org.elasticsearch.common.breaker

Class MemoryCircuitBreaker

java.lang.Object

org.elasticsearch.common.breaker.MemoryCircuitBreaker

All Implemented Interfaces:

CircuitBreaker

public class MemoryCircuitBreaker
extends Object
implements CircuitBreaker

MemoryCircuitBreaker is a circuit breaker that breaks once a configurable memory limit has been reached.

Nested Class Summary

Nested classes/interfaces inherited from interface org.elasticsearch.common.breaker.CircuitBreaker

CircuitBreaker.Type

Field Summary

Fields inherited from interface org.elasticsearch.common.breaker.CircuitBreaker

FIELDDATA, IN_FLIGHT_REQUESTS, PARENT, REQUEST

Constructor Summary

Constructors

Constructor and Description
MemoryCircuitBreaker(ByteSizeValue limit, double overheadConstant, ESLogger logger) Create a circuit breaker that will break if the number of estimated bytes grows above the limit.
MemoryCircuitBreaker(ByteSizeValue limit, double overheadConstant, MemoryCircuitBreaker oldBreaker, ESLogger logger) Create a circuit breaker that will break if the number of estimated bytes grows above the limit.

Method Summary

Methods

Modifier and Type	Method and Description
double	addEstimateBytesAndMaybeBreak(long bytes, String label) Add a number of bytes, tripping the circuit breaker if the aggregated estimates are above the limit.
long	addWithoutBreaking(long bytes) Add an exact number of bytes, not checking for tripping the circuit breaker.
void	circuitBreak(String fieldName, long bytesNeeded) Method used to trip the breaker
long	getLimit()
String	getName()
double	getOverhead()
long	getTrippedCount()
long	getUsed()

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryCircuitBreaker

public MemoryCircuitBreaker(ByteSizeValue limit,
                    double overheadConstant,
                    ESLogger logger)

Create a circuit breaker that will break if the number of estimated bytes grows above the limit. All estimations will be multiplied by the given overheadConstant. This breaker starts with 0 bytes used.

Parameters:

limit - circuit breaker limit

overheadConstant - constant multiplier for byte estimations

MemoryCircuitBreaker

public MemoryCircuitBreaker(ByteSizeValue limit,
                    double overheadConstant,
                    MemoryCircuitBreaker oldBreaker,
                    ESLogger logger)

Create a circuit breaker that will break if the number of estimated bytes grows above the limit. All estimations will be multiplied by the given overheadConstant. Uses the given oldBreaker to initialize the starting offset.

Parameters:

limit - circuit breaker limit

overheadConstant - constant multiplier for byte estimations

oldBreaker - the previous circuit breaker to inherit the used value from (starting offset)

Method Detail

circuitBreak

public void circuitBreak(String fieldName,
                long bytesNeeded)
                  throws CircuitBreakingException

Method used to trip the breaker

Specified by:

circuitBreak in interface CircuitBreaker

Parameters:

fieldName - name of the field responsible for tripping the breaker

bytesNeeded - bytes asked for but unable to be allocated

Throws:

CircuitBreakingException

addEstimateBytesAndMaybeBreak

public double addEstimateBytesAndMaybeBreak(long bytes,
                                   String label)
                                     throws CircuitBreakingException

Add a number of bytes, tripping the circuit breaker if the aggregated estimates are above the limit. Automatically trips the breaker if the memory limit is set to 0. Will never trip the breaker if the limit is set < 0, but can still be used to aggregate estimations.

Specified by:

addEstimateBytesAndMaybeBreak in interface CircuitBreaker

Parameters:

bytes - number of bytes to add to the breaker

label - string label describing the bytes being added

Returns:

number of "used" bytes so far

Throws:

CircuitBreakingException

addWithoutBreaking

public long addWithoutBreaking(long bytes)

Add an exact number of bytes, not checking for tripping the circuit breaker. This bypasses the overheadConstant multiplication.

Specified by:

addWithoutBreaking in interface CircuitBreaker

Parameters:

bytes - number of bytes to add to the breaker

Returns:

number of "used" bytes so far

getUsed

public long getUsed()

Specified by:

getUsed in interface CircuitBreaker

Returns:

the number of aggregated "used" bytes so far

getLimit

public long getLimit()

Specified by:

getLimit in interface CircuitBreaker

Returns:

the number of bytes that can be added before the breaker trips

getOverhead

public double getOverhead()

Specified by:

getOverhead in interface CircuitBreaker

Returns:

the constant multiplier the breaker uses for aggregations

getTrippedCount

public long getTrippedCount()

Specified by:

getTrippedCount in interface CircuitBreaker

Returns:

the number of times the breaker has been tripped

getName

public String getName()

Specified by:

getName in interface CircuitBreaker

Returns:

the name of the breaker