---

id: admin-api-functions title: Manage Functions sidebar_label: Functions

Pulsar Functions are lightweight compute processes that

• consume messages from one or more Pulsar topics
• apply a user-supplied processing logic to each message
• publish the results of the computation to another topic

Functions can be managed via the following methods.

Method	Description
Admin CLI	The functions command of the pulsar-admin tool.
REST API	The /admin/v3/functions endpoint of the admin {@inject: rest:REST:/} API.
Java Admin API	The functions method of the {@inject: javadoc:PulsarAdmin:/admin/org/apache/pulsar/client/admin/PulsarAdmin} object in the Java API.

Function resources

You can perform the following operations on functions.

Create a function

You can create a Pulsar function in cluster mode (deploy it on a Pulsar cluster) using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the create subcommand.

Example

$ pulsar-admin functions create \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --inputs test-input-topic \
  --output persistent://public/default/test-output-topic \
  --classname org.apache.pulsar.functions.api.examples.ExclamationFunction \
  --jar /examples/api-examples.jar

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}

Java Admin API

FunctionConfig functionConfig = new FunctionConfig();
functionConfig.setTenant(tenant);
functionConfig.setNamespace(namespace);
functionConfig.setName(functionName);
functionConfig.setRuntime(FunctionConfig.Runtime.JAVA);
functionConfig.setParallelism(1);
functionConfig.setClassName("org.apache.pulsar.functions.api.examples.ExclamationFunction");
functionConfig.setProcessingGuarantees(FunctionConfig.ProcessingGuarantees.ATLEAST_ONCE);
functionConfig.setTopicsPattern(sourceTopicPattern);
functionConfig.setSubName(subscriptionName);
functionConfig.setAutoAck(true);
functionConfig.setOutput(sinkTopic);
admin.functions().createFunction(functionConfig, fileName);

Update a function

You can update a Pulsar function that has been deployed to a Pulsar cluster using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the update subcommand.

Example

$ pulsar-admin functions update \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --output persistent://public/default/update-output-topic \
  # other options

REST Admin API

{@inject: endpoint|PUT|/admin/v3/functions/{tenant}/{namespace}/{functionName}

Java Admin API

FunctionConfig functionConfig = new FunctionConfig();
functionConfig.setTenant(tenant);
functionConfig.setNamespace(namespace);
functionConfig.setName(functionName);
functionConfig.setRuntime(FunctionConfig.Runtime.JAVA);
functionConfig.setParallelism(1);
functionConfig.setClassName("org.apache.pulsar.functions.api.examples.ExclamationFunction");
UpdateOptions updateOptions = new UpdateOptions();
updateOptions.setUpdateAuthData(updateAuthData);
admin.functions().updateFunction(functionConfig, userCodeFile, updateOptions);

Start an instance of a function

You can start a stopped function instance with instance-id using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the start subcommand.

$ pulsar-admin functions start \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --instance-id 1

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/{instanceId}/start

Java Admin API

admin.functions().startFunction(tenant, namespace, functionName, Integer.parseInt(instanceId));

Start all instances of a function

You can start all stopped function instances using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the start subcommand.

Example

$ pulsar-admin functions start \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/start

Java

admin.functions().startFunction(tenant, namespace, functionName);

Stop an instance of a function

You can stop a function instance with instance-id using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the stop subcommand.

Example

$ pulsar-admin functions stop \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --instance-id 1

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/{instanceId}/stop

Java Admin API

admin.functions().stopFunction(tenant, namespace, functionName, Integer.parseInt(instanceId));

Stop all instances of a function

You can stop all function instances using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the stop subcommand.

Example

$ pulsar-admin functions stop \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/stop

Java Admin API

admin.functions().stopFunction(tenant, namespace, functionName);

Restart an instance of a function

Restart a function instance with instance-id using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the restart subcommand.

Example

$ pulsar-admin functions restart \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --instance-id 1

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/{instanceId}/restart

Java Admin API

admin.functions().restartFunction(tenant, namespace, functionName, Integer.parseInt(instanceId));

Restart all instances of a function

You can restart all function instances using Admin CLI, REST API or Java admin API.

Admin CLI

Use the restart subcommand.

