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/*
* Copyright 2015 Facebook, Inc.
*
* Licensed 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.
*/
#include <folly/stats/TimeseriesHistogram.h>
#include <folly/stats/TimeseriesHistogram-defs.h>
#include <gtest/gtest.h>
using namespace std;
using namespace folly;
using std::chrono::seconds;
namespace IntMTMHTS {
enum Levels {
MINUTE,
TEN_MINUTE,
HOUR,
ALLTIME,
NUM_LEVELS,
};
const seconds kDurations[] = {
seconds(60), seconds(600), seconds(3600), seconds(0)
};
};
namespace IntMHTS {
enum Levels {
MINUTE,
HOUR,
ALLTIME,
NUM_LEVELS,
};
const seconds kDurations[] = {
seconds(60), seconds(3600), seconds(0)
};
};
typedef std::mt19937 RandomInt32;
TEST(TimeseriesHistogram, Percentile) {
RandomInt32 random(5);
// [10, 109], 12 buckets including above and below
{
TimeseriesHistogram<int> h(10, 10, 110,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
EXPECT_EQ(0, h.getPercentileEstimate(0, IntMTMHTS::ALLTIME));
EXPECT_EQ(12, h.getNumBuckets());
EXPECT_EQ(10, h.getBucketSize());
EXPECT_EQ(10, h.getMin());
EXPECT_EQ(110, h.getMax());
for (int i = 0; i < h.getNumBuckets(); ++i) {
EXPECT_EQ(4, h.getBucket(i).numLevels());
}
int maxVal = 120;
h.addValue(seconds(0), 0);
h.addValue(seconds(0), maxVal);
for (int i = 0; i < 98; i++) {
h.addValue(seconds(0), random() % maxVal);
}
h.update(std::chrono::duration_cast<std::chrono::seconds>(
std::chrono::system_clock::now().time_since_epoch()));
// bucket 0 stores everything below min, so its minimum
// is the lowest possible number
EXPECT_EQ(std::numeric_limits<int>::min(),
h.getPercentileBucketMin(1, IntMTMHTS::ALLTIME));
EXPECT_EQ(110, h.getPercentileBucketMin(99, IntMTMHTS::ALLTIME));
EXPECT_EQ(-2, h.getPercentileEstimate(0, IntMTMHTS::ALLTIME));
EXPECT_EQ(-1, h.getPercentileEstimate(1, IntMTMHTS::ALLTIME));
EXPECT_EQ(119, h.getPercentileEstimate(99, IntMTMHTS::ALLTIME));
EXPECT_EQ(120, h.getPercentileEstimate(100, IntMTMHTS::ALLTIME));
}
}
TEST(TimeseriesHistogram, String) {
RandomInt32 random(5);
// [10, 109], 12 buckets including above and below
{
TimeseriesHistogram<int> hist(10, 10, 110,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
int maxVal = 120;
hist.addValue(seconds(0), 0);
hist.addValue(seconds(0), maxVal);
for (int i = 0; i < 98; i++) {
hist.addValue(seconds(0), random() % maxVal);
}
hist.update(seconds(0));
const char* const kStringValues1[IntMTMHTS::NUM_LEVELS] = {
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
};
CHECK_EQ(IntMTMHTS::NUM_LEVELS, hist.getNumLevels());
for (int level = 0; level < hist.getNumLevels(); ++level) {
EXPECT_EQ(kStringValues1[level], hist.getString(level));
}
const char* const kStringValues2[IntMTMHTS::NUM_LEVELS] = {
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
"-2147483648:12:4,10:8:13,20:8:24,30:6:34,40:13:46,50:8:54,60:7:64,"
"70:7:74,80:8:84,90:10:94,100:3:103,110:10:115",
};
CHECK_EQ(IntMTMHTS::NUM_LEVELS, hist.getNumLevels());
for (int level = 0; level < hist.getNumLevels(); ++level) {
EXPECT_EQ(kStringValues2[level], hist.getString(level));
}
}
}
TEST(TimeseriesHistogram, Clear) {
{
TimeseriesHistogram<int> hist(10, 0, 100,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
for (int now = 0; now < 3600; now++) {
for (int i = 0; i < 100; i++) {
hist.addValue(seconds(now), i, 2); // adds each item 2 times
}
}
// check clearing
hist.clear();
for (int b = 0; b < hist.getNumBuckets(); ++b) {
EXPECT_EQ(0, hist.getBucket(b).count(IntMTMHTS::MINUTE));
EXPECT_EQ(0, hist.getBucket(b).count(IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(0, hist.getBucket(b).count(IntMTMHTS::HOUR));
EXPECT_EQ(0, hist.getBucket(b).count(IntMTMHTS::ALLTIME));
}
for (int pct = 0; pct <= 100; pct++) {
