Package com.amazonaws.athena.connector.lambda

Class ThrottlingInvoker

java.lang.Object

com.amazonaws.athena.connector.lambda.ThrottlingInvoker

public class ThrottlingInvoker
extends Object

Utility that implements a basic form of Additive Increase, Multiplicative Decrease for handling retries and backoff against a dependency that is experience congestion. For best results share one instance of this class across as many callers of the same shared resource. If you give each calling thread or entity its own instance the logic will still work but may take a bit longer (couple extra calls) to detect the congestion and converge. This utility works best when all callers use it, otherwise callers that do not use this logic will get a larger % of the available call capacity because the other callers will back off when they see congestion and get starved out by the greedy caller

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ThrottlingInvoker.Builder
static interface	ThrottlingInvoker.ExceptionFilter
static class	ThrottlingInvoker.State

Constructor Summary

Constructors

Constructor	Description
ThrottlingInvoker(ThrottlingInvoker.Builder builder)

Method Summary

Modifier and Type	Method	Description
ThrottlingInvoker.State	getState()
<T> T	invoke(Callable<T> callable)	Attempts to invoke the callable while applying our congestion control logic.
<T> T	invoke(Callable<T> callable, long timeoutMillis)	Attempts to invoke the callable while applying our congestion control logic.
static ThrottlingInvoker.Builder	newBuilder()	Create a new, empty, Builder.
static ThrottlingInvoker.Builder	newDefaultBuilder(ThrottlingInvoker.ExceptionFilter filter, Map<String,String> configOptions)	Produces a Builder with default values set allowing you to override only specific defaults.
void	setBlockSpiller(BlockSpiller spiller)	Throttling Invoker can decide to propogate the congestion events to Athena if your Lambda has not generated any data yet.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ThrottlingInvoker

public ThrottlingInvoker(ThrottlingInvoker.Builder builder)

Method Detail

newBuilder

public static ThrottlingInvoker.Builder newBuilder()

Create a new, empty, Builder.

Returns:

The new Builder.

newDefaultBuilder

public static ThrottlingInvoker.Builder newDefaultBuilder(ThrottlingInvoker.ExceptionFilter filter,
                                                          Map<String,String> configOptions)

Produces a Builder with default values set allowing you to override only specific defaults.

Parameters:

filter - The exception filter to apply to any exception when attemtping to identify congestion.

Returns:

The new Builder with default values.

invoke

public <T> T invoke(Callable<T> callable)
             throws TimeoutException

Attempts to invoke the callable while applying our congestion control logic.

Type Parameters:

T - The return type of the Callable

Parameters:

callable - The callable to invoke.

Returns:

The value returned by the Callable.

Throws:

TimeoutException

invoke

public <T> T invoke(Callable<T> callable,
                    long timeoutMillis)
             throws TimeoutException

Attempts to invoke the callable while applying our congestion control logic.

Type Parameters:

T - The return type of the Callable

Parameters:

callable - The callable to invoke.

timeoutMillis - The max number of milliseconds we should spend retrying if congestion prevents us from making a successful call.

Returns:

The value returned by the Callable, null if we exceeded the timeout.

Throws:

TimeoutException

setBlockSpiller

public void setBlockSpiller(BlockSpiller spiller)

Throttling Invoker can decide to propogate the congestion events to Athena if your Lambda has not generated any data yet. To do this ThrottlingInvoker needs access to your BlockSpiller so that it can see if any data was spilled. Once data is spilled you can not longer throw FederationThrottleException to Athena or the query may fail in order to ensure consistency.

Parameters:

spiller - The BlockSpiller to monitor for spill events.

getState

public ThrottlingInvoker.State getState()

toString

public String toString()

Overrides:

toString in class Object