rich-art-45250
12/18/2025, 2:30 AMtall-airline-16756
12/18/2025, 2:30 AMtall-airline-16756
12/18/2025, 2:30 AMidle_processes_per_agent=1 will prevent the "process memory usage is high" warning and still allow you to scale to ~250 workers on LiveKit Cloud. Short answer: it won't reliably prevent the memory warning, and scaling to 250 workers is still possible — but you should consider additional changes.
Key points about your situation
• Setting idle_processes_per_agent=1 only reduces how many warm (idle) job processes each agent keeps. That can save a small amount of memory per agent but does not prevent a single job process from exceeding 500 MB when it loads large models or handles heavy work.
• The warning you posted shows a single process crossed the 500 MB threshold; that’s caused by what each process loads (models, buffers, contexts), not the count of idle processes.
• LiveKit Cloud can scale to large numbers of workers independently of the idle-process setting, so 250 workers is achievable.
Recommended next steps
1. Measure per-process memory: identify which models or code paths increase memory (VAD, STT, LLMs, large buffers).
2. Prewarm/shared loads: where possible, load heavy models in a prewarm or shared initialization so they aren’t repeatedly loaded in ways that spike memory.
3. Autoscaling and instance sizing: ensure autoscaling is configured on job queue depth/load and consider larger-memory instance types for agents that host memory-heavy jobs.
4. Reduce concurrency per-process: if a single process handles many concurrent tasks, lower that concurrency so each process uses less memory.
5. Monitor and alert thresholds: adjust alerts/thresholds to match expected memory footprints once you’ve profiled processes.
A couple quick clarifying questions so I can give targeted guidance:
• What models or libraries are you loading in each job process (e.g., Silero VAD, specific STT/LLM models)?
• Are you using prewarm/shared initialization today?
• Are you seeing many simultaneous session starts (which would increase cold spawns if idle is 1)?
If you share those details I’ll suggest concrete config changes (instance sizes, autoscale triggers, or process-level adjustments).
Sources: Agent server options | LiveKit docs | Deploy and scale agents on LiveKit Cloud | Deploying to custom environments | LiveKit docsrich-art-45250
12/18/2025, 2:38 AMtall-airline-16756
12/18/2025, 2:38 AMrich-art-45250
12/18/2025, 2:39 AMtall-airline-16756
12/18/2025, 2:40 AMrich-art-45250
12/18/2025, 2:41 AMtall-airline-16756
12/18/2025, 2:41 AMload_threshold example tuned for LiveKit Cloud. Which would you like?rich-art-45250
12/18/2025, 2:45 AMtall-airline-16756
12/18/2025, 2:45 AMrich-art-45250
12/18/2025, 2:46 AMtall-airline-16756
12/18/2025, 2:46 AMidle_processes_per_agent does and what it should be for your stack. Short answer and recommendation:
What it is
• idle_processes_per_agent sets how many warm (idle) job processes each agent keeps ready to accept new sessions without cold-starting.
Effects
• Memory: each idle process consumes RAM, so higher values increase baseline memory usage per agent.
• Latency: more idle processes reduces cold-start latency when traffic spikes.
• Scaling: it does not change per-process memory usage; it only changes how many prewarmed processes sit in RAM. Scaling capacity on LiveKit Cloud is independent of this setting.
Recommended value for your stack (GPT‑4o + VAD + AssemblyAI + ElevenLabs)
• Set to 1–2.
◦ Use 1 to minimize baseline memory if you need max density.
◦ Use 2 if you want lower cold-start latency for brief spikes.
• Combine with autoscaling and 16 GB workers (your current setup) so you still have headroom.
Would you like me to suggest exact idle_processes_per_agent plus autoscale thresholds based on a measured RSS number (paste one sample RSS in MB)?rich-art-45250
12/18/2025, 2:46 AMtall-airline-16756
12/18/2025, 2:46 AMv20251218022643 — deployed release tag/timestamp.
• Region: us-east — where the deployment runs.
• Status: Running — deployment is active.
• CPU: 6m / 8000m — current CPU usage is 6 millicores; quota/limit is 8000 millicores (8 vCPU).
• Mem: 0.82 / 16GB — current memory usage is 0.82 GB; limit is 16 GB per worker.
