So Your Boss Wants You to Performance Test Blackboard

So Your Boss Wants you to Performance Test the Blackboard

Learn™ PlatformSteve Feldman

Quick Bio

• Blackboard since 2003• Performance Engineering

from the start• Platform Architecture in

2005• Security Engineering in

2010

“Love my job…love my team. If you email me, I will respond.”

[email protected]

http://goo.gl/Z4Rq5

http://goo.gl/Z4Rq5

http://goo.gl/Z4Rq5

@SEVEN_SECONDS

Problem Statement

So Your Boss Wants You to Performance Test

Expectation Setting

Expectation Setting

For Yourself• Does this fall in your job requirements?• Are you capable of accomplishing this?

For Your Team• Do they have the skills to contribute?• Can responsibilities be well divided/distributed?

For Your Boss• Can the effort be quantified?• Will he/she be willing to agree on objectives, plan and

schedule?

Expectation Setting

• Why are you going through this exercise?

• What do you expect to get out of it?

• Who will be working this effort?

• When will it be accomplished?

• How much will it cost?• Where do we go next once we accomplish it?

Expectation Setting

Drive FunctionalObjectives

Mine and Analyze

Data

AccessRightTools

DevelopSimulation

Scripts

CaptureAppropriate

Metrics

Analyze and Respond

to theData

Escalate without

Confidence

Benchmarking Figuring Out Your Gaps

Expectation Setting

Performance Goals are Measureable and Traceable.• Goals need to align to vision and direction of institution.• Goals should be attainable and realistic.

Response Times are Necessary for Performance• Avoid averages, maximum and minimum values unless using

Standard Deviation.• Try to use Percentiles instead

Throughput Measurements are Needed for Scalability • Bytes Transferred (Send and Receive)• Hits/Time Interval• Pages/Time Interval (Business Transaction Mapping)

Expectation Setting

Attributes of a Performance Goal

Performance: Response

Time Percentile

Scalability: Concurrency/P

arallelism

Acceptance CriteriaWorkload

Business Context

Failure Rates and Errors

Poor AttributesSystem Utilization Ambiguous Words

Everything You Need to Know

Goals, Targets

and Thresholds

Functional Scenarios

Test Bed

Scripting

Scenario Planning

Load Test Definition


• Planning: Goals and Objectives– Goals should be measureable and traceable– Best goals align to the vision and direction of the

business.– Performance requirements are preferred

• Poor goals involve system utilization metrics as they don’t align to the business.


• Attributes of a good performance/scale goal– Response time percentile– Throughput metric: bytes, hits, pages/transactions

served or processed– Community/Population– Definition of a business transaction– Workload/Data Condition– Database transaction– Failure Rate– HTTP Error Codes


Load Test Environment

Test/Deploy Environment

Monitoring Infrastructure

Synthetic Tools


Analysis Tools


Scripting Frameworks• C• Java and JS• Python and Perl

Record and Playback Systems• Commercial Tools: LoadRunner, SilkPerformer,

Rational, SOASTA, MSVSTS• Open Source Tools: Jmeter, Grinder, OpenSTA, Multi-

Mechanize, Curl-Loader

Rich Client and Browser• Browser: Browser-Mob, Selenium, SOASTA, LISA• Alternative: WebPageTest


• Planning: Scheduling– Defining Objectives– Analyzing Behavior– Analyzing System

Data– Functional Script

Definition (Coverage Model)

– Scripting– Data Set Construction

(Test Bed Data Set)

• Planning: Test Process– Monitoring Setup– Infrastructure Setup– Sample Testing– Restore Process– Calibration (Testing

and Tuning)– Scalability Testing– Analyzing Results– Presenting Results

Everything You Need to Do

• Performance Scenario and Modeling– Conduct Functional Interviews– Functional Analysis (Review Use Cases)– Log Mining– Data Mining– User Experience and Expectations

• Sequence, Order and Probability• Modeling Time

– Time of day, year and universal behavior


Test Bed and Data Conditions

Create Synthetic: Uniform, Controlled and Simplified for Ease of Scripting and Requirements Traceability

Leverage Existing Data: Real data, but requires careful planning and evaluations. Complicates scripting and

makes requirements traceability difficult.

• Multiple techniques for creating test bed and data conditions– Combination of ContentExchange and Snapshot– Use of B2 APIs– Direct SQL

• Two pitfalls to avoid– Avoid creating synthetic data with load test scripts.– Avoid trying to use real customer data for actual

test conditions.



• Two Recommended Synthetic Transactions: Production HTTP Drivers and True Browser Rendering.

• HTTP Drivers: Interval-based simulators usually from external sources.– Regulate Frequency, Define Functional Paths and

Verify Non-Functional Requirements

• Browser Rendering: Execute full browser behavior.– Show full E2E and not just First to Last Byte from a

Server Pespective


• Record and Playback vs. HTTP Capture– R/P acts like a proxy capturing HTTP and allows

playback like a video recorder.– HTTP Capture: HTTPLiveHeaders, Fiddler and

Firebug


• Partial Payloads vs. Full Payloads– Use Partial for Code Simplicity and Management

• Emphasis on Server Side Request• Accelerate scripting delivery time

– Use Full for Total Round Trip Time• Dynamic, but controlled content for simplicity purpose• Doesn’t get browser time

• Nugget: Introduce automated Selenium or WebPage Test script(s) on sampled intervals during life of test for browser and end-2-end time.


