C++ writing TDengine database with error occasionally - tdengine

Question

When I use below code to insert into TDengine database ,sometimes it will lose connection.
you can compile it and run to reproduce issue ,anyone could help on this ?
I use the async taos_query_a API to test the response time .:
//
// Created by jia.wen on 8/15/22.
//
//#include <fmt/format.h>
#include <chrono>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <unistd.h>
#include <vector>
#include <taos.h>
static unsigned long long get_nanosecs_since_epoch()
{
using namespace std::chrono;
return static_cast<unsigned long long>(duration_cast<nanoseconds>(
system_clock::now().time_since_epoch()).count());
}
static std::string format_nanosecs_since_epoch(unsigned long long nanosecs_since_epoch)
{
std::time_t secs_since_epoch(nanosecs_since_epoch / 1000000000);
std::tm secs_since_epoch_tm;
localtime_r(&secs_since_epoch, &secs_since_epoch_tm);
unsigned long long remaining_nanosecs = nanosecs_since_epoch % 1000000000;
char buffer[30];
int year = secs_since_epoch_tm.tm_year + 1900;
buffer[0] = (year / 1000) + '0';
buffer[1] = (year % 1000) / 100 + '0';
buffer[2] = (year % 100) / 10 + '0';
buffer[3] = (year % 10) + '0';
buffer[4] = '-';
int month = secs_since_epoch_tm.tm_mon + 1;
buffer[5] = (month / 10) + '0';
buffer[6] = (month % 10) + '0';
buffer[7] = '-';
buffer[8] = (secs_since_epoch_tm.tm_mday / 10) + '0';
buffer[9] = (secs_since_epoch_tm.tm_mday % 10) + '0';
buffer[10] = ' ';
buffer[11] = (secs_since_epoch_tm.tm_hour / 10) + '0';
buffer[12] = (secs_since_epoch_tm.tm_hour % 10) + '0';
buffer[13] = ':';
buffer[14] = (secs_since_epoch_tm.tm_min / 10) + '0';
buffer[15] = (secs_since_epoch_tm.tm_min % 10) + '0';
buffer[16] = ':';
buffer[17] = (secs_since_epoch_tm.tm_sec / 10) + '0';
buffer[18] = (secs_since_epoch_tm.tm_sec % 10) + '0';
buffer[19] = '.';
buffer[20] = (remaining_nanosecs / 100000000) + '0';
buffer[21] = (remaining_nanosecs % 100000000) / 10000000 + '0';
buffer[22] = (remaining_nanosecs % 10000000) / 1000000 + '0';
buffer[23] = (remaining_nanosecs % 1000000) / 100000 + '0';
buffer[24] = (remaining_nanosecs % 100000) / 10000 + '0';
buffer[25] = (remaining_nanosecs % 10000) / 1000 + '0';
buffer[26] = (remaining_nanosecs % 1000) / 100 + '0';
buffer[27] = (remaining_nanosecs % 100) / 10 + '0';
buffer[28] = (remaining_nanosecs % 10) + '0';
buffer[29] = 0;
return std::string(buffer);
}
void taos_insert_call_back(void* param, TAOS_RES* tres, int code)
{
unsigned long long* insert_time = (unsigned long long *)param;
struct timeval systemTime;
char sql[128];
if (code < 0)
{
printf("Insert failed. code:%d, cause:%s\n", code, taos_errstr(tres));
}
else if (code == 0)
{
// printf("Not inserted.\n");
}
else
{
printf("Succeed.\n");
}
taos_free_result(tres);
}
int main()
{
const char *host = "localhost:6030";
const char *user = "root";
const char *passwd = "taosdata";
const char *db = "test_lts";
uint16_t port = 0; // 0 means use the default port
TAOS *taos = taos_connect(host, user, passwd, db, port);
if (taos == NULL)
{
int errno_n = taos_errno(NULL);
auto msg = taos_errstr(NULL);
printf("%d, %s\n", errno, msg);
}
else
{
printf("connected\n");
std::string ins_sql;
std::vector<int> test_cycles_;
TAOS_RES* exec_result = NULL;
int cycles = 60;
int insert_times = 2000;
for (auto i = 0; i < cycles; ++i)
{
for (auto j = 0; j < insert_times; ++j)
{
auto local_time = format_nanosecs_since_epoch(get_nanosecs_since_epoch());
ins_sql = "INSERT INTO tick_jw VALUES ('" + local_time + "'," + std::to_string(i + 1) + ", 20221018, " + std::to_string(j)
+ ", 'test', 1.2, 200, 1000, 0, 0, 0, "
"1.15, 1.14, 1.13, 1.12, 1.11, 5, 4, 3, 2, 1, 1.16, 1.17, 1.18, 1.19, 1.20, 5, 4, 3, 2, 1)";
taos_query_a(taos, ins_sql.c_str(), taos_insert_call_back, (void *)(0));
// usleep(60);
}
std::cout << "cycles = " << i + 1 << " finished." << std::endl;
// sleep(1);
}
std::cout << "insert_times = " << insert_times << " test async finished." << std::endl;
sleep(60);
taos_close(taos);
}
taos_cleanup();
}
the core part is just :taos_query_a(taos, ins_sql.c_str(), taos_insert_call_back, (void *)(0));