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

# MQTT

> Connect Arc to an MQTT broker to publish messages and subscribe to topics using the Message Queuing Telemetry Transport protocol.

export const TlsClientAuthentication = () => <>
    <p><em>Settings related to client authentication when two-way TLS authentication is required.</em></p>

    <table>
      <thead>
        <tr><th>Setting</th><th>Description</th></tr>
      </thead>
      <tbody>
        <tr>
          <td><strong>Private Certificate</strong></td>
          <td>The private certificate presented during TLS client authentication.</td>
        </tr>
        <tr>
          <td><strong>Certificate Password</strong></td>
          <td>The password required to access the TLS client certificate.</td>
        </tr>
      </tbody>
    </table>
  </>;

export const ServiceLogs = () => <p>The <strong>Logs</strong> tab lists the service logs generated by this connector. Each row represents a log file and shows its date modified, file name, size, and status. Use the search bar or the status filter to find a specific log, click a file name to preview or download it, or click <strong>Download All Logs</strong> to download all of them as a single zip file.</p>;

export const SlasTab = ({siteName = "CData Arc"}) => <>
    <p><em>Settings related to configuring Service Level Agreements (SLAs).</em></p>
    <p>
      SLAs enable you to configure the volume you expect connectors in your flow to send or receive, and to set the time frame in which you expect that volume to be met. {siteName} sends emails to warn the user when an SLA is not met, and marks the SLA as <em>At Risk</em>, which means that if the SLA is not met soon, it will be marked as <em>Violated</em>. This gives the user an opportunity to step in and determine the reasons the SLA is not being met, and to take appropriate actions. If the SLA is still not met at the end of the at-risk time period, the SLA is marked as violated, and the user is notified again.
    </p>
    <p>
      To define an SLA, toggle <strong>Expected Volume</strong> on, then click the <strong>Settings</strong> tab.
    </p>
    <img src="/public/images/sla_empty.png" alt="SLA Empty" />
    <ul>
      <li>If your connector has separate send and receive actions, use the radio buttons to specify which direction the SLA pertains to.</li>
      <li>In the <strong>Expect at least</strong> portion of the window:
        <ul>
          <li>Set the minimum number of transactions you expect to be processed (the volume)</li>
          <li>Use the <strong>Every</strong> fields to specify the time frame</li>
          <li>Indicate when the SLA should go into effect. If you choose <strong>Starting on</strong>, complete the date and time fields.</li>
          <li>Check the boxes for the days of the week that you want the SLA to be in effect. Use the dropdown to choose <strong>Everyday</strong> if necessary.</li>
        </ul>
      </li>
      <li>In the <strong>Set status to 'At Risk'</strong> portion of the window, specify when the SLA should be marked as at risk.
        <ul>
          <li>By default, notifications are not sent until an SLA is in violation. To change that, check <strong>Send an 'At Risk' notification</strong>.</li>
        </ul>
      </li>
    </ul>
    <p>
      The following example shows an SLA configured for a connector that expects to receive 1000 files every day Monday-Friday. An at-risk notification is sent 1 hour before the end of the time period if the 1000 files have not been received.
    </p>
    <img src="/public/images/sla_defined.png" alt="SLA Configuration Example" />
    <Note>
      You can turn off SLA alerts if necessary. This can be useful during maintenance windows. Click <strong>Settings</strong> on the navbar, then navigate to <strong>Alerts &gt; General Alerts</strong>. Click the tablet and pencil icon to edit, and uncheck the <strong>SLA Alerts</strong> setting.
    </Note>
  </>;

