com.netflix.spectator.api

Interface DistributionSummary

All Superinterfaces:

Meter

All Known Implementing Classes:

BucketCounter, BucketDistributionSummary, PercentileDistributionSummary

public interface DistributionSummary
extends Meter

Track the sample distribution of events. An example would be the response sizes for requests hitting and http server.

The precise set of information maintained depends on the implementation. Most should try to provide a consistent implementation of count() and totalAmount(), but some implementations may not. In particular, the implementation from NoopRegistry will always return 0.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	DistributionSummary.BatchUpdater See batchUpdater(int).

Method Summary

Modifier and Type	Method and Description
default DistributionSummary.BatchUpdater	batchUpdater(int batchSize) Returns a helper that can be used to more efficiently update the distribution summary within a single thread.
long	count() The number of times that record has been called since this timer was last reset.
void	record(long amount) Updates the statistics kept by the summary with the specified amount.
default void	record(long[] amounts, int n) Updates the statistics kept by the summary with the specified amounts as a batch.
long	totalAmount() The total amount of all recorded events since this summary was last reset.

Methods inherited from interface com.netflix.spectator.api.Meter

hasExpired, id, measure

Method Detail

record

void record(long amount)

Updates the statistics kept by the summary with the specified amount.

Parameters:

amount - Amount for an event being measured. For example, if the size in bytes of responses from a server. If the amount is less than 0 the value will be dropped.

record

default void record(long[] amounts,
                    int n)

Updates the statistics kept by the summary with the specified amounts as a batch. Behaves as if `record()` was called in a loop, but may be faster in some cases.

Parameters:

amounts - Amounts for an event being measured. For example, if the size in bytes of responses from a server. If the amount is less than 0 the value will be dropped.

n - The number of elements to write from the amounts array (starting from 0). If n is <= 0 no entries will be recorded. If n is greater than amounts.length, all amounts will be recorded.

See Also:

record(long)

count

long count()

The number of times that record has been called since this timer was last reset. How often a timer is reset depends on the underlying registry implementation.

totalAmount

long totalAmount()

The total amount of all recorded events since this summary was last reset. How often a timer is reset depends on the underlying registry implementation.

batchUpdater

default DistributionSummary.BatchUpdater batchUpdater(int batchSize)

Returns a helper that can be used to more efficiently update the distribution summary within a single thread. For example, if you need to update a meter within a loop where the rest of the loop body is fairly cheap, the instrumentation code may add considerable overhead if done in the loop body. A batched updater can offset a fair amount of that cost, but the updates may be delayed a bit in reaching the meter. The updates will only be seen after the updater is explicitly flushed. The caller should ensure that the updater is closed after using to guarantee any resources associated with it are cleaned up. In some cases failure to close the updater could result in a memory leak.

Parameters:

batchSize - Number of updates to batch before forcing a flush to the meter.

Returns:

Batch updater implementation for this meter.