Template Class conservative_strategy

Inheritance Relationships

Base Type

Class Documentation

template<typename Connector>
class stream_client::connector::conservative_strategy : public stream_client::connector::pool_strategy<Connector>

Conservative strategy.

Will try to refill up to 2/3 of vacant places in the pool. If failed will back off with delay and try to add only one new session.

Public Types

using connector_type = typename pool_strategy<Connector>::connector_type
using stream_type = typename pool_strategy<Connector>::stream_type
using append_func_type = typename pool_strategy<Connector>::append_func_type
using clock_type = typename connector_type::clock_type
using time_duration_type = typename connector_type::time_duration_type
using time_point_type = typename connector_type::time_point_type

Public Functions

conservative_strategy(unsigned long first_delay_ms = kDefaultDelayMs, unsigned delay_multiplier = kDefaultDelayMul)

Creates conservative strategy with specified delay and multiplier.

Strategy allows to add new sessions with increasing delays upon failures.

Parameters

  • first_delay_ms – Initial delay to use.

  • delay_multiplier – Multiply delay by this number each time we fail. Should be >= 1

virtual ~conservative_strategy() = default

Destructor.

virtual bool refill(connector_type &connector, std::size_t vacant_places, append_func_type append_func) override

Adds up to 2/3 of vacant_places sessions via connector simultaneously.

On failures will set a delay and until it is passed will do nothing. Also, will add only one session if previously failed.

Delay initially set to first_delay_ms and multiplied by random number in [1..delay_multiplier) interval on each fail.

Parameters

  • connector – Connector to use for new sessions.

  • vacant_places – Number of required connection to fulfill the pool.

  • append_func – Function is used to add new session to the pool.

Returns

true if added at least one session; false if failed or wait time is not reached.

Public Static Attributes

static const unsigned long kMaxBackoffMs = 10000

Maximum allowed delay is ms.

static const unsigned long kDefaultDelayMs = 50
static const unsigned long kDefaultDelayMul = 3