• Replicas: 4 / 1 / 16 — shows replica counts in this format:
◦ first number (4) = desired replicas currently running,
◦ second (1) = minimum replicas configured,
◦ third (16) = maximum replicas allowed.
• Deployed At: timestamp of when this version was deployed.
What this implies for your stack
• Each worker has 16 GB memory (matches earlier). Current usage is low (0.82 GB) across the deployment, so you have plenty of headroom now.
• Desired replicas = 4 means four worker pods are running. Autoscaler can scale between 1 and 16 pods currently.
• CPU quota=8 vCPU per worker; current CPU draw is minimal.
Suggested next actions
• If you plan for 250 concurrent jobs, calculate required replicas from measured per-process RSS and set the max replicas accordingly (you can use the earlier calculations I provided).
• Ensure autoscale policy (scale-up threshold, cooldown) is set to react before pods reach high CPU/memory.
• Monitor per-pod RSS to verify the ~300–500 MB per-process target; if memory per process rises, increase replica max or use larger instance types.
If you want, paste a measured RSS (MB) from a representative process and I’ll compute exact replica targets and a recommended max replicas value for 250 concurrent workers.rich-art-45250
12/18/2025, 2:49 AMtall-airline-16756
12/18/2025, 2:49 AMidle_processes_per_agent = 1–2. Use 1 to maximize density or 2 to reduce cold starts.
• Scale-up trigger: ~50% CPU or job-queue depth threshold (scale early).
• Short scale-up cooldowns; longer scale-down cooldowns.
• Prewarm heavy components (VAD) and pre-download model assets in the image/build step.
• Set process memory alert below 500 MB for early warning.
5) Capacity & safety
• Add at least one extra worker as buffer during deploys/spikes.
• Monitor per-pod RSS and adjust worker count upward if RSS > planned target.
6) Quick next steps I can do for you
• If you paste one representative process RSS (MB), I’ll compute the exact recommended worker count and a sample autoscale policy (scale thresholds and cooldowns). Sources: examples/drive-thru | livekit/livekit_composite | DeepWiki | Deploying to custom environments | LiveKit docs | Deploy and scale agents on LiveKit Cloud | Agent server options | LiveKit docs | LiveKit Pricingrich-art-45250
12/18/2025, 2:51 AMtall-airline-16756
12/18/2025, 2:51 AMidle_processes_per_agent = 1–2 (use 1 for max density, 2 to reduce cold starts).
• Scale-up trigger: ~50% CPU or job-queue depth; short scale-up cooldown, longer scale-down.
• Prewarm/load VAD and other heavy components at build/startup.
• Set memory alerts below 500 MB for earlier warning.
5) Safety buffer
• Keep at least one extra worker for deploys and spikes; monitor per-pod RSS and increase workers if measured RSS > target.
If you want exact numbers and a sample autoscale policy, paste one representative process RSS (MB) and I’ll compute the precise worker count and thresholds.rich-art-45250
12/18/2025, 2:52 AMtall-airline-16756
12/18/2025, 2:52 AMlk agent create / lk agent deploy.
• LiveKit Cloud manages underlying VMs and autoscaling for you; you do not provision nodes manually.
3) Set runtime/prewarm behavior
• Use idle_processes_per_agent = 1–2 (1 for max density, 2 if you want fewer cold starts).
• Pre-download and prewarm heavy components (VAD, any model assets) in your image/startup so processes don’t spike memory on first use.
4) Capacity planning (you have 16 GB workers)
• Target per-process memory: 300–500 MB (profile to refine).
• Plan for ~8–10 workers (16 GB each) to cover 250 concurrent agents with buffer:
◦ ~7–8 workers if per-process ≈ 350 MB
◦ ~9–10 workers if per-process ≈ 500 MB
• Keep at least one extra worker for deploys/spikes.
5) Autoscaling & thresholds
• Rely on LiveKit Cloud autoscaling; ensure your dashboard shows max replicas >= planned workers.
• Use early scale-up (around 50% CPU or job-queue triggers) and short scale-up cooldowns; longer scale-down.
6) Monitoring & verification
• Use the LiveKit Cloud dashboard / lk agent status and lk agent logs to check:
◦ Current replicas, CPU, and per-pod RSS memory.
