Этот доклад будет максимально прикладным. Насколько MetricKit хорош? Какие данные действительно помогут оптимизировать работу приложения? Как подружить MetricKit с другими метриками? В приложении Vivid используется MetricKit и мы уже решили эти вопросы и многие другие.

1. 1

2. Марина Звягина
Vivid Money
Используем MetricKit
в бою

3. План
3
1 MetricKit - основные сущности и как с ними работать
2 Примеры и истории из нашей практики
3 Итоги

4. 4
MXMetricManager
MXMetricManagerSubscriber
MXMetricPayload
MXDiagnosticPayload
MXAppLaunchMetric
MXAppResponsivenessMetric
MXDiskIOMetric
MXMemoryMetric
MXDisplayMetric
MXAnimationMetric
MXAppExitMetric
MXSignpostMetric
MXMetaData
MXCPUExceptionDiagnostic
MXDiskWriteExceptionDiagnostic
MXHangDiagnostic
MXCrashDiagnostic
MetricKit
MXHistogram
MXMetric

5. 5
MXMetricManager
let metrikManager = MXMetricManager.shared
metrikManager.add(self)
open func add(_ subscriber: MXMetricManagerSubscriber)
open func remove(_ subscriber: MXMetricManagerSubscriber)
@available(iOS 13.0, *)
open var pastPayloads: [MXMetricPayload] { get }
open var pastDiagnosticPayloads: [MXDiagnosticPayload] { get }
@available(iOS 14.0, *)
What’s New in MetricKit

6. 6
MXMetricManagerSubscriber
optional func didReceive(_ payloads: [MXMetricPayload])
optional func didReceive(_ payloads: [MXDiagnosticPayload])

7. MXMetricPayload
includesMultipleApplicationVersions Bool
latestApplicationVersion NSTaggedPointerString "1.77.0"
metaData MXMetaData
regionFormat NSTaggedPointerString @"RU"
osVersion NSCFString @"iPhone OS 15.2 (19C56)"
deviceType NSCFString @"iPhone 13,4"
applicationBuildVersion NSTaggedPointerString @"1"
platformArchitecture NSTaggedPointerString @"arm64e"
timeStampBegin NSTaggedDate 2022-02-03 21:00:00 UTC
timeStampEnd NSTaggedDate 2022-02-04 21:00:00 UTC
🤩

8. MXMetricPayload
applicationResponsivenessMetrics MXAppResponsivenessMetric
histogrammedAppHangTime (buckets)
diskIOMetrics MXDiskIOMetric
cumulativeLogicalWrites "1300kB"
locationActivityMetrics MXLocationActivityMetric
cumulativeBestAccuracyTime "20 sec"
cumulativeBastAccuracyForNavigationTime
cumulativeNearestTenMetersAccuracyTime
cumulativeHundredMetersAccuracyTime
cumulativeKilometerAccuracyTime
cumulativeThreeKilometersAccuracyTime
🤩
Improving Your App's Performance
AnyHashable("applicationResponsivenessMetrics"): {
histogrammedAppHangTime = {
histogramNumBuckets = 3;
histogramValue = {
0 = {
bucketCount = 50;
bucketEnd = "100 ms";
bucketStart = "0 ms";
};
1 = {
bucketCount = 60;
bucketEnd = "400 ms";
bucketStart = "100 ms";
};
2 = {
bucketCount = 30;
bucketEnd = "700 ms";
bucketStart = "400 ms";
};
};
};
}

9. 9
MXMetricPayload 🤩
applicationLaunchMetrics MXAppLaunchMetric
histogrammedTimeToFirstDraw
histogrammedApplicationResumeTime
histogrammedOptimizedTimeToFirstDraw
What’s New in MetricKit

10. 10
@available(iOS 14.0, *)
Нормальный выход
Вытеснено другим приложением в foreground
Переходы между стейтами занимают больше 20 секунд
MXMetricPayload 🤩
cumulativeBadAccessExitCount
cumulativeIllegalInstructionExitCount
cumulativeAbnormalExitCount
cumulativeCPUResourceLimitExitCount
cumulativeMemoryResourceLimitExitCount
cumulativePressureExitCount
cumulativeSuspendedWithLockedFileExitCount
cumulativeAppWatchdogExitCount
cumulativeBackgroundTaskAssertionTimeoutExitCount
cumulativeNormalExitCount
Crashes
Segmentation fault
Illegal instruction
Asserts and uncaught exceptions
Understanding Crashes and Crash Logs
Why is my app getting killed
MXBackgroundExitData
Рассмотрим вместе с MXDiagnosticPayload

11. 11
MXMetricPayload 🤔
cellularConditionMetrics MXCellularConditionMetric
cellConditionTime = {
histogramNumBuckets = 3;
histogramValue = {
0 = {
bucketCount = 20;
bucketEnd = "1 bars";
bucketStart = "1 bars";
};
1 = {
bucketCount = 30;
bucketEnd = "2 bars";
bucketStart = "2 bars";
};
2 = {
bucketCount = 50;
bucketEnd = "3 bars";
bucketStart = "3 bars";
};
};
};

