Intermittent failures from ASM public stations running WebDriver script

Products

• CA App Synthetic Monitor

Issue/Introduction

Customers may experience intermittent failures across various CA App Synthetic Monitor (ASM) public stations when executing WebDriver script from different geographic locations. The monitors may fail inconsistently, while other runs from the same stations succeed.

Environment

• Product: CA App Synthetic Monitor (ASM) public stations
• Component: WebDriver script execution

Cause

Intermittent script failures can be caused by local processes or security software on the application host environment that conflict with the WebDriver script execution.

Resolution

To identify and resolve the conflict:

1. Analyze HAR Files: Capture and review HAR (HTTP Archive) files from both successful and failed monitor runs. Look for specific requests that time out or return errors during the failed sessions.
2. Identify Conflicting Processes: Check the application environment for any background processes or security agents that may be intercepting or conflicting with the WebDriver script's browser interactions.
3. WAF/Whitelisting Check: If the stations are behind a WAF, ensure all ASM public stations IP addresses are correctly whitelisted. Intermittent issues can occur if some station IPs are blocked while others are permitted.
4. Terminate Conflicting Tasks: if the application team identifies a conflicting process during script execution. Stopping that process should resolve the intermittent failures.