◦ Concurrent sessions metric reaches 250 in tests.
• Set memory alerts below 500 MB to catch rising usage early.
7) Test with load
• Run a staged load test to 250 concurrent 1:1 rooms and observe:
◦ Per-process RSS, pod count, latency, and cold starts.
• If RSS > target, increase worker count or reduce per-process load (prewarm, lower concurrency).
If you want, paste a measured RSS (MB) from one representative agent process and I’ll compute the exact recommended worker count and a suggested autoscale policy (thresholds and cooldowns) for your LiveKit Cloud setup.
Sources: Deploy and scale agents on LiveKit Cloud | Quotas and limits | LiveKit docs | LiveKit Pricing | Deploying to production | LiveKit Docs | Deploying to custom environments | LiveKit docsrich-art-45250
12/18/2025, 2:57 AMtall-airline-16756
12/18/2025, 2:57 AMidle_processes_per_agent = 1 to maximize density; set to 2 only if you need lower cold-start latency.
• Scale-up trigger: aggressive (e.g., ~50% CPU or increasing job-queue depth). Short scale-up cooldown (1–2 min), longer scale-down (5–10 min).
• Prewarm is working (RSS increased only ~20–24 MB); keep prewarm to avoid cold loads.
5) Monitoring & operational checks
• Monitor per-pod RSS during a load test to confirm ~450 MB holds under peak.
• If observed RSS rises above 500 MB, increase workers to 10–11 and/or move to larger instances.
• Set memory alert threshold at ~480 MB for early warning.
If you want, I can:
• Recalculate with a different per-process RSS (paste measured RSS), or
• Provide suggested autoscale thresholds and sample lk dashboard checks. Which would you like?rich-art-45250
12/18/2025, 3:02 AMtall-airline-16756
12/18/2025, 3:02 AMinference.STT.
• Example (basic):
import { AgentSession } from "@livekit/agents";
const session = new AgentSession({
stt: "assemblyai/universal-streaming:en",
llm: "openai/gpt-4.1-mini",
tts: "cartesia/sonic-3:YOUR_TTS_ID",
});
• Example (advanced options):
import { AgentSession, inference } from "@livekit/agents";
const session = new AgentSession({
stt: new inference.STT({
model: "assemblyai/universal-streaming",
language: "en",
modelOptions: {
format_turns: true,
end_of_turn_confidence_threshold: 0.4,
min_end_of_turn_silence_when_confident: 400,
max_turn_silence: 1280,
},
}),
llm: "openai/gpt-4.1-mini",
});
• Benefits: no AssemblyAI API key needed in your code, LiveKit handles the STT integration and billing; you can pass provider-specific options via modelOptions.
2) Use AssemblyAI directly (if you need full control)
• Use AssemblyAI’s Realtime WebSocket/API from your Node/TS app.
• Example (websocket):
const ws = new WebSocket('<wss://api.assemblyai.com/v2/realtime/ws?token=YOUR_TOKEN>');
ws.onmessage = (ev) => {
const data = JSON.parse(ev.data.toString());
if (data.text) console.log("Transcript:", data.text);
};
• Use this if you need features not exposed by LiveKit Inference or want to use your own AssemblyAI account.
Best practices
• Prefer LiveKit Inference for simplicity, managed scaling, and compatibility with AgentSession flows.
• If using direct AssemblyAI: stream audio with small frames, handle reconnects/backpressure, and secure your API key (server-side only).
• Profile latency and accuracy settings via modelOptions.
• Test end-to-end in a staging load to confirm memory and latency behavior.
If you want, tell me:
• Whether you prefer LiveKit-managed Inference or direct AssemblyAI, and
• One example use case (live transcription, diarization, low-latency captions),
and I’ll give a tailored TypeScript sample and recommended modelOptions.
Sources: AssemblyAI plugin guide | LiveKit Docs | AssemblyAI STT | LiveKit Docs | Models | LiveKit Docsrich-art-45250
12/18/2025, 3:04 AMtall-airline-16756
12/18/2025, 3:04 AMidle_processes_per_agent = 1 (or 2 briefly during rollout) so prewarm memory impact is small but you can reduce cold-start spikes during tests.
