OperationalError: (2003, "Can't connect to MySQL server on 'ip' (99)")

矫情吗；* 2021-06-24 16:11 357阅读 0赞

OperationalError: (2003, "Can't connect to MySQL server on 'ip' (99)")
    InterfaceError: 2013: Lost connection to MySQL server during query

上面是我在服务器的错误日志里看到的2点半到4点半期间报的错误，而且4点半之后自己又莫名奇妙的好了，网上也查了好多有关于数据库方面的问题，我也在这台服务器上做了测试，数据库方面无任何问题，包括ip，port，用户名，密码，域名等都无问题，我还是说一下我此次的原因吧，是 /etc/sysctl.conf 文件里的一些配置，下面是改过之后的配置了，可用

Kernel sysctl configuration file for Red Hat Linux
    #
    # For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and
    # sysctl.conf(5) for more details.
    #
    # Controls IP packet forwarding
    net.ipv4.ip_forward = 0
    #
    # Controls source route verification
    net.ipv4.conf.default.rp_filter = 1
    #
    # Do not accept source routing
    net.ipv4.conf.default.accept_source_route = 0
    #
    # Controls the System Request debugging functionality of the kernel
    kernel.sysrq = 0
    #
    # Controls whether core dumps will append the PID to the core filename.
    # Useful for debugging multi-threaded applications.
    kernel.core_uses_pid = 1
    #
    # Controls the use of TCP syncookies
    net.ipv4.tcp_syncookies = 1
    #
    # Disable netfilter on bridges.
    # net.bridge.bridge-nf-call-ip6tables = 0
    # net.bridge.bridge-nf-call-iptables = 0
    # net.bridge.bridge-nf-call-arptables = 0
    #
    # Controls the default maxmimum size of a mesage queue
    kernel.msgmnb = 65536
    #
    # Controls the maximum size of a message, in bytes
    kernel.msgmax = 65536
    #
    # Controls the maximum shared segment size, in bytes
    kernel.shmmax = 68719476736
    #
    # Controls the maximum number of shared memory segments, in pages
    kernel.shmall = 4294967296
    #
    # Append kernel arguments
    # kernel.exec-shield = 1
    kernel.randomize_va_space = 1 
    # net.ipv4.icmp_echo_ignore_broadcasts = 1
    net.ipv4.tcp_synack_retries = 2
    net.ipv4.conf.all.secure_redirects = 0
    net.ipv4.conf.all.accept_redirects = 0
    net.ipv4.conf.all.rp_filter = 1
    # net.ipv4.conf.all.accept_source_route = 0
    net.ipv4.conf.default.secure_redirects = 0
    net.ipv4.conf.default.accept_redirects = 0
    net.ipv4.conf.all.send_redirects = 0
    net.ipv4.conf.default.send_redirects = 0
    # net.ipv4.icmp_ignore_bogus_error_responses = 1
    # vm.mmap_min_addr = 4096 
    #
    #
    #
    net.core.wmem_max=12582912
    net.core.rmem_max=12582912
    net.ipv4.tcp_sack = 1
    net.core.netdev_max_backlog = 5000
    #
    net.ipv4.tcp_synack_retries = 2
    net.ipv4.tcp_max_syn_backlog = 65535
    #
    net.core.somaxconn = 65535
    #open TIME-WAIT connections reuse
    net.ipv4.tcp_tw_reuse = 1
    ##allowable port range
    net.ipv4.ip_local_port_range = 10240    65000
    ##max TIME-WAIT connections
    net.ipv4.tcp_max_tw_buckets = 100000
    ##max TIME-WAIT time, /2
    net.ipv4.tcp_fin_timeout = 15
    #recycle time
    net.ipv4.tcp_tw_recycle = 1
    #
    fs.file-max = 1024000
    fs.aio-max-nr = 14127000
    vm.min_free_kbytes = 1048576
    vm.swappiness = 10
    vm.vfs_cache_pressure = 150
    vm.dirty_ratio = 10
    vm.drop_caches = 1
    kernel.panic = 60

上面具体参数代表的意思可参考[这里][Link 1]

[Link 1]: https://www.cnblogs.com/Jtianlin/p/4339931.html