EXPECT_EQ(0, hist.getPercentileBucketMin(pct, IntMTMHTS::MINUTE));
EXPECT_EQ(0, hist.getPercentileBucketMin(pct, IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(0, hist.getPercentileBucketMin(pct, IntMTMHTS::HOUR));
EXPECT_EQ(0, hist.getPercentileBucketMin(pct, IntMTMHTS::ALLTIME));
EXPECT_EQ(0, hist.getPercentileEstimate(pct, IntMTMHTS::MINUTE));
EXPECT_EQ(0, hist.getPercentileEstimate(pct, IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(0, hist.getPercentileEstimate(pct, IntMTMHTS::HOUR));
EXPECT_EQ(0, hist.getPercentileEstimate(pct, IntMTMHTS::ALLTIME));
}
}
}
TEST(TimeseriesHistogram, Basic) {
{
TimeseriesHistogram<int> hist(10, 0, 100,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
for (int now = 0; now < 3600; now++) {
for (int i = 0; i < 100; i++) {
hist.addValue(seconds(now), i);
}
}
hist.update(seconds(3599));
for (int pct = 1; pct <= 100; pct++) {
int expected = (pct - 1) / 10 * 10;
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::MINUTE));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct,
IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::HOUR));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::ALLTIME));
}
for (int b = 1; (b + 1) < hist.getNumBuckets(); ++b) {
EXPECT_EQ(600, hist.getBucket(b).count(IntMTMHTS::MINUTE));
EXPECT_EQ(6000, hist.getBucket(b).count(IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(36000, hist.getBucket(b).count(IntMTMHTS::HOUR));
EXPECT_EQ(36000, hist.getBucket(b).count(IntMTMHTS::ALLTIME));
}
EXPECT_EQ(0, hist.getBucket(0).count(IntMTMHTS::MINUTE));
EXPECT_EQ(0, hist.getBucket(hist.getNumBuckets() - 1).count(
IntMTMHTS::MINUTE));
}
// -----------------
{
TimeseriesHistogram<int> hist(10, 0, 100,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
for (int now = 0; now < 3600; now++) {
for (int i = 0; i < 100; i++) {
hist.addValue(seconds(now), i, 2); // adds each item 2 times
}
}
hist.update(seconds(3599));
for (int pct = 1; pct <= 100; pct++) {
int expected = (pct - 1) / 10 * 10;
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::MINUTE));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct,
IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::HOUR));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::ALLTIME));
}
for (int b = 1; (b + 1) < hist.getNumBuckets(); ++b) {
EXPECT_EQ(600 * 2, hist.getBucket(b).count(IntMTMHTS::MINUTE));
EXPECT_EQ(6000 * 2, hist.getBucket(b).count(IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(36000 * 2, hist.getBucket(b).count(IntMTMHTS::HOUR));
EXPECT_EQ(36000 * 2, hist.getBucket(b).count(IntMTMHTS::ALLTIME));
}
EXPECT_EQ(0, hist.getBucket(0).count(IntMTMHTS::MINUTE));
EXPECT_EQ(0, hist.getBucket(hist.getNumBuckets() - 1).count(
IntMTMHTS::MINUTE));
}
// -----------------
{
TimeseriesHistogram<int> hist(10, 0, 100,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
for (int now = 0; now < 3600; now++) {
for (int i = 0; i < 50; i++) {
hist.addValue(seconds(now), i * 2, 2); // adds each item 2 times
}
}
hist.update(seconds(3599));
for (int pct = 1; pct <= 100; pct++) {
int expected = (pct - 1) / 10 * 10;
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::MINUTE));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct,
IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::HOUR));
EXPECT_EQ(expected, hist.getPercentileBucketMin(pct, IntMTMHTS::ALLTIME));
}
EXPECT_EQ(0, hist.getBucket(0).count(IntMTMHTS::MINUTE));
EXPECT_EQ(0, hist.getBucket(0).count(IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(0, hist.getBucket(0).count(IntMTMHTS::HOUR));
EXPECT_EQ(0, hist.getBucket(0).count(IntMTMHTS::ALLTIME));
EXPECT_EQ(0, hist.getBucket(hist.getNumBuckets() - 1).count(
IntMTMHTS::MINUTE));
EXPECT_EQ(0,
hist.getBucket(hist.getNumBuckets() - 1).
