Statsd Anomaly Detection fixes
Minor fixes and notes regarding the setting of refractory periods and
anomaly alarms.
Also changes the anomaly alarms from inexact to exact.
Test: run cts-dev -m CtsStatsdHostTestCases -t android.cts.statsd.alert.AnomalyDetectionTests
Change-Id: Ia4f4c84dd647ebbbad4bab66164cd7709f8628e8
diff --git a/cmds/statsd/src/StatsService.cpp b/cmds/statsd/src/StatsService.cpp
index e111f58..ee38667 100644
--- a/cmds/statsd/src/StatsService.cpp
+++ b/cmds/statsd/src/StatsService.cpp
@@ -669,11 +669,18 @@
"Only system uid can call informAnomalyAlarmFired");
}
- VLOG("StatsService::informAnomalyAlarmFired succeeded");
+ // TODO: This may be a bug. time(nullptr) can be off (wrt AlarmManager's time) and cause us to
+ // miss the alarm! Eventually we will switch to using elapsedRealTime everywhere,
+ // which may hopefully fix the problem, so we'll leave this alone for now.
uint64_t currentTimeSec = time(nullptr);
std::unordered_set<sp<const AnomalyAlarm>, SpHash<AnomalyAlarm>> anomalySet =
mAnomalyMonitor->popSoonerThan(static_cast<uint32_t>(currentTimeSec));
- mProcessor->onAnomalyAlarmFired(currentTimeSec * NS_PER_SEC, anomalySet);
+ if (anomalySet.size() > 0) {
+ VLOG("Found an anomaly alarm that fired.");
+ mProcessor->onAnomalyAlarmFired(currentTimeSec * NS_PER_SEC, anomalySet);
+ } else {
+ VLOG("Cannot find an anomaly alarm that fired. Perhaps it was recently cancelled.");
+ }
return Status::ok();
}
diff --git a/cmds/statsd/src/anomaly/AnomalyMonitor.cpp b/cmds/statsd/src/anomaly/AnomalyMonitor.cpp
index 72d29d0..ca34dc6 100644
--- a/cmds/statsd/src/anomaly/AnomalyMonitor.cpp
+++ b/cmds/statsd/src/anomaly/AnomalyMonitor.cpp
@@ -96,7 +96,7 @@
std::lock_guard<std::mutex> lock(mLock);
for (sp<const AnomalyAlarm> t = mPq.top(); t != nullptr && t->timestampSec <= timestampSec;
- t = mPq.top()) {
+ t = mPq.top()) {
oldAlarms.insert(t);
mPq.pop(); // remove t
}
diff --git a/cmds/statsd/src/anomaly/DurationAnomalyTracker.cpp b/cmds/statsd/src/anomaly/DurationAnomalyTracker.cpp
index fa0bc0c..3ba943c 100644
--- a/cmds/statsd/src/anomaly/DurationAnomalyTracker.cpp
+++ b/cmds/statsd/src/anomaly/DurationAnomalyTracker.cpp
@@ -53,10 +53,11 @@
void DurationAnomalyTracker::startAlarm(const MetricDimensionKey& dimensionKey,
const uint64_t& timestampNs) {
- uint32_t timestampSec = static_cast<uint32_t>(timestampNs / NS_PER_SEC);
+ // Alarms are stored in secs. Must round up, since if it fires early, it is ignored completely.
+ uint32_t timestampSec = static_cast<uint32_t>((timestampNs -1)/ NS_PER_SEC) + 1; // round up
if (isInRefractoryPeriod(timestampNs, dimensionKey)) {
- VLOG("Skipping setting anomaly alarm since it'd fall in the refractory period");
- return;
+ VLOG("Setting a delayed anomaly alarm lest it fall in the refractory period");
+ timestampSec = getRefractoryPeriodEndsSec(dimensionKey) + 1;
}
sp<const AnomalyAlarm> alarm = new AnomalyAlarm{timestampSec};
mAlarms.insert({dimensionKey, alarm});
diff --git a/services/core/java/com/android/server/stats/StatsCompanionService.java b/services/core/java/com/android/server/stats/StatsCompanionService.java
index ef6067a..c22ec4b 100644
--- a/services/core/java/com/android/server/stats/StatsCompanionService.java
+++ b/services/core/java/com/android/server/stats/StatsCompanionService.java
@@ -290,7 +290,8 @@
public final static class AnomalyAlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
- Slog.i(TAG, "StatsCompanionService believes an anomaly has occurred.");
+ Slog.i(TAG, "StatsCompanionService believes an anomaly has occurred at time "
+ + System.currentTimeMillis() + "ms.");
synchronized (sStatsdLock) {
if (sStatsd == null) {
Slog.w(TAG, "Could not access statsd to inform it of anomaly alarm firing");
@@ -361,9 +362,8 @@
final long callingToken = Binder.clearCallingIdentity();
try {
// using RTC, not RTC_WAKEUP, so if device is asleep, will only fire when it awakens.
- // This alarm is inexact, leaving its exactness completely up to the OS optimizations.
// AlarmManager will automatically cancel any previous mAnomalyAlarmIntent alarm.
- mAlarmManager.set(AlarmManager.RTC, timestampMs, mAnomalyAlarmIntent);
+ mAlarmManager.setExact(AlarmManager.RTC, timestampMs, mAnomalyAlarmIntent);
} finally {
Binder.restoreCallingIdentity(callingToken);
}