• Arrival Rates and Load LevelsApproach Overview

Activity Accumulator Event_Type = Login: More precision and already available for query.

Log Analysis /webapps/login: Need to parse and analyze for query purposes, but get so much more data such as host and HTTP statistics.

Changes in SP8 Authetication Framework: Will provide hybrid of 1st and 2nd approach without HTTP statistics.


• Analytics: Study Both as a Transparent Lens

Behavioral

• Closest way to show session lengths.

• Build Probability Models• Narrow Down

Concentration of Systems (See Reads/Writes)

• Network Traffic• Application Behavior

Volumetric/Data Composition

• Shows Writes, but Not Reads

• Good for histograms for studying data orientation.

• Study growth and adoption patterns over time.

• Time Stamped Date: Time Clusters

• Adoption of Tools and Data


• SLA’s Acceptance Criteria on top of Performance and Scalability Requirements.

Objectives Attributes of Performance

Attributes of Scale

TargetsDesired

Resource Conditions

Thresholds Variance and Maximum Willing Resource Conditions


Validation/Verification

Functional• Does it work?• Text Checks Matching• Do I see more than I should?• User Abandonment

Technical• Error Rate• HTTP Failures• Post-Test Log Mining


Area of Focus Recommendations

Key OS Metrics CPU, Memory, Network (Retransmission, Bytes Send/Receive) and I/O (I/Ops)

Key Application Metrics HTTP Codes, Hits/Time, Pages/Time, Failure/Error Rate

Key Container & JVM Metrics

GC Metrics, Thread Counts, JDBC Counts, Cache Statistics, JK Sockets

Key DB Statistics Trans/Sec, Wait Events, SQL Stats (Logical I/O, Physical I/O, Sorts, Parses, Executions), Segment/File Stats, Object Statistics, Cache Stats, Instance Memory Stats

Key Storage Metrics Latency and Seek Time, Disk Throughput, Bytes/Time, I/Ops, Cache, Packet Issues, Reads vs. Writes

When You Can’t Do It Yourself

Load Testing Experts

Technology Experts

Turn-Key Solutions

Key Differentiator?• Portability of Tools• Cost Breakdown• Reuse of Tools• Methodologies• Sample

Documentation• Account for gaps?• Measure of

success?

Key Differentiator?• What tools will

they use?• Leave behinds?• Methodologies?• Benefits of

engagement?• Dependency on

you/team?• Account for gaps?• Measure of

success?

Key Differentiator?• Really LT or TE in

disguise?• What tools will

they use?• Cost breakdown?• Methodologies• Dependency on

you/team?• Artifacts• Measure of

success?


• Lead the objective planning phase Gather requirements and conduct functional interviews.

• Establish relationship w/ PerfEng team at Blackboard

• Product detailed test plan• Execute the benchmark lifecycle• Produce summary report

– Short-term recommendations for configuration– Feedback to Blackboard– Long-term capacity planning guidance


Planning• Goals, Objectives, Targets and Thresholds• Scenario Definition and Test Bed Data Set• Project Plan and Contingency Planning

Test Infrastructure

• Scripting Methodology• Load Generation Capabilities• Measurement Tools

Benchmarking Approach

• Forensics methodology

• Issue Escalation• Tuning/Optimization• Conclusion

How We Do It

Modeling Tools• BbTrends (Custom SQL): Histograms, Star Schema, Adoption and Growth Pattern Analysis• Log Mining: R, Saw Mill, and MS Log Parser

Measurement Tools• ALM: dynaTrace and Quest Foglight• Infrastructure: Cacti, SiteScope and Quest Foglight• Database: Quest Performance Analysis, SQL Server Nexus, ASH/AWR and DMVs

Load Test Tools• HP LoadRunner/Performance Center, Jmeter and SOASTA• Selenium WebPageTest

Analysis Tools• Galileo: Home grown analytics engine

How We Do ItSt

ate

Mod

elin

g • State: Read-only operation, usually a navigation.

• Action: Write-based operation with transactional context

• Action State: Form Sc

ript C

ompo

sitio

n • Every page and operation is fully componentized for reusability.

• Identify vertical and horizontal state movement in the application

• Conventions• Naming• Abandonment• Parameters

Sim

ple

vs. C

ompl

ex • Full vs. Partial

payloads• Dynamic data

awareness• Dynamic data

submission

DEMO

How We Do It

Base Workload

Abandonment

Workload

Interactive Tuning Process

Forecast Theoretical

Determine Theoretical Load/Performance

Model Targets and Thresholds

Develop Ratios

Prove PAR (Discrete Model)

Workload 1

Workload 2

Workload 3

Workload N

How We Do It

User AbandonmentTests

CalibrationTests

Aggregate WorkloadTests

EnduranceTests

Performance Archetype (PAR)Tests

Adoption Tests: S-Curve, Normal Distribution and Altruistic L-Curve

Tests

RegressionTests

Steve Feldman@seven_seconds

@seven_seconds

sevenseconds.wordpress.com

[email protected]

http://goo.gl/Z4Rq5

http://goo.gl/Z4Rq5

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The title of this session is:

So Your Boss Wants you to Performance Test the Blackboard Learn™ Platform Before you Go Live with

the Next Release

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