> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Manage Functions

StreamNative Cloud enables you to manage Pulsar Functions by using a variety of tools, including `snctl`, `pulsarctl`, `pulsar-admin`, `REST API`, and `Terraform`.

<Note title="Note">
  If you want to update or delete functions using `snctl`, `pulsarctl` or `pulsar-admin`, make sure you have set up your client tool. For more information, see [set up client tools](/cloud/process/pulsar-functions/function-setup#set-up-client-tools).
</Note>

## Update a function

When you want to modify configurations or update resources for functions, you can update functions using multiple tools.

The following example shows how to update the parallelism of the Java exclamation function `exclamation` to `2` using different tools.

<Tabs>
  <Tab title="snctl">
    ```bash theme={null}
    snctl pulsar admin functions update \
    --name exclamation \
    --parallelism 2
    ```

    You should see the following output:

    ```bash theme={null}
    Updated successfully
    ```

    And you can further check the status:

    ```bash theme={null}
    snctl pulsar admin functions status --name exclamation

    {
      "numInstances": 2,
      "numRunning": 2,
      "instances": [
        {
          "instanceId": 0,
          "status": {
            "running": true,
            "error": "",
            "numRestarts": 0,
            "numReceivedFromSource": 1799,
            "numSystemExceptions": 0,
            "latestSystemExceptions": [],
            "numSourceExceptions": 0,
            "latestSourceExceptions": [],
            "numWritten": 1799,
            "lastReceivedTime": 1693946327331,
            "workerId": "test"
          }
        },
        {
          "instanceId": 1,
          "status": {
            "running": true,
            "error": "",
            "numRestarts": 0,
            "numReceivedFromSource": 689,
            "numSystemExceptions": 0,
            "latestSystemExceptions": [],
            "numSourceExceptions": 0,
            "latestSourceExceptions": [],
            "numWritten": 689,
            "lastReceivedTime": 1693946327129,
            "workerId": "test"
          }
        }
      ]
    }

    ```
  </Tab>

  <Tab title="pulsarctl">
    ```bash theme={null}
    pulsarctl functions update \
    --name exclamation \
    --parallelism 2
    ```

    You should see the following output:

    ```bash theme={null}
    Updated successfully
    ```

    And you can further check the status:

    ```bash theme={null}
    pulsarctl functions status --name exclamation

    {
      "numInstances": 2,
      "numRunning": 2,
      "instances": [
        {
          "instanceId": 0,
          "status": {
            "running": true,
            "error": "",
            "numRestarts": 0,
            "numReceivedFromSource": 1799,
            "numSystemExceptions": 0,
            "latestSystemExceptions": [],
            "numSourceExceptions": 0,
            "latestSourceExceptions": [],
            "numWritten": 1799,
            "lastReceivedTime": 1693946327331,
            "workerId": "test"
          }
        },
        {
          "instanceId": 1,
          "status": {
            "running": true,
            "error": "",
            "numRestarts": 0,
            "numReceivedFromSource": 689,
            "numSystemExceptions": 0,
            "latestSystemExceptions": [],
            "numSourceExceptions": 0,
            "latestSourceExceptions": [],
            "numWritten": 689,
            "lastReceivedTime": 1693946327129,
            "workerId": "test"
          }
        }
      ]
    }

    ```
  </Tab>

  <Tab title="pulsar-admin">
    ```bash theme={null}
    pulsar-admin \
        --admin-url "${WEB_SERVICE_URL}" \
        --auth-plugin org.apache.pulsar.client.impl.auth.oauth2.AuthenticationOAuth2 \
        --auth-params '{"privateKey":"file:///YOUR-KEY-FILE-PATH",
            "issuerUrl":"https://auth.streamnative.cloud/",
            "audience":"urn:sn:pulsar:${orgName}:${instanceName}}'
    functions update \
    --name exclamation \
    --parallelism 2
    ```

    Replace the placeholder variables with the actual values, which you can get when you set up client tools.

    * `admin-url`: the HTTP service URL of your Pulsar cluster.
    * `private_key`: the path to the downloaded OAuth2 key file.
    * `audience`: the [Uniform Resource Name (URN)](/cloud/references/glossary#uniform-resource-name-urn), which is a combination of the `urn:sn:pulsar`, your organization name, and your Pulsar instance name.
      * `${orgName}`: the name of your [organization](/cloud/references/glossary#organization).
      * `${instanceName}`: the name of your [instance](/cloud/references/glossary#instance).

