{
  "module": "memory-pressure",
  "version": "1",
  "capabilities": [
    "package-manager",
    "service-manager"
  ],
  "emits": [
    "pressure.high",
    "pressure.cleared"
  ],
  "tools": [
    "memory_status",
    "memory_top",
    "memory_oom_history",
    "memory_zram",
    "memory_oomd",
    "memory_guard"
  ],
  "resources": [
    {
      "id": "zram-generator",
      "type": "package",
      "package": "zram-generator"
    },
    {
      "id": "zram",
      "type": "file",
      "path": "/etc/systemd/zram-generator.conf",
      "mode": "0644",
      "content": "# Managed by the mesh (module memory-pressure). Replaced on every push; edit the catalogue instead.\n#\n# Compressed swap in RAM: fast, at a higher priority than any swap on disk, so it takes the everyday\n# pressure before anything spills to a disk. Half the RAM, at most 16 GiB, compressed with zstd.\n# The swap on disk, its size and whether one exists at all are the machine's, not this module's.\n#\n# Read by the generator at boot: a change applies at the next boot.\n[zram0]\nzram-size = min(ram / 2, 16384)\ncompression-algorithm = zstd\nswap-priority = 100\n"
    },
    {
      "id": "sysctl-drop-ins",
      "type": "directory",
      "path": "/etc/sysctl.d",
      "mode": "0755"
    },
    {
      "id": "swap-tunables",
      "type": "file",
      "path": "/etc/sysctl.d/90-memory-pressure.conf",
      "mode": "0644",
      "content": "# Managed by the mesh (module memory-pressure). Replaced on every push; edit the catalogue instead.\n#\n# Swap-in reads one page, not eight: read-ahead exists to amortise a disk's seek, and compressed swap in\n# RAM has none — the speculation only costs decompression and memory.\nvm.page-cluster = 0\n#\n# vm.swappiness is deliberately left alone. The usual zram advice (150-180) holds only while the\n# compressed swap has room; once it is full, a higher swappiness moves pages to the disk swap, the thing\n# being avoided. Raise it only together with zram-size.\n"
    },
    {
      "id": "sysctl",
      "type": "service",
      "unit": "systemd-sysctl.service",
      "restart-on": [
        "swap-tunables"
      ]
    },
    {
      "id": "oomd-drop-ins",
      "type": "directory",
      "path": "/etc/systemd/oomd.conf.d",
      "mode": "0755"
    },
    {
      "id": "oomd-limits",
      "type": "file",
      "path": "/etc/systemd/oomd.conf.d/memory-pressure.conf",
      "mode": "0644",
      "content": "# Managed by the mesh (module memory-pressure). Replaced on every push; edit the catalogue instead.\n#\n# systemd-oomd kills the worst unit before the kernel's OOM killer freezes the machine: when swap is\n# 90 % used, or when a watched unit stalls on memory for 20 s above its limit.\n[OOM]\nSwapUsedLimit=90%\nDefaultMemoryPressureLimit=60%\nDefaultMemoryPressureDurationSec=20s\n"
    },
    {
      "id": "root-slice-drop-ins",
      "type": "directory",
      "path": "/etc/systemd/system/-.slice.d",
      "mode": "0755"
    },
    {
      "id": "root-slice",
      "type": "file",
      "path": "/etc/systemd/system/-.slice.d/10-oomd.conf",
      "mode": "0644",
      "content": "# Managed by the mesh (module memory-pressure). Replaced on every push; edit the catalogue instead.\n#\n# systemd-oomd may act on swap exhaustion across the whole machine.\n[Slice]\nManagedOOMSwap=kill\n"
    },
    {
      "id": "user-manager-drop-ins",
      "type": "directory",
      "path": "/etc/systemd/system/user@.service.d",
      "mode": "0755"
    },
    {
      "id": "user-manager",
      "type": "file",
      "path": "/etc/systemd/system/user@.service.d/10-oomd.conf",
      "mode": "0644",
      "content": "# Managed by the mesh (module memory-pressure). Replaced on every push; edit the catalogue instead.\n#\n# systemd-oomd may kill the worst unit in a person's service manager when its memory pressure stays\n# above 80 % — instead of the kernel freezing the machine.\n[Service]\nManagedOOMMemoryPressure=kill\nManagedOOMMemoryPressureLimit=80%\n"
    },
    {
      "id": "oomd",
      "type": "service",
      "unit": "systemd-oomd.service",
      "state": "running",
      "boot": "enabled",
      "restart-on": [
        "oomd-limits",
        "root-slice",
        "user-manager"
      ]
    }
  ],
  "build": {
    "artifacts": [
      {
        "name": "tools-go",
        "kind": "bundle",
        "language": "go",
        "system": "arch",
        "from": "cmd/memory-pressure",
        "binary": "memory-pressure",
        "loads": [
          "memory-pressure"
        ]
      }
    ]
  }
}