{
  "slug": "mittos",
  "term": "MittOS",
  "aliases": [],
  "definition": "MittOS is a research operating-system design that uses predicted resource delays to reject reads and let applications retry another replica.",
  "note": "The rejection signal is EBUSY, not a media-error diagnosis. MittCFQ can revoke previously admitted reads when higher-priority arrivals consume their slack. The studied three-replica application's final attempt disables its deadline. [mittos-paper]\n\nThe published SSD implementation requires an open-channel SSD and a modified kernel. Its LightNVM layer uses preprofiled NAND timings; this is not an ordinary NVMe configuration option. [mittssd-code]",
  "status": "research",
  "advantages": [],
  "limitations": [
    {
      "text": "Prediction does not cover every software delay, and device performance profiles can drift.",
      "citationIds": [
        "mittos-paper"
      ]
    }
  ],
  "related": [
    "linnos",
    "hedged-request",
    "open-channel-ssd",
    "tail-latency"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "mittos-paper",
      "title": "Hao et al. MittOS: Supporting Millisecond Tail Tolerance with Fast Rejecting SLO-Aware OS Interface. SOSP 2017, sections 3-5, 7.8.1 and 8.1.",
      "url": "https://courses.physics.illinois.edu/ece598ms/sp2018/papers/paper93.pdf",
      "accessed": "2026-11-10"
    },
    {
      "id": "mittssd-code",
      "title": "MittSSD author repository: hardware requirement and modified storage stack, pinned revision f987801.",
      "url": "https://github.com/ucare-uchicago/MittSSD/blob/f987801270e84ff69bac9434b8ff4c0ae8d142c8/README.md",
      "accessed": "2026-11-10"
    }
  ],
  "updated": "2026-11-10",
  "provenance": [
    "Hao, Li, Tong, Pakha, Suminto, Stuardo, Chien and Gunawi, SOSP 2017. DOI 10.1145/3132747.3132774 verified on the manuscript's first page.",
    "Full paper acquired from its university course mirror; sections 3-5, 7 and 8 reviewed. No MittOS execution or hardware replication performed.",
    "Implementation requirements checked against README.md at f987801270e84ff69bac9434b8ff4c0ae8d142c8; no claim that this revision is identical to the paper's evaluated system."
  ]
}