export const AlertsTab = ({siteNameShort = "Arc"}) => <>
    <p><em>Settings related to configuring alerts.</em></p>
    <p>
      Before you can execute Service Level Agreements (SLAs), you need to set up email alerts for notifications. By default, {siteNameShort} uses the global settings on the <a href="/26.3/cloud/en/getting-started/administration/settings/alerts">Alerts</a> tab. To use other settings for this connector, toggle <strong>Override global setting</strong> on.
    </p>
    <p>
      By default, error alerts are enabled, which means that emails are sent whenever there is an error. To turn them off, uncheck the <strong>Enable</strong> checkbox.
    </p>
    <p>
      Enter a <strong>Subject</strong> (mandatory). Check <strong>Allow {siteNameShort}Script in Subject</strong> to use {siteNameShort}Script in the <strong>Subject</strong> field. When you select this, the <strong>{siteNameShort}Script Editor</strong> button appears (<img src="/public/images/rest_arcscript_editor.png" alt="arcscript editor button" style={{
  display: 'inline',
  verticalAlign: 'middle',
  margin: 0
}} />).
    </p>
    <p>
      Optionally, enter a comma-separated list of <strong>Recipient</strong> emails.
    </p>
  </>;

export const MiscConnector = () => <>
    <p><em>Miscellaneous settings are for specific use cases.</em></p>
    <table>
      <thead>
        <tr>
          <th>Setting</th>
          <th>Description</th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <td><strong>Other Settings</strong></td>
          <td>Enables you to configure hidden connector settings in a semicolon-separated list (for example, <code>setting1=value1;setting2=value2</code>). Normal connector use cases and functionality should not require the use of these settings.</td>
        </tr>
      </tbody>
    </table>
  </>;

export const Logging = () => <>
    <p><em>Settings that govern the creation and storage of logs.</em></p>
    <table>
      <thead>
        <tr>
          <th>Setting</th>
          <th>Description</th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <td><strong>Log Level</strong></td>
          <td>The verbosity of logs generated by the connector. When you request support, set this to <strong>Debug</strong>.</td>
        </tr>
        <tr>
          <td><strong>Log Subfolder Scheme</strong></td>
          <td>Instructs the connector to group files in the Logs folder according to the selected interval. The <strong>Weekly</strong> option (which is the default) instructs the connector to create a new subfolder each week and store all logs for the week in that folder. Leaving this setting blank tells the connector to save all logs directly in the Logs folder. For connectors that process many transactions, using subfolders helps keep logs organized and improves performance.</td>
        </tr>
        <tr>
          <td><strong>Log Messages</strong></td>
          <td>Check this to have the log entry for a processed file include a copy of the file itself. If you disable this, you might not be able to download a copy of the file from the <strong>Transactions</strong> tab.</td>
        </tr>
      </tbody>
    </table>
  </>;

export const MacrosExamples = ({extraMacros = []}) => <>
    <p>
      Some macros, such as %Ext% and %ShortDate%, do not require an argument, but others do. All
      macros that take an argument use the following syntax: <code>%Macro:argument%</code>
    </p>

    <p>Here are some examples of the macros that take an argument:</p>

    <ul>
      <li>%Header:headername%: Where <code>headername</code> is the name of a header on a message.</li>
      <li>%Header:mycustomheader% resolves to the value of the <code>mycustomheader</code> header set on the input message.</li>
      <li>%Header:ponum% resolves to the value of the <code>ponum</code> header set on the input message.</li>
      <li>%RegexFilename:pattern%: Where <code>pattern</code> is a regex pattern. For example, <code>%RegexFilename:^([\w][A-Za-z]+)%</code> matches and resolves to the first word in the filename and is case insensitive (<code>test_file.xml</code> resolves to <code>test</code>).</li>
      <li>%Vault:vaultitem%: Where <code>vaultitem</code> is the name of an item in the <a href="/26.3/cloud/en/getting-started/administration/settings/global-settings-vault">vault</a>. For example, <code>%Vault:companyname%</code> resolves to the value of the <code>companyname</code> item stored in the vault.</li>
      <li>%DateFormat:format%: Where <code>format</code> is an accepted date format (see <a href="/26.3/cloud/en/scripting/value-formatters/date-formatters#sample-date-formats">Sample Date Formats</a> for details). For example, <code>%DateFormat:yyyy-MM-dd-HH-mm-ss-fff%</code> resolves to the date and timestamp on the file.</li>
      {extraMacros.filter(item => item.example).map(item => <li key={`ex-${item.name}`}>{item.example}</li>)}
    </ul>

