feat: Add DatagramMonitor, a UDP node-stats exporter

.cspell.config.yaml

@@ -372,6 +372,7 @@ words:
   - writeme
   - wsrch
   - wthread
+  - Xahau
   - xbridge
   - xchain
   - xcrun

.github/scripts/strategy-matrix/linux.json

@@ -1,5 +1,5 @@
 {
-  "image_tag": "sha-473fe44",
+  "image_tag": "sha-060957e",
   "configs": {
     "ubuntu": [
       {

.github/workflows/build-nix-images.yml

@@ -5,15 +5,13 @@ on:
     branches:
       - develop
     paths:
-      - ".github/workflows/build-nix-images.yml"
       - "flake.nix"
       - "flake.lock"
       - "rust-toolchain.toml"
       - "nix/**"
       - "!nix/docker/README.md"
       - "!nix/devshell.nix"
-      - "!nix/check-tools/*.txt"
-      - "bin/check-tools.sh"
+      - "!nix/check-tools/**"
       - "bin/default-loader-path.sh"
       - "bin/install-sanitizer-libs.sh"
   pull_request:
@@ -25,7 +23,7 @@ on:
       - "nix/**"
       - "!nix/docker/README.md"
       - "!nix/devshell.nix"
-      - "!nix/check-tools/*.txt"
+      - "!nix/check-tools/**"
       - "bin/check-tools.sh"
       - "bin/default-loader-path.sh"
       - "bin/install-sanitizer-libs.sh"

.github/workflows/cargo-audit.yml

@@ -34,7 +34,7 @@ permissions:
 jobs:
   audit:
     runs-on: ubuntu-latest
-    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-473fe44
+    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-060957e
     permissions:
       contents: read
       # Needed to open an issue on scheduled failures.

.github/workflows/publish-docs.yml

@@ -41,7 +41,7 @@ env:
 jobs:
   build:
     runs-on: ubuntu-latest
-    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-473fe44
+    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-060957e
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/reusable-clang-tidy.yml

@@ -34,7 +34,7 @@ jobs:
     needs: [determine-files]
     if: ${{ needs.determine-files.outputs.cpp_changed_files != '' || needs.determine-files.outputs.need_full_run == 'true' }}
     runs-on: ["self-hosted", "Linux", "X64", "heavy"]
-    container: "ghcr.io/xrplf/xrpld/nix-debian:sha-473fe44"
+    container: "ghcr.io/xrplf/xrpld/nix-debian:sha-060957e"
     permissions:
       contents: read
       issues: write

.github/workflows/reusable-rust.yml

@@ -1,8 +1,9 @@
 # Clippy, coverage and documentation for the Rust crates in crates/. Each runs
 # as an independent job on a GitHub-hosted runner, but inside the same container
 # image used to build the crates in the C++/Corrosion path, so the toolchain
-# (and therefore the lints, coverage instrumentation and the cargo cache) matches
-# what production builds use.
+# (and therefore the lints and the cargo cache) matches what production builds
+# use. Coverage is the exception: it needs the nightly rustc that honours
+# #[coverage(off)], which the image carries alongside the pinned stable.
 #
 # Rust unit tests are deliberately NOT run here. They run as part of the C++
 # build (reusable-build-test-config.yml), which already compiles the crates on a
@@ -27,7 +28,7 @@ permissions:
 jobs:
   clippy:
     runs-on: ubuntu-latest
-    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-473fe44
+    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-060957e
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -40,11 +41,14 @@ jobs:
 
   coverage:
     runs-on: ubuntu-latest
-    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-473fe44
+    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-060957e
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
+      - name: Use the nightly Rust toolchain
+        run: rust-nightly path >>"${GITHUB_PATH}"
+
       - name: Use cargo artifacts cache
         uses: ./.github/actions/cargo-cache
 
@@ -66,7 +70,7 @@ jobs:
 
   doc:
     runs-on: ubuntu-latest
-    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-473fe44
+    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-060957e
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/reusable-upload-recipe.yml

@@ -40,7 +40,7 @@ defaults:
 jobs:
   upload:
     runs-on: ubuntu-latest
-    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-473fe44
+    container: ghcr.io/xrplf/xrpld/nix-ubuntu:sha-060957e
     env:
       REMOTE_NAME: ${{ inputs.remote_name }}
       CONAN_LOGIN_USERNAME_XRPLF: ${{ secrets.remote_username }}

.pre-commit-config.yaml

@@ -70,6 +70,11 @@ repos:
         language: system
         types: [rust]
         pass_filenames: false # rustfmt formats the whole workspace
+      - id: check-coverage-attrs
+        name: check Rust coverage attributes
+        entry: ./bin/pre-commit/check_rust_coverage_attrs.py
+        language: python
+        files: ^crates/.*\.rs$
 
   - repo: https://github.com/BlankSpruce/gersemi-pre-commit
     rev: e98930bdc210d3387007f9252d8c1694ea7e410f # frozen: 0.27.7

bin/check-tools.sh

@@ -158,6 +158,7 @@ if [ "${os}" = "linux" ] || [ "${os}" = "macos" ]; then
     check cargo-nextest cargo nextest --version
     check clippy-driver
     check rust-analyzer
+    check rust-nightly rust-nightly run rustc --version
     check rustc
     check rustfmt
 fi

