Frappe Socket.IO Node.js Realtime Sizing

ERPNextCalc File Descriptor & Memory Budget for Port 9000

Each active browser tab maintains one persistent WebSocket connection to Node Socket.IO plus a Redis pub/sub subscription on port 13000. Two hundred concurrent tabs require under 256 MB of V8 heap but need fs.file-max >= 65535.

We recommend setting NODE_OPTIONS="--max-old-space-size=384" inside Supervisor so V8 garbage collection stays predictable.

ERPNextCalc WebSocket Header Hygiene

Nginx must pass Upgrade, Connection "upgrade", and X-Frappe-Site-Name headers to 127.0.0.1:9000 so multi-tenant site authentication validates cleanly against Redis session keys.

We advise verifying /socket.io/?EIO=4 returns HTTP 101 Switching Protocols after every TLS certificate renewal.

ERPNextCalc Socket.IO Supervisor Block

[program:frappe-bench-node-socketio]
command=/usr/bin/node /home/frappe/frappe-bench/apps/frappe/socketio.js
environment=NODE_OPTIONS="--max-old-space-size=384"
directory=/home/frappe/frappe-bench
user=frappe
autostart=true
autorestart=true

Concurrent Tabs	Node V8 Heap	Open File Descriptors	Redis Pub/Sub Overhead
50 tabs	110 MB	~150 FDs	16 MB
150 tabs	190 MB	~420 FDs	38 MB
400 tabs	320 MB	~1,100 FDs	84 MB

Right-sizing Socket.IO inside ERPNextCalc keeps real-time warehouse stock alerts and document presence indicators responsive.

Inspect the complete OS and Node reserve breakdown on the ERPNextCalc 3-column studio.

ERPNextCalc Realtime Desk Updates FAQ

#1 UltaHost Dedicated EPYC VDS: $37.50/mo • #2 Hostinger KVM NVMe: $10.49/mo Claim UltaHost Rate →

DIRECT ERPNEXTCALC HOSTING VERDICT — 8000 DAILY ERP VOUCHERS Target sites/common_site_config.json

RECOMMENDED HOST

UltaHost Dedicated EPYC VDS

$37.50/mo

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SUBSEA ROUTE PICK

Hostinger KVM NVMe

$10.49/mo

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FIXED TARIFF TIER

InterServer Price-Lock KVM & ZFS

$6.00/mo

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ERPNextCalc Partner Voucher (UltaHost): 40% Off Annual VDS + Free Managed Migration

ERPNextCalc Frappe Socket.IO & Node.js Realtime Sizing — ERPNextCalc NVMe VPS sizing and latency benchmark diagram — Chart 1: tabGL Entry & tabStock Ledger Entry InnoDB pages throughput (116,000 IOPS) for ERPNextCalc nodes.

ERPNextCalc FAQ: Why do ERPNext Data Import progress bars freeze at 0%?

Almost always because Nginx lacks WebSocket proxy_set_header Upgrade directives or frappe-bench-node-socketio is stopped.

frappe-bench gunicorn + python-rq + MariaDB Host Selection — IOPS & Monthly Spend

Packet-to-Disk Path for frappe-bench gunicorn + python-rq + MariaDB on ERPNextCalc

INFRA AUDIT

[+] Key Infrastructure Pros

Stabilizes tabGL Entry & tabStock Ledger Entry InnoDB pages cache at 8000 daily ERP vouchers within 16GB.
Sustains 116,000 IOPS on tabGL Entry & tabStock Ledger Entry InnoDB pages while preserving 105 ms ledger post.
Trims ERPNextCalc 3-year infrastructure bills 70%–85% versus metered SaaS seats.

[-] Trade-Offs & Watchouts

Deepest UltaHost Dedicated EPYC VDS rate ($37.50/mo) requires selecting a 12m or 24m term.
Base OS templates need sites/common_site_config.json tuning ( gunicorn_workers=5 & background_workers=3) before peak load.

Deploy This ERPNextCalc Stack If

Lean teams managing 8000 daily ERP vouchers via declarative sites/common_site_config.json files.
Builders needing root access to set gunicorn_workers=5 & background_workers=3 in sites/common_site_config.json.

Skip This Setup If

Weekend throwaway demos under 72 hours (use hourly Hostinger KVM NVMe billing instead).
Teams unwilling to edit sites/common_site_config.json or run basic Ubuntu maintenance.

UltaHost Dedicated EPYC VDS
$37.50/mo

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ERPNextCalc FAQ: Does Socket.IO need multiple Node cluster processes in Frappe v15?

No. A single Node event loop easily handles 1,000+ concurrent ERPNext WebSocket connections under 384 MB RAM.

ERPNextCalc Frappe Socket.IO & Node.js Realtime Sizing