    <p>You can also create more sophisticated macros, as shown in the following examples:</p>

    <ul>
      <li>Combining multiple macros in one filename: <code>%DateFormat:yyyy-MM-dd-HH-mm-ss-fff%%EXT%</code></li>
      <li>Including text outside of the macro: <code>MyFile_%DateFormat:yyyy-MM-dd-HH-mm-ss-fff%</code></li>
      <li>Including text within the macro: <code>%DateFormat:'DateProcessed-'yyyy-MM-dd_'TimeProcessed-'HH-mm-ss%</code></li>
    </ul>
  </>;

export const MacrosTable = ({siteName = "CData Arc", extraMacros = []}) => <>
    <p>
      Using macros in file naming strategies can enhance organizational efficiency and contextual
      understanding of data. By incorporating macros into filenames, you can dynamically include
      relevant information such as identifiers, timestamps, and header information, providing
      valuable context to each file.
    </p>

    <p>{siteName} supports these macros, which all use the following syntax: <code>%Macro%</code>.</p>

    <table>
      <thead>
        <tr><th>Macro</th><th>Description</th></tr>
      </thead>
      <tbody>
        <tr><td>ConnectorID</td><td>Evaluates to the ConnectorID of the connector.</td></tr>
        <tr><td>ConnectorName</td><td>Evaluates to the name of the connector. Enables you to include the connection name in file names or paths: for example, to tag backup files by which database connection produced them.</td></tr>
        <tr><td>Ext</td><td>Evaluates to the file extension of the file currently being processed by the connector.</td></tr>
        <tr><td>Filename</td><td>Evaluates to the filename (extension included) of the file currently being processed by the connector.</td></tr>
        <tr><td>FilenameNoExt</td><td>Evaluates to the filename (without the extension) of the file currently being processed by the connector.</td></tr>
        <tr><td>MessageId</td><td>Evaluates to the MessageId of the message being output by the connector.</td></tr>
        <tr><td>RegexFilename:<em>pattern</em></td><td>Applies a RegEx pattern to the filename of the file currently being processed by the connector.</td></tr>
        <tr><td>Header:<em>headername</em></td><td>Evaluates to the value of a targeted header (<code>headername</code>) on the current message being processed by the connector.</td></tr>
        <tr><td>LongDate</td><td>Evaluates to the current datetime of the system in long-handed format (for example, Wednesday, January 24, 2024).</td></tr>
        <tr><td>ShortDate</td><td>Evaluates to the current datetime of the system in a yyyy-MM-dd format (for example, 2024-01-24).</td></tr>
        <tr><td>DateFormat:<em>format</em></td><td>Evaluates to the current datetime of the system in the specified format (<code>format</code>). See <a href="/26.3/cloud/en/scripting/value-formatters/date-formatters#date-formats-with-literal-characters">Sample Date Formats</a> for the available datetime formats.</td></tr>
        <tr><td>Vault:<em>vaultitem</em></td><td>Evaluates to the value of the specified vault item.</td></tr>
        {extraMacros.map(item => <tr key={item.name}>
            <td>{item.name}</td>
            <td>{item.description}</td>
          </tr>)}
      </tbody>
    </table>
  </>;

export const Performance = () => <>
    <p><em>Settings related to the allocation of resources to the connector.</em></p>
    <table>
      <thead>
        <tr>
          <th>Setting</th>
          <th>Description</th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <td><strong>Max Workers</strong></td>
          <td>The maximum number of worker threads consumed from the threadpool to process files on this connector. If set, this overrides the default setting on the <a href="/26.3/cloud/en/getting-started/administration/settings/performance-settings">Performance Settings</a> portion of the <a href="/26.3/cloud/en/getting-started/administration/settings/advanced-settings">Advanced Settings</a> page.</td>
        </tr>
        <tr>
          <td><strong>Max Files</strong></td>
          <td>The maximum number of files sent by each thread assigned to the connector. If set, this overrides the default setting on the <a href="/26.3/cloud/en/getting-started/administration/settings/performance-settings">Performance Settings</a> portion of the <a href="/26.3/cloud/en/getting-started/administration/settings/advanced-settings">Advanced Settings</a> page.</td>
        </tr>
      </tbody>
    </table>
  </>;

export const siteNameShort = "Arc";

export const siteName = "CData Arc";

