Support l3 cache (mooncake store) for hiradix cache (#7211)

Co-authored-by: Zhiqiang Xie <xiezhq@stanford.edu>
Co-authored-by: AniZpZ <zhuangsen.zp@antgroup.com>
Co-authored-by: zuoyuan <zhangzuo21@mails.tsinghua.edu.cn>
Co-authored-by: @wangyueneng.wyn <wangyueneng.wyn@antgroup.com>
Co-authored-by: JinYan Su <jinyansu792@gmail.com>

python/sglang/srt/managers/cache_controller.py

@@ -26,6 +26,10 @@ if TYPE_CHECKING:
     from sglang.srt.mem_cache.memory_pool_host import HostKVCache
 
 from sglang.srt.mem_cache.hicache_storage import HiCacheFile, get_hash_str
+from sglang.srt.mem_cache.mooncake_store.mooncake_store import (
+    MooncakeStore,
+    get_hash_str_mooncake,
+)
 from sglang.srt.mem_cache.storage.hf3fs.storage_hf3fs import HiCacheHF3FS
 
 logger = logging.getLogger(__name__)
@@ -125,7 +129,7 @@ class TransferBuffer:
     """
 
     def __init__(
-        self, stop_event, buffer_count: int = 3, max_buffer_size: int = 1000
+        self, stop_event, buffer_count: int = 3, max_buffer_size: int = 1024
     ) -> None:
         self.stop_event = stop_event
         self.buffers = Queue(maxsize=buffer_count)
@@ -260,6 +264,11 @@ class HiCacheController:
 
             if storage_backend == "file":
                 self.storage_backend = HiCacheFile()
+                self.get_hash_str = get_hash_str
+            elif storage_backend == "mooncake":
+                self.storage_backend = MooncakeStore()
+                self.get_hash_str = get_hash_str_mooncake
+                self.storage_backend.register_buffer(self.mem_pool_host.kv_buffer)
             elif storage_backend == "hf3fs":
                 from sglang.srt.distributed import get_tensor_model_parallel_rank
 
@@ -271,6 +280,7 @@ class HiCacheController:
                 self.storage_backend = HiCacheHF3FS.from_env_config(
                     rank, bytes_per_page, dtype
                 )
+                self.get_hash_str = get_hash_str
             else:
                 raise NotImplementedError(
                     f"Unsupported storage backend: {storage_backend}"
@@ -532,6 +542,37 @@ class HiCacheController:
         operation.mark_done()
         return operation.completed_tokens, operation.hash_value
 
+    def generic_page_transfer(self, operation, batch_size=8):
+        for i in range(0, len(operation.hash_value), batch_size):
+            page_hashes = operation.hash_value[i : i + batch_size]
+            page_data = self.storage_backend.batch_get(page_hashes)
+            if page_data is None:
+                logger.warning(
+                    f"Prefetch operation {operation.request_id} failed to retrieve page {page_hashes}."
+                )
+                break
+            completed_tokens = operation.completed_tokens
+            if operation.increment(self.page_size * len(page_hashes)):
+                for i in range(len(page_hashes)):
+                    self.mem_pool_host.set_from_flat_data_page(
+                        operation.host_indices[completed_tokens],
+                        page_data[i],
+                    )
+                    completed_tokens += self.page_size
+            else:
+                # operation terminated by controller, release pre-allocated memory
+                self.mem_pool_host.free(
+                    operation.host_indices[operation.completed_tokens :]
+                )
+                break
+
+    def mooncake_page_transfer(self, operation):
+        key_strs, buffer_ptrs, buffer_sizes = self.mem_pool_host.get_buffer_meta(
+            operation.hash_value, operation.host_indices
+        )
+        self.storage_backend.batch_get(key_strs, buffer_ptrs, buffer_sizes)
+        operation.increment(len(operation.hash_value) * self.page_size)
+
     def prefetch_io_aux_func(self):
         """
         Auxiliary function conducting IO operations for prefetching.
@@ -539,26 +580,10 @@ class HiCacheController:
         while not self.stop_event.is_set():
             try:
                 operation = self.prefetch_buffer.get(block=True, timeout=1)
-                page_datas = self.storage_backend.batch_get(operation.hash_value)
+                if isinstance(self.storage_backend, MooncakeStore):
-                for h, page_data in zip(operation.hash_value, page_datas):
+                    self.mooncake_page_transfer(operation)
-                    if page_data is None:
-                        logger.warning(
-                            f"Prefetch operation {operation.request_id} failed to retrieve page {h}."
-                        )
-                        break
-                    if operation.increment(self.page_size):
-                        self.mem_pool_host.set_from_flat_data_page(
-                            operation.host_indices[
-                                operation.completed_tokens - self.page_size
-                            ],
-                            page_data,
-                        )
                 else:
-                        # operation terminated by controller, release pre-allocated memory
+                    self.generic_page_transfer(operation)
-                        self.mem_pool_host.free(
-                            operation.host_indices[operation.completed_tokens :]
-                        )
-                        break
             except Empty:
                 continue
 
