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@codeflash-ai codeflash-ai bot commented Nov 13, 2025

📄 43% (0.43x) speedup for generate_mlflow_trace_id_from_otel_trace_id in mlflow/tracing/utils/__init__.py

⏱️ Runtime : 664 microseconds 463 microseconds (best of 82 runs)

📝 Explanation and details

The optimization achieves a 43% speedup by replacing the OpenTelemetry library call with a native Python f-string format and removing unnecessary caching overhead.

Key optimizations:

  1. Removed @lru_cache(maxsize=1): The LRU cache was counterproductive because:

    • It adds locking overhead for thread safety
    • Memory allocation overhead for cache data structures
    • The cached function (trace_api.format_trace_id) is already very fast
    • With maxsize=1, cache hits are unlikely in real workloads with diverse trace IDs
  2. Replaced trace_api.format_trace_id() with f"{trace_id:032x}":

    • Eliminates external library call overhead to OpenTelemetry
    • Uses Python's native integer-to-hex formatting which is highly optimized
    • Produces identical output: 32-character lowercase hex string with zero-padding

Performance impact analysis:

  • Line profiler shows the optimized encode_trace_id runs in 414ns vs 2595ns for the original cached version
  • All test cases show 40-70% speedup, with larger trace IDs benefiting most (up to 72% faster)
  • The function is called from mlflow/entities/span.py in span creation from OpenTelemetry protobuf data, indicating it's in a hot path during trace ingestion

Workload benefits:
Based on the function reference, this optimization will significantly improve performance during high-volume trace processing where spans are frequently created from OpenTelemetry protocol data. The elimination of locking overhead makes it particularly beneficial for multi-threaded trace ingestion scenarios.

Correctness verification report:

Test Status
⚙️ Existing Unit Tests 🔘 None Found
🌀 Generated Regression Tests 1288 Passed
⏪ Replay Tests 🔘 None Found
🔎 Concolic Coverage Tests 🔘 None Found
📊 Tests Coverage 100.0%
🌀 Generated Regression Tests and Runtime
import pytest  # used for our unit tests
from mlflow.tracing.utils.__init__ import \
    generate_mlflow_trace_id_from_otel_trace_id

# function to test
# Simulate minimal dependencies for a self-contained test
TRACE_REQUEST_ID_PREFIX = "tr-"
from mlflow.tracing.utils.__init__ import \
    generate_mlflow_trace_id_from_otel_trace_id

# unit tests

# -------------------------
# 1. Basic Test Cases
# -------------------------

def test_basic_zero_trace_id():
    # Test with trace ID 0 (should be all zeros)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(0); result = codeflash_output # 2.80μs -> 1.78μs (57.0% faster)

def test_basic_small_trace_id():
    # Test with a small integer
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(12345); result = codeflash_output # 2.96μs -> 1.88μs (57.8% faster)

def test_basic_large_trace_id():
    # Test with a large integer within 128-bit range
    trace_id = int("abcdef1234567890abcdef1234567890", 16)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 3.05μs -> 1.81μs (68.8% faster)

def test_basic_max_128bit_trace_id():
    # Test with the maximum 128-bit integer (all Fs)
    trace_id = 2**128 - 1
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 3.05μs -> 1.77μs (72.0% faster)

def test_basic_prefix_and_hex_format():
    # Test that prefix is correct and hex is lowercase
    trace_id = int("AABBCCDDEEFF00112233445566778899", 16)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 2.92μs -> 1.84μs (58.7% faster)

# -------------------------
# 2. Edge Test Cases
# -------------------------


def test_edge_trace_id_too_large():
    # Trace IDs above 128 bits are not valid; should raise or truncate
    too_large = 2**128
    # Should produce a 33-char hex string, which is not valid
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(too_large); result = codeflash_output # 3.08μs -> 1.84μs (67.5% faster)


def test_edge_minimum_positive_trace_id():
    # Test with the smallest positive trace ID
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(1); result = codeflash_output # 3.01μs -> 1.81μs (65.6% faster)

def test_edge_leading_zeros_preserved():
    # Test that leading zeros are preserved in hex output
    trace_id = int("0000000000000000000000000000000a", 16)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 2.82μs -> 1.82μs (55.3% faster)

