// This file is @generated by prost-build.
/// A retry host selector that attempts to spread retries between priorities, even if certain
/// priorities would not normally be attempted due to higher priorities being available.
///
/// As priorities get excluded, load will be distributed amongst the remaining healthy priorities
/// based on the relative health of the priorities, matching how load is distributed during regular
/// host selection. For example, given priority healths of {100, 50, 50}, the original load will be
/// {100, 0, 0} (since P0 has capacity to handle 100% of the traffic). If P0 is excluded, the load
/// changes to {0, 50, 50}, because P1 is only able to handle 50% of the traffic, causing the
/// remaining to spill over to P2.
///
/// Each priority attempted will be excluded until there are no healthy priorities left, at which
/// point the list of attempted priorities will be reset, essentially starting from the beginning.
/// For example, given three priorities P0, P1, P2 with healthy % of 100, 0 and 50 respectively, the
/// following sequence of priorities would be selected (assuming update_frequency = 1):
/// Attempt 1: P0 (P0 is 100% healthy)
/// Attempt 2: P2 (P0 already attempted, P2 only healthy priority)
/// Attempt 3: P0 (no healthy priorities, reset)
/// Attempt 4: P2
///
/// In the case of all upstream hosts being unhealthy, no adjustments will be made to the original
/// priority load, so behavior should be identical to not using this plugin.
///
/// Using this PriorityFilter requires rebuilding the priority load, which runs in O(# of
/// priorities), which might incur significant overhead for clusters with many priorities.
/// \[\#extension: envoy.retry_priorities.previous_priorities\]
#[derive(Clone, Copy, PartialEq, ::prost::Message)]
pub struct PreviousPrioritiesConfig {
    /// How often the priority load should be updated based on previously attempted priorities. Useful
    /// to allow each priorities to receive more than one request before being excluded or to reduce
    /// the number of times that the priority load has to be recomputed.
    ///
    /// For example, by setting this to 2, then the first two attempts (initial attempt and first
    /// retry) will use the unmodified priority load. The third and fourth attempt will use priority
    /// load which excludes the priorities routed to with the first two attempts, and the fifth and
    /// sixth attempt will use the priority load excluding the priorities used for the first four
    /// attempts.
    ///
    /// Must be greater than 0.
    #[prost(int32, tag = "1")]
    pub update_frequency: i32,
}