12. Custom Metric
12
let logHandle = MXMetricManager.makeLogHandle(category: "HomeScreen")
mxSignpost(.begin, log: logHandle, name: "homeScreenLaunching")
mxSignpost(.end, log: logHandle, name: "homeScreenLaunching")
MXSignpostMetric
histogram count
mxSignpost(.event, log: logHandle, name: "homeScreenLaunching")
os_signpost

13. 13
mxSignpost vs os_signpost
1.29ms vs 1.17ms

14. 14
MXDiagnosticPayload
cpuExceptionDiagnostics: [MXCPUExceptionDiagnostic]? cpuMetrics
diskWriteExceptionDiagnostics: [MXDickWriteExceptionDiagnostic]? diskIOMetrics
hangDiagnostics: [MXHangDiagnostic]? applicationResponsivenessMetrics
crashDiagnostics: [MXCrashDiagnostic]? applicationExitMetrics

15. 15
MXCPUExceptionDiagnostic
CPU Exception, or a "high CPU usage termination"
80% CPU over a period of one minute (on background execution)
Why is my app getting killed
Solving CPU Usage Crashes with Xcode's Energy Organizer
cumulativeCPUResourceLimitExitCount
Чтобы избежать этого exception'а:
move work into BGProcessingTask
MXBackgroundExitData

16. 16
MXDiskWriteExceptionDiagnostic
"diskIOMetrics": {
cumulativeLogicalWrites = "1300 kB"
}
Генерируется, если количество записей > 1 ГБ в день
"callStackTree" : {
"callStacks" : [
{
"callStackRootFrames" : [
{
…
"sampleCount" : 20
"diagnosticMetaData" : {
…
"regionFormat" : "GB",
"writesCaused" : "2,000 byte"
…
}
A disk write exception occurs when the app writes an excessive amount of data to the disk.
diskIOMetrics MXDiskIOMetric
cumulativeLogicalWrites "1300kB"

17. 17
MXCrashDiagnostic
MXBackgroundExitData
cumulativeBadAccessExitCount
cumulativeIllegalInstructionExitCount
cumulativeAbnormalExitCount
MXCrashDiagnostic
• Stack trace
• Signal
• Exception code
• Termination reason

18. 18
MXHangDiagnostic
Eliminate animation hitches with XCTest
Все данные unsymbolicated - можно использовать утилиту ATOS
cd ~/Library/Developer/Xcode/Archives/2022-01-26/Vivid 26.01.2022, 20.43.xcarchive/dSYMs/Vivid.app.dSYM/Contents/Resources/DWARF/
atos -arch arm64 -o myApp 0x4329526096
Identify trends with the Power and Performance API
An object representing a diagnostic report for an app that is too busy
to handle user input responsively
applicationResponsivenessMetrics MXAppResponsivenessMetric
histogrammedAppHangTime (buckets)

19. 19
MXMetricPayload Test payloads

20. План
20
1 MetricKit - основные сущности и как с ними работать
2 Примеры и истории из нашей практики
3 Итоги
✅

21. 21
reality
+ +
In
fl
ux data input format
Telegraf
VictoriaMetrics
Grafana
vivid

22. 22

23. reality.code
23
struct PerformanceMeasure {
var callTime: TimeInterval
let type: PerformanceMeasureType
let concreteName: String?
var stopTime: TimeInterval?
}
struct TelegrafEvent {
let name: String
let time: TimeInterval
let tags: [String: String]
let metricType: TelegrafMetricType
}
let time = measure.stopTime - measure.callTime
Date().timeIntervalSince1970
vivid

24. 24
App launch metric
func measureAppStartUpTime() -> (Double, Double) {
var kinfo = kinfo_proc()
var size = MemoryLayout<kinfo_proc>.stride
var mib : [Int32] = [CTL_KERN, KERN_PROC, KERN_PROC_PID, getpid()]
sysctl(&mib, u_int(mib.count), &kinfo, &size, nil, 0)
let startTime = kinfo.kp_proc.p_starttime
var time = timeval(tv_sec: 0, tv_usec: 0)
gettimeofday(&time, nil)
let currentTimeMilliseconds = (Double(Int64(time.tv_sec) * 1_000) + Double(time.tv_usec) / 1_000.0) / 1_000.0
let processTimeMilliseconds = (Double(Int64(startTime.tv_sec) * 1_000) + Double(startTime.tv_usec) / 1_000.0) /
1_000.0
return (processTimeMilliseconds, currentTimeMilliseconds)
}
vivid

