com.yahoo.bard.webservice.web.ratelimit

Class DefaultRateLimiter

java.lang.Object

com.yahoo.bard.webservice.web.ratelimit.DefaultRateLimiter

All Implemented Interfaces:

RateLimiter

public class DefaultRateLimiter
extends Object
implements RateLimiter

This is the default implementation of a rate limiter.

Field Summary

Fields

Modifier and Type	Field and Description
protected static RateLimitRequestToken	BYPASS_TOKEN
protected static int	DEFAULT_REQUEST_LIMIT_GLOBAL
protected static int	DEFAULT_REQUEST_LIMIT_PER_USER
protected static int	DEFAULT_REQUEST_LIMIT_UI
protected static int	DISABLED_RATE
protected AtomicInteger	globalCount
protected static com.codahale.metrics.MetricRegistry	REGISTRY
protected static RateLimitRequestToken	REJECT_REQUEST_TOKEN
protected com.codahale.metrics.Meter	rejectUiMeter
protected com.codahale.metrics.Meter	rejectUserMeter
protected static String	REQUEST_LIMIT_GLOBAL_KEY
protected static String	REQUEST_LIMIT_PER_USER_KEY
protected static String	REQUEST_LIMIT_UI_KEY
protected com.codahale.metrics.Meter	requestBypassMeter
protected com.codahale.metrics.Counter	requestGlobalCounter
protected int	requestLimitGlobal
protected int	requestLimitPerUser
protected int	requestLimitUi
protected com.codahale.metrics.Meter	requestUiMeter
protected com.codahale.metrics.Meter	requestUserMeter
protected static SystemConfig	SYSTEM_CONFIG
protected Map<String,AtomicInteger>	userCounts
protected com.codahale.metrics.Counter	usersCounter

Constructor Summary

Constructors

Constructor and Description
DefaultRateLimiter() Loads defaults and creates DefaultRateLimiter.

Method Summary

Modifier and Type	Method and Description
protected RateLimitRequestToken	createNewRateLimitRequestToken(AtomicInteger count, String userName, boolean isUIQuery, int requestLimit, com.codahale.metrics.Meter requestMeter, com.codahale.metrics.Meter rejectMeter) Creates a new RateLimitRequestToken.
protected RateLimitCleanupOnRequestComplete	generateCleanupClosure(AtomicInteger count, String userName) Creates a callback to be passed to a token to execute when a request has completed.
protected AtomicInteger	getCount(String userName) Get the current count for this username.
RateLimitRequestToken	getToken(javax.ws.rs.container.ContainerRequestContext request) Request a token from the RateLimiter, which represents an in-flight request.
protected boolean	incrementAndCheckCount(AtomicInteger initialCount, int requestLimit) Increment the initial count and check if the count has gone over the request limit.
protected void	rejectRequest(com.codahale.metrics.Meter rejectMeter, boolean isRejectGlobal, boolean isUIQuery, String userName) Do the house keeping needed to reject the request.

Methods inherited from class java.lang.Object

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

Field Detail

SYSTEM_CONFIG

protected static final SystemConfig SYSTEM_CONFIG

REJECT_REQUEST_TOKEN

protected static final RateLimitRequestToken REJECT_REQUEST_TOKEN

BYPASS_TOKEN

protected static final RateLimitRequestToken BYPASS_TOKEN

REQUEST_LIMIT_GLOBAL_KEY

@NotNull
protected static final String REQUEST_LIMIT_GLOBAL_KEY

REQUEST_LIMIT_PER_USER_KEY

@NotNull
protected static final String REQUEST_LIMIT_PER_USER_KEY

REQUEST_LIMIT_UI_KEY

@NotNull
protected static final String REQUEST_LIMIT_UI_KEY

DEFAULT_REQUEST_LIMIT_GLOBAL

protected static final int DEFAULT_REQUEST_LIMIT_GLOBAL

See Also:

Constant Field Values

DEFAULT_REQUEST_LIMIT_PER_USER

protected static final int DEFAULT_REQUEST_LIMIT_PER_USER

See Also:

