07 - Extending with Triggers (Dedicated)¶

Extend beyond HTTP using queue, blob, timer, and Event Hub triggers with annotation-based bindings and clear operational checks.

Prerequisites¶

Tool	Version	Purpose
JDK	17+	Compile and run Java functions locally
Maven	3.6+	Build and package Java artifacts
Azure Functions Core Tools	v4	Start local host and publish artifacts
Azure CLI	2.61+	Provision Azure resources and inspect app state

Dedicated plan basics

Dedicated (App Service Plan) runs Functions on reserved VM instances with fixed monthly cost. B1 provides 1 vCPU and 1.75 GB memory. AlwaysOn keeps the function host loaded, eliminating cold starts. Choose Dedicated when you already operate App Service workloads or need predictable billing.

What You'll Build¶

You will verify all 16 functions deployed to the Dedicated plan, covering HTTP, queue, blob, timer, and Event Hub trigger types. The reference app includes functions for health monitoring, DNS resolution, external dependencies, storage probing, error testing, and more.

flowchart TD
    A[Queue message] --> B["@QueueTrigger handler"]
    C[Blob upload] --> D["@BlobTrigger handler"]
    E[Schedule] --> F["@TimerTrigger handler"]
    G[Event Hub] --> H["@EventHubTrigger handler"]
    I[HTTP request] --> J["@HttpTrigger handler"]
    B --> K[Outputs and logs]
    D --> K
    F --> K
    H --> K
    J --> K

Steps¶

Step 1 - Review deployed function inventory¶

The Java reference app contains 16 functions across 5 trigger types:

Function	Trigger	Route/Binding	Purpose
`health`	HTTP GET	`/api/health`	Health check endpoint
`helloHttp`	HTTP GET/POST	`/api/hello/{name}`	Greeting with path parameter
`info`	HTTP GET	`/api/info`	Runtime environment info
`identityProbe`	HTTP GET	`/api/identity`	Managed identity status
`storageProbe`	HTTP GET	`/api/storage/probe`	Storage connectivity check
`dnsResolve`	HTTP GET	`/api/dns/{hostname}`	DNS resolution test
`externalDependency`	HTTP GET	`/api/dependency`	External HTTP call test
`logLevels`	HTTP GET	`/api/loglevels`	Log severity test
`slowResponse`	HTTP GET	`/api/slow`	Simulated latency (2s)
`testError`	HTTP GET	`/api/testerror`	Controlled error test
`unhandledError`	HTTP GET	`/api/unhandlederror`	Unhandled exception test
`queueProcessor`	Queue	`incoming-orders`	Queue message processing
`blobProcessor`	Blob	`uploads/{name}`	Blob upload processing
`scheduledCleanup`	Timer	`0 0 2 * * *`	Daily scheduled task
`timerLab`	Timer	`0 /5 * * *`	5-minute interval timer
`eventhubLagProcessor`	Event Hub	`events`	Event Hub message processing

Step 2 - Test all HTTP endpoints¶

export APP_NAME="func-jded-04100220"

# Core endpoints
curl --request GET "https://$APP_NAME.azurewebsites.net/api/health"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/hello/Dedicated"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/info"

# Diagnostic endpoints
curl --request GET "https://$APP_NAME.azurewebsites.net/api/identity"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/storage/probe"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/dns/google.com"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/dependency"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/loglevels"
curl --request GET "https://$APP_NAME.azurewebsites.net/api/slow"

Step 3 - Verify trigger resources¶

# List queues
az storage queue list \
  --account-name "$STORAGE_NAME" \
  --output table

# List blob containers
az storage container list \
  --account-name "$STORAGE_NAME" \
  --query "[].name" \
  --output tsv

Step 4 - Test queue trigger¶

# Send a test message
az storage message put \
  --queue-name "incoming-orders" \
  --account-name "$STORAGE_NAME" \
  --content "test-dedicated-queue-message"

# Check queue (message should be consumed quickly)
sleep 10
az storage message peek \
  --queue-name "incoming-orders" \
  --account-name "$STORAGE_NAME" \
  --output table

Step 5 - Test blob trigger¶

# Upload a test file
echo "dedicated blob test content" > /tmp/test-blob.txt
az storage blob upload \
  --container-name "uploads" \
  --account-name "$STORAGE_NAME" \
  --name "test-dedicated.txt" \
  --file "/tmp/test-blob.txt"

Step 6 - Verify timer functions¶

Timer functions run on schedule and can be verified via Application Insights:

az monitor app-insights query \
  --apps "$APP_NAME" \
  --resource-group "$RG" \
  --analytics-query "traces | where message contains 'timer' or message contains 'cleanup' | where timestamp > ago(30m) | project timestamp, message | order by timestamp desc | take 5"

Step 7 - Verify all function responses¶

Test all endpoints and record responses:

for endpoint in health "hello/Dedicated" info identity "storage/probe" "dns/google.com" dependency loglevels slow; do
  printf "%-25s " "/api/$endpoint:"
  curl --silent --max-time 15 "https://$APP_NAME.azurewebsites.net/api/$endpoint" | head -c 100
  echo
done

Verification¶

HTTP endpoint responses:

/api/health:              {"status":"healthy","timestamp":"2026-04-09T17:27:54.901695140Z","version":"1.0.0"}
/api/hello/Dedicated:     {"message":"Hello, Dedicated"}
/api/info:                {"name":"azure-functions-java-guide","version":"1.0.0","java":"17.0.14","os":"Linux",...}
/api/identity:            {"managedIdentity":false,"identityEndpoint":"not configured"}
/api/dns/google.com:      {"hostname":"google.com","addresses":["172.217.213.138",...]}
/api/loglevels:           {"logged":true}
/api/slow:                {"delayed":2,"message":"Response after 2 second(s)"}
/api/storage/probe:       {"storageConfigured":true,"connectionType":"connectionString"}
/api/dependency:          {"url":"https://httpbin.org/get","statusCode":200,"latencyMs":2346,"success":true}

Dedicated identity probe

Like Premium, Dedicated returns {"managedIdentity":false} unless you explicitly enable system-assigned managed identity. Flex Consumption has managed identity enabled by default.

Storage resources:

Queue: incoming-orders
Containers: azure-webjobs-eventhub, azure-webjobs-hosts, azure-webjobs-secrets, uploads

Dedicated function indexing is fast

Unlike Premium where az functionapp function list may show 0 functions for several minutes after deployment, Dedicated indexes all 16 functions immediately after publish. This is because the AlwaysOn setting keeps the host process running continuously.

No execution timeout on Dedicated

Like Premium, Dedicated (App Service Plan) removes the function execution timeout. The /api/slow endpoint with a 2-second delay works identically, but long-running functions that would timeout on Consumption (5 min) or Flex Consumption (30 min default) can run indefinitely on Dedicated.

Clean Up¶

az group delete --name "$RG" --yes --no-wait