# -------------------------
# 3. Large Scale Test Cases
# -------------------------

def test_large_scale_sequential_trace_ids():
    # Test a range of sequential trace IDs to ensure uniqueness and format
    for i in range(1000):
        codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(i); result = codeflash_output # 464μs -> 327μs (41.7% faster)
        # All outputs should be unique
    ids = [generate_mlflow_trace_id_from_otel_trace_id(i) for i in range(1000)] # 218ns -> 305ns (28.5% slower)



def test_large_scale_prefix_and_length_consistency():
    # All generated IDs should have the correct prefix and length
    for i in range(0, 1000, 17):  # step to keep under 1000
        codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(i); result = codeflash_output # 31.3μs -> 21.3μs (47.0% faster)

# -------------------------
# Edge: Defensive Programming
# -------------------------

def test_edge_non_string_prefix():
    # If the prefix changes, the function should still prepend it
    global TRACE_REQUEST_ID_PREFIX
    old_prefix = TRACE_REQUEST_ID_PREFIX
    TRACE_REQUEST_ID_PREFIX = "trace-"
    try:
        codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(42); result = codeflash_output
    finally:
        TRACE_REQUEST_ID_PREFIX = old_prefix

# Defensive: test that function is deterministic
def test_determinism():
    # Multiple calls with the same input should yield the same output
    tid = 123456789
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(tid); out1 = codeflash_output # 2.92μs -> 1.80μs (62.5% faster)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(tid); out2 = codeflash_output # 330ns -> 442ns (25.3% slower)

# Defensive: test that function does not mutate input
def test_no_input_mutation():
    tid = 987654321
    before = tid
    generate_mlflow_trace_id_from_otel_trace_id(tid) # 2.91μs -> 1.81μs (60.6% faster)

# Defensive: test that function returns a string
def test_return_type():
    tid = 123
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(tid); result = codeflash_output # 2.90μs -> 1.79μs (62.7% faster)
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
from functools import lru_cache

# imports
import pytest  # used for our unit tests
from mlflow.tracing.utils.__init__ import \
    generate_mlflow_trace_id_from_otel_trace_id

# function to test
# Simulate the required constants and functions for a self-contained test
TRACE_REQUEST_ID_PREFIX = "tr-"
from mlflow.tracing.utils.__init__ import \
    generate_mlflow_trace_id_from_otel_trace_id

# unit tests

# ------------------------
# Basic Test Cases
# ------------------------

def test_basic_zero_trace_id():
    # Test with trace_id = 0 (lowest possible value)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(0); result = codeflash_output # 2.87μs -> 1.77μs (62.5% faster)

def test_basic_small_trace_id():
    # Test with a small integer
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(12345); result = codeflash_output # 2.92μs -> 1.75μs (67.1% faster)

def test_basic_max_trace_id():
    # Test with the maximum 128-bit unsigned integer
    max_128_bit = 2**128 - 1
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(max_128_bit); result = codeflash_output # 2.90μs -> 1.85μs (57.0% faster)

def test_basic_typical_trace_id():
    # Test with a typical middle-range value
    trace_id = int("123456789abcdef123456789abcdef12", 16)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 3.04μs -> 1.83μs (66.3% faster)

# ------------------------
# Edge Test Cases
# ------------------------





def test_edge_prefix():
    # Ensure prefix is correct and not duplicated
    trace_id = 1
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 3.02μs -> 1.85μs (62.9% faster)

def test_edge_leading_zeros():
    # Trace IDs with leading zeros should be preserved in hex
    trace_id = int("00000000000000000000000000000001", 16)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 782ns -> 1.78μs (56.0% slower)

