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+# Serverless Mode Large File Issue
+
+## Summary
+While the serverless mode deadlock has been partially resolved, files larger than approximately 10KB still experience timeouts in serverless mode.
+
+## Current Status
+- ✅ Files up to 10KB work correctly
+- ❌ Files larger than 100KB timeout
+- ❌ The 72MB test_data.log used in profiling examples still hangs
+
+## Technical Details
+The current fix uses a channel-based approach to prevent deadlocks:
+- Separate goroutines for reading from client/server handlers
+- Buffered channels (100 slots) for data transfer
+- 32KB buffer size for read operations
+
+However, this approach still has limitations with larger files, possibly due to:
+1. Channel buffer exhaustion
+2. Synchronization issues between read/write operations
+3. EOF handling complexities
+4. Memory pressure from buffering large amounts of data
+
+## Workaround
+For profiling large files, avoid serverless mode by specifying a dummy server:
+```bash
+./dcat -profile -profiledir profiles -plain -cfg none -servers dummy test_data.log
+```
+
+## Proposed Solutions
+
+### Short-term
+1. Increase channel buffer sizes dynamically based on file size
+2. Implement backpressure handling
+3. Add proper flow control between readers and writers
+
+### Long-term
+1. Redesign serverless mode to avoid bidirectional copying
+2. Implement a proper streaming architecture
+3. Consider using io.Pipe with proper goroutine management
+4. Add file size detection and automatic mode switching
+
+## Testing
+Use the test_serverless.go script to verify fixes:
+```go
+// Test different file sizes
+sizes := []struct {
+    name string
+    size int
+}{
+    {"tiny", 100},        // ✅ Works
+    {"small", 1024},      // ✅ Works  
+    {"medium", 10240},    // ✅ Works
+    {"large", 102400},    // ❌ Timeouts
+    {"xlarge", 1048576},  // ❌ Timeouts
+}
+```
+
+## Impact
+- Profiling benchmarks work for small to medium test files
+- Large file profiling requires non-serverless mode
+- Integration tests may need adjustment if they use large files in serverless mode
+\ No newline at end of file