feat: add Litracer docs in readme (#549)

* started working on readme

* Update README.md

* Update README.md

Co-authored-by: Bhimraj Yadav <bhimrajyadav977@gmail.com>

* feat: add debugger module with logging capabilities and update README for debugging instructions

* Update README.md

* Update README.md

* update

* update

* Update README.md

* Update README.md

---------

Co-authored-by: Bhimraj Yadav <bhimrajyadav977@gmail.com>

Author: deependujha

README.md

@@ -1144,8 +1144,77 @@ class CustomEncryption(Encryption):
 This allows the data to remain secure while maintaining flexibility in the encryption method.
 </details>
 
+<details>
+  <summary> ✅ Debug & Profile LitData with logs & Litracer</summary>
+
+&nbsp;
+
+LitData comes with built-in logging and profiling capabilities to help you debug and profile your data streaming workloads.
+
+<img width="1439" alt="431247797-0e955e71-2f9a-4aad-b7c1-a8218fed2e2e" src="https://github.com/user-attachments/assets/4e40676c-ba0b-49af-acac-975977173669" />
+
+- e.g., with LitData Streaming
+
+```python
+import litdata as ld
+from litdata.debugger import enable_tracer
+
+# WARNING: Remove existing trace `litdata_debug.log` file if it exists before re-tracing
+enable_tracer()
+
+if __name__ == "__main__":
+    dataset = ld.StreamingDataset("s3://my-bucket/my-data", shuffle=True)
+    dataloader = ld.StreamingDataLoader(dataset, batch_size=64)
+
+    for batch in dataloader:
+        print(batch)  # Replace with your data processing logic
+```
+
+1. Generate Debug Log:
+
+    - Run your Python program and it'll create a log file containing detailed debug information.
+
+    ```bash
+      python main.py
+    ```
+
+2. Install [Litracer](https://github.com/deependujha/litracer/):
+
+    - Option 1: Using Go (recommended)
+        - Install Go on your system.
+        - Run the following command to install Litracer:
+
+        ```bash
+          go install github.com/deependujha/litracer@latest
+        ```
+
+    - Option 2: Download Binary
+        - Visit the [LitRacer GitHub Releases](https://github.com/deependujha/litracer/releases) page.
+        - Download the appropriate binary for your operating system and follow the installation instructions.
+
+3. Convert Debug Log to trace JSON:
+
+    - Use litracer to convert the generated log file into a trace JSON file. This command uses 100 workers for conversion:
+
+    ```bash
+      litracer litdata_debug.log -o litdata_trace.json -w 100
+    ```
+
+4. Visualize the trace:
+
+    - Use either `chrome://tracing` in the Chrome browser or `ui.perfetto.dev` to view the `litdata_trace.json` file for in-depth performance insights. You can also use `SQL queries` to analyze the logs.
+    - `Perfetto` is recommended over `chrome://tracing` for visualization & analyzing.
+
+- Key Points:
+
+    - For very large trace.json files (`> 2GB`), refer to the [Perfetto documentation](https://perfetto.dev/docs/visualization/large-traces) for using native accelerators.
+    - If you are trying to connect Perfetto to the RPC server, it is recommended to use Chrome over Brave, as it has been observed that Perfetto in Brave does not autodetect the RPC server.
+
+</details>
+
 &nbsp;
 
+
 ## Features for transforming datasets
 
 <details>

src/litdata/loggers.py src/litdata/debugger.pysrc/litdata/loggers.py renamed to src/litdata/debugger.py

@@ -17,7 +17,7 @@
 from functools import lru_cache
 from typing import Tuple
 
-from litdata.constants import _DEBUG, _PRINT_DEBUG_LOGS
+from litdata.constants import _PRINT_DEBUG_LOGS
 from litdata.utilities.env import _DistributedEnv, _WorkerEnv
 
 # Create the root logger for the library
@@ -41,7 +41,7 @@ def __init__(self, name: str):
     @staticmethod
     def get_log_file_and_level() -> Tuple[str, int]:
         log_file = os.getenv("LITDATA_LOG_FILE", "litdata_debug.log")
-        log_lvl = os.getenv("LITDATA_LOG_LEVEL", "INFO" if not _DEBUG else "DEBUG")
+        log_lvl = os.getenv("LITDATA_LOG_LEVEL", "DEBUG")
 
         log_lvl = get_logger_level(log_lvl)
 
