mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-10-01 14:10:50 +00:00
39 lines
797 B
C++
39 lines
797 B
C++
#pragma once
|
|
|
|
#include <memory>
|
|
#include <ctime>
|
|
#include <cstddef>
|
|
|
|
#include <Core/BackgroundSchedulePool.h>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
class Context;
|
|
|
|
/// Add a task to BackgroundProcessingPool that watch for ProfileEvents::NetworkErrors and updates DNS cache if it has increased
|
|
class DNSCacheUpdater
|
|
{
|
|
public:
|
|
explicit DNSCacheUpdater(Context & context);
|
|
|
|
/// Checks if it is a network error and increments ProfileEvents::NetworkErrors
|
|
static bool incrementNetworkErrorEventsIfNeeded();
|
|
|
|
private:
|
|
void run();
|
|
|
|
Context & context;
|
|
BackgroundSchedulePool & pool;
|
|
BackgroundSchedulePoolTaskHolder task_handle;
|
|
|
|
size_t last_num_network_erros = 0;
|
|
|
|
static constexpr size_t min_errors_to_update_cache = 3;
|
|
static constexpr time_t min_update_period_seconds = 45;
|
|
};
|
|
|
|
|
|
}
|