Struct Heartbeat 

pub struct Heartbeat {
    pub pc_id: String,
    pub at: DateTime<Utc>,
    pub agent_version: String,
    pub hostname: Option<String>,
    pub os_family: Option<String>,
    pub agent_cpu_pct: Option<f64>,
    pub agent_rss_bytes: Option<i64>,
    pub agent_disk_read_bytes: Option<i64>,
    pub agent_disk_written_bytes: Option<i64>,
}

Liveness ping every agent sends on a 30 s cadence (see inventory_interval / heartbeat_interval in agent_config).

hostname and os_family are enriched baseline facts so the SPA agents page has something to show as soon as the agent boots — even when the full WMI-driven HwInventory hasn’t been (or can’t be) collected. Both stay Option<String> so older agents that don’t send them still deserialize cleanly.

Fields

pc_id: String

at: DateTime<Utc>

agent_version: String

hostname: Option<String>

os_family: Option<String>

Coarse OS bucket from std::env::consts::OS — "windows", "linux", "macos". Rich OS metadata still flows through the inventory path; this is just the “agent is alive on a ” signal.

agent_cpu_pct: Option<f64>

Agent process CPU usage, in percent-of-one-core (a process fully pinning one core reports 100; one pinning two cores reports 200). This is sysinfo’s convention — closer to top than to Windows Task Manager (which normalises by total cores, so a 1-core peg on an 8-core box shows up as ~12.5 % in TM). Divide by host core count if you want a host-normalised view. None is published on the very first heartbeat after process start, because sysinfo’s CPU% needs two consecutive samples to diff — populating it would always report 0.0 there and risk an operator misreading “agent isn’t doing anything”.

agent_rss_bytes: Option<i64>

Agent process resident set size in bytes — sysinfo’s Process::memory(), which on Windows is PROCESS_MEMORY_COUNTERS_EX::WorkingSetSize (full working set, shared + private). Closest Task Manager column is “Working set (memory)”, NOT “Memory (private working set)” which would be PrivateUsage and sysinfo exposes separately as virtual_memory().

agent_disk_read_bytes: Option<i64>

Absolute bytes the agent process has read from disk since it started. Wire format is cumulative (not delta) so dropped / out-of-order heartbeats don’t poison rate math for any client that wants to derive a rate by diffing successive snapshots. Today neither the backend projector nor the SPA does that diff — they just store and render the cumulative value. Future SPA work or an exporter can compute rate without a schema change.

agent_disk_written_bytes: Option<i64>

Absolute bytes the agent process has written to disk since it started. Same shape as agent_disk_read_bytes.

Trait Implementations

impl Clone for Heartbeat

fn clone(&self) -> Heartbeat

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Heartbeat

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Heartbeat

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Heartbeat

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.