[exporter/loadbalancing] Bug introduced in #43721 - Fails to create exporter per endpoints #43950
Description
Component(s)
exporter/loadbalancing
What happened?
Description
- Fix high cardinality metric generated by loadbalancing exporter #43721 may have broken the
loadbalancingexporter. - The creation of exporters for endpoints seem to rely on the exporter component ID.
- Initial tests performed with the DNS resolver, but may be applicable to all resolvers
Steps to Reproduce
- Build from
main - Set the loadbalancingexporter with DNS resolver
Expected Result
- Creation of sub-exporters success
Actual Result
- See below log outputs
Collector version
Environment information
Environment
Build via make otelcontribcol GOOS=linux GOARCH=amd64
OpenTelemetry Collector configuration
exporters:
loadbalancing:
retry_on_failure:
enabled: true
initial_interval: 5s
max_interval: 30s
max_elapsed_time: 60s
sending_queue:
enabled: true
num_consumers: 10
queue_size: 10000
block_on_overflow: false
sizer: items
protocol:
otlp:
timeout: 1s
tls:
insecure: true
resolver:
dns:
hostname: otel-receivers.test
port: '4317'
interval: 5s
timeout: 1sLog output
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter.(*loadBalancer).addMissingExporters
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter@v0.138.0/loadbalancer.go:178
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter.(*loadBalancer).onBackendChanges
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter@v0.138.0/loadbalancer.go:166
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter.(*dnsResolver).resolve
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter@v0.138.0/resolver_dns.go:179
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter.(*dnsResolver).start
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter@v0.138.0/resolver_dns.go:92
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter.(*loadBalancer).Start
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter@v0.138.0/loadbalancer.go:150
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter.(*logExporterImp).Start
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/exporter/loadbalancingexporter@v0.138.0/log_exporter.go:69
2025-10-31 11:39:29 go.opentelemetry.io/collector/component.StartFunc.Start
2025-10-31 11:39:29 go.opentelemetry.io/collector/component@v1.44.1-0.20251028105454-507664fb82dc/component.go:66
2025-10-31 11:39:29 go.opentelemetry.io/collector/exporter/exporterhelper/internal.(*BaseExporter).Start
2025-10-31 11:39:29 go.opentelemetry.io/collector/exporter/exporterhelper@v0.138.1-0.20251028105454-507664fb82dc/internal/base_exporter.go:122
2025-10-31 11:39:29 go.opentelemetry.io/collector/service/internal/graph.(*Graph).StartAll
2025-10-31 11:39:29 go.opentelemetry.io/collector/service@v0.138.1-0.20251028105454-507664fb82dc/internal/graph/graph.go:432
2025-10-31 11:39:29 go.opentelemetry.io/collector/service.(*Service).Start
2025-10-31 11:39:29 go.opentelemetry.io/collector/service@v0.138.1-0.20251028105454-507664fb82dc/service.go:237
2025-10-31 11:39:29 go.opentelemetry.io/collector/otelcol.(*Collector).setupConfigurationComponents
2025-10-31 11:39:29 go.opentelemetry.io/collector/otelcol@v0.138.1-0.20251028105454-507664fb82dc/collector.go:249
2025-10-31 11:39:29 go.opentelemetry.io/collector/otelcol.(*Collector).Run
2025-10-31 11:39:29 go.opentelemetry.io/collector/otelcol@v0.138.1-0.20251028105454-507664fb82dc/collector.go:324
2025-10-31 11:39:29 go.opentelemetry.io/collector/otelcol.NewCommand.func1
2025-10-31 11:39:29 go.opentelemetry.io/collector/otelcol@v0.138.1-0.20251028105454-507664fb82dc/command.go:39
2025-10-31 11:39:29 github.com/spf13/cobra.(*Command).execute
2025-10-31 11:39:29 github.com/spf13/cobra@v1.10.1/command.go:1015
2025-10-31 11:39:29 github.com/spf13/cobra.(*Command).ExecuteC
2025-10-31 11:39:29 github.com/spf13/cobra@v1.10.1/command.go:1148
2025-10-31 11:39:29 github.com/spf13/cobra.(*Command).Execute
2025-10-31 11:39:29 github.com/spf13/cobra@v1.10.1/command.go:1071
2025-10-31 11:39:29 main.runInteractive
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/cmd/otelcontribcol/main.go:70
2025-10-31 11:39:29 main.run
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/cmd/otelcontribcol/main_others.go:10
2025-10-31 11:39:29 main.main
2025-10-31 11:39:29 github.com/open-telemetry/opentelemetry-collector-contrib/cmd/otelcontribcol/main.go:63
2025-10-31 11:39:29 runtime.main
2025-10-31 11:39:29 runtime/proc.go:283
2025-10-31 11:39:29 2025-10-31T18:39:29.447Z error loadbalancingexporter@v0.138.0/loadbalancer.go:178 failed to create new exporter for endpoint {"resource": {"service.instance.id": "3cac90d4-38c5-48eb-af03-27d53c507da5", "service.name": "otelcontribcol", "service.version": "0.138.0-dev"}, "otelcol.component.id": "loadbalancing", "otelcol.component.kind": "exporter", "otelcol.signal": "logs", "endpoint": "172.28.0.22:4317", "error": "component type mismatch: component ID \"loadbalancing\" does not have type \"otlp\""}Additional context
Initial fix
Option A
- Update the component ID to
otlp. - Acceptable approach since the exporter only supports
otlp, and currently hardcoded in few places.. refactoring opportunities.
Problem
- The following seems to only create 1 sub-exporter despite having multiple endpoints
- The ID may need some form of protocol/endpoint identifier
func buildExporterSettings(params exporter.Settings, endpoint string) exporter.Settings {
otlpFactory := otlpexporter.NewFactory()
params.ID = component.NewID(otlpFactory.Type())
params.Logger = params.Logger.With(zap.String(zapEndpointKey, endpoint))
return params
}Option B (Revert)
Revert the changes in #43721
- The following example ensures that we have a unique identifier per protocol/endpoint for the sub-exporter creations
func buildExporterSettings(params exporter.Settings, endpoint string) exporter.Settings {
otlpFactory := otlpexporter.NewFactory()
params.ID = component.NewIDWithName(otlpFactory.Type(), endpoint)
params.Logger = params.Logger.With(zap.String(zapEndpointKey, endpoint))
return params
}Problem
- Possible exporter collisions if naming is not unique. e.g.
otlpvsotlp/<endpoint>vsloadbalancing
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