由于PHP安装的扩展版本不对应问题导致连接不稳定 查看PHP扩展版本
php -r "phpinfo();" | grep -i mongo mongodb MongoDB support => enabled MongoDB extension version => 1.2.6 MongoDB extension stability => stable libmongoc bundled version => 1.5.5 libmongoc SSL => enabled libmongoc SSL library => OpenSSL libmongoc crypto => enabled libmongoc crypto library => libcrypto libmongoc crypto system profile => disabled libmongoc SASL => disabled查看扩展对应的PHP版本： https://docs.mongodb.com/drivers/php
