Cluster (Solr 9.0.0 core API)

```
public interface Cluster
```
A representation of the SolrCloud cluster state, providing information on which nodes and collections are part of the cluster and a way to get to more detailed info.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Iterable<SolrCollection>`	`collections()`	Allow foreach iteration on all collections of the cluster, such as: `for (SolrCollection c : cluster.collections()) {...}`.
`SolrCollection`	`getCollection(String collectionName)`	Returns info about the given collection if one exists.
`Set<Node>`	`getLiveDataNodes()`
`Set<Node>`	`getLiveNodes()`
`Iterator<SolrCollection>`	`iterator()`

- Method Detail
  - getLiveNodes
```
Set<Node> getLiveNodes()
```
    Returns:
    
    current set of live nodes.
  - getLiveDataNodes
```
Set<Node> getLiveDataNodes()
```
    Returns:
    
    current set of live nodes that are supposed to host data.
  - getCollection
```
SolrCollection getCollection(String collectionName)
                      throws IOException
```
    Returns info about the given collection if one exists.
    
    Returns:
    
    null if no collection of the given name exists in the cluster.
    
    Throws:
    
    IOException
  - iterator
```
Iterator<SolrCollection> iterator()
```
    Returns:
    
    an iterator over all SolrCollections in the cluster.
  - collections
```
Iterable<SolrCollection> collections()
```
    Allow foreach iteration on all collections of the cluster, such as: for (SolrCollection c : cluster.collections()) {...}.