Reactor Pool 1.0.5 · reactor.pool.introspection.SamplingAllocationStrategy

Modifier and Type	Field and Description
pack-priv long	countGetting
pack-priv long	countReturning
public final AllocationStrategy	delegate The delegate `AllocationStrategy` backing this sampling strategy.
pack-priv final BitSet	gettingSampleDecisions
public final LinkedList<Throwable>	gettingSamples The list of samples for `getPermits(int)` calls, as `Throwable` that trace back to the callers of the sampled calls.
public final double	gettingSamplingRate The configured sampling rate for `getPermits(int)` calls, as a double between 0d and 1d (percentage).
pack-priv final BitSet	returningSampleDecisions
public final LinkedList<Throwable>	returningSamples The list of samples for `returnPermits(int)` calls, as `Throwable` that trace back to the callers of the sampled calls.
public final double	returningSamplingRate The configured sampling rate for `returnPermits(int)` calls, as a double between 0d and 1d (percentage).

Access	Constructor and Description
pack-priv	SamplingAllocationStrategy(AllocationStrategy delegate, double gettingSamplingRate, double returningSamplingRate)

Method Summary

Modifier and Type	Method and Description
public int	estimatePermitCount() Implements reactor.pool.AllocationStrategy.estimatePermitCount. Best-effort peek at the state of the strategy which indicates roughly how many more resources can currently be allocated.
public int	getPermits(int the desired number of new resources desired) Implements reactor.pool.AllocationStrategy.getPermits. Try to get the permission to allocate a `desired` positive number of new resources.
public int	permitGranted() Implements reactor.pool.AllocationStrategy.permitGranted.
public int	permitMaximum() Implements reactor.pool.AllocationStrategy.permitMaximum.
public int	permitMinimum() Implements reactor.pool.AllocationStrategy.permitMinimum. Return the minimum number of permits this strategy tries to maintain granted (reflecting a minimal size for the pool), or `0` for scale-to-zero.
public void	returnPermits(int returned) Implements reactor.pool.AllocationStrategy.returnPermits. Update the strategy to indicate that N resources were discarded from the `Pool`, potentially leaving space for N new ones to be allocated.
pack-priv static BitSet	Returns: a random bitset sampleBitSet(int cardinality of the bit set selectedOutOf100) Reservoir sampling algorithm borrowed from Stack Overflow.
pack-priv void	sampleGetting(final int desired)
pack-priv void	sampleReturning(final int returned)
pack-priv static AllocationStrategy	sizeBetweenHelper(int min, int max)
public static SamplingAllocationStrategy	Returns: a sampled `AllocationStrategy` that otherwise behaves like the `PoolBuilder#sizeBetween(int, int)` strategy sizeBetweenWithSampling(int the minimum number of permits (see `PoolBuilder#sizeBetween(int, int)`) min, int the maximum number of permits (see `PoolBuilder#sizeBetween(int, int)`) max, double the sampling rate for `AllocationStrategy#getPermits(int)` calls (0.0d to 1.0d) getPermitsSamplingRate, double the sampling rate for `AllocationStrategy#returnPermits(int)` calls (0.0d to 1.0d) returnPermitsSamplingRate) An `SamplingAllocationStrategy` that wraps a `sizeBetween` `AllocationStrategy` and samples calls to `AllocationStrategy#getPermits(int)` and `AllocationStrategy#returnPermits(int)`.
public int	warmupParallelism() Overrides default reactor.pool.AllocationStrategy.warmupParallelism. Return the concurrency level used when the allocator is subscribed to during the warmup phase, if any.
public static SamplingAllocationStrategy	Returns: a sampled `AllocationStrategy` that otherwise behaves like the `delegate` withSampling(AllocationStrategy the underlying `AllocationStrategy` delegate, double the sampling rate for `AllocationStrategy#getPermits(int)` calls (0.0d to 1.0d) getPermitsSamplingRate, double the sampling rate for `AllocationStrategy#returnPermits(int)` calls (0.0d to 1.0d) returnPermitsSamplingRate) An `AllocationStrategy` that wraps a `delegate` and samples calls to `AllocationStrategy#getPermits(int)` and `AllocationStrategy#returnPermits(int)`.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

countGetting	back to summary
pack-priv long countGetting

countReturning	back to summary
pack-priv long countReturning

delegate	back to summary
public final AllocationStrategy delegate The delegate `AllocationStrategy` backing this sampling strategy.

