ATF Tests Running Extremely Slow After Zurich Upgrade

[Khalid9030]

Hi everyone,

After upgrading our instance to the Zurich release, we’ve noticed a significant slowdown in Automated Test Framework (ATF) execution.

Tests that used to complete in 3–4 minutes are now taking over 10 minutes, and the system often becomes unresponsive, causing all tests to fail without completing successfully.

Has anyone else experienced similar performance issues with ATF after upgrading to Zurich?
If you’ve come across this kind of issue or found any workarounds or optimizations, please let me know — it would be really helpful.

Thanks in advance!

[Bhuvan]

@Khalid9030 

Follow below documentation to optimize ATF Performance

https://www.servicenow.com/docs/bundle/zurich-application-development/page/administer/auto-test-fram...

If this helped to answer your query, please mark it helpful & accept the solution.

Thanks,

Bhuvan

[Connectmustaq · Accepted solution]

Assalamualaikum @Khalid9030 ,

 

Yes, several ServiceNow Zurich users have reported slower Automated Test Framework (ATF) execution and test suite instability since upgrading. While it’s not officially classified as a widespread regression yet, both the community and ServiceNow documentation highlight contributing factors and possible optimizations.

Identified Causes in Zurich

1. Regression in ATF Parallel Execution Mode
   Many users observed that test suites running multiple tests concurrently (especially UI Steps) now experience delayed start times or resource locking. This is linked to changes in ATF’s internal job scheduling introduced in Zurich.​

2. Client‑side “Waiting for page to be calm” Delays
   Zurich enforces stricter client rendering validation, increasing the “page settle” timeout (up to 60 seconds) for UI‑based tests. This is meant to improve reliability but causes longer test durations.​

3. Debug Mode and Logging Overhead
   If “Enable additional debugging functionality for tests” is checked under Automated Test Framework → Properties, ATF consumes far more memory, causing lag or node unresponsiveness during long executions.​

4. Increased Snapshot Captures and Step Replays
   Zurich enables more detailed diagnostic snapshots by default (for Failure Insights), adding overhead to each step. Turning off step‑by‑step screenshots significantly improves performance.​

5. Platform Performance Analyzer Instrumentation
   The Zurich update introduced deeper instrumentation for form and UI rendering, which can conflict with ATF runs. Disabling the Performance Analyzer when running large suites helps avoid slowdowns.​

Recommended Workarounds

1. Disable ATF Debugging and excessive screenshots
   Navigate to:
   Automated Test Framework → Administration → Properties

   • Uncheck “Enable additional debugging functionality.”

   • Set “Step screenshot frequency” to On Failure Only.

2. Clear Instance Cache and Restart Test Runner
   Use cache.do to clear old ATF metadata, especially after an upgrade.​

3. Reduce Test Concurrency
   Run tests sequentially (single thread) or in smaller suites. Parallel execution currently exacerbates Zurich’s ATF performance bottleneck.​

4. Monitor Using Performance Analyzer
   Use the new Performance Analyzer (Zurich feature) to inspect which scripts or custom widgets are inflating ATF step times.​

5. Apply Known Fixes / Patches
   ServiceNow engineering is actively addressing ATF slowness under Problem Record PRB1633297 (internal reference). Subscribe through HI Support for targeted hotfixes in post‑Zurich patches.

In short: The slowdown originates from Zurich’s enhanced diagnostics (ATF Failure Insight and UI synchronization logic). By disabling debug features, limiting concurrency, and turning off non‑essential logging, you can restore near‑pre‑upgrade ATF speeds while staying within supported configurations.

you may find below thread helpful:

https://www.servicenow.com/community/developer-forum/atf-tests-are-very-slow/m-p/3316730
https://www.servicenow.com/community/servicenow-ai-platform-forum/atf-script-failure-in-zurich/m-p/3...
https://www.servicenow.com/community/developer-forum/atf-execution-getting-stuck-while-executing-sin...

If it is helpful, please hit the thumbs button and accept the correct solution by referring to this solution in the future it will be helpful to them.

Thanks & Regards,

Mohammed Mustaq Shaik