com.aerospike.client.async

Class EventPolicy

java.lang.Object

com.aerospike.client.async.EventPolicy

public final class EventPolicy
extends Object

Asynchronous event loop configuration.

Field Summary

Fields

Modifier and Type	Field and Description
int	commandsPerEventLoop Expected number of concurrent asynchronous commands in each event loop that are active at any point in time.
int	maxCommandsInProcess Maximum number of async commands that can be processed in each event loop at any point in time.
int	maxCommandsInQueue Maximum number of async commands that can be stored in each event loop's delay queue for later execution.
int	minTimeout Minimum command timeout in milliseconds that will be specified for this event loop group.
int	queueInitialCapacity Initial capacity of each event loop's delay queue.
int	ticksPerWheel The number of ticks per wheel for HashedWheelTimer in each event loop.

Constructor Summary

Constructors

Constructor and Description
EventPolicy()

Method Summary

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

maxCommandsInProcess

public int maxCommandsInProcess

Maximum number of async commands that can be processed in each event loop at any point in time. Each executing async command requires a socket connection. Consuming too many sockets can negatively affect application reliability and performance. If the user does not limit async command count in their application, this field should be used to enforce a limit internally in the client.

If this limit is reached, the next async command will be placed on the event loop's delay queue for later execution. If this limit is zero, all async commands will be executed immediately and the delay queue will not be used.

If defined, a reasonable value is 40. The optimal value will depend on cpu count, cpu speed, network bandwidth and the number of event loops employed.

Default: 0 (execute all async commands immediately)

maxCommandsInQueue

public int maxCommandsInQueue

Maximum number of async commands that can be stored in each event loop's delay queue for later execution. Queued commands consume memory, but they do not consume sockets. This limit should be defined when it's possible that the application executes so many async commands that memory could be exhausted.

If this limit is reached, the next async command will be rejected with exception AerospikeException.AsyncQueueFull. If this limit is zero, all async commands will be accepted into the delay queue.

The optimal value will depend on your application's magnitude of command bursts and the amount of memory available to store commands.

Default: 0 (no delay queue limit)

queueInitialCapacity

public int queueInitialCapacity

Initial capacity of each event loop's delay queue. The delay queue can resize beyond this initial capacity.

Default: 256 (if delay queue is used)

minTimeout

public int minTimeout

Minimum command timeout in milliseconds that will be specified for this event loop group. If command timeouts are less than minTimeout, the actual command timeout will be minTimeout. The absolute minimum timeout value is 5ms.

minTimeout is used to specify the tick duration for HashedWheelTimer in each event loop. minTimeout is also used to specify the direct NIO event loop selector timeout.

Default: 100ms

ticksPerWheel

public int ticksPerWheel

The number of ticks per wheel for HashedWheelTimer in each event loop.

Default: 256

commandsPerEventLoop

public int commandsPerEventLoop

Expected number of concurrent asynchronous commands in each event loop that are active at any point in time. This value is used as each event loop's timeout queue and ByteBuffer pool initial capacity. This value is not a fixed limit and the queues will dynamically resize when necessary.

The real event loop limiting factor is the maximum number of async connections allowed per node (defined in ClientPolicy.maxConnsPerNode).

Default: 256

Constructor Detail

EventPolicy

public EventPolicy()