> For the complete documentation index, see [llms.txt](https://docs.playnance.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.playnance.com/system-reliability/system-reliability.md). # System Reliability System reliability is a first-class design constraint in PlayBlock — not an afterthought and not something delegated to “infrastructure later.”\ Because PlayBlock powers real-money gaming, prediction markets, and continuous settlement flows, failure is not acceptable. The system must remain correct, deterministic, and recoverable under load, partial outages, and restarts. PlayBlock is therefore built around a simple principle: > **Every component must fail safely, recover deterministically, and resume without human intervention.** ### Reliability by Design PlayBlock does not rely on best-effort retries or optimistic assumptions. Instead, reliability is enforced through layered guarantees: #### 1. Deterministic Core Logic * Game settlement, balances, payouts, and state transitions are fully deterministic * No randomness in critical paths * Same inputs → same outputs → same on-chain result * AI, heuristics, and analytics are never allowed to influence settlement or balances This guarantees: * Safe replays * Idempotent retries * Verifiable correctness #### 2. Idempotent Everything Every external or internal action is designed to be idempotent: * Bet execution * Win settlement * Rollbacks * Treasury transfers * Event ingestion * Partner callbacks If the same request is received twice: * The system returns the same result * No double execution * No double spend * No corrupted state This is enforced using: * Transaction IDs * Redis-backed deduplication * On-chain transaction hashes as final truth #### 3. Crash-Safe Processing All long-running and high-throughput flows use durable queues and checkpointed state: * Workers can crash mid-execution * Pods can restart * Nodes can be rescheduled On recovery: * Pending jobs are resumed * Completed jobs are not re-executed * Partial progress is detected and reconciled No manual replay. No human intervention. #### 4. WebSocket & RPC Resilience Blockchain connectivity is treated as unstable by default. PlayBlock services assume: * WebSocket disconnects * Silent stalls * Partial event loss To handle this: * Live event listeners are guarded by watchdogs * Periodic forced reconnects are used * Historical backfills run after reconnect * Redis stores the last confirmed processed block * Lookback windows ensure no missed events The result: * Zero event loss * Zero duplication * Continuous indexing under unstable network conditions ### Built-In Failure Scenarios PlayBlock is explicitly designed to survive: * Pod crashes * Node restarts * Redis failovers * Temporary RPC outages * Partner API timeouts * Burst traffic spikes * Partial system outages Each scenario has a defined recovery path. ### Monitoring, Verification & Observability Reliability is continuously measured, not assumed. PlayBlock includes: * Per-service health checks * Queue lag metrics * Processing latency tracking * Blockchain confirmation monitoring * Cross-system consistency checks (on-chain vs DB vs cache) * Automatic alerts on anomalies In critical paths: * Random verification is used to confirm data was written correctly * Lag between blockchain time and ingestion time is measured * Duplicate detection metrics are tracked explicitly ### Safe Degradation When dependencies fail: * Systems degrade gracefully * Non-critical features pause * Critical settlement paths remain operational Examples: * Analytics may lag, but settlement continues * Discovery may freeze, but balances remain accurate * AI enrichment may pause, but games remain deterministic ### Reliability as a Product Feature In PlayBlock, reliability is not invisible plumbing — it is a product guarantee: * Players trust balances and payouts * Partners trust integrations * Operators trust recovery * Developers trust replays and audits This is what allows PlayBlock to operate continuously, globally, and at scale. --- # Agent Instructions This documentation is published with GitBook. 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