gettingSampleDecisions	back to summary
pack-priv final BitSet gettingSampleDecisions

gettingSamples	back to summary
public final LinkedList<Throwable> gettingSamples The list of samples for `getPermits(int)` calls, as `Throwable` that trace back to the callers of the sampled calls.

gettingSamplingRate	back to summary
public final double gettingSamplingRate The configured sampling rate for `getPermits(int)` calls, as a double between 0d and 1d (percentage).

returningSampleDecisions	back to summary
pack-priv final BitSet returningSampleDecisions

returningSamples	back to summary
public final LinkedList<Throwable> returningSamples The list of samples for `returnPermits(int)` calls, as `Throwable` that trace back to the callers of the sampled calls.

returningSamplingRate	back to summary
public final double returningSamplingRate The configured sampling rate for `returnPermits(int)` calls, as a double between 0d and 1d (percentage).

SamplingAllocationStrategy	back to summary
pack-priv SamplingAllocationStrategy(AllocationStrategy delegate, double gettingSamplingRate, double returningSamplingRate)

Method Detail

estimatePermitCount back to summary

estimatePermitCount	back to summary
public int estimatePermitCount() Implements reactor.pool.AllocationStrategy.estimatePermitCount. Doc from reactor.pool.AllocationStrategy.estimatePermitCount. Best-effort peek at the state of the strategy which indicates roughly how many more resources can currently be allocated. Should be paired with `getPermits(int)` for an atomic permission. Returns:int an ESTIMATED count of how many more resources can currently be allocated Annotations @Override

public int estimatePermitCount()

Implements reactor.pool.AllocationStrategy.estimatePermitCount.

Doc from reactor.pool.AllocationStrategy.estimatePermitCount.

Best-effort peek at the state of the strategy which indicates roughly how many more resources can currently be allocated. Should be paired with getPermits(int) for an atomic permission.

Returns:int

an ESTIMATED count of how many more resources can currently be allocated

Annotations

@Override

getPermits back to summary

getPermits	back to summary
public int getPermits(int desired) Implements reactor.pool.AllocationStrategy.getPermits. Doc from reactor.pool.AllocationStrategy.getPermits. Try to get the permission to allocate a `desired` positive number of new resources. Returns the permissible number of resources which MUST be created (otherwise the internal live counter of the strategy might be off). This permissible number might be zero, and it can also be a greater number than `desired`, which could for example denote a minimum warmed-up size for the pool to maintain (see below). Once a resource is discarded from the pool, it must update the strategy using `returnPermits(int)` (which can happen in batches or with value 1). For the warming up case, the typical pattern would be to call this method with a `desired` of zero. Parameters desired:int the desired number of new resources Returns:int the actual number of new resources that MUST be created, can be 0 and can be more than `desired` Annotations @Override

public int getPermits(int desired)

Implements reactor.pool.AllocationStrategy.getPermits.

Doc from reactor.pool.AllocationStrategy.getPermits.

Try to get the permission to allocate a desired positive number of new resources. Returns the permissible number of resources which MUST be created (otherwise the internal live counter of the strategy might be off). This permissible number might be zero, and it can also be a greater number than desired, which could for example denote a minimum warmed-up size for the pool to maintain (see below). Once a resource is discarded from the pool, it must update the strategy using returnPermits(int) (which can happen in batches or with value 1).

For the warming up case, the typical pattern would be to call this method with a desired of zero.

Parameters

desired:int: the desired number of new resources

Returns:int

the actual number of new resources that MUST be created, can be 0 and can be more than desired

Annotations

@Override

permitGranted back to summary

permitGranted	back to summary
public int permitGranted() Implements reactor.pool.AllocationStrategy.permitGranted. Returns:int Doc from reactor.pool.AllocationStrategy.permitGranted. a best estimate of the number of permits currently granted, between 0 and `Integer#MAX_VALUE` Annotations @Override

public int permitGranted()

Implements reactor.pool.AllocationStrategy.permitGranted.

Returns:int

Doc from reactor.pool.AllocationStrategy.permitGranted.

a best estimate of the number of permits currently granted, between 0 and Integer#MAX_VALUE

Annotations

@Override

permitMaximum back to summary

permitMaximum	back to summary
public int permitMaximum() Implements reactor.pool.AllocationStrategy.permitMaximum. Returns:int Doc from reactor.pool.AllocationStrategy.permitMaximum. the maximum number of permits this strategy can grant in total, or `Integer#MAX_VALUE` for unbounded Annotations @Override

public int permitMaximum()

Implements reactor.pool.AllocationStrategy.permitMaximum.

