{
  "slug": "flashield",
  "term": "Flashield",
  "aliases": [],
  "definition": "Flashield is a hybrid DRAM-and-SSD key-value cache that filters flash admission using predicted reads and updates.",
  "note": "Incoming objects enter DRAM; selected objects move to flash in segments. Admission and eviction use different rankings. [paper]\n\nA Flashield ghost may still serve its current value before segment reclamation. This is not nonresident ARC history. [paper]\n\nIts trace comparison is simulation; hardware microbenchmarks are separate. [paper]",
  "citations": [
    {
      "id": "paper",
      "title": "Eisenman et al. Flashield. NSDI 2019, pp. 65-78; sections 3, 4.3 and 5.",
      "url": "https://www.usenix.org/system/files/nsdi19-eisenman.pdf",
      "accessed": "2026-11-10"
    },
    {
      "id": "hesela",
      "title": "Hesela: cache admission and matched write counters",
      "url": "https://hesela.com/analyses/sieve-cache-eviction-traces/#flashield-accounting",
      "accessed": "2026-11-10"
    }
  ],
  "related": [
    "cache-admission",
    "fifo-replacement",
    "ghost-cache-entry",
    "write-amplification"
  ],
  "status": "research",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-10",
  "provenance": [
    "Source synthesis only; no implementation or benchmark reproduced."
  ]
}