The OASIS Message Queuing Telemetry Transport (MQTT) connector supports publishing MQTT messages and subscribing to MQTT topics.

## Key Capabilities

* Bidirectional IoT message queuing with multiple QoS levels
* TLS encryption and client certificate authentication with configurable keep-alive intervals
* Topic-based filtering with wildcard support and Last Will message handling

## Overview

Sending data through an MQTT connector publishes the data to the configured topic, and messages that are received on any of the topics that the connector is subscribed to are placed in the **Transactions** tab.

## Connector Configuration

This section contains all of the configurable connector properties.

### Settings Tab

#### Host Configuration

*Settings related to the remote MQTT server connection.*

| Setting                   | Description                                                                                                                                                                                                                                                                                                                      |
| ------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Connector Id**          | The static, unique identifier for the connector.                                                                                                                                                                                                                                                                                 |
| **Connector Type**        | Displays the connector name and a description of what it does.                                                                                                                                                                                                                                                                   |
| **Connector Description** | An optional field to provide a free-form description of the connector and its role in the flow.                                                                                                                                                                                                                                  |
| **Connection**            | A list of available connections. Select an existing connection or click **Create** to add a new one.                                                                                                                                                                                                                             |
| **Action**                | Whether to [Publish](#publishing) messages to a topic on an MQTT broker or [Subscribe](#subscribing) to receive messages from one or more MQTT topic filters.                                                                                                                                                                    |
| **Server Status**         | (Only applicable when **Action** is **Subscribe**) The state of the connector's server: **Active** (the server is running; click **Stop Server** to stop it), **Inactive** (the server is not running; click **Start Server** to start it). To review the logs the server produces while it runs, see the [Logs tab](#logs-tab). |

#### Client Authentication

*Settings related to authenticating against the remote MQTT server.*

| Setting      | Description                                         |
| ------------ | --------------------------------------------------- |
| **Username** | The username credential with which to authenticate. |
| **Password** | The password for the specified username.            |

#### TLS Settings

*Settings related to establishing a secure connection via TLS.*

| Setting                    | Description                                                                                                                                                                        |
| -------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Use TLS**                | Whether the connector should negotiate TLS when connecting to the remote server.                                                                                                   |
| **TLS Server Certificate** | The public certificate used to verify the identity of the remote server when establishing a TLS connection. Set this to **Any Certificate** to implicitly trust the target server. |

#### Publish

*Settings related to publishing MQTT messages.*

| Setting   | Description                                                                                                                                                  |
| --------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Topic** | The topic for the message to publish.                                                                                                                        |
| **QoS**   | The service level for message delivery. Options are: *at most once*, *at least once*, or *exactly once*. See [Publishing](#publishing) for more information. |

#### Subscribe

*Settings related to subscribing to MQTT messages.*

| Setting                  | Description                                                                                                                                                  |
| ------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Enable MQTT Receiver** | Whether the connector should receive MQTT messages.                                                                                                          |
| **Topic Filters**        | A comma-separated list of topics for the connector to subscribe to.                                                                                          |
| **QoS**                  | The service level for message delivery. Options are: *at most once*, *at least once*, or *exactly once*. See [Publishing](#publishing) for more information. |

