Struct rocks::rate_limiter::RateLimiter

pub struct RateLimiter { /* fields omitted */ }

RateLimiter object, which can be shared among RocksDB instances to control write rate of flush and compaction.

Implementations

impl RateLimiter

pub fn new(
    rate_bytes_per_sec: i64,
    refill_period_us: i64,
    fairness: i32
) -> RateLimiter

Create a RateLimiter object, which can be shared among RocksDB instances to control write rate of flush and compaction.

rate_bytes_per_sec: this is the only parameter you want to set most of the time. It controls the total write rate of compaction and flush in bytes per second. Currently, RocksDB does not enforce rate limit for anything other than flush and compaction, e.g. write to WAL.

refill_period_us: this controls how often tokens are refilled. For example, when rate_bytes_per_sec is set to 10MB/s and refill_period_us is set to 100ms, then 1MB is refilled every 100ms internally. Larger value can lead to burstier writes while smaller value introduces more CPU overhead. The default should work for most cases.

fairness: RateLimiter accepts high-pri requests and low-pri requests. A low-pri request is usually blocked in favor of hi-pri request. Currently, RocksDB assigns low-pri to request from compaciton and high-pri to request from flush. Low-pri requests can get blocked if flush requests come in continuouly. This fairness parameter grants low-pri requests permission by 1/fairness chance even though high-pri requests exist to avoid starvation.

Trait Implementations

impl Drop for RateLimiter

pub fn drop(&mut self)

Executes the destructor for this type.