@@ -582,18 +607,27 @@ class HiCacheController:
                 remaining_tokens = len(tokens_to_fetch)
                 hash_value = []
                 while remaining_tokens >= self.page_size:
-                    last_hash = get_hash_str(
+                    last_hash = self.get_hash_str(
                         tokens_to_fetch[
                             storage_hit_count : storage_hit_count + self.page_size
                         ],
                         last_hash,
                     )
-                    if self.storage_backend.exists(last_hash):
+
-                        storage_hit_count += self.page_size
+                    # todo, more unified interface
-                        hash_value.append(last_hash)
+                    if not isinstance(self.storage_backend, MooncakeStore):
-                        remaining_tokens -= self.page_size
+                        if not self.storage_backend.exists(last_hash):
-                    else:
                             break
+                    hash_value.append(last_hash)
+                    storage_hit_count += self.page_size
+                    remaining_tokens -= self.page_size
+
+                if isinstance(self.storage_backend, MooncakeStore):
+                    # deferring to batch exists for mooncake store
+                    exist_result = self.storage_backend.exists(hash_value)
+                    storage_hit_count = (
+                        sum(1 for v in exist_result.values() if v != 0) * self.page_size
+                    )
 
                 if self.tp_world_size > 1:
                     storage_hit_count_tensor = torch.tensor(
@@ -641,6 +675,47 @@ class HiCacheController:
         self.backup_queue.put(operation)
         return operation.id
 
+    def generic_page_backup(self, operation, batch_size=8):
+        for i in range(0, len(operation.hash_value), batch_size):
+            page_hashes = operation.hash_value[i : i + batch_size]
+            page_data = [
+                self.mem_pool_host.get_flat_data_pages(
+                    operation.host_indices[j * self.page_size]
+                )
+                for j in range(i, i + len(page_hashes))
+            ]
+            success = self.storage_backend.batch_set(page_hashes, page_data)
+            if not success:
+                logger.warning(f"Failed to write page {page_hashes} to storage.")
+                break
+            operation.completed_tokens += self.page_size * len(page_hashes)
+
+    def mooncake_page_backup(self, operation):
+        if len(operation.hash_value):
+            exist_hashvalues = self.storage_backend.exists(operation.hash_value)
+            indices = operation.host_indices.tolist()
+            non_exist_keys = []
+            non_exist_indices = []
+            for i in range(len(operation.hash_value)):
+                if not exist_hashvalues[operation.hash_value[i]]:
+                    non_exist_keys.append(operation.hash_value[i])
+                    non_exist_indices.extend(
+                        indices[i * self.page_size : (i + 1) * self.page_size]
+                    )
+            if len(non_exist_keys) > 0:
+                key_strs, buffer_ptrs, buffer_sizes = (
+                    self.mem_pool_host.get_buffer_meta(
+                        non_exist_keys, non_exist_indices
+                    )
+                )
+                # TODO: check the return value of batch set to see how many tokens are set successfully
+                self.storage_backend.batch_set(
+                    key_strs,
+                    target_location=buffer_ptrs,
+                    target_sizes=buffer_sizes,
+                )
+        operation.completed_tokens += len(operation.hash_value) * self.page_size
+
     def backup_thread_func(self):
         """
         Manage backup operations from host memory to storage backend.
@@ -654,23 +729,25 @@ class HiCacheController:
                 last_hash = operation.last_hash
                 tokens_to_backup = operation.token_ids
 
