time completions use case (#397)

* time use case

* name

* update fake

Author: saiatmakuri

model-engine/model_engine_server/api/llms_v1.py

@@ -44,6 +44,7 @@
     logger_name,
     make_logger,
 )
+from model_engine_server.core.utils.timer import timer
 from model_engine_server.domain.exceptions import (
     DockerImageNotFoundException,
     EndpointDeleteFailedException,
@@ -313,16 +314,18 @@ async def create_completion_sync_task(
             llm_model_endpoint_service=external_interfaces.llm_model_endpoint_service,
             tokenizer_repository=external_interfaces.tokenizer_repository,
         )
-        response = await use_case.execute(
-            user=auth, model_endpoint_name=model_endpoint_name, request=request
-        )
+        with timer() as use_case_timer:
+            response = await use_case.execute(
+                user=auth, model_endpoint_name=model_endpoint_name, request=request
+            )
         background_tasks.add_task(
             external_interfaces.monitoring_metrics_gateway.emit_token_count_metrics,
             TokenUsage(
                 num_prompt_tokens=response.output.num_prompt_tokens if response.output else None,
                 num_completion_tokens=response.output.num_completion_tokens
                 if response.output
                 else None,
+                total_duration=use_case_timer.duration,
             ),
             metric_metadata,
         )
@@ -374,15 +377,17 @@ async def create_completion_stream_task(
 
     async def event_generator():
         try:
-            async for message in response:
-                yield {"data": message.json()}
+            with timer() as use_case_timer:
+                async for message in response:
+                    yield {"data": message.json()}
             background_tasks.add_task(
                 external_interfaces.monitoring_metrics_gateway.emit_token_count_metrics,
                 TokenUsage(
                     num_prompt_tokens=message.output.num_prompt_tokens if message.output else None,
                     num_completion_tokens=message.output.num_completion_tokens
                     if message.output
                     else None,
+                    total_duration=use_case_timer.duration,
                 ),
                 metric_metadata,
             )

model-engine/model_engine_server/common/dtos/llms.py

@@ -280,13 +280,27 @@ class CompletionStreamV1Response(BaseModel):
 
 
 class TokenUsage(BaseModel):
+    """
+    Token usage for a prompt completion task.
+    """
+
     num_prompt_tokens: Optional[int] = 0
     num_completion_tokens: Optional[int] = 0
+    total_duration: Optional[float] = None
+    """Includes time spent waiting for the model to be ready."""
 
     @property
     def num_total_tokens(self) -> int:
         return (self.num_prompt_tokens or 0) + (self.num_completion_tokens or 0)
 
+    @property
+    def total_tokens_per_second(self) -> float:
+        return (
+            self.num_total_tokens / self.total_duration
+            if self.total_duration and self.total_duration > 0
+            else 0.0
+        )
+
 
 class CreateFineTuneRequest(BaseModel):
     model: str

model-engine/model_engine_server/infra/gateways/fake_monitoring_metrics_gateway.py

@@ -21,6 +21,7 @@ def __init__(self):
         self.database_cache_miss = 0
         self.route_call = defaultdict(int)
         self.token_count = 0
+        self.total_tokens_per_second = 0
 
     def reset(self):
         self.attempted_build = 0
@@ -35,6 +36,7 @@ def reset(self):
         self.database_cache_miss = 0
         self.route_call = defaultdict(int)
         self.token_count = 0
+        self.total_tokens_per_second = 0
 
     def emit_attempted_build_metric(self):
         self.attempted_build += 1
@@ -71,3 +73,4 @@ def emit_route_call_metric(self, route: str, _metadata: MetricMetadata):
 
     def emit_token_count_metrics(self, token_usage: TokenUsage, _metadata: MetricMetadata):
         self.token_count += token_usage.num_total_tokens
+        self.total_tokens_per_second = token_usage.total_tokens_per_second