PASSEDcloud / azure_functions

Azure: Azure Functions Cold Start Causing Timeouts

Azure Functions on Consumption plan experiencing 30+ second cold starts during a traffic spike. HTTP trigger functions timing out.

Pattern

AZURE_CLOUD

Expected: AZURE_FUNCTIONS_TIMEOUT

Severity

HIGH

Confidence

68%

Remediation

Auto-Heal

Test Results

Metric	Expected	Actual
Pattern Recognition	AZURE_FUNCTIONS_TIMEOUT	AZURE_CLOUD
Severity Assessment	HIGH	HIGH
Incident Correlation	N/A	None
Cascade Escalation	N/A	No
Remediation	—	Auto-Heal — Corax resolves autonomously

Scenario Conditions

Azure Functions Consumption plan. 50 functions. Cold start time: 35 seconds. HTTP trigger timeout: 30 seconds. Traffic spike from 0 to 500 req/s.

Injected Error Messages (1)

Azure Functions cold start timeout — 35 second cold start exceeding 30 second HTTP timeout, consumption plan scaling from 0, 500 req/s traffic spike, 90% of initial requests timing out

Neural Engine Root Cause Analysis

Azure cloud infrastructure event detected — an Azure resource may be failing, an App Service is unhealthy, Azure AD authentication is disrupted, or a Service Bus queue is backed up. Azure outages can cascade across dependent services and affect both cloud-hosted applications and hybrid on-premises integrations relying on Azure AD.

Remediation Plan

1. Check Azure Service Health (status.azure.com) for any active incidents in your region. 2. Review Azure Monitor alerts and resource health for the affected service. 3. For App Service issues, check the Kudu console for application logs and restart the app if needed. 4. For Azure AD issues, verify conditional access policies and check the Azure AD sign-in logs for failure reasons. 5. For Service Bus, check dead-letter queues and verify the sending/receiving applications are connected and processing messages.

Improvements Applied

Pattern classified as AZURE_CLOUD (expected AZURE_FUNCTIONS_TIMEOUT)

Tested: 2026-04-02Monitors: 1 | Incidents: 1Test ID: cmnhnr9bk09c4lig7d9o72joh