Publishes a message to an MQTT topic
publish, MQTT, IOT
In the list below, the names of required properties appear in bold. Any other properties (not in bold) are considered optional. The table also indicates any default values, and whether a property supports the NiFi Expression Language.
Display Name | API Name | Default Value | Allowable Values | Description |
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Broker URI | Broker URI | The URI(s) to use to connect to the MQTT broker (e.g., tcp://localhost:1883). The 'tcp', 'ssl', 'ws' and 'wss' schemes are supported. In order to use 'ssl', the SSL Context Service property must be set. When a comma-separated URI list is set (e.g., tcp://localhost:1883,tcp://localhost:1884), the processor will use a round-robin algorithm to connect to the brokers on connection failure. Supports Expression Language: true (will be evaluated using variable registry only) | ||
MQTT Specification Version | MQTT Specification Version | v3 AUTO |
| The MQTT specification version when connecting with the broker. See the allowable value descriptions for more details. |
Username | Username | Username to use when connecting to the broker Supports Expression Language: true (will be evaluated using variable registry only) | ||
Password | Password | Password to use when connecting to the broker Sensitive Property: true | ||
SSL Context Service | SSL Context Service | Controller Service API: SSLContextService Implementations: StandardSSLContextService StandardRestrictedSSLContextService | The SSL Context Service used to provide client certificate information for TLS/SSL connections. | |
Session state | Session state | Clean Session |
| Whether to start a fresh or resume previous flows. See the allowable value descriptions for more details. |
Session Expiry Interval | Session Expiry Interval | 24 hrs | After this interval the broker will expire the client and clear the session state. This Property is only considered if all of the following conditions are met:
| |
Client ID | Client ID | MQTT client ID to use. If not set, a UUID will be generated. Supports Expression Language: true (will be evaluated using variable registry only) | ||
Topic | Topic | The topic to publish the message to. Supports Expression Language: true (will be evaluated using flow file attributes and variable registry) | ||
Retain Message | Retain Message | Whether or not the retain flag should be set on the MQTT message. Supports Expression Language: true (will be evaluated using flow file attributes and variable registry) | ||
Quality of Service (QoS) | Quality of Service(QoS) | The Quality of Service (QoS) to send the message with. Accepts three values '0', '1' and '2'; '0' for 'at most once', '1' for 'at least once', '2' for 'exactly once'. Expression language is allowed in order to support publishing messages with different QoS but the end value of the property must be either '0', '1' or '2'. Supports Expression Language: true (will be evaluated using flow file attributes and variable registry) | ||
Record Reader | record-reader | Controller Service API: RecordReaderFactory Implementations: CEFReader SyslogReader ReaderLookup ProtobufReader Syslog5424Reader CSVReader GrokReader WindowsEventLogReader ScriptedReader AvroReader ParquetReader JsonPathReader ExcelReader JsonTreeReader YamlTreeReader XMLReader | The Record Reader to use for parsing the incoming FlowFile into Records. | |
Record Writer | record-writer | Controller Service API: RecordSetWriterFactory Implementations: JsonRecordSetWriter RecordSetWriterLookup AvroRecordSetWriter XMLRecordSetWriter FreeFormTextRecordSetWriter CSVRecordSetWriter ParquetRecordSetWriter ScriptedRecordSetWriter | The Record Writer to use for serializing Records before publishing them as an MQTT Message. | |
Message Demarcator | message-demarcator | With this property, you have an option to publish multiple messages from a single FlowFile. This property allows you to provide a string (interpreted as UTF-8) to use for demarcating apart the FlowFile content. This is an optional property ; if not provided, and if not defining a Record Reader/Writer, each FlowFile will be published as a single message. To enter special character such as 'new line' use CTRL+Enter or Shift+Enter depending on the OS. Supports Expression Language: true (will be evaluated using variable registry only) | ||
Connection Timeout (seconds) | Connection Timeout (seconds) | 30 | Maximum time interval the client will wait for the network connection to the MQTT server to be established. The default timeout is 30 seconds. A value of 0 disables timeout processing meaning the client will wait until the network connection is made successfully or fails. | |
Keep Alive Interval (seconds) | Keep Alive Interval (seconds) | 60 | Defines the maximum time interval between messages sent or received. It enables the client to detect if the server is no longer available, without having to wait for the TCP/IP timeout. The client will ensure that at least one message travels across the network within each keep alive period. In the absence of a data-related message during the time period, the client sends a very small "ping" message, which the server will acknowledge. A value of 0 disables keepalive processing in the client. | |
Last Will Message | Last Will Message | The message to send as the client's Last Will. | ||
Last Will Topic | Last Will Topic | The topic to send the client's Last Will to. This Property is only considered if the [Last Will Message] Property has a value specified. | ||
Last Will Retain | Last Will Retain | false |
| Whether to retain the client's Last Will. This Property is only considered if the [Last Will Message] Property has a value specified. |
Last Will QoS Level | Last Will QoS Level | 0 - At most once |
| QoS level to be used when publishing the Last Will Message. This Property is only considered if the [Last Will Message] Property has a value specified. |
Name | Description |
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success | FlowFiles that are sent successfully to the destination are transferred to this relationship. |
failure | FlowFiles that failed to send to the destination are transferred to this relationship. |
Resource | Description |
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MEMORY | An instance of this component can cause high usage of this system resource. Multiple instances or high concurrency settings may result a degradation of performance. |