-                last_hashes, data_pages = [], []
+                backup_hit_count = 0
-                for i in range(0, len(tokens_to_backup), self.page_size):
+                remaining_tokens = len(tokens_to_backup)
-                    last_hash = get_hash_str(
+                hash_value = []
-                        tokens_to_backup[i : i + self.page_size], last_hash
+                while remaining_tokens >= self.page_size:
+                    last_hash = self.get_hash_str(
+                        tokens_to_backup[
+                            backup_hit_count : backup_hit_count + self.page_size
+                        ],
+                        last_hash,
                     )
-                    data_page = self.mem_pool_host.get_flat_data_page(
+                    backup_hit_count += self.page_size
-                        operation.host_indices[i]
+                    hash_value.append(last_hash)
-                    )
+                    remaining_tokens -= self.page_size
-                    last_hashes.append(last_hash)
+                operation.hash_value = hash_value
-                    data_pages.append(data_page)
 
-                success = self.storage_backend.batch_set(last_hashes, data_pages)
+                if isinstance(self.storage_backend, MooncakeStore):
-                if not success:
+                    self.mooncake_page_backup(operation)
-                    logger.warning(f"Failed to write page {last_hashes} to storage.")
                 else:
-                    operation.completed_tokens += len(tokens_to_backup)
+                    self.generic_page_backup(operation)
-                    operation.hash_value.extend(last_hashes)
 
                 min_completed_tokens = operation.completed_tokens
                 if self.tp_world_size > 1:

python/sglang/srt/mem_cache/hicache_storage.py

@@ -2,7 +2,7 @@ import hashlib
 import logging
 import os
 from abc import ABC, abstractmethod
-from typing import List, Optional
+from typing import Any, List, Optional
 
 import torch
 
@@ -39,7 +39,10 @@ class HiCacheStorage(ABC):
 
     @abstractmethod
     def get(
-        self, key: str, target_location: Optional[torch.Tensor] = None
+        self,
+        key: str,
+        target_location: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
     ) -> torch.Tensor | None:
         """
         Retrieve the value associated with the given key.
@@ -49,7 +52,10 @@ class HiCacheStorage(ABC):
 
     @abstractmethod
     def batch_get(
-        self, keys: List[str], target_locations: Optional[List[torch.Tensor]] = None
+        self,
+        keys: List[str],
+        target_locations: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
     ) -> List[torch.Tensor | None]:
         """
         Retrieve values for multiple keys.
@@ -58,7 +64,13 @@ class HiCacheStorage(ABC):
         pass
 
     @abstractmethod
-    def set(self, key, value) -> bool:
+    def set(
+        self,
+        key: str,
+        value: Optional[Any] = None,
+        target_location: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
+    ) -> bool:
         """
         Store the value associated with the given key.
         Returns True if the operation was successful, False otherwise.
@@ -66,7 +78,13 @@ class HiCacheStorage(ABC):
         pass
 
     @abstractmethod
-    def batch_set(self, keys: List[str], values: List[torch.Tensor]) -> bool:
+    def batch_set(
+        self,
+        keys: List[str],
+        values: Optional[Any] = None,
+        target_locations: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
+    ) -> bool:
         """
         Store multiple key-value pairs.
         Returns True if all operations were successful, False otherwise.
@@ -74,7 +92,7 @@ class HiCacheStorage(ABC):
         pass
 
