Apache NiFi - Configuring MiNiFi - C++


The ‘conf’ directory in the root contains a template config.yml document.

This is compatible with the format used with the Java MiNiFi application. Currently, a subset of the configuration is supported and MiNiFi C++ is currently compatible with version 1 of the MiNiFi YAML schema. Additional information on the YAML format for the config.yml and schema versioning can be found in the MiNiFi System Administrator Guide.

Additionally, users can utilize the MiNiFi Toolkit Converter (version 0.0.1 - schema version 1) to aid in creating a flow configuration from a generated template exported from a NiFi instance. The MiNiFi Toolkit Converter tool can be downloaded from http://nifi.apache.org/minifi/download.html under the MiNiFi Toolkit Binaries section. Information on its usage is available at https://nifi.apache.org/minifi/minifi-toolkit.html.

Flow Controller:
    id: 471deef6-2a6e-4a7d-912a-81cc17e3a205
    name: MiNiFi Flow

    - name: GetFile
      id: 471deef6-2a6e-4a7d-912a-81cc17e3a206
      class: org.apache.nifi.processors.standard.GetFile
      max concurrent tasks: 1
      scheduling strategy: TIMER_DRIVEN
      scheduling period: 1 sec
      penalization period: 30 sec
      yield period: 1 sec
      run duration nanos: 0
      auto-terminated relationships list:
          Input Directory: /tmp/getfile
          Keep Source File: true

    - name: TransferFilesToRPG
      id: 471deef6-2a6e-4a7d-912a-81cc17e3a207
      source name: GetFile
      source id: 471deef6-2a6e-4a7d-912a-81cc17e3a206
      source relationship name: success
      destination id: 471deef6-2a6e-4a7d-912a-81cc17e3a204
      max work queue size: 0
      max work queue data size: 1 MB
      flowfile expiration: 60 sec

Remote Processing Groups:
    - name: NiFi Flow
      id: 471deef6-2a6e-4a7d-912a-81cc17e3a208
      url: http://localhost:8080/nifi
      timeout: 30 secs
      yield period: 10 sec
      Input Ports:
          - id: 471deef6-2a6e-4a7d-912a-81cc17e3a204
            name: From Node A
            max concurrent tasks: 1

SiteToSite Security Configuration

in minifi.properties

enable tls

if you want to enable client certificate base authorization
setup the client certificate and private key PEM files
setup the client private key passphrase file
setup the client CA certificate file

if you do not want to enable client certificate base authorization

You have the option of specifying an SSL Context Service definition for the RPGs instead of the properties above. This will link to a corresponding SSL Context service defined in the flow.

To do this specify the SSL Context Service Property in your RPGs and link it to a defined controller service. If you do not take this approach the options, above, will be used for TCP and secure HTTPS communications.

Remote Processing Groups:
- name: NiFi Flow
  id: 2438e3c8-015a-1000-79ca-83af40ec1998
  timeout: 30 secs
  yield period: 5 sec
  Input Ports:
      - id: 2438e3c8-015a-1000-79ca-83af40ec1999
        name: fromnifi
        max concurrent tasks: 1
            SSL Context Service: SSLServiceName
  Output Ports:
      - id: ac82e521-015c-1000-2b21-41279516e19a
        name: tominifi
        max concurrent tasks: 2
	SSL Context Service: SSLServiceName
Controller Services:
- name: SSLServiceName
  id: 2438e3c8-015a-1000-79ca-83af40ec1974
  class: SSLContextService
      Client Certificate: <client cert path>
      Private Key: < private key path > 
      Passphrase: <passphrase path or passphrase>
      CA Certificate: <CA cert path>

HTTP SiteToSite Configuration

To enable HTTPSiteToSite globally you must set the following flag to true.


To enable HTTPSiteToSite for a remote process group. Remote Processing Groups: - name: NiFi Flow transport protocol: HTTP

HTTP SiteToSite Proxy Configuration

To enable HTTP Proxy for a remote process group.

Remote Processing Groups:
- name: NiFi Flow
  transport protocol: HTTP
  proxy host: localhost
  proxy port: 8888
  proxy user:
  proxy password:

Command and Control Configuration

Please see the C2 readme for more informatoin

Configuring Repository storage locations

Persistent repositories, such as the Flow File repository, use a configurable path to store data. The repository locations and their defaults are defined below. By default the MINIFI_HOME env variable is used. If this is not specified we extrapolate the path and use the root installation folder. You may specify your own path in place of these defaults.

 in minifi.properties

Configuring Volatile and NO-OP Repositories

Each of the repositories can be configured to be volatile ( state kept in memory and flushed upon restart ) or persistent. Currently, the flow file and provenance repositories can persist to RocksDB. The content repository will persist to the local file system if a volatile repo is not configured.

To configure the repositories:

 in minifi.properties
 # For Volatile Repositories:

 # configuration options
 # maximum number of entries to keep in memory
 # maximum number of bytes to keep in memory, also limited by option above

 # maximum number of entries to keep in memory
 # maximum number of bytes to keep in memory, also limited by option above

 # maximum number of entries to keep in memory
 # maximum number of bytes to keep in memory, also limited by option above
 # limits locking for the content repository
 # For NO-OP Repositories:


Systems that have limited memory must be cognizant of the options above. Limiting the max count for the number of entries limits memory consumption but also limits the number of events that can be stored. If you are limiting the amount of volatile content you are configuring, you may have excessive session rollback due to invalid stream errors that occur when a claim cannot be found.

