site2/docs/admin-api-functions.md

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

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';

:::tip

This page only shows some frequently used operations.

For the latest and complete information about Pulsar admin, including commands, flags, descriptions, and more, see Pulsar admin doc
For the latest and complete information about REST API, including parameters, responses, samples, and more, see {@inject: rest:REST:/} API doc.
For the latest and complete information about Java admin API, including classes, methods, descriptions, and more, see Java admin API doc.

:::

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 `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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`create`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

$ 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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName|operation/registerFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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);

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`update`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|PUT|/admin/v3/functions/:tenant/:namespace/:functionName|operation/updateFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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);

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`start`](/tools/pulsar-admin/) subcommand. 

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/start|operation/startFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

Start all instances of a function

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

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`start`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/start|operation/startFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

Stop an instance of a function

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

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`stop`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/stop|operation/stopFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

Stop all instances of a function

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

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`stop`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/stop|operation/stopFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

Restart an instance of a function

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

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`restart`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/restart|operation/restartFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

Restart all instances of a function

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

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`restart`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/restart|operation/restartFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`list`](/tools/pulsar-admin/) subcommand.

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace|operation/listFunctions?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`delete`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|DELETE|/admin/v3/functions/:tenant/:namespace/:functionName|operation/deregisterFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`get`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName|operation/getFunctionInfo?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`status`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/status|operation/getFunctionInstanceStatus?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`status`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/status|operation/getFunctionStatus?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`stats`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/stats|operation/getFunctionInstanceStats?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`stats`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/stats|operation/getFunctionStats?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

Trigger a function

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

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`trigger`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

$ 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)

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/trigger|operation/triggerFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`putstate`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/state/:key|operation/putFunctionState?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>

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.

<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java Admin API","value":"Java Admin API"}]}>
<TabItem value="Admin CLI">

Use the [`querystate`](/tools/pulsar-admin/) subcommand. 

**Example**

```shell

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

```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/state/:key|operation/getFunctionState?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java Admin API">

```java

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

```

</TabItem>

</Tabs>