     @abstractmethod
-    def exists(self, key: str) -> bool:
+    def exists(self, key: str) -> bool | dict:
         """
         Check if the key exists in the storage.
         Returns True if the key exists, False otherwise.
@@ -97,7 +115,10 @@ class HiCacheFile(HiCacheStorage):
         return key + self.tp_suffix
 
     def get(
-        self, key: str, target_location: Optional[torch.Tensor] = None
+        self,
+        key: str,
+        target_location: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
     ) -> torch.Tensor | None:
         key = self._get_suffixed_key(key)
         tensor_path = os.path.join(self.file_path, f"{key}.bin")
@@ -115,7 +136,8 @@ class HiCacheFile(HiCacheStorage):
     def batch_get(
         self,
         keys: List[str],
-        target_locations: Optional[List[torch.Tensor]] = None,
+        target_locations: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
     ) -> List[torch.Tensor | None]:
         return [
             self.get(key, target_location)
@@ -124,7 +146,13 @@ class HiCacheFile(HiCacheStorage):
             )
         ]
 
-    def set(self, key: str, value: torch.Tensor) -> bool:
+    def set(
+        self,
+        key: str,
+        value: Optional[Any] = None,
+        target_location: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
+    ) -> bool:
         key = self._get_suffixed_key(key)
         tensor_path = os.path.join(self.file_path, f"{key}.bin")
         if self.exists(key):
@@ -137,7 +165,13 @@ class HiCacheFile(HiCacheStorage):
             logger.error(f"Failed to save tensor {key}: {e}")
             return False
 
-    def batch_set(self, keys: List[str], values: List[torch.Tensor]) -> bool:
+    def batch_set(
+        self,
+        keys: List[str],
+        values: Optional[Any] = None,
+        target_locations: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
+    ) -> bool:
         for key, value in zip(keys, values):
             if not self.set(key, value):
                 return False

python/sglang/srt/mem_cache/hiradix_cache.py

@@ -594,6 +594,10 @@ class HiRadixCache(RadixCache):
         if child.backuped:
             new_node.host_value = child.host_value[:split_len]
             child.host_value = child.host_value[split_len:]
+
+        if child.hash_value:
+            new_node.hash_value = child.hash_value[: split_len // self.page_size]
+            child.hash_value = child.hash_value[split_len // self.page_size :]
         child.parent = new_node
         child.key = child.key[split_len:]
         new_node.parent.children[self.get_child_key_fn(key)] = new_node

python/sglang/srt/mem_cache/memory_pool_host.py

@@ -265,6 +265,43 @@ class MHATokenToKVPoolHost(HostKVCache):
             self.head_dim,
         )
 