• Pre-download and prewarm VAD/STT assets in your image/startup. You already saw only ~20–24MB RSS increase on prewarm — prewarm helps.
• Implement exponential backoff + jitter and a short retry window for websocket connects; failover to AssemblyAI after N failed attempts.
• Instrument and alert on websocket failure rate and session connect latency so you can detect gateway regressions quickly.
If you want, I will:
• Provide a minimal TypeScript fallback pattern (pseudo-code + reconnect logic) you can drop into your AgentSession STT wiring, or
• Provide a sample using the AssemblyAI plugin/direct WS connect with reconnection/backpressure handling.
Which would help you most right now?
Sources: Deploy and scale agents on LiveKit Cloud | Quotas and limits | LiveKit docs | LiveKit Pricing | Deploying to custom environments | LiveKit docs | Models | LiveKit Docsrich-art-45250
12/18/2025, 3:15 AMtall-airline-16756
12/18/2025, 3:16 AMnumbers: ["*"] if you’ll set sip_number per call.
• Use username/password auth (not IP auth) and enable TLS if provider supports it.
3) Dial flow best practices
• Use CreateSIPParticipant with wait_until_answered: true to avoid starting agent logic before answer.
• Include helpful metadata (caller id, attempt id) so logs correlate to calls.
4) Capacity & worker sizing (practical)
• With your measured ~450 MB RSS/process and 16 GB workers: plan ~32 concurrent processes per worker.
• For 250 agents, provision 8 workers and keep a 9th as buffer (autoscaler max ≥9–10).
• Ensure idle_processes_per_agent = 1 (or 2 briefly during rollout) and prewarm heavy components.
5) Autoscale & thresholds
• Scale-up early (e.g., ~50% CPU or increasing job-queue depth). Short scale-up cooldown (1–2 min); longer scale-down (5–10 min).
• Ensure dashboard max replicas ≥ planned workers and set min replicas = 1–2 if you want baseline capacity.
6) STT reliability
• If LiveKit Inference websocket is flaky, use a fallback: try Inference first, then fall back to direct AssemblyAI (plugin or direct WS).
• For production stability prefer using AssemblyAI plugin/direct WS (with your API key) if Inference remains unreliable.
7) Connection resilience & retries
• Implement exponential backoff + jitter for websocket reconnects; fail to fallback STT after N attempts.
• Retry SIP participant creation with idempotency keys and backoff on transient SIP errors.
8) Observability & alerts
• Monitor per-pod RSS, connect latency, websocket failure rate, and SIP call status.
• Set memory alert ~480 MB, and alert on >X% increase in websocket failures or call drop rate.
9) Call failure handling
• Detect call states (sip.callStatus → active, failed) and implement retry/callbacks and escalation logic.
• Log SIP codes and provider responses for troubleshooting (Telnyx/Plivo logs are invaluable).
10) Testing & rollout
• Do staged load tests: start at 25%, 50%, 75% of target concurrency, verify RSS, CPU, latency, and cold-start behavior.
• Use short ramp-up windows before full production; keep one or two warm extra workers during deploys.
If you want, I can:
• Provide a minimal TypeScript snippet that creates SIP participants with wait_until_answered and retry logic, or
• Draft a fallback STT pattern (Inference → AssemblyAI) in TypeScript you can drop into your agent session.
Which would you like?
Sources: SIP outbound trunk | LiveKit docs | Make outbound calls | LiveKit docs | Agents telephony integration | LiveKit docs | Deploy and scale agents on LiveKit Cloud | Deploying to custom environments | LiveKit docsrich-art-45250
12/18/2025, 3:19 AMtall-airline-16756
12/18/2025, 3:19 AMrich-art-45250
12/18/2025, 3:20 AMtall-airline-16756
12/18/2025, 3:21 AMlk agent status to see current replica count, min/max replicas, and worker memory/CPU. Ensure max replicas ≥ the number of workers you plan to reach.
1. Observe autoscaling in a ramp test
◦ Run a staged load (25% → 50% → 75% → 100%) and watch:
▪︎ Replica count increasing as load rises.
▪︎ Per-pod RSS and CPU remain within expected bounds.
▪︎ New pods become Ready and accept sessions without errors.