bin/pre-commit/check_rust_coverage_attrs.py

@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+"""
+Check that Rust unit tests stay out of the coverage report.
+
+cargo-llvm-cov instruments the test code along with everything else, so a test
+module that is not excluded counts its own body as covered and inflates the
+reported number. Excluding it takes two attributes:
+
+  * every `#[cfg(test)]` module carries
+    `#[cfg_attr(coverage_nightly, coverage(off))]`;
+  * every crate root (lib.rs, main.rs) carries
+    `#![cfg_attr(coverage_nightly, feature(coverage_attribute))]`, which the
+    attribute above needs in order to compile.
+
+Both are inert outside the coverage job: cargo-llvm-cov defines
+`coverage_nightly` only when it runs on a nightly toolchain.
+
+The crate-root gate is checked even in a crate that has no tests yet, because
+that is what lets the first test module added later carry the attribute without
+a build failure. Missing it is a hard error, so it cannot go unnoticed; a
+missing `coverage(off)` fails open, which is why this check exists.
+
+Matching is on exact attribute text, which works because `cargo fmt` runs over
+the whole workspace in the hook ahead of this one: rustfmt puts every attribute
+on its own line and normalizes what is inside it, turning `#[cfg( test )]`
+and `#[cfg(test,)]` alike into `#[cfg(test)]`. So there is nothing here that
+parses Rust. The price is that a cfg this file does not spell out literally --
+`all(test, ...)`, `any(test, ...)`, `not(test)` -- is reported rather than
+classified, on the grounds that guessing at coverage semantics is how a check
+like this ends up quietly wrong.
+
+Usage: ./bin/pre-commit/check_rust_coverage_attrs.py <file1> <file2> ...
+
+Exit status is non-zero if any violation is found.
+"""
+
+import re
+import sys
+from dataclasses import dataclass
+from pathlib import Path
+
+CRATE_ROOTS = {"lib.rs", "main.rs"}
+
+FEATURE_ATTR = "#![cfg_attr(coverage_nightly, feature(coverage_attribute))]"
+COVERAGE_OFF_ATTR = "#[cfg_attr(coverage_nightly, coverage(off))]"
+CFG_TEST_ATTR = "#[cfg(test)]"
+
+# Any other cfg that mentions `test`. String literals are blanked before this
+# runs, so `feature = "test"` does not read as the `test` cfg.
+RE_CFG_MENTIONS_TEST = re.compile(r"^#\[cfg\(.*\btest\b.*\)\]$")
+RE_STRING = re.compile(r'"(?:[^"\\]|\\.)*"')
+RE_MOD = re.compile(r"^(?:pub(?:\([^)]*\))?\s+)?mod\s+([A-Za-z_]\w*)")
+
+
+@dataclass(frozen=True)
+class Finding:
+    line: int
+    label: str
+    message: str
+
+
+def _check_module(attrs: list[str], line: int, name: str) -> list[Finding]:
+    """Findings for one module, given the attributes attached to it."""
+    if COVERAGE_OFF_ATTR in attrs:
+        return []  # excluded from coverage; which cfg gates it does not matter
+    if CFG_TEST_ATTR in attrs:
+        return [
+            Finding(
+                line,
+                "missing-coverage-off",
+                f"`mod {name}` is #[cfg(test)] but not excluded from coverage; "
+                f"add {COVERAGE_OFF_ATTR}",
+            )
+        ]
+    unclassified = [
+        attr for attr in attrs if RE_CFG_MENTIONS_TEST.match(RE_STRING.sub('""', attr))
+    ]
+    if unclassified:
+        return [
+            Finding(
+                line,
+                "unclassified-cfg",
+                f"`mod {name}` is gated on {unclassified[0]}, which this check "
+                f"cannot tell apart from a module that ships in the library; "
+                f"add {COVERAGE_OFF_ATTR} if it is test-only, or teach this "
+                f"check the cfg if it is not",
+            )
+        ]
+    return []
+
+
+def _check_test_modules(lines: list[str]) -> list[Finding]:
+    """Findings for every test module that is not excluded from coverage."""
+    findings: list[Finding] = []
+    attrs: list[str] = []
+    attrs_line = 0
+    for number, raw in enumerate(lines, start=1):
+        stripped = raw.strip()
+        # Blank lines and comments are allowed between an attribute and its item.
+        if not stripped or stripped.startswith("//"):
+            continue
+        if stripped.startswith("#["):
+            if not attrs:
+                attrs_line = number
+            attrs.append(stripped)
+            continue
+        module = RE_MOD.match(stripped)
+        if module is not None and attrs:
+            findings += _check_module(attrs, attrs_line, module.group(1))
+        attrs = []
+    return findings
+
+
+def _check_crate_root(name: str, lines: list[str]) -> list[Finding]:
+    """A finding if a crate root is missing the coverage_attribute feature gate."""
+    if name not in CRATE_ROOTS:
+        return []
+    if any(line.strip() == FEATURE_ATTR for line in lines):
+        return []
+    return [
+        Finding(
+            1,
+            "missing-feature-gate",
+            f"crate root is missing {FEATURE_ATTR}",
+        )
+    ]
+
+
+def check_source(name: str, text: str) -> list[Finding]:
+    """Findings for one file's contents; `name` is its base name (lib.rs, ...)."""
+    lines = text.splitlines()
+    return _check_crate_root(name, lines) + _check_test_modules(lines)
+
+
+def check_file(path: Path) -> list[Finding]:
+    return check_source(path.name, path.read_text(encoding="utf-8"))
+
+
+def main() -> int:
+    total = 0
+    for path in (Path(name) for name in sys.argv[1:]):
+        for finding in check_file(path):
+            total += 1
+            print(f"{path}:{finding.line}: {finding.label}: {finding.message}")
+    return 1 if total else 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

crates/Cargo.toml

@@ -8,6 +8,9 @@ cxx = { version = "1.0.198", features = ["c++20"] }
 [workspace.package]
 edition = "2024"
 
+[workspace.lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = [ 'cfg(coverage)', 'cfg(coverage_nightly)' ] }
+
 [profile.release]
 opt-level = 3
 overflow-checks = true

crates/hello_world/Cargo.toml

@@ -8,3 +8,6 @@ crate-type = ["staticlib"]
 
 [dependencies]
 cxx.workspace = true
+
+[lints]
+workspace = true

crates/hello_world/src/lib.rs

@@ -1,3 +1,5 @@
+#![cfg_attr(coverage_nightly, feature(coverage_attribute))]
+
 #[cxx::bridge(namespace = "rs::hello_world")]
 mod ffi {
     extern "Rust" {
@@ -8,3 +10,14 @@ mod ffi {
 pub fn hello_world() -> String {
     "hello_world".to_string()
 }
+
+#[cfg(test)]
+#[cfg_attr(coverage_nightly, coverage(off))]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn hello_world_returns_hello_world() {
+        assert_eq!(hello_world(), "hello_world")
+    }
+}

include/xrpl/config/Constants.h

@@ -11,6 +11,7 @@ struct Sections
     static constexpr auto kCompression = "compression";
     static constexpr auto kCrawl = "crawl";
     static constexpr auto kDatabasePath = "database_path";
+    static constexpr auto kDatagramMonitor = "datagram_monitor";
     static constexpr auto kDebugLogfile = "debug_logfile";
     static constexpr auto kElbSupport = "elb_support";
     static constexpr auto kFeatures = "features";

include/xrpl/server/NetworkOPs.h

@@ -12,6 +12,7 @@
 
 #include <boost/asio.hpp>
 
+#include <array>
 #include <chrono>
 #include <cstddef>
 #include <cstdint>
@@ -19,6 +20,7 @@
 #include <optional>
 #include <sstream>
 #include <string>
+#include <tuple>
 
 namespace xrpl {
 
@@ -83,6 +85,18 @@ class NetworkOPs : public InfoSub::Source
 public:
     using clock_type = beast::AbstractClock<std::chrono::steady_clock>;
 
+    // Snapshot of per-operating-mode accounting, exposed for the datagram monitor.
+    struct AccountingCounter
+    {
+        std::uint64_t transitions{0};
+        std::chrono::microseconds dur{std::chrono::microseconds(0)};
+    };
+    using StateAccountingData = std::tuple<
+        std::array<AccountingCounter, 5>,
+        OperatingMode,
+        std::chrono::steady_clock::time_point,
+        std::uint64_t>;
+
     enum class FailHard : unsigned char { No, Yes };
     static FailHard
     doFailHard(bool noMeansDont)
@@ -103,6 +117,8 @@ public:
 
