All Known Implementing Classes:

DefaultPerChannelBookieClientPool
```
public interface PerChannelBookieClientPool
```
An interface to manage channel pooling for bookie client.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`checkTimeoutOnPendingOperations()`	Check if any ops on any channel needs to be timed out.
`void`	`close(boolean wait)`	Close the pool.
`void`	`disconnect(boolean wait)`	Disconnect the connections in the pool.
`long`	`getNumPendingCompletionRequests()`	Get the number of pending completion requests in the channel.
`void`	`initialize()`	initialize the pool.
`default boolean`	`isWritable(long key)`	Returns status of a client.
`void`	`obtain(BookkeeperInternalCallbacks.GenericCallback<PerChannelBookieClient> callback, long key)`	Obtain a channel from channel pool to execute operations.
`void`	`obtain(BookkeeperInternalCallbacks.GenericCallback<PerChannelBookieClient> callback, long key, boolean forceUseV3)`	Obtain a channel from channel pool by version to execute operations.
`void`	`recordError()`	record any read/write error on `PerChannelBookieClientPool`.

- Method Detail
  - initialize
```
void initialize()
```
    initialize the pool. the implementation should not be blocked.
  - obtain
```
void obtain(BookkeeperInternalCallbacks.GenericCallback<PerChannelBookieClient> callback,
            long key)
```
    Obtain a channel from channel pool to execute operations.
    
    Parameters:
    
    callback - callback to return channel from channel pool.
  - obtain
```
void obtain(BookkeeperInternalCallbacks.GenericCallback<PerChannelBookieClient> callback,
            long key,
            boolean forceUseV3)
```
    Obtain a channel from channel pool by version to execute operations.
    
    Parameters:
    
    callback - callback to return channel from channel pool
    
    forceUseV3 - whether or not use v3 protocol for connection
  - isWritable
```
default boolean isWritable(long key)
```
    Returns status of a client. It is suggested to delay/throttle requests to this channel if isWritable is false.
    
    Parameters:
    
    key -
    
    Returns:
  - recordError
```
void recordError()
```
    record any read/write error on PerChannelBookieClientPool.
  - checkTimeoutOnPendingOperations
```
void checkTimeoutOnPendingOperations()
```
    Check if any ops on any channel needs to be timed out. This is called on all channels, even if the channel is not yet connected.
  - disconnect
```
void disconnect(boolean wait)
```
    Disconnect the connections in the pool.
    
    Parameters:
    
    wait - whether need to wait until pool disconnected.
  - close
```
void close(boolean wait)
```
    Close the pool.
    
    Parameters:
    
    wait - whether need to wait until pool closed.
  - getNumPendingCompletionRequests
```
long getNumPendingCompletionRequests()
```
    Get the number of pending completion requests in the channel.

Interface PerChannelBookieClientPool

Method Summary

Method Detail

initialize

obtain

obtain

isWritable

recordError

checkTimeoutOnPendingOperations

disconnect

close

getNumPendingCompletionRequests