org.apache.hadoop.fs.statistics.impl.IOStatisticsStore Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.fs.statistics.impl;
import java.time.Duration;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.hadoop.fs.statistics.IOStatistics;
import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
import org.apache.hadoop.fs.statistics.DurationTrackerFactory;
import org.apache.hadoop.fs.statistics.MeanStatistic;
/**
* Interface of an IOStatistics store intended for
* use in classes which track statistics for reporting.
*/
public interface IOStatisticsStore extends IOStatistics,
IOStatisticsAggregator,
DurationTrackerFactory {
/**
* Increment a counter by one.
*
* No-op if the counter is unknown.
* @param key statistics key
* @return old value or, if the counter is unknown: 0
*/
default long incrementCounter(String key) {
return incrementCounter(key, 1);
}
/**
* Increment a counter.
*
* No-op if the counter is unknown.
* If the value is negative, it is ignored.
* @param key statistics key
* @param value value to increment
* @return the updated value or, if the counter is unknown: 0
*/
long incrementCounter(String key, long value);
/**
* Set a counter.
*
* No-op if the counter is unknown.
* @param key statistics key
* @param value value to set
*/
void setCounter(String key, long value);
/**
* Set a gauge.
*
* No-op if the gauge is unknown.
* @param key statistics key
* @param value value to set
*/
void setGauge(String key, long value);
/**
* Increment a gauge.
*
* No-op if the gauge is unknown.
*
* @param key statistics key
* @param value value to increment
* @return new value or 0 if the key is unknown
*/
long incrementGauge(String key, long value);
/**
* Set a maximum.
* No-op if the maximum is unknown.
* @param key statistics key
* @param value value to set
*/
void setMaximum(String key, long value);
/**
* Increment a maximum.
*
* No-op if the maximum is unknown.
*
* @param key statistics key
* @param value value to increment
* @return new value or 0 if the key is unknown
*/
long incrementMaximum(String key, long value);
/**
* Set a minimum.
*
* No-op if the minimum is unknown.
*
* @param key statistics key
* @param value value to set
*/
void setMinimum(String key, long value);
/**
* Increment a minimum.
*
* No-op if the minimum is unknown.
*
* @param key statistics key
* @param value value to increment
* @return new value or 0 if the key is unknown
*/
long incrementMinimum(String key, long value);
/**
* Add a minimum sample: if less than the current value,
* updates the value.
*
* No-op if the minimum is unknown.
*
* @param key statistics key
* @param value sample value
*/
void addMinimumSample(String key, long value);
/**
* Add a maximum sample: if greater than the current value,
* updates the value.
*
* No-op if the key is unknown.
*
* @param key statistics key
* @param value sample value
*/
void addMaximumSample(String key, long value);
/**
* Set a mean statistic to a given value.
*
* No-op if the key is unknown.
*
* @param key statistic key
* @param value new value.
*/
void setMeanStatistic(String key, MeanStatistic value);
/**
* Add a sample to the mean statistics.
*
* No-op if the key is unknown.
*
* @param key key
* @param value sample value.
*/
void addMeanStatisticSample(String key, long value);
/**
* Reset all statistics.
* Unsynchronized.
*/
void reset();
/**
* Get a reference to the atomic instance providing the
* value for a specific counter. This is useful if
* the value is passed around.
* @param key statistic name
* @return the reference
* @throws NullPointerException if there is no entry of that name
*/
AtomicLong getCounterReference(String key);
/**
* Get a reference to the atomic instance providing the
* value for a specific maximum. This is useful if
* the value is passed around.
* @param key statistic name
* @return the reference
* @throws NullPointerException if there is no entry of that name
*/
AtomicLong getMaximumReference(String key);
/**
* Get a reference to the atomic instance providing the
* value for a specific minimum. This is useful if
* the value is passed around.
* @param key statistic name
* @return the reference
* @throws NullPointerException if there is no entry of that name
*/
AtomicLong getMinimumReference(String key);
/**
* Get a reference to the atomic instance providing the
* value for a specific gauge. This is useful if
* the value is passed around.
* @param key statistic name
* @return the reference
* @throws NullPointerException if there is no entry of that name
*/
AtomicLong getGaugeReference(String key);
/**
* Get a reference to the atomic instance providing the
* value for a specific meanStatistic. This is useful if
* the value is passed around.
* @param key statistic name
* @return the reference
* @throws NullPointerException if there is no entry of that name
*/
MeanStatistic getMeanStatistic(String key);
/**
* Add a duration to the min/mean/max statistics, using the
* given prefix and adding a suffix for each specific value.
*
* The update is not-atomic, even though each individual statistic
* is updated thread-safely. If two threads update the values
* simultaneously, at the end of each operation the state will
* be correct. It is only during the sequence that the statistics
* may be observably inconsistent.
* @param prefix statistic prefix
* @param durationMillis duration in milliseconds.
*/
void addTimedOperation(String prefix, long durationMillis);
/**
* Add a duration to the min/mean/max statistics, using the
* given prefix and adding a suffix for each specific value.;
* increment tha counter whose name == prefix.
*
* If any of the statistics are not registered, that part of
* the sequence will be omitted -the rest will proceed.
*
* The update is not-atomic, even though each individual statistic
* is updated thread-safely. If two threads update the values
* simultaneously, at the end of each operation the state will
* be correct. It is only during the sequence that the statistics
* may be observably inconsistent.
* @param prefix statistic prefix
* @param duration duration
*/
void addTimedOperation(String prefix, Duration duration);
}