    You should see the following output:

    ```bash theme={null}
    Updated successfully
    ```

    And you can further check the status:

    ```bash theme={null}
    pulsar-admin functions status --name test
    {
      "numInstances" : 2,
      "numRunning" : 2,
      "instances" : [ {
        "instanceId" : 0,
        "status" : {
          "running" : true,
          "error" : "",
          "numRestarts" : 0,
          "numReceivedFromSource" : 1287,
          "numSystemExceptions" : 0,
          "latestSystemExceptions" : [ ],
          "numSourceExceptions" : 0,
          "latestSourceExceptions" : [ ],
          "numWritten" : 1287,
          "lastReceivedTime" : 1693946605095,
          "workerId" : "test"
        }
      }, {
        "instanceId" : 1,
        "status" : {
          "running" : true,
          "error" : "",
          "numRestarts" : 0,
          "numReceivedFromSource" : 909,
          "numSystemExceptions" : 0,
          "latestSystemExceptions" : [ ],
          "numSourceExceptions" : 0,
          "latestSourceExceptions" : [ ],
          "numWritten" : 909,
          "lastReceivedTime" : 1693946605023,
          "workerId" : "test"
        }
      } ]
    }
    ```
  </Tab>

  <Tab title="Terraform">
    To update the submitted function, you only need to update the Terraform file and then call the following command.

    ```bash theme={null}
    terraform apply
    ```

    You should see something like following:

    ```bash theme={null}
    pulsar_function.function-1: Refreshing state... [id=public/default/function1]

    Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
      ~ update in-place

    Terraform will perform the following actions:

      # pulsar_function.function-1 will be updated in-place
      ~ resource "pulsar_function" "function-1" {
          ~ custom_runtime_options          = jsonencode(
              ~ {
                  - clusterName         = "oxia-test"
                  - enableStateStore    = false
                  - inputTypeClassName  = "java.lang.String"
                  - logTopicAgent       = "runtime"
                  - managed             = true
                  - maxReplicas         = 0
                  - outputTypeClassName = "java.lang.String"
                  - runnerImage         = "streamnative/pulsar-functions-sn-java-runner:3.1.0.4"
                  - serviceAccountName  = "oxia-test-function-pulsarcluster"
                    # (1 unchanged attribute hidden)
                }
            )
          ~ disk_mb                         = 10240 -> 128
            id                              = "public/default/function1"
            name                            = "function1"
          ~ parallelism                     = 1 -> 2
          ~ ram_mb                          = 140 -> 128
            # (21 unchanged attributes hidden)
        }

    Plan: 0 to add, 1 to change, 0 to destroy.

    Do you want to perform these actions?
      Terraform will perform the actions described above.
      Only 'yes' will be accepted to approve.

      Enter a value:
    ```

    Enter yes and then you should get:

    ```bash theme={null}
    pulsar_function.function-1: Modifying... [id=public/default/function1]
    pulsar_function.function-1: Modifications complete after 0s [id=public/default/function1]

    Apply complete! Resources: 0 added, 1 changed, 0 destroyed.
    ```
  </Tab>

  <Tab title="REST API">
    For the REST API you can simply call CURL to update your function.

    ```bash theme={null}
      curl -X POST ${WEB_SERVICE_URL}/admin/v3/functions/public/default/${FUNCTION_NAME} \
      -H 'Authorization: Bearer ${TOKEN}' \
      -H "Content-Type: multipart/form-data" \
      -F 'functionConfig={"name": "${FUNCTION_NAME}", "parallelism": 2};type=application/json' \
      -F 'url=function://public/default/${FUNCTION_NAME}@${FUNCTION_VERSION}' \
    ```

    <Note title="Note">
      Replace the placeholder variables with the actual values that you can get when [setting up client tools](/cloud/process/pulsar-functions/function-setup#set-up-client-tools).

      * `WEB_SERVICE_URL`: the HTTPS service URL of your Pulsar cluster.
      * `TOKEN`: a valid token to interact with your Pulsar cluster.
      * `FUNCTION_NAME`: the name of your function.
      * `FUNCTION_VERSION`: the version of your function you want to deploy e.g. 1.12.
    </Note>
  </Tab>
</Tabs>

## Delete a function

The following example shows how to delete the Java exclamation function `exclamation` using different tools.

<Tabs>
  <Tab title="snctl">
    To delete the function `exclamation`, use the following command.

    ```bash theme={null}
    snctl pulsar admin functions delete --tenant public --namespace default --name exclamation
    ```

    You should see the following output:

    ```bash theme={null}
    Deleted exclamation successfully
    ```

    If you want to verify whether the function has been deleted successfully, run the following command.

    ```bash theme={null}
    snctl pulsar admin functions get --tenant public --namespace default --name exclamation
    ```

    You should see the following output:

    ```bash theme={null}
    [✖]  code: 500 reason: failed to perform the request: responseCode: 404, responseMessage: functions.compute.functionmesh.io "exclamation-XXXXX" not found
    ```
  </Tab>

  <Tab title="pulsarctl">
    To delete the function `exclamation`, use the following command.

