QOSBasedQueue (venice API)

java.lang.Object
- com.linkedin.alpini.base.queuing.AbstractQOS
- - com.linkedin.alpini.base.queuing.AbstractQOSBasedQueue<T>
  - - com.linkedin.alpini.base.queuing.QOSBasedQueue<T>

Type Parameters:

T -

All Implemented Interfaces:

SimpleQueue<T>
```
public class QOSBasedQueue<T extends QOSBasedRequestRunnable>
extends AbstractQOSBasedQueue<T>
```
Implementation of SimpleQueue. Internally, it maintains separate queues for each QOS level and responds to poll() or peek() requests from any one of the queues (probabilistically). Addition to this queue, causes the element to be queued together with elements of the same QOS type. Each sub-queue can be configured with a "percentage-slice" i.e. the fraction of poll()/peek() requests that must delegate to it. For e.g. the default slices are "HIGH-80%, NORMAL-15%, LOW-5%". This means that LOW QOS requests will be dequeued at most 5% of the time. Thus a large volume of LOW QOS requests cannot affect higher QOS level, and it also means that higher QOS requests cannot starve lower QOS requests.

- Field Summary
  - Fields inherited from class com.linkedin.alpini.base.queuing.AbstractQOS
    _allocationTotal, _log, _qosBasedAllocations
- Constructor Summary
  
  Constructors
  Constructor Description
  
  QOSBasedQueue()
  
  QOSBasedQueue(java.util.Map<QOS,java.lang.Integer> qosBasedAllocations)
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  boolean add(T e)
  
  boolean isEmpty()
  Checks if queue is empty.
  
  int size()
  - Methods inherited from class com.linkedin.alpini.base.queuing.AbstractQOSBasedQueue
    getQOS, getQueueName, poll
  - Methods inherited from class com.linkedin.alpini.base.queuing.AbstractQOS
    getDefaultQOSAllocation, getQueuePollOrder
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - QOSBasedQueue
```
public QOSBasedQueue()
```
  - QOSBasedQueue
```
public QOSBasedQueue(java.util.Map<QOS,java.lang.Integer> qosBasedAllocations)
```
- Method Detail
  - add
```
public boolean add(@Nonnull
                   T e)
```
    See Also:
    
    Queue.add(Object)
  - size
```
public int size()
```
    See Also:
    
    Collection.size()
  - isEmpty
```
public boolean isEmpty()
```
    Description copied from interface: SimpleQueue
    
    Checks if queue is empty.
    
    Returns:
    
    true if Queue contains no elements, false otherwise.