◦ Use lk agent logs and dashboard metrics to correlate scaling events with load.
1. Validate behavior you expect
◦ Cold-starts: verify idle_processes_per_agent prewarm behavior is working (1–2).
◦ Drain/rollout: perform a deployment and confirm rolling update + drain windows allow active calls to finish.
What you can configure (and what you can’t)
• You can: choose plan, set idle_processes_per_agent, prewarm assets, and set min replicas (via dashboard if desired). You can also request higher max concurrency from LiveKit if needed.
• You cannot: set explicit scale-up CPU% or cooldown timers — LiveKit Cloud manages those internals.
If autoscaling seems slow or you hit limits
• Verify plan/concurrency quota (upgrade or request pre-provisioning).
• Increase min replicas to keep baseline capacity during ramps.
• Add one or two warm extra workers before expected spikes (short-term manual buffer).
• Run rolling load tests and capture timestamps/logs showing scale events — share them and I can interpret whether scaling lag is platform-related or caused by policy/usage.
If you’d like, I can:
• Provide a step-by-step ramp test script and what to watch in the dashboard, or
• Review your lk agent status output and recent logs and point out any scaling issues.
Which would you prefer?
Sources: Deploying to production | LiveKit Docs | Deploying to custom environments | LiveKit docs | AssemblyAI plugin guide | LiveKit Docs | Agents Framework | livekit/livekit_composite | DeepWiki | Resolving &#34;InvalidState - failed to capture frame&#34; errors in AudioSourcerich-art-45250
12/18/2025, 3:22 AMtall-airline-16756
12/18/2025, 3:22 AM#!/usr/bin/env bash
URL="<wss://your-domain.livekit.cloud>"
KEY="YOUR_API_KEY"
SECRET="YOUR_API_SECRET"
ROOM="staged-load-test"
DURATION="5m" # per stage
PAUSE="180" # pause between stages (seconds)
STAGES=(62 125 187 250) # 25%,50%,75%,100% for 250 target
for SUBS in "${STAGES[@]}"; do
echo "Starting stage: $SUBS subscribers"
lk load-test \
--url "$URL" \
--api-key "$KEY" \
--api-secret "$SECRET" \
--room "$ROOM" \
--video-publishers 0 \
--subscribers "$SUBS" \
--duration "$DURATION" \
--render-type scalable
echo "Stage complete. Waiting $PAUSE seconds to observe autoscaling..."
sleep "$PAUSE"
done
echo "Staged load test finished."
What to watch during and between stages
• Dashboard: replica count, pod readiness, concurrent sessions.
• Per-pod metrics: RSS, heap, CPU. Confirm RSS ~450MB and CPU <70%.
• Error rates: websocket/STT failures, call drops, SIP errors.
• Cold starts: check whether new pods accept sessions quickly.
• Autoscaling behavior: replica count should increase before pods hit capacity.
If anything fails
• Pause ramp, diagnose logs (lk agent logs), check websocket/STT errors, increase prewarm to 2 briefly or add one extra worker, then resume after fixes.
Optional enhancements
• Automate gates: script API checks to read metrics and only continue when gates pass.
• Run load-test from multiple machines if the single client becomes a bottleneck.
• Increase ulimit -n on test machine (e.g., 65535) to avoid file descriptor limits.
Would you like:
• A version of the script that auto-aborts on a failed gate (CPU/RSS thresholds), or
• A sample Node/TS harness for more control and parallel generation? Sources: Benchmarking | LiveKit docs | Self-hosting the Ingress Service | LiveKit docs | Self-hosting the Egress Service | LiveKit docsrich-art-45250
12/18/2025, 3:23 AMidle_processes_per_agent, prewarm assets, and set min replicas (via dashboard if desired). You can also request higher max concurrency from LiveKit if needed.tall-airline-16756
12/18/2025, 3:23 AMidle_processes_per_agent and prewarm assets (agent code / image)
• In your agent code (AgentServer/AgentSession), set idle_processes_per_agent (or num_idle_processes) to 1–2:
◦ 1 = maximize density, 2 = fewer cold starts.
• Pre-download heavy assets in your container build or startup script so they’re already on disk before process start (example: run your model download script in Dockerfile during build).