Returns:int

Doc from reactor.pool.AllocationStrategy.permitMaximum.

the maximum number of permits this strategy can grant in total, or Integer#MAX_VALUE for unbounded

Annotations

@Override

permitMinimum back to summary

permitMinimum	back to summary
public int permitMinimum() Implements reactor.pool.AllocationStrategy.permitMinimum. Doc from reactor.pool.AllocationStrategy.permitMinimum. Return the minimum number of permits this strategy tries to maintain granted (reflecting a minimal size for the pool), or `0` for scale-to-zero. Returns:int the minimum number of permits this strategy tries to maintain, or `0` Annotations @Override

public int permitMinimum()

Implements reactor.pool.AllocationStrategy.permitMinimum.

Doc from reactor.pool.AllocationStrategy.permitMinimum.

Return the minimum number of permits this strategy tries to maintain granted (reflecting a minimal size for the pool), or 0 for scale-to-zero.

Returns:int

the minimum number of permits this strategy tries to maintain, or 0

Annotations

@Override

returnPermits back to summary

returnPermits	back to summary
public void returnPermits(int returned) Implements reactor.pool.AllocationStrategy.returnPermits. Doc from reactor.pool.AllocationStrategy.returnPermits. Update the strategy to indicate that N resources were discarded from the `Pool`, potentially leaving space for N new ones to be allocated. Users MUST ensure that this method isn't called with a value greater than the number of held permits it has. Some strategy MIGHT throw an `IllegalArgumentException` if it can be determined the number of returned permits is not consistent with the strategy's limits and delivered permits. Annotations @Override

public void returnPermits(int returned)

Implements reactor.pool.AllocationStrategy.returnPermits.

Doc from reactor.pool.AllocationStrategy.returnPermits.

Update the strategy to indicate that N resources were discarded from the Pool, potentially leaving space for N new ones to be allocated. Users MUST ensure that this method isn't called with a value greater than the number of held permits it has.

Some strategy MIGHT throw an IllegalArgumentException if it can be determined the number of returned permits is not consistent with the strategy's limits and delivered permits.

Annotations

@Override

sampleBitSet	back to summary
pack-priv static BitSet sampleBitSet(int selectedOutOf100) Reservoir sampling algorithm borrowed from Stack Overflow. https://stackoverflow.com/questions/12817946/generate-a-random-bitset-with-n-1s Parameters selectedOutOf100:int cardinality of the bit set Returns:BitSet a random bitset

sampleBitSet

back to summary

pack-priv static BitSet sampleBitSet(int selectedOutOf100)

Reservoir sampling algorithm borrowed from Stack Overflow. https://stackoverflow.com/questions/12817946/generate-a-random-bitset-with-n-1s

Parameters

selectedOutOf100:int: cardinality of the bit set

Returns:BitSet

a random bitset

sampleGetting	back to summary
pack-priv void sampleGetting(final int desired)

sampleReturning	back to summary
pack-priv void sampleReturning(final int returned)

sizeBetweenHelper	back to summary
pack-priv static AllocationStrategy sizeBetweenHelper(int min, int max)

sizeBetweenWithSampling back to summary

sizeBetweenWithSampling	back to summary
public static SamplingAllocationStrategy sizeBetweenWithSampling(int min, int max, double getPermitsSamplingRate, double returnPermitsSamplingRate) An `SamplingAllocationStrategy` that wraps a `sizeBetween` `AllocationStrategy` and samples calls to `AllocationStrategy#getPermits(int)` and `AllocationStrategy#returnPermits(int)`. Parameters min:int the minimum number of permits (see `PoolBuilder#sizeBetween(int, int)`) max:int the maximum number of permits (see `PoolBuilder#sizeBetween(int, int)`) getPermitsSamplingRate:double the sampling rate for `AllocationStrategy#getPermits(int)` calls (0.0d to 1.0d) returnPermitsSamplingRate:double the sampling rate for `AllocationStrategy#returnPermits(int)` calls (0.0d to 1.0d) Returns:SamplingAllocationStrategy a sampled `AllocationStrategy` that otherwise behaves like the `PoolBuilder#sizeBetween(int, int)` strategy

public static SamplingAllocationStrategy sizeBetweenWithSampling(int min, int max, double getPermitsSamplingRate, double returnPermitsSamplingRate)

An SamplingAllocationStrategy that wraps a sizeBetween AllocationStrategy and samples calls to AllocationStrategy#getPermits(int) and AllocationStrategy#returnPermits(int).