count(IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(0, hist.getBucket(hist.getNumBuckets() - 1).count(
IntMTMHTS::HOUR));
EXPECT_EQ(0,
hist.getBucket(hist.getNumBuckets() - 1).count(
IntMTMHTS::ALLTIME));
for (int b = 1; (b + 1) < hist.getNumBuckets(); ++b) {
EXPECT_EQ(600, hist.getBucket(b).count(IntMTMHTS::MINUTE));
EXPECT_EQ(6000, hist.getBucket(b).count(IntMTMHTS::TEN_MINUTE));
EXPECT_EQ(36000, hist.getBucket(b).count(IntMTMHTS::HOUR));
EXPECT_EQ(36000, hist.getBucket(b).count(IntMTMHTS::ALLTIME));
}
for (int i = 0; i < 100; ++i) {
hist.addValue(seconds(3599), 200 + i);
}
hist.update(seconds(3599));
EXPECT_EQ(100,
hist.getBucket(hist.getNumBuckets() - 1).count(
IntMTMHTS::ALLTIME));
}
}
TEST(TimeseriesHistogram, QueryByInterval) {
TimeseriesHistogram<int> mhts(8, 8, 120,
MultiLevelTimeSeries<int>(
60, IntMHTS::NUM_LEVELS,
IntMHTS::kDurations));
mhts.update(seconds(0));
int curTime;
for (curTime = 0; curTime < 7200; curTime++) {
mhts.addValue(seconds(curTime), 1);
}
for (curTime = 7200; curTime < 7200 + 3540; curTime++) {
mhts.addValue(seconds(curTime), 10);
}
for (curTime = 7200 + 3540; curTime < 7200 + 3600; curTime++) {
mhts.addValue(seconds(curTime), 100);
}
mhts.update(seconds(7200 + 3600 - 1));
struct TimeInterval {
TimeInterval(int s, int e)
: start(s), end(e) {}
std::chrono::seconds start;
std::chrono::seconds end;
};
TimeInterval intervals[12] = {
{ curTime - 60, curTime },
{ curTime - 3600, curTime },
{ curTime - 7200, curTime },
{ curTime - 3600, curTime - 60 },
{ curTime - 7200, curTime - 60 },
{ curTime - 7200, curTime - 3600 },
{ curTime - 50, curTime - 20 },
{ curTime - 3020, curTime - 20 },
{ curTime - 7200, curTime - 20 },
{ curTime - 3000, curTime - 1000 },
{ curTime - 7200, curTime - 1000 },
{ curTime - 7200, curTime - 3600 },
};
int expectedSums[12] = {
6000, 41400, 32400, 35400, 32129, 16200, 3000, 33600, 32308, 20000, 27899,
16200
};
int expectedCounts[12] = {
60, 3600, 7200, 3540, 7139, 3600, 30, 3000, 7178, 2000, 6199, 3600
};
// The first 7200 values added all fell below the histogram minimum,
// and went into the bucket that tracks all of the too-small values.
// This bucket reports a minimum value of the smallest possible integer.