The content repository has a default option for “minimal.locking” set to true. This will attempt to use lock free structures. This may or may not be optimal as this requires additional additional searching of the underlying vector. This may be optimal for cases where max.count is not excessively high. In cases where object permanence is low within the repositories, minimal locking will result in better performance. If there are many processors and/or timing is such that the content repository fills up quickly, performance may be reduced. In all cases a locking cache is used to avoid the worst case complexity of O(n) for the content repository; however, this caching is more heavily used when “minimal.locking” is set to false.

Provenance Reporter

Add Provenance Reporting to config.yml
Provenance Reporting:
  scheduling strategy: TIMER_DRIVEN
  scheduling period: 1 sec
  url: http://localhost:8080/nifi
  port uuid: 471deef6-2a6e-4a7d-912a-81cc17e3a204
  batch size: 100

REST API access

Configure REST API user name and password

if you want to enable client certificate

UID generation

MiNiFi needs to generate many unique identifiers in the course of operations. There are a few different uid implementations available that can be configured in minifi-uid.properties.

Implementation for uid generation can be selected using the uid.implementation property values:

  1. time - use uuid_generate_time (default option if the file or property value is missing or invalid)
  2. random - use uuid_generate_random
  3. uuid_default - use uuid_generate (will attempt to use uuid_generate_random and fall back to uuid_generate_time if no high quality randomness is available)
  4. minifi_uid - use custom uid algorthim

If minifi_uuid is selected MiNiFi will use a custom uid algorthim consisting of first N bits device identifier, second M bits as bottom portion of a timestamp where N + M = 64, the last 64 bits is an atomic incrementor.

This is faster than the random uuid generator and encodes the device id and a timestamp into every value, making tracing of flowfiles, etc easier.

It does require more configuration. uid.minifi.device.segment.bits is used to specify how many bits at the beginning to reserve for the device identifier. It also puts a limit on how many distinct devices can be used. With the default of 16 bits, there are a maximum of 65,535 unique device identifiers that can be used. The 48 bit timestamp won‘t repeat for almost 9,000 years. With 24 bits for the device identifier, there are a maximum of 16,777,215 unique device identifiers and the 40 bit timestamp won’t repeat for about 35 years.

Additionally, a unique hexadecimal uid.minifi.device.segment should be assigned to each MiNiFi instance.

Controller Services

If you need to reference a controller service in your config.yml file, use the following template. In the example, below, ControllerServiceClass is the name of the class defining the controller Service. ControllerService1 is linked to ControllerService2, and requires the latter to be started for ControllerService1 to start.

Controller Services:
  - name: ControllerService1
    id: 2438e3c8-015a-1000-79ca-83af40ec1974
  	class: ControllerServiceClass
      Property one: value
      Linked Services:
        - value: ControllerService2
  - name: ControllerService2
    id: 2438e3c8-015a-1000-79ca-83af40ec1992
  	class: ControllerServiceClass

Linux Power Manager Controller Service

The linux power manager controller service can be configured to monitor the battery level and status ( discharging or charging ) via the following configuration. Simply provide the capacity path and status path along with your threshold for the trigger and low battery alarm and you can monitor your battery and throttle the threadpools within MiNiFi C++. Note that the name is identified must be ThreadPoolManager.

Controller Services:
- name: ThreadPoolManager
  id: 2438e3c8-015a-1000-79ca-83af40ec1888
  class: LinuxPowerManagerService
      Battery Capacity Path: /path/to/battery/capacity
      Battery Status Path: /path/to/battery/status
      Trigger Threshold: 90
      Low Battery Threshold: 50
      Wait Period: 500 ms

MQTT Controller service

The MQTTController Service can be configured for MQTT connectivity and provide that capability to your processors when MQTT is built.

Controller Services:
- name: mqttservice
  id: 294491a38-015a-1000-0000-000000000001
  class: MQTTContextService
      Broker URI: localhost:1883
	    Client ID: client ID
      Quality of Service: 2

Network Prioritizer Controller Service

The network prioritizer controller service can be configured to manage prioritizing and binding to specific network interfaces. Linked Services, can be used as a prioritized list to create a disjunction among multiple networking prioritizers. This allows you to create classes with different configurations that create multiple prioritizations. Max Throughput is the maximum throughput in bytes per second. Max Payload is the maximum number of bytes supported by that prioritizer. If a prioritizer is configured with the option “Default Prioritizer: true,” then all socket communications will use that default prioritizer.

In the configuration below there are two classes defined under “NetworkPrioritizerService”, one class “NetworkPrioritizerService2” defines en0, and en1. If en0 is down at any point, then en1 will be given priority before resorting to en2 and en3 of “NetworkPrioritizerService3”. If the throughput for “NetworkPrioritizerService2” exceeds the defined throughput or the max payload of 1024, then “NetworkPrioritizerService3” will be used. If Max Payload and Max Throughput are not defined, then they will not be limiting factors. As of release, 0.5.0, Max Payload will only be used for processors that custom implement that feature. RPGs will not support max payloads until 0.6.0. Additionally, since connection queues aren‘t prioritized, you must have a live connection for your data to send it. Since connection queues can’t be re-prioritized, this can create a starvation problem.┬áThe configuration is required to account for this.

Controller Services:

  • name: NetworkPrioritizerService id: 2438e3c8-015a-1000-79ca-83af40ec1883 class: NetworkPrioritizerService Properties: Linked Services: NetworkPrioritizerService2,NetworkPrioritizerService3
  • name: NetworkPrioritizerService2 id: 2438e3c8-015a-1000-79ca-83af40ec1884 class: NetworkPrioritizerService Properties: Network Controllers: en0,en1 Max Throughput: 1,024,1024 Max Payload: 1024
  • name: NetworkPrioritizerService3 id: 2438e3c8-015a-1000-79ca-83af40ec1884 class: NetworkPrioritizerService Properties: Network Controllers: en2,en3 Max Throughput: 1,024,1024 Max Payload: 1,024,1024