     [[nodiscard]] virtual OperatingMode
     getOperatingMode() const = 0;
+    [[nodiscard]] virtual StateAccountingData
+    getStateAccountingData() = 0;
     [[nodiscard]] virtual std::string
     strOperatingMode(OperatingMode const mode, bool const admin = false) const = 0;
     [[nodiscard]] virtual std::string
@@ -220,6 +236,12 @@ public:
 
     virtual json::Value
     getConsensusInfo() = 0;
+    // Proposers and round time of the last consensus round, for out-of-band
+    // telemetry (DatagramMonitor) that cannot reach the private consensus object.
+    [[nodiscard]] virtual std::size_t
+    getPrevProposers() const = 0;
+    [[nodiscard]] virtual std::chrono::milliseconds
+    getPrevRoundTime() const = 0;
     virtual json::Value
     getServerInfo(bool human, bool admin, bool counters) = 0;
     virtual void

nix/check-tools/macos.txt

@@ -131,6 +131,9 @@ Rust toolchain:
   ✅ rust-analyzer
      rust-analyzer 1.97.1 (8bab26f4 2026-07-14)
      /nix/store/j6apc5pmd0giy15da9p650r8zklslmvi-rust-analyzer-preview-1.97.1-aarch64-apple-darwin/bin/rust-analyzer
+  ✅ rust-nightly
+     rustc 1.99.0-nightly (87e5904f5 2026-07-20)
+     /nix/store/fqpjz4l0nsnji8b2pz57mnj0akbp6hcl-rust-nightly/bin/rust-nightly
   ✅ rustc
      rustc 1.97.1 (8bab26f4f 2026-07-14)
      /nix/store/bnfk1sl4s9angb0vj1cj9a5y5zvqinwy-rust-minimal-1.97.1/bin/rustc
@@ -140,4 +143,4 @@ Rust toolchain:
 
 Skipping git-over-HTTPS check (CHECK_TOOLS_SKIP_CLONE is set).
 
-✅ All 44 checked tools are present and runnable.
+✅ All 45 checked tools are present and runnable.

nix/check-tools/nix-ubuntu-amd64.txt

@@ -131,6 +131,9 @@ Rust toolchain:
   ✅ rust-analyzer
      rust-analyzer 1.97.1 (8bab26f 2026-07-14)
      /nix/store/lr3m97p3hx1k22a7c44pb0wa7rbayhfi-rust-analyzer-preview-1.97.1-x86_64-unknown-linux-gnu/bin/rust-analyzer
+  ✅ rust-nightly
+     rustc 1.99.0-nightly (87e5904f5 2026-07-20)
+     /nix/store/j7kf7a5h4xypzp6x1skg4dsdx2k4fwb3-rust-nightly/bin/rust-nightly
   ✅ rustc
      rustc 1.97.1 (8bab26f4f 2026-07-14)
      /nix/store/40d3mzka7r1ps71l0yv2fs6616nbw85m-rust-minimal-1.97.1/bin/rustc
@@ -168,4 +171,4 @@ Mold:
 
 Skipping git-over-HTTPS check (CHECK_TOOLS_SKIP_CLONE is set).
 
-✅ All 52 checked tools are present and runnable.
+✅ All 53 checked tools are present and runnable.

nix/check-tools/nix-ubuntu-arm64.txt

@@ -131,6 +131,9 @@ Rust toolchain:
   ✅ rust-analyzer
      rust-analyzer 1.97.1 (8bab26f 2026-07-14)
      /nix/store/262830dlw2517lnagfx7i7agqgl4fmsd-rust-analyzer-preview-1.97.1-aarch64-unknown-linux-gnu/bin/rust-analyzer
+  ✅ rust-nightly
+     rustc 1.99.0-nightly (87e5904f5 2026-07-20)
+     /nix/store/c59pxk1yikdlf129qwyg4fplmxcrha0k-rust-nightly/bin/rust-nightly
   ✅ rustc
      rustc 1.97.1 (8bab26f4f 2026-07-14)
      /nix/store/a6p27cg6b8szfixfyvkssx6l0c345zw8-rust-minimal-1.97.1/bin/rustc
@@ -168,4 +171,4 @@ Mold:
 
 Skipping git-over-HTTPS check (CHECK_TOOLS_SKIP_CLONE is set).
 
-✅ All 52 checked tools are present and runnable.
+✅ All 53 checked tools are present and runnable.

src/xrpld/app/main/Application.cpp

@@ -19,6 +19,7 @@
 #include <xrpld/app/main/LoadManager.h>
 #include <xrpld/app/main/NodeIdentity.h>
 #include <xrpld/app/main/NodeStoreScheduler.h>
+#include <xrpld/app/misc/DatagramMonitor.h>
 #include <xrpld/app/misc/SHAMapStore.h>
 #include <xrpld/app/misc/TxQ.h>
 #include <xrpld/app/misc/ValidatorKeys.h>
@@ -222,6 +223,7 @@ public:
     std::unique_ptr<JobQueue> jobQueue_;
     NodeStoreScheduler nodeStoreScheduler_;
     std::unique_ptr<SHAMapStore> shaMapStore_;
+    std::unique_ptr<DatagramMonitor> datagramMonitor_;
     PendingSaves pendingSaves_;
     std::optional<OpenLedger> openLedger_;
 
@@ -1525,6 +1527,14 @@ ApplicationImp::start(bool withTimers)
 
     ledgerCleaner_->start();
     perfLog_->start();
+
+    // Datagram monitor: UDP node-stats exporter (XDGM). Off in standalone or
+    // when [datagram_monitor] has no endpoints.
+    if (!config_->standalone() && !config_->DATAGRAM_MONITOR.empty())
+    {
+        datagramMonitor_ = std::make_unique<DatagramMonitor>(*this);
+        datagramMonitor_->start();
+    }
 }
 