Parameters

min:int: the minimum number of permits (see PoolBuilder#sizeBetween(int, int))
max:int: the maximum number of permits (see PoolBuilder#sizeBetween(int, int))
getPermitsSamplingRate:double: the sampling rate for AllocationStrategy#getPermits(int) calls (0.0d to 1.0d)
returnPermitsSamplingRate:double: the sampling rate for AllocationStrategy#returnPermits(int) calls (0.0d to 1.0d)

Returns:SamplingAllocationStrategy

a sampled AllocationStrategy that otherwise behaves like the PoolBuilder#sizeBetween(int, int) strategy

warmupParallelism back to summary

warmupParallelism	back to summary
public int warmupParallelism() Overrides default reactor.pool.AllocationStrategy.warmupParallelism. Doc from reactor.pool.AllocationStrategy.warmupParallelism. Return the concurrency level used when the allocator is subscribed to during the warmup phase, if any. The number of resources created concurrently will not exceed the value returned by `warmupParallelism()`. If the concurrency level is set to 1, pre-allocation of resources will be performed sequentially by subscribing to the allocator one at a time. The process waits for a resource to be created before subscribing again to the allocator. This sequence continues until all pre-allocated resources have been successfully created. Defaults to 1 Returns:int The concurrency level used when the allocator is subscribed to during the warmup phase, must be positive, `1` by default Annotations @Override

public int warmupParallelism()

Overrides default reactor.pool.AllocationStrategy.warmupParallelism.

Doc from reactor.pool.AllocationStrategy.warmupParallelism.

Return the concurrency level used when the allocator is subscribed to during the warmup phase, if any.

The number of resources created concurrently will not exceed the value returned by warmupParallelism(). If the concurrency level is set to 1, pre-allocation of resources will be performed sequentially by subscribing to the allocator one at a time. The process waits for a resource to be created before subscribing again to the allocator. This sequence continues until all pre-allocated resources have been successfully created.

Defaults to 1

Returns:int

The concurrency level used when the allocator is subscribed to during the warmup phase, must be positive, 1 by default

Annotations

@Override

withSampling back to summary

withSampling	back to summary
public static SamplingAllocationStrategy withSampling(AllocationStrategy delegate, double getPermitsSamplingRate, double returnPermitsSamplingRate) An `AllocationStrategy` that wraps a `delegate` and samples calls to `AllocationStrategy#getPermits(int)` and `AllocationStrategy#returnPermits(int)`. Only a given percentage of calls are sampled, and these are stored as stacktraces in the sampling strategy. If a `AllocationStrategy#returnPermits(int)` call fails, a new `IllegalArgumentException` is thrown with a composite cause that represents all the sampled calls (see `Exceptions#unwrapMultiple(Throwable)`). The two types of calls are sampled separately. The reservoir sampling algorithm is used to instantiate a sampling decision bitset over 100 slots, which are then applied live to windows of 100 calls. Parameters delegate:AllocationStrategy the underlying `AllocationStrategy` getPermitsSamplingRate:double the sampling rate for `AllocationStrategy#getPermits(int)` calls (0.0d to 1.0d) returnPermitsSamplingRate:double the sampling rate for `AllocationStrategy#returnPermits(int)` calls (0.0d to 1.0d) Returns:SamplingAllocationStrategy a sampled `AllocationStrategy` that otherwise behaves like the `delegate`

public static SamplingAllocationStrategy withSampling(AllocationStrategy delegate, double getPermitsSamplingRate, double returnPermitsSamplingRate)

An AllocationStrategy that wraps a delegate and samples calls to AllocationStrategy#getPermits(int) and AllocationStrategy#returnPermits(int). Only a given percentage of calls are sampled, and these are stored as stacktraces in the sampling strategy. If a AllocationStrategy#returnPermits(int) call fails, a new IllegalArgumentException is thrown with a composite cause that represents all the sampled calls (see Exceptions#unwrapMultiple(Throwable)).

The two types of calls are sampled separately. The reservoir sampling algorithm is used to instantiate a sampling decision bitset over 100 slots, which are then applied live to windows of 100 calls.

Parameters

delegate:AllocationStrategy: the underlying AllocationStrategy
getPermitsSamplingRate:double: the sampling rate for AllocationStrategy#getPermits(int) calls (0.0d to 1.0d)
returnPermitsSamplingRate:double: the sampling rate for AllocationStrategy#returnPermits(int) calls (0.0d to 1.0d)

Returns:SamplingAllocationStrategy

a sampled AllocationStrategy that otherwise behaves like the delegate

public final Class SamplingAllocationStrategy

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