best Practices: Backup and Recovery (S316821)


4:45 pm – 5:45 pmOracle Exadata Tips, Tricks, and Best Practices: Migrating to the Oracle Exadata (S316822)


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Upcoming Exadata SessionsThursday, September 23

12:00 pm – 1:00 pm

Oracle Exadata Technical Deep Dive: Architecture and Internals (S316820)


3:00 pm – 4:00 pmThe X-Files: Managing the Oracle Exadata and Highly Available Oracle Databases (S316974)


- oracle · performance tuning use the best tools sql tuning sets, database replay identify tuning...

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