KEDA Component

Kubernetes Event-driven Autoscaler. Scales workloads based on external metrics from queues, databases, Prometheus, Loki, and more.

Architecture

                KEDA Operator - ScaledObject controller

                Metrics Server - External metrics adapter

                ScaledObject - Autoscaling configuration

                Triggers - Event sources (60+ scalers)

                TriggerAuth - Scaler credentials

Quick Reference

Attribute	Example	Default	Effect
`namespace` REQ	`keda`	-	KEDA operator namespace
`log_level`	`info`	info	debug, info, error

Link to Sub-Components (ScaledObject Generation)

KEDA links to sub-components of other infrastructure to auto-generate ScaledObjects with appropriate triggers.

keda-queue LINK

KEDA → RabbitMQ queue sub-component. Generates: k8s/deploy/base/scaleup/rabbitmq.yaml

Link Attribute	Example	Description
`keda_queue_mode`	`QueueLength`	QueueLength \| MessageRate
`keda_queue_value`	`10`	Threshold value to trigger scaling

                    Creates: Secret (AMQP connection), TriggerAuthentication, ScaledObject
                

keda-topic LINK

KEDA → Kafka topic sub-component. Generates: k8s/deploy/base/scaleup/kafka.yaml

Link Attribute	Example	Description
`keda_lagthreshold`	`100`	Consumer lag threshold
`keda_pollinginterval`	`30`	Polling interval (seconds)
`keda_cooldownperiod`	`300`	Cooldown period (seconds)
`keda_minreplicacount`	`0`	Minimum replicas (0 = scale-to-zero)
`keda_maxreplicacount`	`10`	Maximum replicas

keda-db LINK

KEDA → CNPG db sub-component. Generates: k8s/deploy/base/scaleup/cnpg.yaml

Link Attribute	Example	Description
`keda_query`	`SELECT COUNT(*) FROM jobs WHERE status='pending'`	SQL query returning numeric
`keda_activation_query_value`	`1`	Activation threshold

                    Creates: Secret (PostgreSQL creds), TriggerAuthentication, ScaledObject
                

keda-database LINK

KEDA → PostgreSQL database sub-component. Generates: k8s/deploy/base/scaleup/psql.yaml

Link Attribute	Example	Description
`keda_query`	`SELECT COUNT(*) FROM tasks`	SQL query returning numeric
`keda_activation_query_value`	`5`	Activation threshold

keda-mongo_db LINK

KEDA → MongoDB mongo_db sub-component. Generates: k8s/deploy/base/scaleup/mongodb.yaml

Link Attribute	Example	Description
`keda_query`	`{"status":"pending"}`	MongoDB query filter
`keda_collection`	`jobs`	Collection to query

keda-model LINK

KEDA → vLLM model sub-component. Generates Prometheus-based ScaledObject for LLM inference scaling.

Link Attribute	Example	Description
`keda_query`	`vllm:num_requests_running`	Prometheus query for vLLM metrics
`keda_threshold`	`10`	Request threshold for scaling

Query-Based Scalers (prometheus_query / loki_query)

Special sub-component types that can target any component for scaling based on custom queries.

Sub-Component Type	Variable	Use Case
`prometheus_query`	`__prometheus_query`	Scale any workload based on PromQL query result
`loki_query`	`__loki_query`	Scale any workload based on LogQL query result

                prometheus_query attributes:

                - query: PromQL query (e.g., sum(rate(http_requests_total[5m])))

                - threshold: Scaling threshold value

                - serverAddress: Prometheus server URL (auto-populated from link)

                loki_query attributes:

                - query: LogQL query (e.g., sum(rate({app="myapp"} |= "error" [5m])))

                - threshold: Scaling threshold value

                - serverAddress: Loki server URL (auto-populated from link)

Component Link Variables

Variable	Link Type	Effect
`__prometheus`	prometheus-keda	ServiceMonitor for KEDA metrics
`__prometheus_scale`	keda-prometheus	Prometheus server for query scaler
`__loki_scale`	keda-loki	Loki server for log-based scaler
`__rabbitmq`	keda-rabbitmq	RabbitMQ connection for scaler
`__kafka`	keda-kafka	Kafka connection for scaler
`__postgresql`	keda-postgresql	PostgreSQL connection for scaler
`__mongodb`	keda-mongodb	MongoDB connection for scaler

Generated Files

File	Condition	Contains
scaleup/rabbitmq.yaml	keda-queue link	Secret, TriggerAuth, ScaledObject
scaleup/kafka.yaml	keda-topic link	ScaledObject for Kafka
scaleup/cnpg.yaml	keda-db link	Secret, TriggerAuth, ScaledObject
scaleup/psql.yaml	keda-database link	Secret, TriggerAuth, ScaledObject
scaleup/mongodb.yaml	keda-mongo_db link	Secret, TriggerAuth, ScaledObject

Ports

Port	Purpose	Protocol
8080	Metrics server	HTTP
9666	Prometheus metrics	HTTP

Technical Info

                Chart Version: 2.18.0

                KEDA Version: 2.18.0

                Extensions: local_extensions.b64encode

                CRDs: ScaledObject, ScaledJob, TriggerAuthentication, ClusterTriggerAuthentication