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paas

app deploy platform

Heroku, Fly.io

SystemTechniques · 26Primitives · 76 paas Desired-state reconciliationdistributed · medium: Declare the target in a store; controllers repeatedly diff actual against desired from full state and apply idempotent fixes, so missed events only delay convergence.›Deterministic simulation testingdistributed · medium: Run the whole system in one thread under a seeded scheduler with simulated network, disk and clock, so every failure replays from its seed.›Primary-backup replicationdistributed · medium: One node orders all writes and ships them to standbys; the acknowledgement rule (none, one, all) sets what a crash loses, and an external arbiter decides who takes over.›Vm snapshot restorehardware-os · medium: Snapshot an initialised VM/isolate heap and restore it for fast cold startsReverse proxynetworking · medium: A server-side intermediary that terminates client connections and forwards each request to one of a pool of upstream servers, with routing, health checks, timeouts and safe retries.›Acme protocolsecurity · medium: Automated TLS certificate issuance and renewal via ACME HTTP-01/DNS-01 challengesCoverage-guided fuzzingsecurity · medium: Mutate inputs, run an instrumented target, and keep any input that reaches a new code edge; feedback turns blind guessing into incremental search.›Health checkingsystems · low: Decide per backend whether to route to it using probes and real-traffic errors, with consecutive-count hysteresis, capped ejection and a panic fallback.›Hardware virtualization kvmhardware-os · low: VT-x/AMD-V via KVM: vCPU run loop, VM exits, MMIO emulationOci image layoutsystems · low: OCI manifests, image index, layer tarballs and config, addressed by digestSecrets managementsecurity · low: Keep keys and passwords out of code and logs, give workloads short-lived identity instead of static keys, and make rotation routine.›Hdr histogramdata-structures · low: Log-linear bucketed histograms with bounded relative error for latency percentilesProcess supervisionhardware-os · low: A parent process starts services, reaps their exits and restarts them under a delay and burst-limit policy, then stops them with SIGTERM before SIGKILL.›Anycastnetworking · low: Announce one IP prefix from many sites over BGP; routing sends each client to its preferred site, and a failed site leaves by withdrawing the route.›Bin packingoptimization · low: Pack items of given sizes into the fewest fixed-capacity bins; sort descending, then first-fit, gives at most 11/9 of optimal and runs in O(n log n).›Mutual TLSsecurity · low: TLS where the client also proves a certificate key, so every connection carries a verified, rotatable machine identity.›WireGuardsecurity · low: A UDP tunnel whose peers are public keys, with a 1-RTT Noise handshake, one fixed cipher suite and a key-to-address routing table.›Graceful drainingsystems · low: On a termination signal, stop taking new work, finish in-flight work until a deadline, tell clients to reconnect elsewhere, then exit; clients resume from a token.›Conditional writesdistributed · low: Put-if-absent / if-match compare-and-swap on objects or keys as a commit primitiveExponential backoff with jittersystems · low: Retry after delays that grow geometrically and are randomized, so failed clients spread out instead of hammering a recovering service in synchronized waves.›Cooperative schedulingconcurrency · low: Green threads/coroutines yielding at await points on a user-space schedulerRecord replaydistributed · low: Record every nondeterministic input (time, randomness, I/O, model and tool outputs, per-tick player input) and re-execute deterministically for debugging, replays and state rebuildPRNGs (PCG, xoshiro)numerics · low: Small, fast, statistically strong non-cryptographic generators: PCG32 and xoshiro256**, with seeding, parallel streams and unbiased ranges.›+ 19 more techniques+ 60 more primitives

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