 void

src/xrpld/app/misc/DatagramMonitor.h

@@ -0,0 +1,880 @@
+#pragma once
+
+#include <xrpld/app/ledger/AcceptedLedger.h>
+#include <xrpld/app/ledger/InboundLedgers.h>
+#include <xrpld/app/ledger/LedgerMaster.h>
+#include <xrpld/app/main/Application.h>
+#include <xrpld/app/misc/ValidatorList.h>
+#include <xrpld/app/rdb/backend/SQLiteDatabase.h>
+#include <xrpld/overlay/Overlay.h>
+
+#include <xrpl/basics/UptimeClock.h>
+#include <xrpl/basics/mulDiv.h>
+#include <xrpl/beast/utility/Journal.h>
+#include <xrpl/ledger/CachedSLEs.h>
+#include <xrpl/nodestore/Database.h>
+#include <xrpl/protocol/BuildInfo.h>
+#include <xrpl/protocol/ErrorCodes.h>
+#include <xrpl/protocol/jss.h>
+#include <xrpl/server/LoadFeeTrack.h>
+#include <xrpl/server/NetworkOPs.h>
+
+#include <arpa/inet.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+
+#include <netdb.h>
+
+#include <array>
+#include <atomic>
+#include <chrono>
+#include <cstring>
+#include <fstream>
+#include <sstream>
+#include <string>
+#if defined(__linux__)
+#include <sys/statvfs.h>
+#include <sys/sysinfo.h>
+#elif defined(__APPLE__)
+#include <mach/host_info.h>
+#include <mach/mach.h>
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <sys/mount.h>
+#include <sys/sysctl.h>
+#include <sys/types.h>
+
+#include <ifaddrs.h>
+#endif
+#include <thread>
+#include <vector>
+
+namespace xrpl {
+
+// Magic number for server info packets: 'XDGM' (le) Xahau DataGram Monitor
+constexpr uint32_t SERVER_INFO_MAGIC = 0x4D474458;
+constexpr uint32_t SERVER_INFO_VERSION = 1;
+
+// Warning flag bits
+constexpr uint32_t WARNING_AMENDMENT_BLOCKED = 1 << 0;
+constexpr uint32_t WARNING_UNL_BLOCKED = 1 << 1;
+constexpr uint32_t WARNING_AMENDMENT_WARNED = 1 << 2;
+constexpr uint32_t WARNING_NOT_SYNCED = 1 << 3;
+
+// Time window statistics for rates
+struct [[gnu::packed]] MetricRates
+{
+    double rate_1m;   // Average rate over last minute
+    double rate_5m;   // Average rate over last 5 minutes
+    double rate_1h;   // Average rate over last hour
+    double rate_24h;  // Average rate over last 24 hours
+};
+
+struct AllRates
+{
+    MetricRates network_in;
+    MetricRates network_out;
+    MetricRates disk_read;
+    MetricRates disk_write;
+};
+
+// Structure to represent a ledger sequence range
+struct [[gnu::packed]] LgrRange
+{
+    uint32_t start;
+    uint32_t end;
+};
+
+// Map is returned separately since variable-length data
+// shouldn't be included in network structures
+using ObjectCountMap = std::vector<std::pair<std::basic_string<char>, int>>;
+
+struct [[gnu::packed]] DebugCounters
+{
+    // Database metrics
+    std::uint64_t dbKBTotal{0};
+    std::uint64_t dbKBLedger{0};
+    std::uint64_t dbKBTransaction{0};
+    std::uint64_t localTxCount{0};
+
+    // Basic metrics
+    std::uint32_t writeLoad{0};
+    std::int32_t historicalPerMinute{0};
+
+    // Cache metrics
+    std::uint32_t sleHitRate{0};     // Stored as fixed point, multiplied by 1000
+    std::uint32_t ledgerHitRate{0};  // Stored as fixed point, multiplied by 1000
+    std::uint32_t alSize{0};
+    std::uint32_t alHitRate{0};  // Stored as fixed point, multiplied by 1000
+    std::int32_t fullbelowSize{0};
+    std::uint32_t treenodeCacheSize{0};
+    std::uint32_t treenodeTrackSize{0};
+
+    // Node store metrics
+    std::uint64_t nodeWriteCount{0};
+    std::uint64_t nodeWriteSize{0};
+    std::uint64_t nodeFetchCount{0};
+    std::uint64_t nodeFetchHitCount{0};
+    std::uint64_t nodeFetchSize{0};
+};
+
+// Core server metrics in the fixed header
+struct [[gnu::packed]] ServerInfoHeader
+{
+    // Fixed header fields come first
+    uint32_t magic;               // Magic number to identify packet type
+    uint32_t version;             // Protocol version number
+    uint32_t network_id;          // Network ID from config
+    uint32_t server_state;        // Operating mode as enum
+    uint32_t peer_count;          // Number of connected peers
+    uint32_t node_size;           // Size category (0=tiny through 4=huge)
+    uint32_t cpu_cores;           // CPU core count
+    uint32_t ledger_range_count;  // Number of range entries
+    uint32_t warning_flags;       // Warning flags (reduced size)
+
+    uint32_t padding_1;  // padding for alignment
+
+    // 64-bit metrics
+    uint64_t timestamp;          // System time in microseconds
+    uint64_t uptime;             // Server uptime in seconds
+    uint64_t io_latency_us;      // IO latency in microseconds
+    uint64_t validation_quorum;  // Validation quorum count
+    uint64_t fetch_pack_size;    // Size of fetch pack cache
+    uint64_t proposer_count;     // Number of proposers in last close
+    uint64_t converge_time_ms;   // Last convergence time in ms
+    uint64_t load_factor;        // Load factor (scaled by 1M)
+    uint64_t load_base;          // Load base value
+    uint64_t reserve_base;       // Reserve base amount
+    uint64_t reserve_inc;        // Reserve increment amount
+    uint64_t ledger_seq;         // Latest ledger sequence
+
+    // Fixed-size byte arrays
+    uint8_t ledger_hash[32];      // Latest ledger hash
+    uint8_t node_public_key[33];  // Node's public key
+    uint8_t padding2[7];          // Padding to maintain 8-byte alignment
+    uint8_t version_string[32];
+
+    // System metrics
+    uint64_t process_memory_pages;  // Process memory usage in bytes
+    uint64_t system_memory_total;   // Total system memory in bytes
+    uint64_t system_memory_free;    // Free system memory in bytes
+    uint64_t system_memory_used;    // Used system memory in bytes
+    uint64_t system_disk_total;     // Total disk space in bytes
+    uint64_t system_disk_free;      // Free disk space in bytes
+    uint64_t system_disk_used;      // Used disk space in bytes
+    uint64_t io_wait_time;          // IO wait time in milliseconds
+    double load_avg_1min;           // 1 minute load average
+    double load_avg_5min;           // 5 minute load average
+    double load_avg_15min;          // 15 minute load average
+
+    // State transition metrics
+    uint64_t state_transitions[5];  // Count for each operating mode
+    uint64_t state_durations[5];    // Duration in each mode
+    uint64_t initial_sync_us;       // Initial sync duration
+
+    // Network and disk rates remain unchanged
+    struct
+    {
+        MetricRates network_in;
+        MetricRates network_out;
+        MetricRates disk_read;
+        MetricRates disk_write;
+    } rates;
+
+    DebugCounters dbg_counters;
+};
+
+// System metrics collected for rate calculations
+struct SystemMetrics
+{
+    uint64_t timestamp;           // When metrics were collected
+    uint64_t network_bytes_in;    // Current total bytes in
+    uint64_t network_bytes_out;   // Current total bytes out
+    uint64_t disk_bytes_read;     // Current total bytes read
+    uint64_t disk_bytes_written;  // Current total bytes written
+};
+
+class MetricsTracker
+{
+private:
+    static constexpr size_t SAMPLES_1M = 60;     // 1 sample/second for 1 minute
+    static constexpr size_t SAMPLES_5M = 300;    // 1 sample/second for 5 minutes
+    static constexpr size_t SAMPLES_1H = 3600;   // 1 sample/second for 1 hour
+    static constexpr size_t SAMPLES_24H = 1440;  // 1 sample/minute for 24 hours
+
+    std::vector<SystemMetrics> samples_1m{SAMPLES_1M};
+    std::vector<SystemMetrics> samples_5m{SAMPLES_5M};
+    std::vector<SystemMetrics> samples_1h{SAMPLES_1H};
+    std::vector<SystemMetrics> samples_24h{SAMPLES_24H};
+
+    size_t index_1m{0}, index_5m{0}, index_1h{0}, index_24h{0};
+    std::chrono::system_clock::time_point last_24h_sample{};
+
+    double
+    calculateRate(
+        SystemMetrics const& current,
+        std::vector<SystemMetrics> const& samples,
+        size_t current_index,
+        size_t max_samples,
+        bool is_24h_window,
+        std::function<uint64_t(SystemMetrics const&)> metric_getter)
+    {
+        // If we don't have at least 2 samples, the rate is 0
+        if (current_index < 2)
+        {
+            return 0.0;
+        }
+
+        // Calculate time window based on the window type
