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