Example

$ pulsar-admin functions restart \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/restart

Java Admin API

admin.functions().restartFunction(tenant, namespace, functionName);

List all functions

You can list all Pulsar functions running under a specific tenant and namespace using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the list subcommand.

Example

$ pulsar-admin functions list \
  --tenant public \
  --namespace default

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}

Java Admin API

admin.functions().getFunctions(tenant, namespace);

Delete a function

You can delete a Pulsar function that is running on a Pulsar cluster using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the delete subcommand.

Example

$ pulsar-admin functions delete \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) 

REST API

{@inject: endpoint|DELETE|/admin/v3/functions/{tenant}/{namespace}/{functionName}

Java Admin API

admin.functions().deleteFunction(tenant, namespace, functionName);

Get info about a function

You can get information about a Pulsar function currently running in cluster mode using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the get subcommand.

Example

$ pulsar-admin functions get \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) 

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}/{functionName}

Java Admin API

admin.functions().getFunction(tenant, namespace, functionName);

Get status of an instance of a function

You can get the current status of a Pulsar function instance with instance-id using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the status subcommand.

Example

$ pulsar-admin functions status \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --instance-id 1

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}/{functionName}/{instanceId}/status

Java Admin API

admin.functions().getFunctionStatus(tenant, namespace, functionName, Integer.parseInt(instanceId));

Get status of all instances of a function

You can get the current status of a Pulsar function instance using Admin CLI, REST API or Java Admin API.

Admin CLI

Use the status subcommand.

Example

$ pulsar-admin functions status \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) 

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}/{functionName}/status

Java Admin API

admin.functions().getFunctionStatus(tenant, namespace, functionName);

Get stats of an instance of a function

You can get the current stats of a Pulsar Function instance with instance-id using Admin CLI, REST API or Java admin API.

Admin CLI

Use the stats subcommand.

Example

$ pulsar-admin functions stats \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --instance-id 1

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}/{functionName}/{instanceId}/stats

Java Admin API

admin.functions().getFunctionStats(tenant, namespace, functionName, Integer.parseInt(instanceId));

Get stats of all instances of a function

You can get the current stats of a Pulsar function using Admin CLI, REST API or Java admin API.

Admin CLI

Use the stats subcommand.

Example

$ pulsar-admin functions stats \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) 

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}/{functionName}/stats

Java Admin API

admin.functions().getFunctionStats(tenant, namespace, functionName);

Trigger a function

You can trigger a specified Pulsar function with a supplied value using Admin CLI, REST API or Java admin API.

Admin CLI

Use the trigger subcommand.

Example

$ pulsar-admin functions trigger \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --topic (the name of input topic) \
  --trigger-value \"hello pulsar\"
  # or --trigger-file (the path of trigger file)

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/trigger

Java Admin API

admin.functions().triggerFunction(tenant, namespace, functionName, topic, triggerValue, triggerFile);

Put state associated with a function

You can put the state associated with a Pulsar function using Admin CLI, REST API or Java admin API.

Admin CLI

Use the putstate subcommand.

Example

$ pulsar-admin functions putstate \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --state "{\"key\":\"pulsar\", \"stringValue\":\"hello pulsar\"}" 

REST API

{@inject: endpoint|POST|/admin/v3/functions/{tenant}/{namespace}/{functionName}/state/{key}

Java Admin API

TypeReference<FunctionState> typeRef = new TypeReference<FunctionState>() {};
FunctionState stateRepr = ObjectMapperFactory.getThreadLocal().readValue(state, typeRef);
admin.functions().putFunctionState(tenant, namespace, functionName, stateRepr);

Fetch state associated with a function

You can fetch the current state associated with a Pulsar function using Admin CLI, REST API or Java admin API.

Admin CLI

Use the querystate subcommand.

Example

$ pulsar-admin functions querystate \
  --tenant public \
  --namespace default \
  --name (the name of Pulsar Functions) \
  --key (the key of state) 

REST API

{@inject: endpoint|GET|/admin/v3/functions/{tenant}/{namespace}/{functionName}/state/{key}

Java Admin CLI

admin.functions().getFunctionState(tenant, namespace, functionName, key);