+        uint64_t expected_window_micros;
+        if (is_24h_window)
+        {
+            expected_window_micros =
+                24ULL * 60ULL * 60ULL * 1000000ULL;  // 24 hours in microseconds
+        }
+        else
+        {
+            expected_window_micros =
+                max_samples * 1000000ULL;  // window in seconds * 1,000,000 for microseconds
+        }
+
+        // For any window where we don't have full data, we should scale the
+        // rate based on the actual time we have data for
+        uint64_t actual_window_micros = current.timestamp - samples[0].timestamp;
+        double window_scale =
+            std::min(1.0, static_cast<double>(actual_window_micros) / expected_window_micros);
+
+        // Get the oldest valid sample
+        size_t oldest_index =
+            (current_index >= max_samples) ? ((current_index + 1) % max_samples) : 0;
+        auto const& oldest = samples[oldest_index];
+
+        double elapsed = actual_window_micros / 1000000.0;  // Convert microseconds to seconds
+
+        // Ensure we have a meaningful time difference
+        if (elapsed < 0.001)
+        {  // Less than 1ms difference
+            return 0.0;
+        }
+
+        uint64_t current_value = metric_getter(current);
+        uint64_t oldest_value = metric_getter(oldest);
+
+        // Handle counter wraparound
+        uint64_t diff = (current_value >= oldest_value)
+            ? (current_value - oldest_value)
+            : (std::numeric_limits<uint64_t>::max() - oldest_value + current_value + 1);
+
+        // Calculate the rate and scale it based on our window coverage
+        return (static_cast<double>(diff) / elapsed) * window_scale;
+    }
+
+    MetricRates
+    calculateMetricRates(
+        SystemMetrics const& current,
+        std::function<uint64_t(SystemMetrics const&)> metric_getter)
+    {
+        MetricRates rates;
+        rates.rate_1m =
+            calculateRate(current, samples_1m, index_1m, SAMPLES_1M, false, metric_getter);
+        rates.rate_5m =
+            calculateRate(current, samples_5m, index_5m, SAMPLES_5M, false, metric_getter);
+        rates.rate_1h =
+            calculateRate(current, samples_1h, index_1h, SAMPLES_1H, false, metric_getter);
+        rates.rate_24h =
+            calculateRate(current, samples_24h, index_24h, SAMPLES_24H, true, metric_getter);
+        return rates;
+    }
+
+public:
+    void
+    addSample(SystemMetrics const& metrics)
+    {
+        auto now = std::chrono::system_clock::now();
+
+        // Update 1-minute window (every second)
+        samples_1m[index_1m++ % SAMPLES_1M] = metrics;
+
+        // Update 5-minute window (every second)
+        samples_5m[index_5m++ % SAMPLES_5M] = metrics;
+
+        // Update 1-hour window (every second)
+        samples_1h[index_1h++ % SAMPLES_1H] = metrics;
+
+        // Update 24-hour window (every minute)
+        if (last_24h_sample + std::chrono::minutes(1) <= now)
+        {
+            samples_24h[index_24h++ % SAMPLES_24H] = metrics;
+            last_24h_sample = now;
+        }
+    }
+
+    AllRates
+    getRates(SystemMetrics const& current)
+    {
+        AllRates rates;
+        rates.network_in = calculateMetricRates(
+            current, [](SystemMetrics const& m) { return m.network_bytes_in; });
+        rates.network_out = calculateMetricRates(
+            current, [](SystemMetrics const& m) { return m.network_bytes_out; });
+        rates.disk_read =
+            calculateMetricRates(current, [](SystemMetrics const& m) { return m.disk_bytes_read; });
+        rates.disk_write = calculateMetricRates(
+            current, [](SystemMetrics const& m) { return m.disk_bytes_written; });
+        return rates;
+    }
+};
+
+class DatagramMonitor
+{
+private:
+    Application& app_;
+    beast::Journal j_;
+    std::atomic<bool> running_{false};
+    std::thread monitor_thread_;
+    MetricsTracker metrics_tracker_;
+
+    struct EndpointInfo
+    {
+        std::string ip;
+        uint16_t port;
+        bool is_ipv6;
+    };
+    EndpointInfo
+    parseEndpoint(std::string const& endpoint)
+    {
+        auto space_pos = endpoint.find(' ');
+        if (space_pos == std::string::npos)
+            throw std::runtime_error("Invalid endpoint format");
+
+        EndpointInfo info;
+        info.ip = endpoint.substr(0, space_pos);
+        info.port = std::stoi(endpoint.substr(space_pos + 1));
+        info.is_ipv6 = info.ip.find(':') != std::string::npos;
+        return info;
+    }
+
+    int
+    createSocket(EndpointInfo const& endpoint)
+    {
+        int sock = socket(endpoint.is_ipv6 ? AF_INET6 : AF_INET, SOCK_DGRAM, 0);
+        if (sock < 0)
+            throw std::runtime_error("Failed to create socket");
+        return sock;
+    }
+
+    void
+    sendPacket(int sock, EndpointInfo const& endpoint, std::vector<uint8_t> const& buffer)
+    {
+        struct sockaddr_storage addr;
+        socklen_t addr_len;
+
+        if (endpoint.is_ipv6)
+        {
+            struct sockaddr_in6* addr6 = reinterpret_cast<struct sockaddr_in6*>(&addr);
+            addr6->sin6_family = AF_INET6;
+            addr6->sin6_port = htons(endpoint.port);
+            inet_pton(AF_INET6, endpoint.ip.c_str(), &addr6->sin6_addr);
+            addr_len = sizeof(struct sockaddr_in6);
+        }
+        else
+        {
+            struct sockaddr_in* addr4 = reinterpret_cast<struct sockaddr_in*>(&addr);
+            addr4->sin_family = AF_INET;
+            addr4->sin_port = htons(endpoint.port);
+            inet_pton(AF_INET, endpoint.ip.c_str(), &addr4->sin_addr);
+            addr_len = sizeof(struct sockaddr_in);
+        }
+
+        sendto(
+            sock,
+            buffer.data(),
+            buffer.size(),
+            0,
+            reinterpret_cast<struct sockaddr*>(&addr),
+            addr_len);
+    }
+
+    // Returns both the counters and object count map separately
+    std::pair<DebugCounters, ObjectCountMap>
+    getDebugCounters()
+    {
+        DebugCounters counters;
+        ObjectCountMap objectCounts = CountedObjects::getInstance().getCounts(1);
+
+        // Database metrics if applicable
+        if (app_.config().useTxTables())
+        {
+            auto const db = dynamic_cast<SQLiteDatabase*>(&app_.getRelationalDatabase());
+            if (!db)
+                Throw<std::runtime_error>("Failed to get relational database");
+
+            if (auto dbKB = db->getKBUsedAll())
+                counters.dbKBTotal = dbKB;
+            if (auto dbKB = db->getKBUsedLedger())
+                counters.dbKBLedger = dbKB;
+            if (auto dbKB = db->getKBUsedTransaction())
+                counters.dbKBTransaction = dbKB;
+            if (auto count = app_.getOPs().getLocalTxCount())
+                counters.localTxCount = count;
+        }
+
+        // Basic metrics
+        counters.writeLoad = app_.getNodeStore().getWriteLoad();
+        counters.historicalPerMinute =
+            static_cast<std::int32_t>(app_.getInboundLedgers().fetchRate());
+
+        // Cache metrics - convert floating point rates to fixed point
+        counters.sleHitRate = 0;  // TODO: SLE cache hit-rate accessor absent on this fork
+        counters.ledgerHitRate =
+            static_cast<std::uint32_t>(app_.getLedgerMaster().getCacheHitRate() * 1000);
+        counters.alSize = app_.getAcceptedLedgerCache().size();
+        counters.alHitRate =
+            static_cast<std::uint32_t>(app_.getAcceptedLedgerCache().getHitRate() * 1000);
+        counters.fullbelowSize =
+            static_cast<std::int32_t>(app_.getNodeFamily().getFullBelowCache()->size());
+        counters.treenodeCacheSize = app_.getNodeFamily().getTreeNodeCache()->getCacheSize();
+        counters.treenodeTrackSize = app_.getNodeFamily().getTreeNodeCache()->getTrackSize();
+
+        // Get regular node store metrics
+        counters.nodeWriteCount = app_.getNodeStore().getStoreCount();
+        counters.nodeWriteSize = app_.getNodeStore().getStoreSize();
+        counters.nodeFetchCount = app_.getNodeStore().getFetchTotalCount();
