Rate-Limit Headers That Teach Clients to Back Off from 429
Define scope and time semantics for Limit, Remaining, Reset, and Retry-After across layered quotas, clock skew, caching, and privacy.
uCopy Technical Blog
Clear explanations for connections that work in real life · Page 7
Practical uCopy guides to WebRTC, P2P file transfer, STUN and TURN, LAN discovery, resumable transfers, screen sharing, privacy, and security.
WebRTCP2P transferSTUN / TURNPrivacy & security
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Detecting Reconnect Loops Before Users See Endless Connecting
Track transitions, backoff level, repeated errors, and stop intent under short-lived anonymous sessions to detect, break, and report high-frequency reconnect loops.
Controlling Reconnect Storms When a Real-Time Service Recovers
Combine exponential backoff, full jitter, server Retry-After, connection budgets, and staged recovery to reduce synchronized load after deploys, regional failures, and network blips.
Reconnection UX That Recovers Aggressively but Respects Stop
Separate brief disruption, sustained loss, background recovery, user stop, and renewed consent into explicit states with quiet recovery, progress, and manual retry.
Modeling Presence in Redis with Expiry, Sets, and Atomic Scripts
Maintain device presence with expiring instance keys, sorted sets, and atomic Lua updates while handling multiple tabs, node crashes, expiry notification, and cluster sharding.
Reduced Motion for Real-Time Progress and Connection Changes
Respect prefers-reduced-motion by replacing connection pulses, progress shimmer, list fly-ins, and auto-scroll while keeping state changes clear.
Forecasting TURN Capacity Across Growth, Seasonality, and Relay Ratio
Forecast hourly bandwidth and allocations by region with relay ratio and product events, producing intervals, scenarios, and procurement lead time rather than one number.
TURN Quotas and Abuse Controls Must Be Enforced at the Relay
Combine short-lived credentials, daily quota, allocation limits, shaping, anomaly detection, and regional capacity to control relay cost without harming legitimate files.
Handshake Replay Protection with Nonces, Windows, and Session Binding
Bind connection and authentication messages to high-entropy nonces, unique session IDs, both identities, protocol context, and a bounded acceptance window.
Injecting Corruption into Resume Tests Beyond 100 Percent Progress
Inject bit flips, truncation, duplication, and offsets into persisted chunks, range maps, file reselection, and final assembly to prove hashes detect and repair only required ranges.
Can a Browser File Transfer Resume After a Page Refresh?
Learn what survives receiver or sender refresh and network loss, why the sender may need to reselect the source, and which manifests and terminal states make resume reliable.
Data Retention Must Cover Backups, Derived Tables, and Logs
Define retention justification, online deletion, backup expiry, derived-data propagation, and legal holds separately for accounts, analytics, errors, quota, and security audit.
Retries Are a Contract: Idempotency Across Writes and Side Effects
Start from uncertain timeout outcomes and design idempotency keys, request digests, result caching, and side-effect deduplication so retries do not duplicate notifications or quota charges.
Reverse-Proxy WebSocket Tuning for Upgrade, Timeout, and Buffering
Configure HTTP Upgrade, HTTP/2 boundaries, idle timeouts, proxy buffering, connection limits, and trusted client addresses to avoid silent 60-second drops and spoofing.
Restoring the Right Route After Refresh Without Reviving Stale Work
Restore a workspace from URL, persisted tasks, device state, and feature permission while handling invalid tabs, ended work, private parameters, and deep links.
Runtime Secret Management Without Repositories or Process Arguments
Inject secrets through restricted files, credential agents, or secret services with access control, rotation, caching, audit, and crash-output protection.
Safe Filenames Across Path Traversal, Unicode, and Downloads
Separate display names from storage keys, normalize Unicode, remove path semantics, bound length, and generate Content-Disposition safely to prevent overwrite and UI deception.
Cancellation in Long-Running Sagas Is Not a Database Rollback
Define forward steps, compensations, irreversible boundaries, and cancellation priority for cross-service or peer file workflows so both sides converge after a stop.
Why WebRTC Uses TURN Even on the Same Local Network
Diagnose same-LAN relay use through mDNS host candidates, AP isolation, multiple interfaces, IPv6, firewalls, and candidate priority.
Screen Capture Track Lifecycle: What Must Be Cleaned After ended
Keep sender and viewer state consistent across getDisplayMedia, track ended, replaceTrack, browser stop controls, source closure, and connection loss.
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