Limit log batching to maximum 100 logs per batch

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 - [HTTP Client errors](https://docs.sentry.io/platforms/apple/guides/ios/configuration/http-client-errors/) now mark sessions as errored (#6633)
 
+### Fixes
+
+- Limit log batching to maximum 100 logs per batch (#6768)
+
 ## 9.0.0-alpha.1
 
 ### Breaking Changes

Sources/Swift/Tools/SentryLogBatcher.swift

@@ -12,6 +12,7 @@ import Foundation
 
     private let options: Options
     private let flushTimeout: TimeInterval
+    private let maxLogCount: Int
     private let maxBufferSizeBytes: Int
     private let dispatchQueue: SentryDispatchQueueWrapper
 
@@ -24,14 +25,16 @@ import Foundation
 
     private weak var delegate: SentryLogBatcherDelegate?
 
-    /// Convenience initializer with default flush timeout and buffer size.
+    /// Convenience initializer with default flush timeout, max log count (100), and buffer size.
     /// - Parameters:
     ///   - options: The Sentry configuration options
     ///   - dispatchQueue: A **serial** dispatch queue wrapper for thread-safe access to mutable state
     ///   - delegate: The delegate to handle captured log batches
     ///
     /// - Important: The `dispatchQueue` parameter MUST be a serial queue to ensure thread safety.
     ///              Passing a concurrent queue will result in undefined behavior and potential data races.
+    ///
+    /// - Note: Setting `maxLogCount` to 100. While Replay hard limit is 1000, we keep this lower, as it's hard to lower once released.
     @_spi(Private) public convenience init(
         options: Options,
         dispatchQueue: SentryDispatchQueueWrapper,
@@ -40,7 +43,8 @@ import Foundation
         self.init(
             options: options,
             flushTimeout: 5,
-            maxBufferSizeBytes: 1_024 * 1_024, // 1MB
+            maxLogCount: 100, // Maximum 100 logs per batch
+            maxBufferSizeBytes: 1_024 * 1_024, // 1MB buffer size
             dispatchQueue: dispatchQueue,
             delegate: delegate
         )
@@ -50,21 +54,26 @@ import Foundation
     /// - Parameters:
     ///   - options: The Sentry configuration options
     ///   - flushTimeout: The timeout interval after which buffered logs will be flushed
+    ///   - maxLogCount: Maximum number of logs to batch before triggering an immediate flush.
     ///   - maxBufferSizeBytes: The maximum buffer size in bytes before triggering an immediate flush
     ///   - dispatchQueue: A **serial** dispatch queue wrapper for thread-safe access to mutable state
     ///   - delegate: The delegate to handle captured log batches
     ///
     /// - Important: The `dispatchQueue` parameter MUST be a serial queue to ensure thread safety.
     ///              Passing a concurrent queue will result in undefined behavior and potential data races.
+    ///
+    /// - Note: Logs are flushed when either `maxLogCount` or `maxBufferSizeBytes` limit is reached.
     @_spi(Private) public init(
         options: Options,
         flushTimeout: TimeInterval,
+        maxLogCount: Int,
         maxBufferSizeBytes: Int,
         dispatchQueue: SentryDispatchQueueWrapper,
         delegate: SentryLogBatcherDelegate
     ) {
         self.options = options
         self.flushTimeout = flushTimeout
+        self.maxLogCount = maxLogCount
         self.maxBufferSizeBytes = maxBufferSizeBytes
         self.dispatchQueue = dispatchQueue
         self.delegate = delegate
@@ -189,7 +198,8 @@ import Foundation
             encodedLogs.append(encodedLog)
             encodedLogsSize += encodedLog.count
 
-            if encodedLogsSize >= maxBufferSizeBytes {
+            // Flush when we reach max log count or max buffer size
+            if encodedLogs.count >= maxLogCount || encodedLogsSize >= maxBufferSizeBytes {
                 performCaptureLogs()
             } else if encodedLogsWereEmpty && timerWorkItem == nil {
                 startTimer()

Tests/SentryTests/SentryLogBatcherTests.swift

@@ -24,7 +24,8 @@ final class SentryLogBatcherTests: XCTestCase {
         sut = SentryLogBatcher(
             options: options,
             flushTimeout: 0.1, // Very small timeout for testing
-            maxBufferSizeBytes: 800, // byte limit for testing (log with attributes ~390 bytes)
+            maxLogCount: 10, // Maximum 10 logs per batch
+            maxBufferSizeBytes: 8_000, // byte limit for testing (log with attributes ~390 bytes)
             dispatchQueue: testDispatchQueue,
             delegate: testDelegate
         )
@@ -69,7 +70,7 @@ final class SentryLogBatcherTests: XCTestCase {
 
     func testBufferReachesMaxSize_FlushesImmediately() throws {
         // Arrange
-        let largeLogBody = String(repeating: "A", count: 600) // Larger than 500 byte limit
+        let largeLogBody = String(repeating: "A", count: 8_000) // Larger than 8000 byte limit
         let largeLog = createTestLog(body: largeLogBody)
 
         // Act
@@ -84,6 +85,27 @@ final class SentryLogBatcherTests: XCTestCase {
         XCTAssertEqual(capturedLogs[0].body, largeLogBody)
     }
 
+    // MARK: - Max Log Count Tests
+
+    func testMaxLogCount_FlushesWhenReached() throws {
+        // Act - Add exactly maxLogCount logs
+        for i in 0..<9 {
+            let log = createTestLog(body: "Log \(i + 1)")
+            sut.addLog(log, scope: scope)
+        }
+
+        XCTAssertEqual(testDelegate.captureLogsDataInvocations.count, 0)
+
+        let log = createTestLog(body: "Log \(10)") // Reached 10 max logs limit
+        sut.addLog(log, scope: scope)
+
+        // Assert - Should have flushed once when reaching maxLogCount
+        XCTAssertEqual(testDelegate.captureLogsDataInvocations.count, 1)
+
+        let capturedLogs = testDelegate.getCapturedLogs()
+        XCTAssertEqual(capturedLogs.count, 10, "Should have captured exactly \(10) logs")
+    }
+
     // MARK: - Timeout Tests
 
     func testTimeout_FlushesAfterDelay() throws {
@@ -185,7 +207,7 @@ final class SentryLogBatcherTests: XCTestCase {
 
     func testScheduledFlushAfterBufferAlreadyFlushed_DoesNothing() throws {
         // Arrange
-        let largeLogBody = String(repeating: "B", count: 300)
+        let largeLogBody = String(repeating: "B", count: 4_000)
         let log1 = createTestLog(body: largeLogBody)
         let log2 = createTestLog(body: largeLogBody)
 
@@ -235,6 +257,7 @@ final class SentryLogBatcherTests: XCTestCase {
         let sutWithRealQueue = SentryLogBatcher(
             options: options,
             flushTimeout: 5,
+            maxLogCount: 1_000, // Maximum 1000 logs per batch
             maxBufferSizeBytes: 10_000,
             dispatchQueue: SentryDispatchQueueWrapper(),
             delegate: testDelegate
@@ -264,6 +287,7 @@ final class SentryLogBatcherTests: XCTestCase {
         let sutWithRealQueue = SentryLogBatcher(
             options: options,
             flushTimeout: 0.2,
+            maxLogCount: 1_000, // Maximum 1000 logs per batch
             maxBufferSizeBytes: 10_000,
             dispatchQueue: SentryDispatchQueueWrapper(),
             delegate: testDelegate