+        counters.nodeFetchHitCount = app_.getNodeStore().getFetchHitCount();
+        counters.nodeFetchSize = app_.getNodeStore().getFetchSize();
+
+        return {counters, objectCounts};
+    }
+
+    uint32_t
+    getPhysicalCPUCount()
+    {
+        static uint32_t count = 0;
+        if (count > 0)
+            return count;
+
+#if defined(__linux__)
+        try
+        {
+            std::ifstream cpuinfo("/proc/cpuinfo");
+            if (!cpuinfo)
+            {
+                JLOG(j_.error()) << "Unable to open file: /proc/cpuinfo";
+                return count;
+            }
+            std::string line;
+            std::set<std::string> physical_ids;
+            std::string current_physical_id;
+
+            while (std::getline(cpuinfo, line))
+            {
+                if (line.find("core id") != std::string::npos)
+                {
+                    current_physical_id = line.substr(line.find(":") + 1);
+                    // Trim whitespace
+                    current_physical_id.erase(0, current_physical_id.find_first_not_of(" \t"));
+                    current_physical_id.erase(current_physical_id.find_last_not_of(" \t") + 1);
+                    physical_ids.insert(current_physical_id);
+                }
+            }
+
+            count = physical_ids.size();
+        }
+        catch (std::exception const& e)
+        {
+            JLOG(j_.error()) << "Error getting CPU count: " << e.what();
+        }
+
+        // Return at least 1 if we couldn't determine the count
+        return count > 0 ? count : (count = 1);
+#elif defined(__APPLE__)
+        int value = 0;
+        size_t size = sizeof(value);
+        if (sysctlbyname("hw.physicalcpu", &value, &size, NULL, 0) == 0)
+            count = value;
+        return count > 0 ? count : (count = 1);
+#endif
+    }
+
+    SystemMetrics
+    collectSystemMetrics()
+    {
+        SystemMetrics metrics{};
+        metrics.timestamp = std::chrono::duration_cast<std::chrono::microseconds>(
+                                std::chrono::system_clock::now().time_since_epoch())
+                                .count();
+
+#if defined(__linux__)
+        // Network stats collection
+        try
+        {
+            std::ifstream net_file("/proc/net/dev");
+            if (!net_file)
+            {
+                JLOG(j_.error()) << "Unable to open file /proc/net/dev";
+                return metrics;
+            }
+
+            std::string line;
+            uint64_t total_bytes_in = 0, total_bytes_out = 0;
+
+            // Skip header lines
+            std::getline(net_file, line);  // Inter-|   Receive...
+            std::getline(net_file, line);  // face |bytes...
+
+            while (std::getline(net_file, line))
+            {
+                if (line.find(':') != std::string::npos)
+                {
+                    std::string interface = line.substr(0, line.find(':'));
+                    interface = interface.substr(interface.find_first_not_of(" \t"));
+                    interface = interface.substr(0, interface.find_last_not_of(" \t") + 1);
+
+                    // Skip loopback interface
+                    if (interface == "lo")
+                        continue;
+
+                    uint64_t bytes_in, bytes_out;
+                    std::istringstream iss(line.substr(line.find(':') + 1));
+                    iss >> bytes_in;  // First field after : is bytes_in
+                    for (int i = 0; i < 8; ++i)
+                        iss >> std::ws;  // Skip 8 fields
+                    iss >> bytes_out;    // 9th field is bytes_out
+
+                    total_bytes_in += bytes_in;
+                    total_bytes_out += bytes_out;
+                }
+            }
+            metrics.network_bytes_in = total_bytes_in;
+            metrics.network_bytes_out = total_bytes_out;
+        }
+        catch (std::exception const& e)
+        {
+            JLOG(j_.error()) << "Error collecting network stats: " << e.what();
+        }
+
+        // Disk stats collection
+        try
+        {
+            std::ifstream disk_file("/proc/diskstats");
+            if (!disk_file)
+            {
+                JLOG(j_.error()) << "Unable to open file: /proc/diskstats";
+                return metrics;
+            }
+            std::string line;
+            uint64_t total_bytes_read = 0, total_bytes_written = 0;
+
+            while (std::getline(disk_file, line))
+            {
+                unsigned int major, minor;
+                char dev_name[32];
+                uint64_t reads, read_sectors, writes, write_sectors;
+
+                if (sscanf(
+                        line.c_str(),
+                        "%u %u %31s %lu %*u %lu %*u %lu %*u %lu",
+                        &major,
+                        &minor,
+                        dev_name,
+                        &reads,
+                        &read_sectors,
+                        &writes,
+                        &write_sectors) == 7)
+                {
+                    // Only process physical devices
+                    std::string device_name(dev_name);
+                    if (device_name.substr(0, 3) == "dm-" || device_name.substr(0, 4) == "loop" ||
+                        device_name.substr(0, 3) == "ram")
+                    {
+                        continue;
+                    }
+
+                    // Skip partitions (usually have a number at the end)
+                    if (std::isdigit(device_name.back()))
+                    {
+                        continue;
+                    }
+
+                    uint64_t bytes_read = read_sectors * 512;
+                    uint64_t bytes_written = write_sectors * 512;
+
+                    total_bytes_read += bytes_read;
+                    total_bytes_written += bytes_written;
+                }
+            }
+            metrics.disk_bytes_read = total_bytes_read;
+            metrics.disk_bytes_written = total_bytes_written;
+        }
+        catch (std::exception const& e)
+        {
+            JLOG(j_.error()) << "Error collecting disk stats: " << e.what();
+        }
+#elif defined(__APPLE__)
+        // Network stats collection
+        try
+        {
+            struct ifaddrs* ifap;
+            if (getifaddrs(&ifap) == 0)
+            {
+                uint64_t total_bytes_in = 0, total_bytes_out = 0;
+                for (struct ifaddrs* ifa = ifap; ifa; ifa = ifa->ifa_next)
+                {
+                    if (ifa->ifa_addr != NULL && ifa->ifa_addr->sa_family == AF_LINK)
+                    {
+                        struct if_data* ifd = (struct if_data*)ifa->ifa_data;
+                        if (ifd != NULL)
+                        {
+                            // Skip loopback interface
+                            if (strcmp(ifa->ifa_name, "lo0") == 0)
+                                continue;
+
+                            total_bytes_in += ifd->ifi_ibytes;
+                            total_bytes_out += ifd->ifi_obytes;
+                        }
+                    }
+                }
+                freeifaddrs(ifap);
+
+                metrics.network_bytes_in = total_bytes_in;
+                metrics.network_bytes_out = total_bytes_out;
+            }
+        }
+        catch (std::exception const& e)
+        {
+            JLOG(j_.error()) << "Error collecting network stats: " << e.what();
+        }
+
+        // Disk stats collection
+        // Disk IO stats are not easily accessible in macOS.
+        // We'll set these values to zero for now.
+        metrics.disk_bytes_read = 0;
+        metrics.disk_bytes_written = 0;
+#endif
+        return metrics;
+    }
+
+    std::vector<uint8_t>
+    generateServerInfo()
+    {
+        auto& ops = app_.getOPs();
+        auto& ledgerMaster = app_.getLedgerMaster();
+
+        auto currentMetrics = collectSystemMetrics();
+        metrics_tracker_.addSample(currentMetrics);
+
+        // Slimmed for this fork (3.2.0-b0): ledger ranges, DB debug-counters and
+        // the object-count map are omitted (divergent accessors). The packet is