+    def get_buffer_meta(self, keys, indices):
+        ptr_list = []
+        key_list = []
+        kv_buffer_data_ptr = self.kv_buffer.data_ptr()
+        v_offset = (
+            self.layer_num
+            * self.size
+            * self.head_num
+            * self.head_dim
+            * self.dtype.itemsize
+        )
+        for index in range(0, len(indices), self.page_size):
+            for layer_id in range(self.layer_num):
+                k_ptr = (
+                    kv_buffer_data_ptr
+                    + indices[index]
+                    * self.head_num
+                    * self.head_dim
+                    * self.dtype.itemsize
+                    + layer_id
+                    * self.size
+                    * self.head_num
+                    * self.head_dim
+                    * self.dtype.itemsize
+                )
+                v_ptr = k_ptr + v_offset
+                ptr_list.append(k_ptr)
+                ptr_list.append(v_ptr)
+                key_ = keys[index // self.page_size]
+                key_list.append(f"{key_}_{layer_id}_k")
+                key_list.append(f"{key_}_{layer_id}_v")
+        element_size = (
+            self.dtype.itemsize * self.page_size * self.head_num * self.head_dim
+        )
+        element_size_list = [element_size] * len(key_list)
+        return key_list, ptr_list, element_size_list
+
     @property
     def k_buffer(self):
         return self.kv_buffer[0]
@@ -325,3 +362,30 @@ class MLATokenToKVPoolHost(HostKVCache):
             1,
             self.kv_lora_rank + self.qk_rope_head_dim,
         )
+
+    def get_buffer_meta(self, keys, indices):
+        ptr_list = []
+        key_list = []
+        kv_buffer_data_ptr = self.kv_buffer.data_ptr()
+        for index in range(0, len(indices), self.page_size):
+            for layer_id in range(self.layer_num):
+                k_ptr = (
+                    kv_buffer_data_ptr
+                    + indices[index]
+                    * (self.kv_lora_rank + self.qk_rope_head_dim)
+                    * self.dtype.itemsize
+                    + layer_id
+                    * self.size
+                    * (self.kv_lora_rank + self.qk_rope_head_dim)
+                    * self.dtype.itemsize
+                )
+                ptr_list.append(k_ptr)
+                key_ = keys[index // self.page_size]
+                key_list.append(f"{key_}_{layer_id}_k")
+        element_size = (
+            self.dtype.itemsize
+            * self.page_size
+            * (self.kv_lora_rank + self.qk_rope_head_dim)
+        )
+        element_size_list = [element_size] * len(key_list)
+        return key_list, ptr_list, element_size_list

python/sglang/srt/mem_cache/mooncake_store/README.md

@@ -0,0 +1,71 @@
+# Mooncake as L3 KV Cache
+
+This document describes how to use Mooncake as the L3 KV cache for SGLang.
+For more details about Mooncake, please refer to: https://kvcache-ai.github.io/
+
+## Install Mooncake
+
+### Method 1: with pip
+
+```bash
+pip install mooncake-transfer-engine
+```
+
+### Method 2: from source
+
+Clone Mooncake project:
+
+```bash
+git clone https://github.com/kvcache-ai/Mooncake --recursive
+```
+
+Install dependencies:
+
+```bash
+cd Mooncake
+bash dependencies.sh
+```
+
+Build the project. For additional build options, please refer to [the official guide](https://kvcache-ai.github.io/Mooncake/getting_started/build.html).
+
+```bash
+mkdir build
+cd build
+cmake ..
+make -j
+```
+
+Install Mooncake:
+
+```bash
+sudo make install
+```
+
+## Use Mooncake
+
+Launch Mooncake master server:
+
+```bash
+mooncake_master
+```
+
+Launch Mooncake meta server:
+
+```bash
+python -m mooncake.http_metadata_server
+```
+
+Start the SGLang server with Mooncake enabled. Mooncake configuration can be provided via environment variables:
+
+```bash
+MOONCAKE_TE_META_DATA_SERVER="http://127.0.0.1:8080/metadata" \
+MOONCAKE_GLOBAL_SEGMENT_SIZE=4294967296 \
+MOONCAKE_LOCAL_BUFFER_SIZE=134217728 \
+MOONCAKE_PROTOCOL="rdma" \
+MOONCAKE_DEVICE="erdma_0,erdma_1" \
+MOONCAKE_MASTER=127.0.0.1:50051 \
+python -m sglang.launch_server \
+    --enable-hierarchical-cache \
+    --hicache-storage-backend mooncake\
+    --model-path [model_path]
+```