25. 25

26. 26
MetricKit
@available(iOS 13.0, *)
func didReceive(_ payloads: [MXMetricPayload]) {
payloads.forEach { payload in
print(payload.dictionaryRepresentation())
var currentSaveValues: [String] = payloadsStored.get() ?? []
currentSaveValues.append("MXMetricPayload = (payload.dictionaryRepresentation().description)")
payloadsStored.set(value: currentSaveValues)
let firstDrawBuckets: [MXHistogramBucket] =
(payload.applicationLaunchMetrics?.histogrammedTimeToFirstDraw.bucketEnumerator.allObjects as?
[MXHistogramBucket<Unit>])
.rescue([])
firstDrawBuckets.forEach { bucket in
addMetricsIfNeeded(bucket: bucket, measureType: .appLaunchMetricsTime)
}
let resumeBackets: [MXHistogramBucket] =
(payload.applicationLaunchMetrics?.histogrammedApplicationResumeTime.bucketEnumerator.allObjects
as? [MXHistogramBucket<Unit>])
.rescue([])
resumeBackets.forEach { bucket in
addMetricsIfNeeded(bucket: bucket, measureType: .appResumeMetricsTime)
}
}
}
vivid

27. 27

28. 28
struct PerformanceNewMeasure {
var callTime: TimeInterval
let type: PerformanceMeasureType
let concreteName: String?
var stopTime: TimeInterval?
}
struct TelegrafEvent {
let name: String
let time: TimeInterval
let tags: [String: String]
let metricType: TelegrafMetricType
}
let time = measure.stopTime - measure.callTime
Date().timeIntervalSince1970
Date().timeIntervalSince1970
event.time.multiply(1_000)
Ответ
Date().timeIntervalSince1970
vivid reality.code

29. 29
histogrammedTimeToFirstDrawKey = {
histogramNumBuckets = 3;
histogramValue = {
0 = {
bucketCount = 50;
bucketEnd = "1010 ms";
bucketStart = "1000 ms";
};
1 = {
bucketCount = 60;
bucketEnd = "2010 ms";
bucketStart = "2000 ms";
};
2 = {
bucketCount = 30;
bucketEnd = "3010 ms";
bucketStart = "3000 ms";
};
};
};
"time_obtain_short_i,name=BeforeApp,env=stable,ver=1.77.0 ms=682.904005050659"
vivid reality.code

30. 30
@available(iOS 13.0, *)
func addMetricsIfNeeded(bucket: MXHistogramBucket<Unit>, measureType: PerformanceMeasureType) {
let bucketEnd = bucket.bucketEnd
let bucketStart = bucket.bucketStart
let countOfEvents = bucket.bucketCount
if bucketEnd.unit.symbol == "ms" && bucketStart.unit.symbol == "ms" {
let averageValue = (bucketEnd.value.plus(bucketStart.value)) / 2
let appLaunchEvent = performanceTracker.getEvent(with: .fastRequestLoading)
guard countOfEvents > 0 else { return }
for _ in 1...countOfEvents {
appLaunchEvent.addMeasure(callTime: 0, stopTime: averageValue, measureType:
measureType, kind: .simple)
}
}
}
vivid reality.code

31. reality Grafana
31
vivid

32. План
32
1 MetricKit - основные сущности и как с ними работать
2 Примеры и истории из нашей практики
3 Итоги
✅
✅

33. 33
💚 MetricKit легко добавить
💚 MetricKit можно использовать вместе с остальными метриками, но есть 2 нюанса:
- Нужно учитывать, в каком они формате (их 3 - бакеты, количество и длительность)
- Следить за единицами измерения
💚 Удобно использовать метрики в связке с Pro
fi
ler и с Organizer - они позволяют смотреть в моменте
и регресс, а MetricKit позволяет смотреть в динамике от сборки к сборке
💚 Сопоставление MXMetricPayload vs MXDiagnosticPayload
❌ MXDiagnostic не доступен без dSYMs - не получится в реальном времени отслеживать данные
❌ Не все метрики кажутся полезными
❌ Perf tests
Итоги

34. MetricKit
What’s New in MetricKit
Improving Your App's Performance
Understanding Crashes and Crash Logs
Why is my app getting killed
Solving CPU Usage Crashes with Xcode's Energy Organizer
Eliminate animation hitches with XCTest
Identify trends with the Power and Performance API
Telegraf
VictoriaMetrics
Grafana
https://stackoverflow.com/questions/64378095/metrickit-mxdiagnostic-symbolication
https://swiftrocks.com/debug-cpu-exceptions-xcode-energy-reports
https://medium.com/naukri-engineering/overview-of-dsym-crashlytics-in-ios-dfd72eae8b58
iOS Performance Engineer Android Performance Engineer
https://jobs.vivid.money/jobs/Careers/33579000004386184/iOS-developer-Performance-team-?source=CareerSite
https://jobs.vivid.money/jobs/Careers/33579000004386170/Android-developer-Performance-team-?source=CareerSite