### Advanced Tab

#### TLS Client Authentication

<TlsClientAuthentication />

#### Advanced Settings

*Settings not included in the previous categories.*

| Setting                 | Description                                                                                                                                                                                                                             |
| ----------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Keep Alive Interval** | The maximum period of inactivity the connector allows before sending a keep-alive packet.                                                                                                                                               |
| **Last Will Message**   | The message that the server should publish in the event of an ungraceful disconnection.                                                                                                                                                 |
| **Last Will Topic**     | The topic of the Last Will Message.                                                                                                                                                                                                     |
| **Republish Interval**  | The number of seconds that the connector waits before republishing unacknowledged messages.                                                                                                                                             |
| **Timeout**             | The length of time (in seconds) the connector waits for a connection response before throwing a timeout error.                                                                                                                          |
| **Local File Scheme**   | A scheme for assigning filenames to messages that are output by the connector. You can use macros in your filenames dynamically to include information such as identifiers and timestamps. For more information, see [Macros](#macros). |

#### Logging

<Logging />

#### Miscellaneous

<MiscConnector />

### Automation Tab

#### Automation Settings

*Settings related to the automatic processing of files by the connector.*

| Setting            | Description                                                                                                                                                                                        |
| ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Send**           | Whether files arriving at the connector are automatically sent as messages to the MQTT server.                                                                                                     |
| **Retry Interval** | The number of minutes before a failed send is retried.                                                                                                                                             |
| **Max Attempts**   | The maximum number of times the connector processes the file. Success is measured based on a successful server acknowledgement. If you set this to 0, the connector retries the file indefinitely. |

#### Performance

<Performance />

### Alerts Tab

<AlertsTab />

### SLAs Tab

<SlasTab />

### Logs Tab

<ServiceLogs />

## Establishing a Connection

At a minimum, set **Remote Host** on the [Settings tab](#settings-tab) to the domain name or IP address of the MQTT server. If you are using a non-standard port, set **Remote Port**. If authentication is required, set **Username** and **Password**.

If you require a secure connection, check **Use TLS**, and optionally set the **TLS Server Certificate** to the server's public certificate, or choose *Any Certificate* to accept any certificate presented by the server. If this field is used improperly, it creates a security risk. Use extreme caution when setting this field.

## Publishing

To publish data, set **Topic** in the [Publish](#publish) section to the topic where the connector should publish messages. **QoS** values range from 0 to 2 and have the following meanings:

* 0 — At most once. The published message is sent once, and if it does not arrive it is lost.
* 1 — At least once. Guarantees that the published message arrives, but there might be duplicates.
* 2 — Exactly once. Guarantees that the published message arrives and that there are no duplicates.

In the [Advanced Settings](#advanced-settings) portion of the Advanced tab, you can set **Republish Interval** to the number of seconds that you want the connector to wait for acknowledgements to messages that require them. If this time elapses without receiving an acknowledgement, the connector republishes the message. Republished messages reuse the packet Id from the original message, and automatically set the Duplicate flag on the message. Specifying a value of 0 for **Republish Interval** prevents the connector from automatically republishing messages.

## Subscribing

In the [Subscribe](#subscribe) section of the settings page, you can check **Enable MQTT Receiver** to indicate that the connector should also receive data. When checked, the connector subscribes to the topics you specify in **Topic Filters**, and incoming messages are automatically placed on the **Transactions** tab, named based on the value specified in **Local File Scheme** in the [Advanced Settings](#advanced-settings) portion of the Advanced tab. By default, the connector names files with the topic and packet Id of the message, using `%topic%_%packetid%.data` as the **Local File Scheme** value.

You can supply a comma-separated list of topic filters that the connector should subscribe to in **Topic Filters**. The following characters have special meanings in a topic filter:

* / — The topic level separator
* \# — The multi-level wildcard (zero or more levels)
* \+ — The single-level wildcard (exactly one level)
* Leading \$ — Denotes a "system topic"

You can use **Last Will Message** and **Last Will Topic** on the Advanced tab to specify the message that the server should publish, and the topic it should publish that message to, in the event of an ungraceful disconnection.

## Macros

<MacrosTable />

### Examples

<MacrosExamples />