perf: bypass Celery for web chat — stream LLM directly from WebSocket

Eliminates 5-10s of overhead by calling the LLM pool's streaming
endpoint directly from the WebSocket handler instead of going through
Celery queue → worker → asyncio.run() → Redis pub-sub → WebSocket.

New flow: WebSocket → agent lookup → memory → LLM stream → WebSocket
Old flow: WebSocket → Celery → worker → DB → memory → LLM → Redis → WebSocket

Memory still saved (Redis sliding window + fire-and-forget embedding).
Slack/WhatsApp still use Celery (async webhook pattern).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-03-25 18:32:16 -06:00
parent 2116059157
commit dd80e2b822

View File

@@ -42,11 +42,15 @@ import redis.asyncio as aioredis
from fastapi import APIRouter, WebSocket, WebSocketDisconnect
from sqlalchemy import select, text
from orchestrator.tasks import handle_message
from orchestrator.agents.builder import build_messages_with_memory, build_system_prompt
from orchestrator.agents.runner import run_agent_streaming
from orchestrator.memory.short_term import get_recent_messages, append_message
from orchestrator.tasks import handle_message, embed_and_store
from shared.config import settings
from shared.db import async_session_factory, engine
from shared.models.chat import WebConversation, WebConversationMessage
from shared.models.message import ChannelType, KonstructMessage, MessageContent, SenderInfo
from shared.models.tenant import Agent
from shared.redis_keys import webchat_response_key
from shared.rls import configure_rls_hook, current_tenant_id
@@ -225,7 +229,12 @@ async def _handle_websocket_connection(
current_tenant_id.reset(rls_token)
# -------------------------------------------------------------------
# c. Normalize and dispatch to Celery pipeline
# c. Build KonstructMessage and stream LLM response DIRECTLY
#
# Bypasses Celery entirely for web chat — calls the LLM pool's
# streaming endpoint from the WebSocket handler. This eliminates
# ~5-10s of Celery queue + Redis pub-sub round-trip overhead.
# Slack/WhatsApp still use Celery (async webhook pattern).
# -------------------------------------------------------------------
event = {
"text": text_content,
@@ -237,67 +246,92 @@ async def _handle_websocket_connection(
}
normalized_msg = normalize_web_event(event)
extras = {
"conversation_id": saved_conversation_id,
"portal_user_id": user_id_str,
}
task_payload = normalized_msg.model_dump(mode="json") | extras
handle_message.delay(task_payload)
# -------------------------------------------------------------------
# d. Subscribe to Redis pub-sub and forward streaming chunks to client
#
# The orchestrator publishes two message types to the response channel:
# {"type": "chunk", "text": "<token>"} — zero or more times (streaming)
# {"type": "done", "text": "<full>", "conversation_id": "..."} — final marker
#
# We forward each "chunk" immediately to the browser so text appears
# word-by-word. On "done" we save the full response to the DB.
# -------------------------------------------------------------------
response_channel = webchat_response_key(tenant_id_str, saved_conversation_id)
subscribe_redis = aioredis.from_url(settings.redis_url)
response_text: str = ""
# Load agent for this tenant
agent: Agent | None = None
rls_token3 = current_tenant_id.set(tenant_uuid)
try:
pubsub = subscribe_redis.pubsub()
await pubsub.subscribe(response_channel)
deadline = asyncio.get_event_loop().time() + _RESPONSE_TIMEOUT_SECONDS
while asyncio.get_event_loop().time() < deadline:
message = await pubsub.get_message(ignore_subscribe_messages=True, timeout=1.0)
if message and message.get("type") == "message":
try:
payload = json.loads(message["data"])
except (json.JSONDecodeError, KeyError):
await asyncio.sleep(0.01)
continue
msg_type = payload.get("type")
if msg_type == "chunk":
# Forward token immediately — do not break the loop
token = payload.get("text", "")
if token:
try:
await websocket.send_json({
"type": "chunk",
"text": token,
})
except Exception:
# Client disconnected mid-stream — exit cleanly
break
elif msg_type == "done":
# Final marker — full text for DB persistence
response_text = payload.get("text", "")
break
else:
await asyncio.sleep(0.05)
await pubsub.unsubscribe(response_channel)
async with async_session_factory() as session:
from sqlalchemy import select as sa_select
agent_stmt = sa_select(Agent).where(
Agent.tenant_id == tenant_uuid,
Agent.is_active == True,
).limit(1)
agent_result = await session.execute(agent_stmt)
agent = agent_result.scalar_one_or_none()
finally:
await subscribe_redis.aclose()
current_tenant_id.reset(rls_token3)
if agent is None:
await websocket.send_json({
"type": "done",
"text": "No active AI employee is configured for this workspace.",
"conversation_id": saved_conversation_id,
})
continue
# Build memory-enriched messages (Redis sliding window only — fast)
redis_mem = aioredis.from_url(settings.redis_url)
try:
recent_messages = await get_recent_messages(
redis_mem, tenant_id_str, str(agent.id), user_id_str
)
finally:
await redis_mem.aclose()
enriched_messages = build_messages_with_memory(
agent=agent,
current_message=text_content,
recent_messages=recent_messages,
relevant_context=[],
channel="web",
)
# Stream LLM response directly to WebSocket — no Celery, no pub-sub
response_text = ""
try:
async for token in run_agent_streaming(
msg=normalized_msg,
agent=agent,
messages=enriched_messages,
):
response_text += token
try:
await websocket.send_json({"type": "chunk", "text": token})
except Exception:
break # Client disconnected
except Exception:
logger.exception("Direct streaming failed for conversation=%s", saved_conversation_id)
if not response_text:
response_text = "I encountered an error processing your message. Please try again."
# Save to Redis sliding window (fire-and-forget, non-blocking)
redis_mem2 = aioredis.from_url(settings.redis_url)
try:
await append_message(redis_mem2, tenant_id_str, str(agent.id), user_id_str, "user", text_content)
if response_text:
await append_message(redis_mem2, tenant_id_str, str(agent.id), user_id_str, "assistant", response_text)
finally:
await redis_mem2.aclose()
# Fire-and-forget embedding for long-term memory
try:
embed_and_store.delay({
"tenant_id": tenant_id_str,
"agent_id": str(agent.id),
"user_id": user_id_str,
"role": "user",
"content": text_content,
})
if response_text:
embed_and_store.delay({
"tenant_id": tenant_id_str,
"agent_id": str(agent.id),
"user_id": user_id_str,
"role": "assistant",
"content": response_text,
})
except Exception:
pass # Non-fatal — memory will rebuild over time
# -------------------------------------------------------------------
# e. Save assistant message and send final "done" to client