Snippet Name: Kill_runaway_query_in_Atlas

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Created Date: 2025-06-16 13:12:42
Last Modified Date: 2025-05-31 10:32:12

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Title: Kill runaway query in Atlas
Author: user
In Mongo db Atlas, i have a runaway query that is eating resources. the query is attached. how can i find any query running that command and kill it

Author: ChatGPT
In MongoDB Atlas, you can identify and terminate a runaway query by following these steps:

### 1. **Identify the Query**
To find running queries, you can use the **Atlas Performance Advisor** or **Cloud Monitoring Tools**, but if you have direct access to your cluster via `mongosh`, you can run:

```js
db.currentOp({
  "command.find": "your_collection_name" // Replace with your collection name
});
```

If you're looking for a specific operation, you can also filter by:

```js
db.currentOp({
  "active": true, // Finds active operations
  "secs_running": { $gt: 5 }, // Queries running for more than 5 seconds
  "command.query": { $exists: true } // Only query operations
});
```

This will return details of running operations, including their `opid` (operation ID).

---

### 2. **Terminate the Query**
Once you've identified the query using `db.currentOp()`, you can terminate it using:

```js
db.killOp(opid);
```

Replace `opid` with the operation ID retrieved from the previous command.

---

### 3. **Monitor and Prevent Future Runaway Queries**
- **Set Query Execution Timeout:** In MongoDB Atlas, you can set timeouts using the `maxTimeMS` option to prevent long-running queries.
  ```js
  db.collection.find({ your_query }).maxTimeMS(5000);
  ```
- **Use Indexes:** Check the query patterns and ensure appropriate indexes are in place to avoid performance issues.
- **Analyze Query Performance:** Use `explain("executionStats")` to check why the query is slow.

---

### 4. **Check Atlas Logs**
- Go to **MongoDB Atlas > Cluster > Metrics > Real-Time Performance Panel**, and check running queries.
- Use **Atlas Performance Advisor** to identify slow queries.

---

If you need further assistance analyzing the query, feel free to share the query details (excluding sensitive data), and I can help optimize it.