jhoongo
commented
4 months ago I was thinking about something like this; wondering if this would work
diff --git a/Sources/OpenTelemetrySdk/Metrics/Stable/State/SynchronousMetricStorage.swift b/Sources/OpenTelemetrySdk/Metrics/Stable/State/SynchronousMetricStorage.swift
index 17f487a..1c6b484 100644
--- a/Sources/OpenTelemetrySdk/Metrics/Stable/State/SynchronousMetricStorage.swift
+++ b/Sources/OpenTelemetrySdk/Metrics/Stable/State/SynchronousMetricStorage.swift
@@ -20,6 +20,7 @@ public class SynchronousMetricStorage: SynchronousMetricStorageProtocol {
var aggregatorHandles = [[String: AttributeValue]: AggregatorHandle]()
let attributeProcessor: AttributeProcessor
var aggregatorHandlePool = [AggregatorHandle]()
+. let storageLock = Lock()
static func empty() -> SynchronousMetricStorageProtocol {
return EmptyMetricStorage.instance
@@ -67,20 +68,30 @@ public class SynchronousMetricStorage: SynchronousMetricStorageProtocol {
}
public func collect(resource: Resource, scope: InstrumentationScopeInfo, startEpochNanos: UInt64, epochNanos: UInt64) -> StableMetricData {
+ storageLock.lock()
+ defer {
+ storageLock.unlock()
+ }
+
let reset = aggregatorTemporality == .delta
let start = reset ? registeredReader.lastCollectedEpochNanos : startEpochNanos
var points = [PointData]()
+ let keys = aggregatorHandles.keys
aggregatorHandles.forEach { key, value in
let point = value.aggregateThenMaybeReset(startEpochNano: start, endEpochNano: epochNanos, attributes: key, reset: reset)
if reset {
- aggregatorHandles.removeValue(forKey: key)
aggregatorHandlePool.append(value)
}
points.append(point)
}
-
+ if reset {
+ for removeKey in keys {
+ aggregatorHandles.removeValue(forKey: removeKey)
+ }
+ }
+
if points.isEmpty {
return StableMetricData.empty
}
@@ -92,6 +103,11 @@ public class SynchronousMetricStorage: SynchronousMetricStorageProtocol {
}
public func recordLong(value: Int, attributes: [String: OpenTelemetryApi.AttributeValue]) {
+ storageLock.lock()
+ defer {
+ storageLock.unlock()
+ }
+
do {
let handle = try getAggregatorHandle(attributes: attributes)
handle.recordLong(value: value, attributes: attributes)
@@ -103,6 +119,11 @@ public class SynchronousMetricStorage: SynchronousMetricStorageProtocol {
}
public func recordDouble(value: Double, attributes: [String: OpenTelemetryApi.AttributeValue]) {
+. storageLock.lock()
+ defer {
+ storageLock.unlock()
+ }
+
do {
let handle = try getAggregatorHandle(attributes: attributes)
handle.recordDouble(value: value, attributes: attributes)
nachoBonafonte
Issue Details
I'm using
opentelemetry-swiftSDK to emit (stable) metrics with HTTP Exporter, and I'm getting occasional crash with following exception:Basically,
OtlpClientis a class that instruments metric emission, and we are emitting not a lot, but around 10~20 metrics (Counter/Histogram) at a given time (with 10 seconds export interval). And this is accounting for 0.05% of session crashes for over 10M sessions (which is small, but still consistent and can increase on how you use the SDK).It looks like when SynchronousMetricStorage collects metric and when a new metric is being recorded, it crashes.
I suspect that it tries to add/export at the same time and result in crash based on the look of the code.
Can we safeguard it with
Lockas aSynchronusMetricStorageproperty forcollect/recordLong/recordDoubleso that it doesn't interrupt each others? Any thought or suggestion?