+        // just the fixed header with core node + OS metrics.
+        std::vector<uint8_t> buffer(sizeof(ServerInfoHeader));
+        auto* header = reinterpret_cast<ServerInfoHeader*>(buffer.data());
+        memset(header, 0, sizeof(ServerInfoHeader));
+
+        header->magic = SERVER_INFO_MAGIC;
+        header->version = SERVER_INFO_VERSION;
+        header->network_id = app_.config().networkId;
+        header->timestamp = std::chrono::duration_cast<std::chrono::microseconds>(
+                                std::chrono::system_clock::now().time_since_epoch())
+                                .count();
+        header->uptime = UptimeClock::now().time_since_epoch().count();
+        header->io_latency_us = app_.getIOLatency().count();
+        header->validation_quorum = app_.getValidators().quorum();
+        header->server_state = static_cast<std::uint32_t>(ops.getOperatingMode());
+        header->peer_count = app_.getOverlay().size();
+        header->node_size = app_.config().nodeSize;
+
+        auto const [counters, mode, start, initialSync] = ops.getStateAccountingData();
+        for (size_t i = 0; i < 5; ++i)
+        {
+            header->state_transitions[i] = counters[i].transitions;
+            header->state_durations[i] = counters[i].dur.count();
+        }
+        header->initial_sync_us = initialSync;
+
+        if (ops.isAmendmentBlocked())
+            header->warning_flags |= WARNING_AMENDMENT_BLOCKED;
+        if (ops.isUNLBlocked())
+            header->warning_flags |= WARNING_UNL_BLOCKED;
+        if (ops.isAmendmentWarned())
+            header->warning_flags |= WARNING_AMENDMENT_WARNED;
+        if (ops.getOperatingMode() != OperatingMode::FULL)
+            header->warning_flags |= WARNING_NOT_SYNCED;
+
+        header->proposer_count = ops.getPrevProposers();
+        header->converge_time_ms = ops.getPrevRoundTime().count();
+
+        auto const fp = ledgerMaster.getFetchPackCacheSize();
+        if (fp != 0)
+            header->fetch_pack_size = fp;
+
+        // Load factor (server only; fee-escalation term omitted on this fork).
+        header->load_factor = static_cast<std::uint64_t>(app_.getFeeTrack().getLoadFactor());
+        header->load_base = app_.getFeeTrack().getLoadBase();
+
+#if defined(__linux__)
+        // Get system info using sysinfo
+        struct sysinfo si;
+        if (sysinfo(&si) == 0)
+        {
+            header->system_memory_total = si.totalram * si.mem_unit;
+            header->system_memory_free = si.freeram * si.mem_unit;
+            header->system_memory_used = header->system_memory_total - header->system_memory_free;
+            header->load_avg_1min = si.loads[0] / (float)(1 << SI_LOAD_SHIFT);
+            header->load_avg_5min = si.loads[1] / (float)(1 << SI_LOAD_SHIFT);
+            header->load_avg_15min = si.loads[2] / (float)(1 << SI_LOAD_SHIFT);
+        }
+#elif defined(__APPLE__)
+        // Get total physical memory
+        int64_t physical_memory;
+        size_t length = sizeof(physical_memory);
+        if (sysctlbyname("hw.memsize", &physical_memory, &length, NULL, 0) == 0)
+        {
+            header->system_memory_total = physical_memory;
+        }
+
+        // Get free and used memory
+        vm_statistics_data_t vm_stats;
+        mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
+        if (host_statistics(mach_host_self(), HOST_VM_INFO, (host_info_t)&vm_stats, &count) ==
+            KERN_SUCCESS)
+        {
+            uint64_t page_size;
+            length = sizeof(page_size);
+            sysctlbyname("hw.pagesize", &page_size, &length, NULL, 0);
+
+            header->system_memory_free = (uint64_t)vm_stats.free_count * page_size;
+            header->system_memory_used = header->system_memory_total - header->system_memory_free;
+        }
+
+        // Get load averages
+        double loadavg[3];
+        if (getloadavg(loadavg, 3) == 3)
+        {
+            header->load_avg_1min = loadavg[0];
+            header->load_avg_5min = loadavg[1];
+            header->load_avg_15min = loadavg[2];
+        }
+#endif
+
+        // Get process memory usage
+        struct rusage usage;
+        getrusage(RUSAGE_SELF, &usage);
+        header->process_memory_pages = usage.ru_maxrss;
+
+        // Get disk usage
+#if defined(__linux__)
+        struct statvfs fs;
+        if (statvfs("/", &fs) == 0)
+        {
+            header->system_disk_total = fs.f_blocks * fs.f_frsize;
+            header->system_disk_free = fs.f_bfree * fs.f_frsize;
+            header->system_disk_used = header->system_disk_total - header->system_disk_free;
+        }
+#elif defined(__APPLE__)
+        struct statfs fs;
+        if (statfs("/", &fs) == 0)
+        {
+            header->system_disk_total = fs.f_blocks * fs.f_bsize;
+            header->system_disk_free = fs.f_bfree * fs.f_bsize;
+            header->system_disk_used = header->system_disk_total - header->system_disk_free;
+        }
+#endif
+
+        // Get CPU core count
+        header->cpu_cores = getPhysicalCPUCount();
+
+        // Get rate statistics
+        auto rates = metrics_tracker_.getRates(currentMetrics);
+        header->rates.network_in = rates.network_in;
+        header->rates.network_out = rates.network_out;
+        header->rates.disk_read = rates.disk_read;
+        header->rates.disk_write = rates.disk_write;
+
+        // Ledger height + hash via stable accessors (this fork's Ledger lacks
+        // info()). The hash lets the collector detect a fork: divergent
+        // ledger_hash across nodes at the same ledger_seq.
+        std::uint32_t const validSeq = ledgerMaster.getValidLedgerIndex();
+        header->ledger_seq = validSeq;
+        uint256 const validHash = ledgerMaster.getHashBySeq(validSeq);
+        std::memcpy(header->ledger_hash, validHash.data(), 32);
+        header->reserve_base = app_.config().fees.accountReserve.drops();
+        header->reserve_inc = app_.config().fees.ownerReserve.drops();
+
+        // Node public key + version string.
+        auto const& nodeKey = app_.nodeIdentity().first;
+        std::memcpy(header->node_public_key, nodeKey.data(), 33);
+        memset(&header->version_string, 0, 32);
+        memcpy(
+            &header->version_string,
+            build_info::getVersionString().c_str(),
+            build_info::getVersionString().size() > 32 ? 32
+                                                       : build_info::getVersionString().size());
+
+        header->ledger_range_count = 0;
+        return buffer;
+    }
+    void
+    monitorThread()
+    {
+        std::vector<std::pair<EndpointInfo, int>> endpoints;
+
+        for (auto const& epStr : app_.config().DATAGRAM_MONITOR)
+        {
+            auto endpoint = parseEndpoint(epStr);
+            endpoints.push_back(std::make_pair(endpoint, createSocket(endpoint)));
+        }
+
+        while (running_)
+        {
+            try
+            {
+                auto info = generateServerInfo();
+                for (auto const& ep : endpoints)
+                {
+                    sendPacket(ep.second, ep.first, info);
+                }
+                std::this_thread::sleep_for(std::chrono::seconds(1));
+            }
+            catch (std::exception const& e)
+            {
+                // Log error but continue monitoring
+                JLOG(j_.error()) << "Server info monitor error: " << e.what();
+            }
+        }
+
+        for (auto const& ep : endpoints)
+        {
+            close(ep.second);
+        }
+    }
+
+public:
+    DatagramMonitor(Application& app) : app_(app), j_(beast::Journal::getNullSink())
+    {
+    }
+
+    void
+    start()
+    {
+        if (!running_.exchange(true))
+        {
+            monitor_thread_ = std::thread(&DatagramMonitor::monitorThread, this);
+        }
+    }
+
+    void
+    stop()
+    {
+        if (running_.exchange(false))
+        {
+            if (monitor_thread_.joinable())
+                monitor_thread_.join();
+        }
+    }
+
+    ~DatagramMonitor()
+    {
+        stop();
+    }
+};
+}  // namespace xrpl