python/sglang/srt/mem_cache/mooncake_store/mooncake_store.py

@@ -0,0 +1,264 @@
+import hashlib
+import json
+import logging
+import os
+import uuid
+from dataclasses import dataclass
+from typing import Any, List, Optional
+
+import numpy as np
+import torch
+
+from sglang.srt.distributed import get_tensor_model_parallel_rank
+from sglang.srt.mem_cache.hicache_storage import HiCacheStorage
+
+DEFAULT_GLOBAL_SEGMENT_SIZE = 4 * 1024 * 1024 * 1024  # 4 GiB
+DEFAULT_LOCAL_BUFFER_SIZE = 128 * 1024 * 1024  # 128 MB
+
+logger = logging.getLogger(__name__)
+
+
+def get_hash_str_mooncake(current_page_ids: List, prefix_block_key: str):
+    local_rank = get_tensor_model_parallel_rank()
+    prefix_str = ""
+    if prefix_block_key:
+        if len(prefix_block_key):
+            prefix_str = hashlib.sha256(prefix_block_key.encode()).hexdigest()
+    current_token_ids_bytes = np.array(current_page_ids).tobytes()
+    current_hash_object = hashlib.sha256(current_token_ids_bytes)
+    current_hash_hex = current_hash_object.hexdigest()
+    return f"{prefix_str}_{int(current_hash_hex[:16], 16)}_{local_rank}"
+
+
+@dataclass
+class MooncakeStoreConfig:
+    local_hostname: str
+    metadata_server: str
+    global_segment_size: int
+    local_buffer_size: int
+    protocol: str
+    device_name: str
+    master_server_address: str
+
+    @staticmethod
+    def from_file() -> "MooncakeStoreConfig":
+        """Load the config from a JSON file."""
+        file_path = os.getenv("MOONCAKE_CONFIG_PATH")
+        if file_path is None:
+            raise ValueError(
+                "The environment variable 'MOONCAKE_CONFIG_PATH' is not set."
+            )
+        with open(file_path) as fin:
+            config = json.load(fin)
+        return MooncakeStoreConfig(
+            local_hostname=config.get("local_hostname"),
+            metadata_server=config.get("metadata_server"),
+            global_segment_size=config.get(
+                "global_segment_size", DEFAULT_GLOBAL_SEGMENT_SIZE
+            ),
+            local_buffer_size=config.get(
+                "local_buffer_size", DEFAULT_LOCAL_BUFFER_SIZE
+            ),
+            protocol=config.get("protocol", "tcp"),
+            device_name=config.get("device_name", "auto"),
+            master_server_address=config.get("master_server_address"),
+        )
+
+    @staticmethod
+    def load_from_env() -> "MooncakeStoreConfig":
+        """Load config from a file specified in the environment variable.
+        export MOONCAKE_MASTER=10.13.3.232:50051
+        export MOONCAKE_PROTOCOL="rdma"
+        export MOONCAKE_DEVICE="auto"
+        export MOONCAKE_TE_META_DATA_SERVER="P2PHANDSHAKE"
+        """
+        # other required environment variables...
+        if not os.getenv("MOONCAKE_MASTER"):
+            raise ValueError("The environment variable 'MOONCAKE_MASTER' is not set.")
+        return MooncakeStoreConfig(
+            local_hostname=os.getenv("LOCAL_HOSTNAME", "localhost"),
+            metadata_server=os.getenv("MOONCAKE_TE_META_DATA_SERVER", "P2PHANDSHAKE"),
+            global_segment_size=int(
+                os.getenv("MOONCAKE_GLOBAL_SEGMENT_SIZE", DEFAULT_GLOBAL_SEGMENT_SIZE)
+            ),
+            local_buffer_size=int(
+                os.getenv("MOONCAKE_LOCAL_BUFFER_SIZE", DEFAULT_LOCAL_BUFFER_SIZE)
+            ),
+            protocol=os.getenv("MOONCAKE_PROTOCOL", "tcp"),
+            device_name=os.getenv("MOONCAKE_DEVICE", "auto"),
+            master_server_address=os.getenv("MOONCAKE_MASTER"),
+        )
+
+    def __post_init__(self):
+        if self.device_name == "auto":
+            os.environ["MC_MS_AUTO_DISC"] = "1"
+            os.environ["MC_MS_FILTERS"] = (
+                "mlx5_bond_0, mlx5_bond_1, mlx5_bond_2, mlx5_bond_3"
+            )
+
+
+class MooncakeStore(HiCacheStorage):
+    def __init__(self):
+        try:
+            from mooncake.store import MooncakeDistributedStore
+        except ImportError as e:
+            raise ImportError(
+                "Please install mooncake by following the instructions at "
+                "https://kvcache-ai.github.io/Mooncake/getting_started/build.html"
+                "to run SGLang with MooncakeConnector."
+            ) from e
+
+        try:
+            self.store = MooncakeDistributedStore()
+            self.config = MooncakeStoreConfig.load_from_env()
+            logger.info("Mooncake Configuration loaded from env successfully.")
+
+            ret_code = self.store.setup(
+                self.config.local_hostname,
+                self.config.metadata_server,
+                self.config.global_segment_size,
+                self.config.local_buffer_size,
+                self.config.protocol,
+                self.config.device_name,
+                self.config.master_server_address,
+            )
+            if ret_code:
+                logger.error(f"failed to setup mooncake store, error code: {ret_code}")
+
+            logger.info("Connect to Mooncake store successfully.")
