Application performance monitoring in Elasticsearch - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Understanding APM transaction search query output

You run this Elasticsearch query to find APM transactions with duration over 500ms:

{
  "query": {
    "range": {
      "transaction.duration.us": { "gt": 500000 }
    }
  }
}

What does the query output represent?

Elasticsearch

{
  "query": {
    "range": {
      "transaction.duration.us": { "gt": 500000 }
    }
  }
}

A Documents where transaction duration is missing

B Documents where transaction duration equals exactly 500 milliseconds

C Documents where transaction duration is greater than 500 milliseconds

D Documents where transaction duration is less than 500 milliseconds

💡 Hint

Look at the 'range' query and the 'gt' operator meaning.

The 'range' query with 'gt' means 'greater than'. The field 'transaction.duration.us' is in microseconds, so 500000 us equals 500 ms. The query returns documents with duration above 500 ms.

🧠 Conceptual

intermediate

Purpose of APM agents in application monitoring

What is the main role of an APM agent installed in an application?

A Collect performance data and send it to the APM server

B Store logs locally on the application server

C Replace the application’s database for faster queries

D Manage user authentication and authorization

💡 Hint

Think about what data helps monitor app performance remotely.

APM agents collect metrics like response times, errors, and traces from the application and send them to the APM server for analysis.

❓ Troubleshoot

advanced

Diagnosing missing APM data in Elasticsearch

You notice no APM transaction data appears in Elasticsearch after deploying the agent. Which is the most likely cause?

A The APM server is running on a different port than Elasticsearch

B Elasticsearch cluster is running out of disk space

C The application code has no functions

D The APM agent is not configured with the correct server URL

💡 Hint

Check the agent’s connection settings to the APM server.

If the agent cannot reach the APM server due to wrong URL, no data will be sent and stored in Elasticsearch.

🔀 Workflow

advanced

Steps to set up APM monitoring for a new service

What is the correct order of steps to enable APM monitoring for a new application service?

A 1,2,3,4

B 2,1,3,4

C 2,3,1,4

D 1,3,2,4

💡 Hint

Think about infrastructure setup before code changes.

First set up the APM server and Elasticsearch, then install the agent, deploy the app, and finally check the UI.

✅ Best Practice

expert

Choosing the best APM data retention strategy

Your Elasticsearch cluster stores APM data for 90 days but is running low on disk space. What is the best practice to manage data retention without losing critical monitoring info?

A Use ILM (Index Lifecycle Management) to delete old data and keep recent data optimized

B Manually delete random old indices to free space

C Increase the cluster size without changing retention policies

D Disable APM data collection temporarily

💡 Hint

Think about automated management of data lifecycle.

ILM automates moving data through phases like hot, warm, and delete, preserving important data while freeing space.