- `Deploying DeepSeek with PD Disaggregation and Large-Scale Expert Parallelism on 96 H100 GPUs <https://lmsys.org/blog/2025-05-05-large-scale-ep/>`_
- `Deploying Kimi K2 with PD Disaggregation and Large-Scale Expert Parallelism on 128 H200 GPUs <https://lmsys.org/blog/2025-07-20-k2-large-scale-ep/>`_
SGLang exposes the following metrics via Prometheus. The metrics are namespaced by `$name` (the model name).
SGLang exposes the following metrics via Prometheus. You can enable it by adding `--enable-metrics` when you launch the server.
An example of the monitoring dashboard is available in [examples/monitoring/grafana.json](https://github.com/sgl-project/sglang/blob/main/examples/monitoring/grafana/dashboards/json/sglang-dashboard.json).
This page lists common errors and tips for resolving them.
## CUDA Out of Memory
If you encounter out-of-memory (OOM) errors, you can adjust the following parameters:
- If OOM occurs during prefill, try reducing `--chunked-prefill-size` to `4096` or `2048`. This saves memory but slows down the prefill speed for long prompts.
- If OOM occurs during decoding, try lowering `--max-running-requests`.
- You can also reduce `--mem-fraction-static` to a smaller value, such as 0.8 or 0.7. This decreases the memory usage of the KV cache memory pool and helps prevent OOM errors during both prefill and decoding. However, it limits maximum concurrency and reduces peak throughput.
- Another common case for OOM is requesting input logprobs for a long prompt as it requires significant memory. To address this, set `logprob_start_len` in your sampling parameters to include only the necessary parts. If you do need input logprobs for a long prompt, try reducing `--mem-fraction-static`.
## CUDA Error: Illegal Memory Access Encountered
This error may result from kernel errors or out-of-memory issues:
- If it is a kernel error, resolving it may be challenging. Please file an issue on GitHub.
- If it is an out-of-memory issue, it may sometimes be reported as this error instead of "Out of Memory." Refer to the section above for guidance on avoiding OOM issues.
By default, we will use sglang implementation if it is available. Otherwise, we will fall back to transformers one. However, you can switch the implementation by setting `impl` to `transformers`.
By default, we will use sglang implementation if it is available. Otherwise, we will fall back to transformers one. However, you can switch the implementation by setting `--model-impl` to `transformers`.
```shell
python3 -m sglang.launch_server \
--model-path meta-llama/Llama-3.2-1B-Instruct \
--host 0.0.0.0 \
--port 30000 \
--impl transformers
--model-impl transformers
```
#### Supported features
## Supported features
##### Quantization
### Quantization
Transformers fall back has supported most of available quantization in SGLang (except GGUF). See [Quantization page](https://docs.sglang.ai/backend/quantization.html) for more information about supported quantization in SGLang.
##### Remote code
### Remote code
This fallback also means that any model on the hub that can be used in `transformers` with `trust_remote_code=True` that correctly implements attention can be used in production!
- Create new test files under `test/srt` or `test/lang` depending on the type of test.
- Ensure they are referenced in the respective `run_suite.py` (e.g., `test/srt/run_suite.py` or `test/lang/run_suite.py`) so they’re picked up in CI. For most small test cases, they can be added to the `per-commit` suite.
- Ensure they are referenced in the respective `run_suite.py` (e.g., `test/srt/run_suite.py`) so they’re picked up in CI. For most small test cases, they can be added to the `per-commit` suite. Sort the test cases alphabetically.
- The CI will run the `per-commit` and `nightly` automatically. If you need special setup or custom test groups, you may modify the workflows in [`.github/workflows/`](https://github.com/sgl-project/sglang/tree/main/.github/workflows).
