component.hpp

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#pragma once
 
/// @file userver/storages/redis/component.hpp
/// @brief @copybrief components::Redis
 
#include <memory>
#include <string>
#include <unordered_map>
 
#include <userver/components/component_base.hpp>
#include <userver/components/component_fwd.hpp>
#include <userver/dynamic_config/source.hpp>
#include <userver/rcu/rcu.hpp>
#include <userver/storages/redis/base.hpp>
#include <userver/storages/redis/fwd.hpp>
#include <userver/storages/redis/wait_connected_mode.hpp>
#include <userver/storages/secdist/secdist.hpp>
#include <userver/testsuite/redis_control.hpp>
#include <userver/utils/statistics/fwd.hpp>
 
USERVER_NAMESPACE_BEGIN
 
/// Components, clients and helpers for different databases and storages
namespace storages {}
 
/// Valkey and Redis client and helpers
namespace storages::redis {
 
class SubscribeClientImpl;
 
namespace impl {
class Sentinel;
class ThreadPools;
class HealthCheckManager;
}  // namespace impl
}  // namespace storages::redis
 
namespace components {
 
/// @ingroup userver_components
///
/// @brief Valkey and Redis client component
///
/// Provides access to a valkey or redis cluster.
///
/// ## Dynamic options:
/// * @ref REDIS_COMMANDS_BUFFERING_SETTINGS
/// * @ref REDIS_DEFAULT_COMMAND_CONTROL
/// * @ref REDIS_METRICS_SETTINGS
/// * @ref REDIS_PUBSUB_METRICS_SETTINGS
/// * @ref REDIS_RETRY_BUDGET_SETTINGS
/// * @ref REDIS_REPLICA_MONITORING_SETTINGS
/// * @ref REDIS_SUBSCRIBER_DEFAULT_COMMAND_CONTROL
/// * @ref REDIS_SUBSCRIPTIONS_REBALANCE_MIN_INTERVAL_SECONDS
/// * @ref REDIS_WAIT_CONNECTED
/// * @ref REDIS_IGNORE_HEALTH_CHECK
///
/// ## Static options of components::Redis :
/// @include{doc} scripts/docs/en/components_schema/redis/src/storages/redis/component.md
///
/// Options inherited from @ref components::ComponentBase :
/// @include{doc} scripts/docs/en/components_schema/core/src/components/impl/component_base.md
///
/// ## Static configuration example:
///
/// ```
///    # yaml
///    redis:
///        groups:
///          - config_name: cats
///            db: hello_service_cats_catalogue
///            sharding_strategy: RedisCluster
///          - config_name: dogs
///            db: hello_service_dogs_catalogue
///        subscribe_groups:
///          - config_name: food
///            db: hello_service_pet_food_orders
///        thread_pools:
///            redis_thread_pool_size: 8
///            sentinel_thread_pool_size: 1
/// ```
///
/// ## Secdist format
///
/// If a `config_name` option is provided, for example
/// `groups.some.config_name: some_name_of_your_database`, then the Secdist
/// entry for that alias should look like following:
/// @code{.json}
/// {
///   "redis_settings": {
///     "some_name_of_your_database": {
///       "password": "the_password_of_your_database",
///       "sentinel_password": "the_password_for_sentinels_if_any",
///       "secure_connection": false,
///       "sentinels": [
///         {"host": "the_host1_of_your_database", "port": 11564}
///       ],
///       "shards": [
///         {"name": "test_master0"}
///       ]
///     }
///   }
/// }
/// @endcode
///
/// For an example of Secdist setup for standalone, sentinel and cluster testsuite configurations see the snippet:
///
/// @snippet redis/functional_tests/integration_tests/tests/conftest.py  Sample pytest redis configuration
///
/// Note that if the components::Secdist component has `update-period` other
/// than 0, then new connections are created or gracefully closed as the secdist configuration change to new value.
///
/// ## Cluster Valkey or Cluster Redis setup
///
/// Valkey/Redis cluster is the new recommended way of setting up key-value datastores with improved stability.
///
/// To start, set `sharding_strategy: RedisCluster` in the static config
/// as shown above.
///
/// Secdist configuration is simplified:
///
/// 1. `"shards"` field is ignored, you can specify an empty array there;
/// 2. `"sentinels"` field should contain some of the cluster nodes. They are
///    only used for topology discovery; it is not necessary to list all nodes.
class Redis : public ComponentBase {
public:
    Redis(const ComponentConfig& config, const ComponentContext& component_context);
 
    ~Redis() override;
 
    /// @ingroup userver_component_names
    /// @brief The default name of components::Redis
    static constexpr std::string_view kName = "redis";
 
    std::shared_ptr<storages::redis::Client> GetClient(
        const std::string& name,
        storages::redis::RedisWaitConnected wait_connected = {}
    ) const;
    [[deprecated("use GetClient()")]] std::shared_ptr<storages::redis::impl::Sentinel> Client(const std::string& name
    ) const;
    std::shared_ptr<storages::redis::SubscribeClient> GetSubscribeClient(
        const std::string& name,
        storages::redis::RedisWaitConnected wait_connected = {}
    ) const;
 
    ComponentHealth GetComponentHealth() const override;
 
    static yaml_config::Schema GetStaticConfigSchema();
 
private:
    void OnConfigUpdate(const dynamic_config::Snapshot& cfg);
    void OnSecdistUpdate(const storages::secdist::SecdistConfig& cfg);
 
    void Connect(
        const ComponentConfig& config,
        const ComponentContext& component_context,
        const testsuite::RedisControl& testsuite_redis_control
    );
 
    void WriteStatistics(utils::statistics::Writer& writer);
    void WriteStatisticsPubsub(utils::statistics::Writer& writer);
 
    std::shared_ptr<storages::redis::impl::ThreadPools> thread_pools_;
    std::unordered_map<std::string, std::shared_ptr<storages::redis::impl::Sentinel>> sentinels_;
    std::unordered_map<std::string, std::shared_ptr<storages::redis::Client>> clients_;
    std::unordered_map<std::string, std::shared_ptr<storages::redis::SubscribeClientImpl>> subscribe_clients_;
 
    std::shared_ptr<storages::redis::impl::HealthCheckManager> health_check_manager_;
 
    dynamic_config::Source config_;
    concurrent::AsyncEventSubscriberScope config_subscription_;
    concurrent::AsyncEventSubscriberScope secdist_subscription_;
 
    rcu::Variable<storages::redis::MetricsSettings> metrics_settings_;
    rcu::Variable<storages::redis::PubsubMetricsSettings> pubsub_metrics_settings_;
};
 
template <>
inline constexpr bool kHasValidate<Redis> = true;
 
}  // namespace components
 
USERVER_NAMESPACE_END