Class: LoadBalancer::LeastResponseTime

Inherits:
Algo
  • Object
show all
Defined in:
lib/multi_dbs_load_balancer/load_balancer/least_response_time.rb

Instance Attribute Summary

Attributes inherited from Algo

#database_configs, #key, #redis

Instance Method Summary collapse

Methods inherited from Algo

#connected_to_next_db, #fail_over, #initialize

Methods included from Healthcheck

#db_available?, #mark_db_down, #mark_redis_down, #redis_available?

Methods included from RedisLua

eval_lua_script

Constructor Details

This class inherits a constructor from LoadBalancer::Algo

Instance Method Details

#after_connected ⇒ Object 



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# File 'lib/multi_dbs_load_balancer/load_balancer/least_response_time.rb', line 37

def after_connected
    @start_time = Time.now
end

#after_executed ⇒ Object 



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# File 'lib/multi_dbs_load_balancer/load_balancer/least_response_time.rb', line 41

def after_executed
    update_response_time(Time.now - @start_time) if @start_time
end

#next_db(**options) ⇒ Object 



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# File 'lib/multi_dbs_load_balancer/load_balancer/least_response_time.rb', line 29

def next_db(**options)
    @least_db_index = top_least.to_i
    return @database_configs[@least_db_index], @least_db_index if db_available?(@least_db_index)
    
    # fail over
    fail_over(next_dbs)
end

#warm_up ⇒ Object 



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# File 'lib/multi_dbs_load_balancer/load_balancer/least_response_time.rb', line 8

def warm_up
    pq_mutex.synchronize do
        begin
            unless @redis.exists?(db_conns_pq_key)
                @database_configs.size.times do |i|
                    @redis.zincrby(db_conns_pq_key, 0, i)
                end
            end
        rescue => error
            mark_redis_down if error.is_a?(Redis::CannotConnectError)
        ensure
            return if @@response_times.has_key?(db_conns_pq_key)

            @@response_times[db_conns_pq_key] = MinHeap.new
            @database_configs.size.times do |i|
                @@response_times[db_conns_pq_key].push([0, i])
            end
        end
    end
end