Verify MongoDB is running

# Linux
sudo systemctl status mongod
 
# macOS
brew services list | grep mongodb
 
# Check process
ps aux | grep mongod

Check MongoDB is listening

# Verify MongoDB port is open
sudo netstat -tulpn | grep 27017
 
# Or use lsof
sudo lsof -i :27017

Verify bind IP in MongoDB config Check /etc/mongod.conf:

net:
  port: 27017
  bindIp: 0.0.0.0  # Listen on all interfaces

Restart after changes: sudo systemctl restart mongod

Test connection locally

# From MongoDB server
mongo localhost:27017
 
# Or use telnet
telnet localhost 27017

Verify hostname spelling

• Double-check connection string
• Ensure no extra spaces or typos
• Verify domain is correct

Test DNS resolution

# Test DNS lookup
nslookup cluster0.mongodb.net
 
# Or use dig
dig cluster0.mongodb.net
 
# Test from specific DNS server
nslookup cluster0.mongodb.net 8.8.8.8

Check network DNS settings

• Verify DNS servers in network settings
• Try Google DNS (8.8.8.8, 8.8.4.4)
• Try Cloudflare DNS (1.1.1.1, 1.0.0.1)

Use IP address temporarily

• Resolve hostname manually
• Replace hostname with IP in connection string
• Example: mongodb://192.168.1.100:27017/db
• Note: Not recommended for production

Verify credentials

• Check username and password for typos
• Ensure no extra spaces
• Verify password special characters are URL-encoded
• Example: password#123 becomes password%23123

Check authentication database Add authSource=admin to connection string:

mongodb://user:pass@host:27017/db?authSource=admin

Common auth databases: admin, $external

Verify user exists

use admin
db.getUser("username")

Check user permissions

use admin
db.getUser("username", { showPrivileges: true })

Ensure user has required roles (e.g., read, readWrite)

Test credentials locally

mongo "mongodb://user:pass@host:27017/db?authSource=admin"

Increase timeout values Add to connection string:

mongodb://host:27017/db?connectTimeoutMS=30000&serverSelectionTimeoutMS=30000

Check firewall rules

# Test port connectivity
telnet host 27017
 
# Or use nc
nc -zv host 27017
 
# Test with timeout
timeout 5 bash -c "</dev/tcp/host/27017" && echo "Port open"

Verify IP whitelisting

• Check MongoDB Atlas Network Access settings
• Ensure MongoDash IPs are whitelisted
• Temporarily add 0.0.0.0/0 for testing (remove after)

Check MongoDB server load

db.serverStatus()
db.currentOp()

High CPU or connections may cause timeouts

Test geographic latency

# Ping MongoDB host
ping -c 5 host
 
# Test latency with time
time mongo host:27017 --eval "db.serverStatus()"

High latency (>500ms) may require timeout increases

Verify TLS is enabled on MongoDB Check MongoDB config:

net:
  tls:
    mode: requireTLS
    certificateKeyFile: /path/to/cert.pem
    CAFile: /path/to/ca.pem

Upload CA certificate to MongoDash

• For self-signed certificates, upload CA cert
• Navigate to Connection → TLS/SSL Settings
• Upload CA certificate file

Check certificate validity

# View certificate details
openssl s_client -connect host:27017 -showcerts
 
# Check expiration
echo | openssl s_client -connect host:27017 2>/dev/null | openssl x509 -noout -dates

Verify hostname matches certificate

• Certificate CN or SAN must match hostname
• Use IP address if certificate is for IP
• Or use tlsAllowInvalidHostnames=true (testing only)

Skip validation for testing Add to connection string (development only):

mongodb://host:27017/db?tls=true&tlsAllowInvalidCertificates=true

Verify replica set name Check MongoDB replica set config:

rs.conf()

Use exact name in connection string:

mongodb://host1,host2,host3/db?replicaSet=myReplicaSet

Check replica set status

rs.status()

Verify:

• At least one PRIMARY member
• Members are reachable
• No recent elections

List all replica set members Include all members in connection string:

mongodb://host1:27017,host2:27017,host3:27017/db?replicaSet=rs0

Check network connectivity between members

# From each member, ping other members
ping host1
ping host2
ping host3

Wait for primary election

• Elections typically complete in seconds
• Check rs.status() for state changes
• Retry connection after election completes

Enable connection pooling

mongodb://host:27017/db?maxPoolSize=50&minPoolSize=10

Use SRV records for Atlas

mongodb+srv://cluster.mongodb.net/db

SRV records provide faster connection discovery

Choose geographically closer region

• Use MongoDB Atlas region selector
• Deploy database near MongoDash region
• Consider multi-region deployment

Optimize DNS caching

• Configure longer DNS TTL
• Use local DNS caching resolver
• Pre-resolve hostnames

Increase operation timeout

mongodb://host:27017/db?socketTimeoutMS=60000

Check query execution plan

db.collection.find({field: "value"}).explain("executionStats")

Look for COLLSCAN (collection scan) instead of IXSCAN (index scan)

Add indexes for slow queries

db.collection.createIndex({field: 1})

Monitor server performance

db.serverStatus()
db.currentOp()

Check for high CPU, memory, or active operations

Gather diagnostic information

• Connection string (redact password)
• Error messages
• Connection test results
• MongoDB logs
• Network configuration

Check documentation

• Review connection type guide
• Check SSH tunnel setup
• Verify security configuration

Contact support

• Email: support@mongodash.com
• Include diagnostic information
• Provide reproduction steps