Struct SchedulerConfig 

pub struct SchedulerConfig {
    pub max_partitions_per_scan: u16,
    pub rotation_window_ms: u64,
}

Tunable scheduler behavior, separate from the topology-level PartitionConfig. Lives in ff-scheduler because every field is a scheduler-internal scan policy — none of it leaks into persisted keys, Lua scripts, or cross-crate wire shapes (unlike PartitionConfig). If a future RFC needs a unified knob surface we can lift this up; not premature today.

Fields

max_partitions_per_scan: u16

Maximum number of partitions to probe in a single Scheduler::claim_for_worker call before giving up and returning Ok(None).

Trade-off: smaller = lower worst-case no-hit latency per claim call (each probe is a ZRANGEBYSCORE round-trip, ~0.1ms LAN), larger = better fairness per call (more partitions seen before a worker yields). At the default of 32 with 256 partitions, any given partition is reached within ceil(256/32) = 8 scheduling ticks — combined with the rotation cursor, that bounds worst-case starvation for a specific partition’s head-of-queue execution.

rotation_window_ms: u64

Duration a rotation cursor position stays stable before advancing.

Trade-off: too short and tight-loop workers re-enter the same window on every tick (cursor never actually rotates relative to them); too long and slow-poll workers keep seeing the same cursor across many ticks (reducing fairness benefit). 250ms is a middle ground: tight-loop workers (sub-ms claim cycles) see a fresh window every ~250 ticks, 1s-poll workers see a fresh window every 4 ticks. Tune down if your workers all idle-poll >1s; tune up if you run a fleet of tight-loop claimers and want less cursor churn.

Implementations

impl SchedulerConfig

pub const DEFAULT_MAX_PARTITIONS_PER_SCAN: u16 = 32

Default scan budget: probe 32 partitions per claim call. See Self::max_partitions_per_scan for the latency/fairness rationale.

pub const DEFAULT_ROTATION_WINDOW_MS: u64 = 250

Default rotation window: advance the cursor every 250ms. See Self::rotation_window_ms.

Trait Implementations

impl Clone for SchedulerConfig

fn clone(&self) -> SchedulerConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SchedulerConfig

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

Formats the value using the given formatter.

impl Default for SchedulerConfig

fn default() -> Self

Returns the “default value” for a type.

impl Copy for SchedulerConfig