int belowMinBucket = std::numeric_limits<int>::min();
int expectedValues[12][3] = {
{96, 96, 96},
{ 8, 8, 96},
{ belowMinBucket, belowMinBucket, 8}, // alltime
{ 8, 8, 8},
{ belowMinBucket, belowMinBucket, 8}, // alltime
{ belowMinBucket, belowMinBucket, 8}, // alltime
{96, 96, 96},
{ 8, 8, 96},
{ belowMinBucket, belowMinBucket, 8}, // alltime
{ 8, 8, 8},
{ belowMinBucket, belowMinBucket, 8}, // alltime
{ belowMinBucket, belowMinBucket, 8} // alltime
};
for (int i = 0; i < 12; i++) {
const auto& itv = intervals[i];
int s = mhts.sum(itv.start, itv.end);
EXPECT_EQ(expectedSums[i], s);
int c = mhts.count(itv.start, itv.end);
EXPECT_EQ(expectedCounts[i], c);
}
// 3 levels
for (int i = 1; i <= 100; i++) {
EXPECT_EQ(96, mhts.getPercentileBucketMin(i, 0));
EXPECT_EQ(96, mhts.getPercentileBucketMin(i, seconds(curTime - 60),
seconds(curTime)));
EXPECT_EQ(8, mhts.getPercentileBucketMin(i, seconds(curTime - 3540),
seconds(curTime - 60)));
}
EXPECT_EQ(8, mhts.getPercentileBucketMin(1, 1));
EXPECT_EQ(8, mhts.getPercentileBucketMin(98, 1));
EXPECT_EQ(96, mhts.getPercentileBucketMin(99, 1));
EXPECT_EQ(96, mhts.getPercentileBucketMin(100, 1));
EXPECT_EQ(belowMinBucket, mhts.getPercentileBucketMin(1, 2));
EXPECT_EQ(belowMinBucket, mhts.getPercentileBucketMin(66, 2));
EXPECT_EQ(8, mhts.getPercentileBucketMin(67, 2));
EXPECT_EQ(8, mhts.getPercentileBucketMin(99, 2));
EXPECT_EQ(96, mhts.getPercentileBucketMin(100, 2));
// 0 is currently the value for bucket 0 (below min)
for (int i = 0; i < 12; i++) {
const auto& itv = intervals[i];
int v = mhts.getPercentileBucketMin(1, itv.start, itv.end);
EXPECT_EQ(expectedValues[i][0], v);
v = mhts.getPercentileBucketMin(50, itv.start, itv.end);
EXPECT_EQ(expectedValues[i][1], v);
v = mhts.getPercentileBucketMin(99, itv.start, itv.end);
EXPECT_EQ(expectedValues[i][2], v);
}
for (int i = 0; i < 12; i++) {
const auto& itv = intervals[i];
int c = mhts.count(itv.start, itv.end);
// Some of the older intervals that fall in the alltime bucket
// are off by 1 or 2 in their estimated counts.
size_t tolerance = 0;
if (itv.start <= seconds(curTime - 7200)) {
tolerance = 2;
} else if (itv.start <= seconds(curTime - 3000)) {
tolerance = 1;
}
size_t actualCount = (itv.end - itv.start).count();
size_t estimatedCount = mhts.count(itv.start, itv.end);
EXPECT_GE(actualCount, estimatedCount);
EXPECT_LE(actualCount - tolerance, estimatedCount);
}
}
TEST(TimeseriesHistogram, SingleUniqueValue) {
int values[] = {-1, 0, 500, 1000, 1500};
for (int ii = 0; ii < 5; ++ii) {
int value = values[ii];
TimeseriesHistogram<int> h(10, 0, 1000,
MultiLevelTimeSeries<int>(
60, IntMTMHTS::NUM_LEVELS,
IntMTMHTS::kDurations));
const int kNumIters = 1000;
for (int jj = 0; jj < kNumIters; ++jj) {
h.addValue(seconds(time(nullptr)), value);
}
h.update(seconds(time(nullptr)));
// since we've only added one unique value, all percentiles should
// be that value
EXPECT_EQ(h.getPercentileEstimate(10, 0), value);
EXPECT_EQ(h.getPercentileEstimate(50, 0), value);
EXPECT_EQ(h.getPercentileEstimate(99, 0), value);
// Things get trickier if there are multiple unique values.
const int kNewValue = 750;
for (int kk = 0; kk < 2*kNumIters; ++kk) {
h.addValue(seconds(time(nullptr)), kNewValue);
}
h.update(seconds(time(nullptr)));
EXPECT_NEAR(h.getPercentileEstimate(50, 0), kNewValue+5, 5);
if (value >= 0 && value <= 1000) {
// only do further testing if value is within our bucket range,
// else estimates can be wildly off
if (kNewValue > value) {
EXPECT_NEAR(h.getPercentileEstimate(10, 0), value+5, 5);
EXPECT_NEAR(h.getPercentileEstimate(99, 0), kNewValue+5, 5);
} else {
EXPECT_NEAR(h.getPercentileEstimate(10, 0), kNewValue+5, 5);
EXPECT_NEAR(h.getPercentileEstimate(99, 0), value+5, 5);
}
}
}
}