DiscoverySpiDataExchange (Ignite 2.17.0)

```
public interface DiscoverySpiDataExchange
```
Handler for initial data exchange between Ignite nodes. Data exchange is initiated by a new node when it tries to join topology and finishes before it actually joins.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`DiscoveryDataBag`	`collect(DiscoveryDataBag dataBag)`	Collects data from all components.
`void`	`onExchange(DiscoveryDataBag dataBag)`	Notifies discovery manager about data received from remote node.

- Method Detail
  - collect
```
DiscoveryDataBag collect(DiscoveryDataBag dataBag)
```
    Collects data from all components. This method is called both on new node that joins topology to transfer its data to existing nodes and on all existing nodes to transfer their data to new node.
    
    Parameters:
    
    dataBag - DiscoveryDataBag object managing discovery data during node joining process.
    
    Returns:
    
    Collected discovery data.
  - onExchange
```
void onExchange(DiscoveryDataBag dataBag)
```
    Notifies discovery manager about data received from remote node.
    
    Parameters:
    
    dataBag - Collection of discovery data objects from different components.