AxonOps Kafka Connections Dashboard Metrics Mapping

Overview

The Kafka Connections Dashboard provides comprehensive monitoring of client connections to Kafka brokers. It tracks connection counts, creation/close rates, client versions, and acceptor performance to help identify connection issues and optimize network resource usage.

Metrics Mapping

Dashboard Metric	Description	Attributes
Connection Metrics
kaf_socket_server_metrics_ (function='connection_count')	Current number of active connections	listener={listener}, networkProcessor={id}
kaf_socket_server_metrics_ (function='connection_creation_rate')	Rate of new connections created per second	listener={listener}
kaf_socket_server_metrics_ (function='connection_close_rate')	Rate of connections closed per second	listener={listener}
kaf_socket_server_metrics_ (function='connections')	Connections by client software version	listener={listener}, clientSoftwareName={name}, clientSoftwareVersion={version}
Acceptor Metrics
kaf_Acceptor_AcceptorBlockedPercent	Percentage of time acceptor thread is blocked	listener={listener}

Query Examples

Connection Count

// Total connections per broker
sum(kaf_socket_server_metrics_{function='connection_count',rack=~'$rack',host_id=~'$host_id'}) by (host_id)

// Total connections per listener
sum(kaf_socket_server_metrics_{function='connection_count',rack=~'$rack',host_id=~'$host_id'}) by (listener)

Connection Creation Rate

// Connection creation rate per broker
sum(kaf_socket_server_metrics_{function='connection_creation_rate',rack=~'$rack',host_id=~'$host_id'}) by (host_id)

// Connection creation rate per listener
sum(kaf_socket_server_metrics_{function='connection_creation_rate',rack=~'$rack',host_id=~'$host_id'}) by (listener)

Connection Close Rate

// Connection close rate per broker
sum(kaf_socket_server_metrics_{function='connection_close_rate',rack=~'$rack',host_id=~'$host_id'}) by (host_id)

// Connection close rate per listener
sum(kaf_socket_server_metrics_{function='connection_close_rate',rack=~'$rack',host_id=~'$host_id'}) by (listener)

Client Version Distribution

// Connections grouped by client software and version
sum(kaf_socket_server_metrics_{function='connections',rack=~'$rack',host_id=~'$host_id'}) by (clientSoftwareVersion, clientSoftwareName)

Acceptor Performance

// Acceptor blocked percentage
kaf_Acceptor_AcceptorBlockedPercent{function='MeanRate',rack=~'$rack',host_id=~'$host_id'}

Panel Organization

Overview Section

• Empty row for spacing/organization

Connections

• Connections count per broker
• Connections count per listener
• Connections creation rate per broker
• Connections creation rate per listener
• Connections close rate per broker
• Connections close rate per listener
• Connections per client version
• Acceptor Blocked Percentage

Filters

• rack: Filter by rack location

• host_id: Filter by specific host/broker

Best Practices

Connection Monitoring

• Monitor total connection count against broker limits
• Track connection creation/close rates for unusual patterns
• High connection churn may indicate client issues

Listener Analysis

• Monitor connections per listener (PLAINTEXT, SSL, SASL)
• Different listeners may have different performance characteristics
• Ensure balanced connection distribution across listeners

Client Version Tracking

• Track client software versions for compatibility
• Identify outdated clients that need upgrading
• Monitor for unauthorized or unexpected client versions

Acceptor Performance

• High acceptor blocked percentage indicates connection bottlenecks
• May need to tune acceptor thread configuration
• Consider increasing network threads if consistently blocked

Connection Limits

• Set appropriate connection limits per broker
• Monitor approaching connection limit thresholds
• Plan capacity based on connection growth trends

Security Considerations

• Monitor for connection spikes (potential DoS)
• Track connections from unexpected sources
• Ensure proper authentication/authorization on all listeners

Performance Tuning

• Adjust max.connections.per.ip for client fairness
• Tune num.network.threads based on connection load
• Monitor connection creation rate during peak times