+            self.warmup()
+            logger.info("Mooncake store warmup successfully.")
+
+        except ValueError as e:
+            logger.error("Configuration loading failed: %s", e)
+            raise
+        except Exception as exc:
+            logger.error("An error occurred while loading the configuration: %s", exc)
+            raise
+
+    def warmup(self):
+        warmup_key = "sglang_mooncake_store_warmup_key" + uuid.uuid4().hex
+        # 10 MB
+        warmup_value = bytes(10 * 1024 * 1024)
+        self.store.put(warmup_key, warmup_value)
+        assert self.store.is_exist(warmup_key) == 1
+        self.store.get(warmup_key)
+        self.store.remove(warmup_key)
+
+    def register_buffer(self, buffer: torch.Tensor) -> None:
+        try:
+            buffer_ptr = buffer.data_ptr()
+            buffer_size = buffer.numel() * buffer.element_size()
+            ret_code = self.store.register_buffer(buffer_ptr, buffer_size)
+            if ret_code:
+                logger.error(f"failed to register buffer, error code: {ret_code}")
+        except TypeError as err:
+            logger.error("Failed to register buffer to Mooncake Store: %s", err)
+            raise TypeError("Mooncake Store Register Buffer Error.") from err
+
+    def set(
+        self,
+        key,
+        value: Optional[Any] = None,
+        target_location: Optional[List[int]] = None,
+        target_sizes: Optional[List[int]] = None,
+    ) -> bool:
+        assert len(key) == len(target_location) == len(target_sizes)
+        if len(key) == 0:
+            return
+
+        for i in range(len(key)):
+            if key[i] is None or target_location[i] is None or target_sizes[i] is None:
+                return
+
+        self._put_batch_zero_copy_impl(key, target_location, target_sizes)
+
+    def batch_set(
+        self,
+        keys: List[str],
+        value: Optional[Any] = None,
+        target_location: Optional[List[int]] = None,
+        target_sizes: Optional[List[int]] = None,
+    ) -> bool:
+        assert len(keys) == len(target_location) == len(target_sizes)
+        if len(keys) == 0:
+            return
+
+        for i in range(len(keys)):
+            if keys[i] is None or target_location[i] is None or target_sizes[i] is None:
+                return
+
+        self._put_batch_zero_copy_impl(keys, target_location, target_sizes)
+
+    def get(
+        self,
+        key,
+        target_location: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
+    ) -> torch.Tensor | None:
+        assert len(key) == len(target_location) == len(target_sizes)
+        if len(key) == 0:
+            return
+
+        for i in range(len(key)):
+            if key[i] is None or target_location[i] is None or target_sizes[i] is None:
+                return
+
+        return self._get_batch_zero_copy_impl(key, target_location, target_sizes)
+
+    def batch_get(
+        self,
+        keys: List[str],
+        target_location: Optional[Any] = None,
+        target_sizes: Optional[Any] = None,
+    ) -> torch.Tensor | None:
+        assert len(keys) == len(target_location) == len(target_sizes)
+        if len(keys) == 0:
+            return
+
+        for i in range(len(keys)):
+            if keys[i] is None or target_location[i] is None or target_sizes[i] is None:
+                return
+
+        return self._get_batch_zero_copy_impl(keys, target_location, target_sizes)
+
+    def exists(self, keys) -> bool | dict:
+        _keys = []
+        local_rank = torch.cuda.current_device()
+        for key in keys:
+            if key is None:
+                return None
+            # Since mooncake store is stored in layer by layer,
+            # only the first layer is checked here.
+            _keys.append(f"{key}_{local_rank}_k")
+        result = {k: v for k, v in zip(keys, self.store.batch_is_exist(_keys))}
+        return result
+
+    def delete(self, key) -> None:
+        raise (NotImplementedError)
+
+    def close(self):
+        # MooncakeDistributedStore will automatically call the destructor, so
+        # it is unnecessary to close it manually.
+        pass
+
+    def clear(self) -> None:
+        raise (NotImplementedError)
+
+    def _put_batch_zero_copy_impl(
+        self, key_strs: List[str], buffer_ptrs: List[int], buffer_sizes: List[int]
+    ) -> None:
+        try:
+            self.store.batch_put_from(key_strs, buffer_ptrs, buffer_sizes)
+        except TypeError as err:
+            logger.error("Failed to put value to Mooncake Store: %s", err)
+            raise TypeError("Mooncake Store Put Type Error.") from err
+
+    def _get_batch_zero_copy_impl(
+        self, key_strs: List[str], buffer_ptrs: List[int], buffer_sizes: List[int]
+    ) -> None:
+        try:
+            self.store.batch_get_into(key_strs, buffer_ptrs, buffer_sizes)
+        except TypeError as err:
+            logger.error("Failed to get value from Mooncake Store: %s", err)
+            raise TypeError("Mooncake Store Get Type Error.") from err

