settings.hpp

Go to the documentation of this file.

#pragma once
 
/// @file userver/ydb/dist_lock/settings.hpp
/// @brief @copybrief ydb::DistLockSettings
 
#include <chrono>
 
#include <userver/yaml_config/fwd.hpp>
 
USERVER_NAMESPACE_BEGIN
 
namespace ydb {
 
/// A set of tweak-able settings for ydb::DistLockWorker.
struct DistLockSettings {
    /// @brief For how long we will try to restore session after a network failure
    /// before dropping it. Corresponds to `TSessionSettings::Timeout`.
    ///
    /// If the network connection to the coordination node is temporarily lost,
    /// some normal reconnect attempts will be performed
    /// within `session_timeout`.
    /// After the session finally gives up, YDB Coordinator drops the active lock
    /// held by the current host, if any.
    std::chrono::milliseconds session_timeout{5000};
 
    /// @brief Backoff before attempting to reconnect session after it returns
    /// "permanent failure".
    ///
    /// If the network connection to the coordination node is temporarily lost,
    /// some normal reconnect attempts will be performed
    /// within `session_timeout`.
    /// After the session finally gives up, ydb::DistLockWorker will attempt
    /// to restart the coordination session after this time.
    std::chrono::milliseconds restart_session_delay{1000};
 
    /// Backoff before repeating a failed Acquire call.
    std::chrono::milliseconds acquire_interval{100};
 
    /// Backoff before calling DoWork again after it returns or throws.
    std::chrono::milliseconds restart_delay{100};
 
    /// @brief Time, within which a cancelled `DoWork` is expected to finish.
    ///
    /// Ignoring cancellations for this long can lead to a "brain split" where
    /// `DoWork` is running on multiple hosts. Practically speaking, this time
    /// can be computed as:
    ///
    /// `TNodeSettings::SessionGracePeriod - TSessionSettings::Timeout`
    ///
    /// and should be set to that or a smaller value.
    std::chrono::milliseconds cancel_task_time_limit{5000};
};
 
}  // namespace ydb
 
namespace formats::parse {
 
// ydb::Parse is a variable template, thus have to define formats Parse here.
ydb::DistLockSettings Parse(const yaml_config::YamlConfig& config, To<ydb::DistLockSettings>);
 
}  // namespace formats::parse
 
USERVER_NAMESPACE_END