Constant Field Values

DEFAULT_REQUEST_LIMIT_UI

protected static final int DEFAULT_REQUEST_LIMIT_UI

See Also:

Constant Field Values

REGISTRY

protected static final com.codahale.metrics.MetricRegistry REGISTRY

DISABLED_RATE

protected static final int DISABLED_RATE

See Also:

Constant Field Values

requestLimitGlobal

protected final int requestLimitGlobal

requestLimitPerUser

protected final int requestLimitPerUser

requestLimitUi

protected final int requestLimitUi

globalCount

protected final AtomicInteger globalCount

userCounts

protected final Map<String,AtomicInteger> userCounts

requestGlobalCounter

protected final com.codahale.metrics.Counter requestGlobalCounter

usersCounter

protected final com.codahale.metrics.Counter usersCounter

requestBypassMeter

protected final com.codahale.metrics.Meter requestBypassMeter

requestUiMeter

protected final com.codahale.metrics.Meter requestUiMeter

requestUserMeter

protected final com.codahale.metrics.Meter requestUserMeter

rejectUiMeter

protected final com.codahale.metrics.Meter rejectUiMeter

rejectUserMeter

protected final com.codahale.metrics.Meter rejectUserMeter

Constructor Detail

DefaultRateLimiter

public DefaultRateLimiter()
                   throws SystemConfigException

Loads defaults and creates DefaultRateLimiter.

Throws:

SystemConfigException - If any parameters fail to load

Method Detail

getCount

protected AtomicInteger getCount(String userName)

Get the current count for this username. If user does not have a counter, create one.

Parameters:

userName - Username to get the count for

Returns:

The atomic count for the user

incrementAndCheckCount

protected boolean incrementAndCheckCount(AtomicInteger initialCount,
                                         int requestLimit)

Increment the initial count and check if the count has gone over the request limit.

Parameters:

initialCount - Initial count that we're incrementing and checking against the limit

requestLimit - Limit to check the incremented initial count against

Returns:

True if the incremented count is less than or equal to the request limit, false if it's gone over and the request limit isn't the DISABLED_RATE (-1).

rejectRequest

protected void rejectRequest(com.codahale.metrics.Meter rejectMeter,
                             boolean isRejectGlobal,
                             boolean isUIQuery,
                             String userName)

Do the house keeping needed to reject the request.

Parameters:

rejectMeter - Meter to count the rejection in

isRejectGlobal - Whether or not the rejection is on the global rate limit

isUIQuery - Whether or not the request is a UI Query

userName - Username of the user who made the request

getToken

public RateLimitRequestToken getToken(javax.ws.rs.container.ContainerRequestContext request)

Description copied from interface: RateLimiter

Request a token from the RateLimiter, which represents an in-flight request.

Specified by:

getToken in interface RateLimiter

Parameters:

request - The object representing the request

Returns:

a RateLimitRequestToken object representing a request.

createNewRateLimitRequestToken

protected RateLimitRequestToken createNewRateLimitRequestToken(AtomicInteger count,
                                                               String userName,
                                                               boolean isUIQuery,
                                                               int requestLimit,
                                                               com.codahale.metrics.Meter requestMeter,
                                                               com.codahale.metrics.Meter rejectMeter)

Creates a new RateLimitRequestToken.

Parameters:

count - The atomic reference that holds the amount of in-flight requests the user owns

userName - The user who launched the request

isUIQuery - Whether or not this query was generated from the UI

requestLimit - The limit of requests the user is allowed to launch

requestMeter - Meter tracking the amount of requests that have been launched

rejectMeter - Meter tracking the amount of requests that have been rejected

Returns:

a new RateLimitRequestToken, representing an in-flight (or rejected) request that is tracked by the RateLimiter

generateCleanupClosure

protected RateLimitCleanupOnRequestComplete generateCleanupClosure(AtomicInteger count,
                                                                   String userName)

Creates a callback to be passed to a token to execute when a request has completed. The callback handles decrementing the global and user counters.

Parameters:

count - The AtomicInteger that stores the amount of in-flight requests an individual user owns

userName - The name of the user that made the request

Returns:

A callback implementation to be given to a CallbackRateLimitRequestToken