src/xrpld/app/misc/NetworkOPs.cpp

@@ -356,6 +356,9 @@ public:
     OperatingMode
     getOperatingMode() const override;
 
+    StateAccountingData
+    getStateAccountingData() override;
+
     std::string
     strOperatingMode(OperatingMode const mode, bool const admin) const override;
 
@@ -521,6 +524,10 @@ public:
 
     json::Value
     getConsensusInfo() override;
+    std::size_t
+    getPrevProposers() const override;
+    std::chrono::milliseconds
+    getPrevRoundTime() const override;
     json::Value
     getServerInfo(bool human, bool admin, bool counters) override;
     void
@@ -1091,6 +1098,16 @@ NetworkOPsImp::getOperatingMode() const
     return mode_;
 }
 
+NetworkOPs::StateAccountingData
+NetworkOPsImp::getStateAccountingData()
+{
+    auto const data = accounting_.getCounterData();
+    std::array<NetworkOPs::AccountingCounter, 5> out;
+    for (std::size_t i = 0; i < out.size(); ++i)
+        out[i] = {data.counters[i].transitions, data.counters[i].dur};
+    return {out, data.mode, data.start, data.initialSyncUs};
+}
+
 inline std::string
 NetworkOPsImp::strOperatingMode(bool const admin /* = false */) const
 {
@@ -2804,6 +2821,18 @@ NetworkOPsImp::getConsensusInfo()
     return consensus_.getJson(true);
 }
 
+std::size_t
+NetworkOPsImp::getPrevProposers() const
+{
+    return consensus_.prevProposers();
+}
+
+std::chrono::milliseconds
+NetworkOPsImp::getPrevRoundTime() const
+{
+    return consensus_.prevRoundTime();
+}
+
 json::Value
 NetworkOPsImp::getServerInfo(bool human, bool admin, bool counters)
 {

src/xrpld/core/Config.h

@@ -150,6 +150,10 @@ public:
     // Entries from [ips_fixed] config stanza
     std::vector<std::string> ipsFixed;
 
+    // Entries from [datagram_monitor]: "<IP> <port>" UDP targets the
+    // DatagramMonitor sends node-stats packets to (XDGM, every 1s).
+    std::vector<std::string> DATAGRAM_MONITOR;
+
     StartUpType startUp = StartUpType::Normal;
 
     bool startValid = false;

src/xrpld/core/detail/Config.cpp

@@ -481,6 +481,9 @@ Config::loadFromString(std::string const& fileContents)
     if (auto s = getIniFileSection(secConfig, Sections::kIpsFixed))
         ipsFixed = *s;
 
+    if (auto s = getIniFileSection(secConfig, Sections::kDatagramMonitor))
+        DATAGRAM_MONITOR = *s;
+
     // if the user has specified ip:port then replace : with a space.
     {
         auto replaceColons = [](std::vector<std::string>& strVec) {