← Back
Home › Systems › Simulation and scientific computing

storm-surge

storm surge and tsunami modelling

ADCIRC, GeoClaw

SystemTechniques · 10Primitives · 39 storm-surge Batch checkpoint restartdistributed · medium: Large batch jobs (end-of-day, settlement, payroll runs) that checkpoint and restart idempotentlyHalo exchangedistributed · medium: Each rank stores its block plus a border copy of its neighbours' edge cells, refreshed by small messages every step; communication scales with block surface, not volume.›Delaunay triangulationgeometry · medium: Bowyer-Watson and incremental flips; maximizes minimum angles, dual of VoronoiGraph partitioninggraphs · medium: Split a graph into k balanced parts with few edges between them; multilevel coarsen-partition-refine (METIS, KaHIP) for quality, streaming heuristics (LDG, Fennel) for one-pass scale.›Finite elementsnumerics · medium: Writes the PDE in weak form, approximates it with piecewise polynomials on a mesh and assembles a sparse system; handles any geometry.›Finite volume methodnumerics · medium: Conservative cell-averaged discretization with numerical fluxes on structured and unstructured meshesFlux limiters upwindingnumerics · medium: Upwind schemes, TVD flux limiters, MUSCL and Riemann solvers for shock-capturing advectionSparse matrices (CSR)numerics · low: Compressed sparse row stores only nonzeros as row pointers, column indices and values; SpMV streams them once, so it is memory-bandwidth bound.›Conjugate gradientnumerics · low: Krylov iteration for symmetric positive definite Ax = b using one matrix-vector product and two dot products per step; converges in about √κ iterations.›Unstructured mesh representationnumerics · low: Cell-face-node connectivity in CSR form for FEM and FVM meshes; partition-friendly orderingMap projectionsgeometry · low: Web Mercator, UTM and equal-area projections, datums and coordinate transformsCollective communicationml-training · low: The family of group exchanges (broadcast, reduce, all-gather, reduce-scatter, all-to-all) and the latency-plus-bytes cost model that picks ring, tree or direct algorithms by message size and topology.›Common alerting protocolnetworking · low: CAP alert message format: areas as polygons/circles, severity, urgency, multilingual info blocksMonte Carlo integrationnumerics · low: Estimate an expectation by averaging random samples; error falls as σ/√N in any dimension, and variance reduction (antithetic, control variates, importance sampling) shrinks σ.›Spherical gridsnumerics · low: Lat-lon, cubed-sphere and icosahedral grids for global models; pole and area issuesIdempotency keysfinance · low: Client-chosen unique key per logical operation, stored with a request fingerprint and the final response, so retries replay the first result instead of acting twice.›Write-ahead logstorage · low: Append each change to a checksummed sequential log and fsync it before touching data pages; the basis of crash durability in nearly every database.›Cron schedulingsystems · low: Cron expression parsing and next-fire-time computation, with catch-up and time-zone rulesEager rendezvous protocoldistributed · low: MPI point-to-point: eager sends for small messages, rendezvous handshake for large onesRdmanetworking · low: RDMA verbs over InfiniBand/RoCE: queue pairs, memory registration, one-sided opsZero-copy I/Onetworking · low: Move bytes between files, sockets and NICs by passing page references instead of copying through user space: sendfile, splice, MSG_ZEROCOPY, kTLS.›Exact geometric predicatesgeometry · low: Robust orient and incircle tests with adaptive-precision floats (Shewchuk) or exact arithmeticSpace filling curvesgeometry · low: Z-order/Morton (geohash) and Hilbert curves mapping multi-dimensional points to sortable keys+ 3 more techniques+ 23 more primitives

Similar systems

Share the most building blocks with this one.