python使用DBUtil连接池封装psycopg2/hologres

import psycopg2
import datetime
import base64

import sys
import psycopg2.extras
from dbutils.pooled_db import PooledDB
import threading
import traceback
 

u = ''
p = ''

 
"""
全局单例 连接池
"""
class PsycopgConn:
    # 多线程的锁 针对单例初始化的过程 加锁
    _instance_lock = threading.Lock()
 
    """
    init在new之后被调用
    """
    def __init__(self):
        self.init_pool()
 
    """
    重载构造函数 实现全局单例
    """
    def __new__(cls, *args, **kwargs):
        if not hasattr(cls, '_instance'):
            with PsycopgConn._instance_lock:
                if not hasattr(cls, '_instance'):
                    PsycopgConn._instance = object.__new__(cls)
                return PsycopgConn._instance
 
    def get_pool_conn(self):
        """
        获取连接池连接
        :return:
        """
        if not self._pool:
            self.init_pool()
        return self._pool.connection()
 
    def init_pool(self):
        """
        初始化连接池
        :return:
        """
        try:
            pool = PooledDB(
                creator=psycopg2,  # 使用连接数据库的模块 psycopg2
                maxconnections=20,  # 连接池允许的最大连接数，0 和 None 表示不限制连接数
                mincached=1,  # 初始化时，链接池中至少创建的空闲的链接，0 表示不创建
                maxcached=5,  # 链接池中最多闲置的链接，0 和 None 不限制
                blocking=True,  # 连接池中如果没有可用连接后，是否阻塞等待。True，等待；False，不等待然后报错
                maxusage=None,  # 一个链接最多被重复使用的次数，None 表示无限制
                setsession=[],  # 开始会话前执行的命令列表
                host='imp-sothebys-cn-internal-zhangbei.hologres.aliyuncs.com',
                port=8099,
                user=u.decode("utf-8"),
                password=p.decode("utf-8"),
                database='sothebys_data')
            self._pool = pool
        except:
            logger.error("trace back: %s", traceback.format_exc())
            logger.info('connect postgresql error')
            self.close_pool()
 
    def close_pool(self):
        """
        关闭连接池连接
        :return:
        """
        if self._pool != None:
            self._pool.close()
 
    def SelectSql(self, sql):
        """
        查询
        :param sql:
        :return:
        """
        try:
            conn = self.get_pool_conn()
            cursor = conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor)  # 设置返回格式为字典
            cursor.execute(sql)
            result = cursor.fetchall()
        except Exception as e:
            logger.error("trace back: %s", traceback.format_exc())
            logger.info('execute sql {0} is error'.format(sql))
        finally:
            cursor.close()
            conn.close()
        return result
 
    def InsertSql(self, sql):
        """
        插入数据
        :param sql:
        :return:
        """
        try:
            conn = self.get_pool_conn()
            cursor = conn.cursor()
            cursor.execute(sql)
            result = True
        except Exception as e:
            logger.error("trace back: %s", traceback.format_exc())
            logger.info('ERROR: execute  {0} causes error'.format(sql))
        finally:
            cursor.close()
            conn.commit()
            conn.close()
        return result
 
    def UpdateSql(self, sql):
        """
        更新数据
        :param sql:
        :return:
        """
        try:
            conn = self.get_pool_conn()
            cursor = conn.cursor()
            cursor.execute(sql)
            result = True
        except Exception as e:
            logger.error("trace back: %s", traceback.format_exc())
            logger.info('ERROR: execute  {0} causes error'.format(sql))
        finally:
            cursor.close()
            conn.commit()
            conn.close()
        return result

ImportError: /home/admin/.pyenv/versions/3.6.2/
lib/python3.6/site-packages/psycopg2/
_psycopg.cpython-36m-x86_64-linux-gnu.so: undefined symbol: PQconninfo