• Call your prewarm logic at agent start so processes load VAD/STT weights and hold them warmed.
3) Set min replicas / view max replicas (dashboard)
• Open LiveKit Cloud dashboard → Agents/Deployment view. You can:
◦ See current replica count and the configured max replicas.
◦ Set a sensible min replicas (1–2) via the dashboard if you want baseline always-warm capacity.
• If you don’t see controls for max replicas or need higher concurrency limits, request it from LiveKit (sales/support contact in dashboard).
4) Verify autoscaling behavior (dashboard + tests)
• Autoscaling is automatic on LiveKit Cloud; it uses effective load (job count, CPU/memory). You cannot set CPU% thresholds directly.
• Verify autoscaling by running staged load tests (CLI script I provided earlier) and watching replica changes in the dashboard.
5) Practical actions to perform now
• Upgrade to Scale/Enterprise if not already done.
• Update agent image to pre-download models in Dockerfile and call prewarm in startup.
• Set idle_processes_per_agent = 1 in your server config and deploy.
• In dashboard set min replicas = 1–2 and confirm max replicas ≥ planned workers (or request higher).
• Run staged load test and observe autoscaling; adjust min replicas or ask LiveKit to pre-provision capacity if you see slow scale-up.
If you want, I can:
• Provide a small Dockerfile snippet for pre-downloading assets and a short AgentServer config example with idle_processes_per_agent, or
• Walk through where to click in your LiveKit Cloud dashboard if you paste a screenshot of the Agents/Deployment page.
Which would help most?rich-art-45250
12/18/2025, 3:44 AMtall-airline-16756
12/18/2025, 3:46 AMagent_name on dispatch and ServerType.ROOM so one agent = one call.
2) Prewarm heavy components
• Pre-download model assets in your Dockerfile/build step.
• Run a prewarm function at agent start to load VAD/STT into memory once per worker (reduces cold-start spikes).
3) Start muted / wait until answered
• When creating SIP participant, use wait_until_answered: true.
• Keep agent audio input disabled until answer, then enable listening; prevents premature speech.
4) Retry & idempotency for SIP creation
• Wrap CreateSIPParticipant in retry with exponential backoff and idempotency keys.
• Log SIP status codes and provider responses for debugging.
5) Keep calls isolated
• Use ROOM type (one agent per room) to avoid resource contention and simplify scaling/observability.
6) Tune idle processes and prewarm counts
• idle_processes_per_agent = 1 to maximize density; use 2 during ramp if you need fewer cold starts.
• Prewarm only the necessary models to limit RSS growth.
7) Drain/rollout safety
• Ensure drain timeout is long enough for typical call length (default 30m is usually fine).
• Keep at least one extra worker during deploys to avoid capacity gaps.
8) Observability & alerts
• Monitor per-pod RSS, CPU, websocket/STT error rate, and call answer rate.
• Set memory alert around ~480 MB (your measured ~450 MB/process).
• Alert on websocket failure rate and SIP failure rate.
9) STT fallback & resilience
• If LiveKit Inference is flaky, implement fallback: try Inference first, then switch to direct AssemblyAI (plugin or WS) after N failures.
• Use exponential backoff + jitter for reconnects and fallback switching.
10) Load testing & safe ramp
• Do staged ramps (25/50/75/100%) using lk load-test script. Pause between stages to verify autoscaling and metrics.
• Validate gates before proceeding (RSS, CPU, error rate, answer rate).
11) Separate inbound vs outbound deployments
• Run distinct agent deployments for inbound and outbound traffic for isolated scaling and easier troubleshooting.
12) Region & compliance
• Pin trunk destination region when necessary for regulatory or latency reasons (destination_country).
If you’d like, I can:
• Provide a short TypeScript or Node snippet that:
◦ Creates SIP participants with retries and wait_until_answered, and
◦ Implements STT fallback (Inference → AssemblyAI).
• Or produce a small Dockerfile + prewarm example you can use today.
Which would you prefer?
Sources: Agent server options | LiveKit docs | Introducing LiveKit Inference: A unified model interface for voice AI | AssemblyAI plugin guide | LiveKit Docs | Deploy and scale agents on LiveKit Cloud | AssemblyAI STT | LiveKit Docs