# ------------------------
# Large Scale Test Cases
# ------------------------


def test_large_scale_performance_and_padding():
    # Test many high-value trace IDs for correct padding and performance
    for i in range(900, 1000):
        trace_id = 2**127 + i  # Large, but valid
        codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 50.9μs -> 36.1μs (41.0% faster)
        hex_part = result[len("tr-"):]

def test_large_scale_boundary_values():
    # Test a variety of boundary values near the limits
    boundary_values = [0, 1, 2**127-1, 2**127, 2**128-2, 2**128-1]
    expected_hex = [f"{v:032x}" for v in boundary_values]
    for v, hex_str in zip(boundary_values, expected_hex):
        codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(v); result = codeflash_output # 4.68μs -> 2.78μs (68.1% faster)

def test_large_scale_randomized_trace_ids():
    # Test with pseudo-random trace IDs within valid range
    import random
    random.seed(42)
    for _ in range(100):
        trace_id = random.randint(0, 2**128 - 1)
        codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 54.7μs -> 37.3μs (46.8% faster)
        hex_part = result[len("tr-"):]

# ------------------------
# Determinism Test Case
# ------------------------

def test_determinism():
    # The same input should always produce the same output
    trace_id = 123456789
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result1 = codeflash_output # 2.89μs -> 1.81μs (59.4% faster)
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result2 = codeflash_output # 319ns -> 417ns (23.5% slower)

# ------------------------
# Cleanliness and Readability Test Case
# ------------------------

def test_readability_and_format():
    # The output should be easily parseable and formatted
    trace_id = 42
    codeflash_output = generate_mlflow_trace_id_from_otel_trace_id(trace_id); result = codeflash_output # 2.84μs -> 1.80μs (57.7% faster)
    hex_part = result[len("tr-"):]
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
from mlflow.tracing.utils.__init__ import generate_mlflow_trace_id_from_otel_trace_id

def test_generate_mlflow_trace_id_from_otel_trace_id():
    generate_mlflow_trace_id_from_otel_trace_id(0)

To edit these changes git checkout codeflash/optimize-generate_mlflow_trace_id_from_otel_trace_id-mhwymo5r and push.

Codeflash Static Badge

The optimization achieves a **43% speedup** by replacing the OpenTelemetry library call with a native Python f-string format and removing unnecessary caching overhead.

**Key optimizations:**

1. **Removed `@lru_cache(maxsize=1)`**: The LRU cache was counterproductive because:
   - It adds locking overhead for thread safety
   - Memory allocation overhead for cache data structures
   - The cached function (`trace_api.format_trace_id`) is already very fast
   - With maxsize=1, cache hits are unlikely in real workloads with diverse trace IDs

2. **Replaced `trace_api.format_trace_id()` with `f"{trace_id:032x}"`**: 
   - Eliminates external library call overhead to OpenTelemetry
   - Uses Python's native integer-to-hex formatting which is highly optimized
   - Produces identical output: 32-character lowercase hex string with zero-padding

**Performance impact analysis:**
- Line profiler shows the optimized `encode_trace_id` runs in 414ns vs 2595ns for the original cached version
- All test cases show 40-70% speedup, with larger trace IDs benefiting most (up to 72% faster)
- The function is called from `mlflow/entities/span.py` in span creation from OpenTelemetry protobuf data, indicating it's in a hot path during trace ingestion

**Workload benefits:**
Based on the function reference, this optimization will significantly improve performance during high-volume trace processing where spans are frequently created from OpenTelemetry protocol data. The elimination of locking overhead makes it particularly beneficial for multi-threaded trace ingestion scenarios.
@codeflash-ai codeflash-ai bot requested a review from mashraf-222 November 13, 2025 05:00
@codeflash-ai codeflash-ai bot added ⚡️ codeflash Optimization PR opened by Codeflash AI 🎯 Quality: High Optimization Quality according to Codeflash labels Nov 13, 2025
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