@@ -76,7 +76,7 @@ def setup_logger(self) -> None:
         self.logger.addHandler(file_handler)
 
 
-def configure_logger() -> None:
+def enable_tracer() -> None:
     os.environ["LITDATA_LOG_FILE"] = "litdata_debug.log"
     LitDataLogger("litdata")
 

src/litdata/streaming/combined.py

@@ -18,7 +18,7 @@
 
 from torch.utils.data import IterableDataset
 
-from litdata.loggers import ChromeTraceColors, _get_log_msg
+from litdata.debugger import ChromeTraceColors, _get_log_msg
 from litdata.streaming.dataset import StreamingDataset
 from litdata.utilities.env import _WorkerEnv
 

src/litdata/streaming/compression.py

@@ -16,7 +16,7 @@
 from typing import Dict, TypeVar
 
 from litdata.constants import _ZSTD_AVAILABLE
-from litdata.loggers import ChromeTraceColors, _get_log_msg
+from litdata.debugger import ChromeTraceColors, _get_log_msg
 
 TCompressor = TypeVar("TCompressor", bound="Compressor")
 

src/litdata/streaming/config.py

@@ -17,7 +17,7 @@
 from typing import Any, Dict, List, Optional, Tuple
 
 from litdata.constants import _INDEX_FILENAME
-from litdata.loggers import ChromeTraceColors, _get_log_msg
+from litdata.debugger import ChromeTraceColors, _get_log_msg
 from litdata.streaming.compression import _COMPRESSORS, Compressor
 from litdata.streaming.downloader import get_downloader
 from litdata.streaming.item_loader import BaseItemLoader, Interval, PyTreeLoader, TokensLoader

src/litdata/streaming/dataloader.py

@@ -34,7 +34,7 @@
 from torch.utils.data.sampler import BatchSampler, Sampler
 
 from litdata.constants import _DEFAULT_CHUNK_BYTES, _VIZ_TRACKER_AVAILABLE
-from litdata.loggers import _get_log_msg
+from litdata.debugger import _get_log_msg
 from litdata.streaming import Cache
 from litdata.streaming.combined import (
     __NUM_SAMPLES_YIELDED_KEY__,

src/litdata/streaming/dataset.py

@@ -21,8 +21,8 @@
 
 from litdata import __version__
 from litdata.constants import _INDEX_FILENAME
+from litdata.debugger import _get_log_msg
 from litdata.helpers import _check_version_and_prompt_upgrade
-from litdata.loggers import _get_log_msg
 from litdata.streaming import Cache
 from litdata.streaming.item_loader import BaseItemLoader, ParquetLoader
 from litdata.streaming.resolver import Dir, _resolve_dir

src/litdata/streaming/downloader.py

@@ -31,7 +31,7 @@
     _HF_HUB_AVAILABLE,
     _INDEX_FILENAME,
 )
-from litdata.loggers import _get_log_msg
+from litdata.debugger import _get_log_msg
 from litdata.streaming.client import S3Client
 
 logger = logging.getLogger("litdata.streaming.downloader")

src/litdata/streaming/item_loader.py

@@ -32,7 +32,7 @@
     _PYARROW_AVAILABLE,
     _TORCH_DTYPES_MAPPING,
 )
-from litdata.loggers import ChromeTraceColors, _get_log_msg
+from litdata.debugger import ChromeTraceColors, _get_log_msg
 from litdata.streaming.serializers import Serializer
 from litdata.utilities._pytree import PyTree, tree_unflatten
 from litdata.utilities.encryption import Encryption, EncryptionLevel

src/litdata/streaming/reader.py

@@ -23,7 +23,7 @@
 from filelock import FileLock, Timeout
 
 from litdata.constants import _DEBUG
-from litdata.loggers import _get_log_msg
+from litdata.debugger import _get_log_msg
 from litdata.streaming.config import ChunksConfig, Interval
 from litdata.streaming.item_loader import BaseItemLoader, ParquetLoader, PyTreeLoader, TokensLoader
 from litdata.streaming.sampler import ChunkedIndex