    ```bash theme={null}
    pulsarctl functions delete --tenant public --namespace default --name exclamation
    ```

    You should see the following output:

    ```bash theme={null}
    Deleted exclamation successfully
    ```

    If you want to verify whether the function has been deleted successfully, run the following command.

    ```bash theme={null}
    pulsarctl functions get --tenant public --namespace default --name exclamation
    ```

    You should see the following output:

    ```bash theme={null}
    [✖]  code: 500 reason: failed to perform the request: responseCode: 404, responseMessage: functions.compute.functionmesh.io "exclamation-XXXXX" not found
    ```
  </Tab>

  <Tab title="pulsar-admin">
    To delete the function `exclamation`, run the following command.

    ```bash theme={null}
    ./bin/pulsar-admin functions delete  --tenant public --namespace default --name exclamation
    ```

    You should see the following output:

    ```bash theme={null}
    Delete exclamation successfully
    ```

    To verify the function has been deleted, run the following command.

    ```bash theme={null}
    ./bin/pulsar-admin functions get --tenant public --namespace default --name exclamation
    ```

    You should see the following output:

    ```bash theme={null}
    failed to perform the request: responseCode: 404, responseMessage: functions.compute.functionmesh.io "exclamation-XXXXX" not found
    ```
  </Tab>

  <Tab title="Terraform">
    To delete the function `exclamation` with terraform, run the following command and type `yes` on the prompt.

    ```bash theme={null}
    terraform destroy
    ```

    You should see the following output:

    ```bash theme={null}
    pulsar_function.function-1: Refreshing state... [id=public/default/function1]

    Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
      - destroy

    Terraform will perform the following actions:

      # pulsar_function.function-1 will be destroyed
      - resource "pulsar_function" "function-1" {
          - auto_ack                        = true -> null
          - classname                       = "org.apache.pulsar.functions.api.examples.ExclamationFunction" -> null
          - cleanup_subscription            = true -> null
          - cpu                             = 0.5 -> null
          - custom_runtime_options          = jsonencode(
                {
                  - clusterName         = "oxia-test"
                  - enableStateStore    = false
                  - env                 = {
                      - HELLO = "WORLD"
                    }
                  - inputTypeClassName  = "java.lang.String"
                  - logTopicAgent       = "runtime"
                  - managed             = true
                  - maxReplicas         = 0
                  - outputTypeClassName = "java.lang.String"
                  - runnerImage         = "streamnative/pulsar-functions-sn-java-runner:3.1.0.4"
                  - serviceAccountName  = "oxia-test-function-pulsarcluster"
                }
            ) -> null
          - dead_letter_topic               = "public/default/dlt" -> null
          - disk_mb                         = 10240 -> null
          - forward_source_message_property = true -> null
          - id                              = "public/default/function1" -> null
          - inputs                          = [
              - "persistent://public/default/test-java-input",
            ] -> null
          - jar                             = "function://public/default/exclamation@v0.1" -> null
          - log_topic                       = "public/default/lt" -> null
          - max_message_retries             = 100 -> null
          - name                            = "function1" -> null
          - namespace                       = "default" -> null
          - output                          = "persistent://public/default/test-java-output" -> null
          - parallelism                     = 2 -> null
          - processing_guarantees           = "ATLEAST_ONCE" -> null
          - ram_mb                          = 140 -> null
          - retain_key_ordering             = true -> null
          - retain_ordering                 = false -> null
          - secrets                         = jsonencode(
                {
                  - SECRET1 = {
                      - key  = "hello"
                      - path = "sectest"
                    }
                }
            ) -> null
          - skip_to_latest                  = true -> null
          - subscription_name               = "test-sub" -> null
          - subscription_position           = "Latest" -> null
          - tenant                          = "public" -> null
          - timeout_ms                      = 6666 -> null
        }

    Plan: 0 to add, 0 to change, 1 to destroy.

    Do you really want to destroy all resources?
      Terraform will destroy all your managed infrastructure, as shown above.
      There is no undo. Only 'yes' will be accepted to confirm.

      Enter a value:
    ```

    Enter yes and you will get:

    ```bash theme={null}
    pulsar_function.function-1: Destroying... [id=public/default/function1]
    pulsar_function.function-1: Destruction complete after 0s

    Destroy complete! Resources: 1 destroyed.
    ```
  </Tab>
</Tabs>

## What’s next?

* Learn how to [configure stateful functions](/cloud/process/pulsar-functions/function-state).
* Learn how to [monitor functions](/cloud/process/pulsar-functions/function-monitoring).
* Reference [common configurations](/cloud/process/pulsar-functions/function-config).