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Description

Error 89, 'Network Timeout', indicates that a MongoDB client failed to establish or maintain a connection with the MongoDB server within the specified timeout duration. This typically occurs when the client attempts an operation, but the server does not respond in time, suggesting underlying network issues or an overloaded server.

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Error Message

Network Timeout

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Known Causes

4 known causes

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Intermittent Network Issues

Unstable or slow network connections between the client and the MongoDB server can lead to dropped packets and timeouts.

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Firewall Blocking Connection

Firewall rules on either the client or server machine might be blocking the necessary ports for MongoDB communication.

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Overloaded or Unavailable Server

If the MongoDB server is under heavy load, unresponsive, or not running, it may not respond to client requests in time.

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Insufficient Timeout Settings

Client-side connection or operation timeout settings may be too aggressive for the network conditions or server response times.

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Solutions

4 solutions available

1. Verify Network Connectivity and Firewall Rules easy

Ensure that the MongoDB server is reachable from the client machine and that firewalls are not blocking the connection.

1

From the client machine experiencing the error, attempt to ping the MongoDB server's IP address or hostname.

ping <mongodb_server_ip_or_hostname>

2

If ping fails, check if the MongoDB port (default 27017) is open on the MongoDB server's firewall. You can use `ufw` on Ubuntu/Debian or `firewall-cmd` on CentOS/RHEL.

# For ufw (Ubuntu/Debian)
sudo ufw status
sudo ufw allow 27017/tcp

# For firewall-cmd (CentOS/RHEL)
sudo firewall-cmd --list-all
sudo firewall-cmd --zone=public --add-port=27017/tcp --permanent
sudo firewall-cmd --reload

3

Also, ensure that any intermediate network devices (routers, load balancers) between the client and server are not blocking traffic on the MongoDB port.

2. Adjust MongoDB Connection Timeout Settings medium

Increase the connection timeout value on the client to allow more time for the connection to establish.

1

When establishing a connection to MongoDB using your driver or shell, specify a longer `connectTimeoutMS` or equivalent option. The default is often 10 seconds (10000 ms).

// Example using the Node.js driver
const MongoClient = require('mongodb').MongoClient;
const uri = "mongodb://localhost:27017";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true, connectTimeoutMS: 30000 }); // 30 seconds

client.connect(err => {
  if (err) {
    console.error('Connection Error:', err);
  } else {
    console.log('Connected successfully to server');
    // ... operations
    client.close();
  }
});

2

For the `mongo` shell, you can use the `--connectTimeoutMS` option.

mongo --host <mongodb_server_ip> --port 27017 --username <user> --password <password> --authenticationDatabase admin --connectTimeoutMS 30000

3. Monitor and Optimize MongoDB Server Performance advanced

If the server is under heavy load, it might be slow to respond to new connections, leading to timeouts.

1

Use MongoDB's built-in tools like `mongostat` and `mongotop` to observe server activity, including connections, read/write operations, and lock percentages.

# Run mongostat on the MongoDB server
mongostat --host <mongodb_server_ip> --port 27017 --username <user> --password <password> --authenticationDatabase admin

2

Analyze slow queries and optimize them by adding appropriate indexes. Use `db.collection.explain().find(...)` to understand query execution plans.

// Example: Find slow queries in the logs (adjust log path as needed)
grep "query" /var/log/mongodb/mongod.log | grep "ms" | sort -k 10 -n | head -n 20

// Example: Adding an index
db.mycollection.createIndex({ myfield: 1 })

3

Check server resource utilization (CPU, RAM, Disk I/O) on the MongoDB host. If resources are consistently maxed out, consider scaling up the server or distributing the load across a replica set or sharded cluster.

4. Investigate Network Latency and Packet Loss medium

High network latency or packet loss between the client and server can cause connection timeouts.

1

Use tools like `traceroute` (Linux/macOS) or `tracert` (Windows) to identify network hops between the client and server and check for high latency at any point.

# On Linux/macOS
traceroute <mongodb_server_ip_or_hostname>

# On Windows
traceroute <mongodb_server_ip_or_hostname>

2

Use `ping` with a larger packet size and for a sustained period to check for packet loss.

# On Linux/macOS
ping -c 100 -s 1024 <mongodb_server_ip_or_hostname>

# On Windows
ping -n 100 -l 1024 <mongodb_server_ip_or_hostname>

3

If high latency or packet loss is detected, consult your network administrator to diagnose and resolve network issues. This might involve checking network infrastructure, router configurations, or internet service provider problems.

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Related Errors

5 related errors

MongoDB Error 89: Connection Timeout