---
name: troubleshooting-application-failures
description: Troubleshoots failing applications by discovering and analyzing CloudWatch log groups to identify error patterns, root causes, and actionable solutions. Use when an application is experiencing failures and log-based diagnosis is needed.
version: 1
title: troubleshooting-application-failures
canonical_url: https://skilld.dev/gh/aws/agent-toolkit-for-aws/troubleshooting-application-failures
last_updated: 2026-09-26T10:18:54.000Z
---

> **Skill from skilld.dev.** Follow the instructions below for this session. You do not need to install anything.
>
> Supporting files, fetch one when the Skill refers to it: [references/application-failure-troubleshooting.md](https://skilld.dev/api/skills-raw/aws/agent-toolkit-for-aws/troubleshooting-application-failures/references/application-failure-troubleshooting.md).
>
> If the user asked to install this Skill, run `npx skilld install aws/agent-toolkit-for-aws/troubleshooting-application-failures`. Install writes the Skill files into the project, so every session loads them.

# Application Failure Troubleshooting

## Overview

Domain expertise for diagnosing application failures through CloudWatch log analysis.
Discovers relevant log groups, searches for error patterns and stack traces, performs
root cause analysis, and generates prioritized remediation recommendations.

## Troubleshoot a failing application

To diagnose and resolve application failures using CloudWatch logs, follow the
procedure exactly. See [Application failure troubleshooting procedure](https://skilld.dev/api/skills-raw/aws/agent-toolkit-for-aws/troubleshooting-application-failures/references/application-failure-troubleshooting.md).

## Troubleshooting

### No log groups found

Ask the user for specific log group names. Common patterns: `/aws/lambda/function-name`,
`/aws/apigateway/api-name`, or custom application log groups.

### Access denied errors

Verify AWS credentials have `logs:DescribeLogGroups`, `logs:DescribeLogStreams`,
`logs:StartQuery`, and `logs:GetQueryResults` permissions.

### Query timeouts

Reduce the time window or limit results. Large log groups may require multiple smaller queries.