python/sglang/srt/mem_cache/mooncake_store/unit_test.py

@@ -0,0 +1,40 @@
+import torch
+from mooncake_store import MooncakeStore
+
+
+def test_init_and_warmup():
+    store = MooncakeStore()
+    assert store.store is not None
+
+
+def test_register_buffer():
+    store = MooncakeStore()
+    tensor = torch.zeros(1024, dtype=torch.float32)
+    store.register_buffer(tensor)
+
+
+def test_set_and_get():
+    store = MooncakeStore()
+
+    key = ["test_key_" + str(i) for i in range(2)]
+    tensor = torch.arange(256, dtype=torch.float32).cuda()
+    ptrs = [tensor.data_ptr(), tensor.data_ptr()]
+    sizes = [tensor.numel() * tensor.element_size()] * 2
+
+    store.set(key, target_location=ptrs, target_sizes=sizes)
+    store.get(key, target_location=ptrs, target_sizes=sizes)
+
+
+def test_exists():
+    store = MooncakeStore()
+    keys = ["test_key_0", "non_existent_key"]
+    result = store.exists(keys)
+    assert isinstance(result, dict)
+    assert "test_key_0" in result
+
+
+if __name__ == "__main__":
+    test_init_and_warmup()
+    test_register_buffer()
+    test_set_and_get()
+    test_exists()

python/sglang/srt/server_args.py

@@ -1476,7 +1476,7 @@ class ServerArgs:
         parser.add_argument(
             "--hicache-storage-backend",
             type=str,
-            choices=["file", "hf3fs"],  # todo, mooncake
+            choices=["file", "mooncake", "hf3fs"],
             default=ServerArgs.hicache_storage_backend,
             help="The storage backend for hierarchical KV cache.",
         )