DelegationTokenManager (Flink : 2.0-SNAPSHOT API)

All Known Implementing Classes:

DefaultDelegationTokenManager, NoOpDelegationTokenManager
```
@Internal
public interface DelegationTokenManager
```
Manager for delegation tokens in a Flink cluster.
When delegation token renewal is enabled, this manager will make sure long-running apps can run without interruption while accessing secured services. It must contact all the configured secure services to obtain delegation tokens to be distributed to the rest of the application.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface DelegationTokenManager.Listener
Listener for events in the DelegationTokenManager.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`obtainDelegationTokens()`	Obtains new tokens in a one-time fashion and automatically distributes them to all local JVM receivers.
`void`	`obtainDelegationTokens(DelegationTokenContainer container)`	Obtains new tokens in a one-time fashion and leaves it up to the caller to distribute them.
`void`	`start(DelegationTokenManager.Listener listener)`	Creates a re-occurring task which obtains new tokens and automatically distributes them to all receivers (in local JVM as well as in registered task managers too).
`void`	`stop()`	Stops re-occurring token obtain task.

- Method Detail
  - obtainDelegationTokens
```
void obtainDelegationTokens(DelegationTokenContainer container)
                     throws Exception
```
    Obtains new tokens in a one-time fashion and leaves it up to the caller to distribute them.
    
    Throws:
    
    Exception
  - obtainDelegationTokens
```
void obtainDelegationTokens()
                     throws Exception
```
    Obtains new tokens in a one-time fashion and automatically distributes them to all local JVM receivers.
    
    Throws:
    
    Exception
  - start
```
void start(DelegationTokenManager.Listener listener)
    throws Exception
```
    Creates a re-occurring task which obtains new tokens and automatically distributes them to all receivers (in local JVM as well as in registered task managers too). Task manager distribution must be implemented in the listener logic in order to keep the manager logic clean.
    
    Throws:
    
    Exception
  - stop
```
void stop()
```
    Stops re-occurring token obtain task.