Welcome
Runtimes
Descriptions of Link runtime services.
SDK
The LNK programming interface includes language-specific methods and objects that provide common functionality across multiple environments.
C API
The C API enables applications to invoke maps and to develop adapters to use with HCL Link.
Custom adapters
The custom adapters interface makes it possible for users to develop adapters with as much functionality as those provided with the product.
Methods provided by adapter
Connection instance overview
Instances of connection objects are created in the same way as adapter instances. When a new connection is required, a connection instance is created.
Connection instance creation and destruction
The CreateConnectionInstance and DestroyConnectionInstance methods are called to create an instance of the adapter connection object, and to destroy this object.
DestroyConnectionInstance
The DestroyConnectionInstace method cleans up and destroys a connection object.

Introduction
Congratulations on your selection of HCL Link as your data integration solution!
What's new
Learn about the new and changed functions and features in HCL Link version 1.3.2.0.
Release notes
Read the latest release specific information for HCL Link version 1.3.2.0.
System requirements
A complete desciption of the hardware and software requirements for both Windows and Linux systems.
Installation
Everything you need to know to install HCL Link.
Administration
Here you will find the tasks that are required for administration of your HCL Link product.
Projects
A project is a container for HCL Link artifacts.
Services
Service definitions define REST services and the endpoints of a service. This guide provides step-by-step instructions for creating, importing, and managing services using the system interface, following Microsoft standards.
Connectors
This documentation describes the connectors and how they are used.
Packages
Servers
This documentation contains a description of the server groups and servers.
Variables
The variables described here include Configuration variables, flow variables, and cache variables.
Dashboards
A description of HCL Link dashboards, including the Server dashboard and the Kibana dashboard.
Runtimes
Descriptions of Link runtime services.
- REST API
  The REST Runtime provides a REST API used to run maps and flows that have been deployed.
- Flow Command Server
  Deploy a flow from the HCL Link to the local filesystem using Execution flow server definition.
- Map Command Server
  To use the Map Command Server to execute a map, you will prepare the maps for execution.
- SDK
  The LNK programming interface includes language-specific methods and objects that provide common functionality across multiple environments.
  - Link programming interface overview
    The Link programming interface is an object-oriented approach that enables applications to invoke HCL Link maps, thus removing reliance on command lines.
  - C API
    The C API enables applications to invoke maps and to develop adapters to use with HCL Link.
    - C API interface methods overview
      The map, card, and adapter object properties define the properties that can be set for each object. Use the C API interface methods to GET or SET the adapter object properties.
    - Object methods
    - Loading, running, and controlling maps
      There are various methods you can use to load, run, and control maps when you use APIs with HCL Link.
    - Custom adapters
      The custom adapters interface makes it possible for users to develop adapters with as much functionality as those provided with the product.
      - Developing custom adapters
        The custom adapters interface makes it possible for users to develop adapters with as much functionality as those provided with the product.
      - Adapter registration and the library virtual table
        The first step required to develop an adapter is to add the adapter to the adapters.xml registration file.
      - Initializing the adapter
        InitializeLibrary provides an entry point by which any global structures, critical sections, or lists that are required by the adapter can be initialized.
      - Point to adapter methods
        After your adapter is loaded, you call the virtual table (vtable) structure to obtain pointers to the methods.
      - Adapter registration file
        The adapters.xml registration file contains a single tag for each adapter, including a number of attributes to provide information about the adapter.
      - Vtable adapter library
      - Methods provided by adapter
        Methods provided by an adapter
        Various methods must be provided by an adapter.
        Adapter methods used post-instance creation
        After you create an instance of the adapter and connection objects, the map can use these objects to get data, put data, or to listen for events. The adapter virtual table, MPI_ADAPTER_VTABLE, points to a number of methods that are provided by the adapter.
        Adapter instance overview
        When a map executes, there are a number of objects created (for example, map and card). Each card has an associated adapter instance. The adapter instance contains a number of properties that determine the behavior of the adapter. The number and type of these properties are defined through the mpiObjectNewPropColl method.
        Connection instance overview
        Instances of connection objects are created in the same way as adapter instances. When a new connection is required, a connection instance is created.
        Connection instance creation and destruction
        The CreateConnectionInstance and DestroyConnectionInstance methods are called to create an instance of the adapter connection object, and to destroy this object.
        CreateConnectionInstance
        The CreateConnectionInstance method creates a connection object and initializes it.
        DestroyConnectionInstance
        The DestroyConnectionInstace method cleans up and destroys a connection object.
        Connection interface
        The connection interface methods are called to connect to a resource and to control connection pooling.
        Library initialization and termination methods
        The InitializeLibrary and DestroyLibrary custom adapter methods are called to perform one-time initialization tasks and to clean up from these tasks.
        Listener interface
        The Listener interface uses the Listen, CombinedListen, and CompareWatches methods to listen for single or multiple events from the resource.
        Method invocation
        The method invocation examples demonstrate the sequence of calls made to an adapter.
        Source and target interface
        Source and target interface methods are called to get data from a resource, to put data to a resource, and to control a transaction while developing custom adapters.
        Property interface
        The ValidateProperties custom adapter method is called to validate the adapter’s properties.
        C API return codes
        There are three types of C API return codes: success, warning, or error.
      - Additional adapter methods
        There are a number of additional methods that are part of the HCL Link Programming Interface library that are of particular relevance to adapter developers.
      - Passing data to and from maps
        Data is passed between adapters and the engine through stream objects. From the adapter perspective, there is no need to create these stream objects; they are already created when either the Get or Put method is called.
      - Threads, connections, and transactions overview
        It is important to understand how threads, connections, and transactions interact.
  - Python API
    Use the Python API to create, edit, and run maps and schemas from a Python program. For details, see the documentation installed in install_dir/python/api/hip/docs/html/index.html. Examples of the Python API are installed in install_dir/python/api/examples. Documentation for the Python API examples is available in install_dir/python/api/docs/html/examples.html.
  - Java API
    The Java API interfaces enable you to create, edit, and run maps and schemas from a Java™ program.
  - Java Tools
    The Java™ Tools provide objects and JNI utilities that you can use to get information about your map instances.
Resource Adapters
About the HCL Link Resource Adapters, and how to use them.
Cloud Native Link
Cloud Native Link refers to the HCL Link product installation on a Kubernetes cluster.
Reference
This documentation provides HCL Link reference information.
Notices

DestroyConnectionInstance

The DestroyConnectionInstace method cleans up and destroys a connection object.

MPIRC 
DestroyConnectionInstance (HMPICONNECT  hConnection)

Inputs

hConnection: Connection handle

Outputs

None

Returns

Success status