Turn Recorded Activity Into Working Performance Tests
StresStimulus automatically handles dynamic application behavior that requires substantial manual scripting in other performance testing tools. Its Auto-Correlation engine continuously evolves through our unique knowledge-gathering process, where insights gained while providing scripting services to our customers are directly incorporated into StresStimulus development.
Recorded Traffic Is Only Useful If It Can Replay Reliably
Modern applications frequently generate session values, tokens, identifiers, and other dynamic data that change from one user session to another. If these values are replayed exactly as recorded, the test can fail even though the recording itself looks correct.
StresStimulus' proprietary Auto-Correlation engine automatically detects and replaces these dynamic values so recorded activity can become a working multi-user test with substantially less manual scripting.
Record or Import
Capture application traffic or import Playwright test cases to automatically generate protocol requests and responses.
Detect Dynamic Values
Identify session-specific values that cannot be replayed exactly as recorded.
Auto-Correlation
Create the extraction and substitution logic needed for reliable replay.
Working Test Script
Replay the scenario with the correct dynamic values for each virtual user.
Automatically Carry Dynamic Server Values into the Requests That Need Them
Web applications often create dynamic values such as session IDs, security tokens, record identifiers, and application-state values. The server sends these values in a response and expects the client to return them in one or more later requests.
A real browser handles much of this behavior automatically. Protocol-level virtual users used in modern performance testing solutions efficiently replay recorded traffic at scale. However, they do not automatically reproduce every piece of browser logic. If a request sends a stale recorded value instead of the new dynamic value required for the current session, the application may reject the request or return an incorrect result. This is a correlation error.
Correlating a test means identifying a dynamic value in a server response, extracting it, and substituting it for the recorded value wherever the application expects it later. Correlation can be performed automatically or manually. Manual correlation requires complicated scripting and can become one of the most labor-intensive parts of creating a working performance test.
Auto-Correlation automatically creates these extraction and substitution rules. StresStimulus handles many dynamic values this way so recorded activity can replay reliably with far less manual scripting. StresStimulus also applies its automatic correlation technology to protocol test cases generated from Playwright functional tests.
Server Creates a Dynamic Value
The application returns a session-specific token, ID, cookie, or state value.
Auto-Correlation Extracts It
StresStimulus identifies the value in the response and captures it during replay.
Later Requests Use the New Value
The stale recorded value is replaced with the correct value for the current virtual user and session.
Why This Matters
Correlation is not an optional optimization. When required dynamic values are replayed incorrectly, transactions can fail, application behavior can break, and performance results can become misleading. Reliable correlation is a prerequisite for a valid performance test.
How We Transform Auto-Correlation
Unlike other performance testing tool vendors, StresStimulus provides complete scripting and test configuration services as part of Premium Support, taking responsibility for helping customers deliver working test scripts.
That hands-on involvement provides an important secondary benefit. Our support team is continuously exposed to hundreds of real applications and platforms with custom implementations, authentication flows, and difficult correlation challenges.
Through this daily fieldwork, our scripting experts uncover undocumented correlation patterns that performance testers without specialized training and continuous experience in this type of analysis can struggle to discover. We then use proprietary AI-assisted technology to transform this know-how into anonymized, generalized correlation patterns that are added to the knowledge base used by the StresStimulus Auto-Correlation engine.
After more than a decade of applying this incremental discovery approach, StresStimulus has accumulated an extensive knowledge base of real application correlation patterns that continues to grow with our scripting experience. This continuously expanding expertise enables our Auto-Correlation engine to handle challenging scripting scenarios that other performance testing tools may leave users to resolve manually.
The Result
Auto-Correlation is improved not only from theoretical models and laboratory examples, but from continuous exposure to real performance testing across the enterprise application landscape.
How Real Testing Experience Improves Auto-Correlation
Customer Application
Our scripting experts configure real customer workflows across a wide range of applications and platforms.
New Pattern Discovered
Difficult replay issues reveal undocumented dynamic-data and correlation patterns.
Knowledge Productized
The newly discovered correlation know-how is AI-processed and transformed into anonymized, reusable patterns that are added to the Auto-Correlation engine's knowledge base.
More Scripts Work Out of the Box
The improved Auto-Correlation engine is made available to all users, enabling more of their scripts to work out of the box.
Especially Valuable for Enterprise Workflows
The benefits of advanced Auto-Correlation become most visible when testing applications with long business workflows, framework-generated values, multiple authentication layers, customized behavior, and large amounts of session-specific data.
This is one reason StresStimulus is well suited for performance testing Microsoft Dynamics 365, Power Apps, ERP systems, and other enterprise applications where manual script maintenance can otherwise consume a large part of the testing effort.
- Automatic handling of many dynamic application values
- Reduced dependence on manual correlation rules
- Support for long and data-intensive business workflows
- Continuous improvement based on real customer scenarios
- Expert scripting support when automation alone is not enough
The Support Model Makes the Technology Better
StresStimulus scripting service is not separate from product innovation. Every difficult application we help customers test expands the practical knowledge available to improve future automation. Customers benefit immediately from hands-on support, while the product benefits from a continuous stream of real testing experience.
See How Much Scripting StresStimulus Can Eliminate
Evaluate StresStimulus with one of your own application scenarios. Our team can help you determine how much of the test can be configured automatically and where expert scripting support may be useful.