mysql服务无法启动/挂断-超时（Ubuntu，MariaDB）

Question

我在这里使用本教程使用Ubuntu
16.04，nginx，php7.0，MariaDB，nextcloud和外部DynDNS设置了我的第一个Ubuntu服务器：在Ubuntu
16.04上安装Nextcloud 9

一切正常，但是自从第二天重新启动服务器以来，nextcloud只是显示空白页面。浏览完nginx，MariaDB和nextcloud的所有日志后，我发现mysql服务只是无法启动。因此运行service mysql start，一切都再次正常运行（从服务器以及其他工作站调用nextcloud）。我只是想知道终端没有“关闭”生产线。就像它仍在执行命令一样。大约5分钟后，该行“关闭”，并出现以下消息：

“ mariadb.service的作业失败，因为超过了超时。有关详细信息，请参见“ systemctl status
mariadb.service”和“ journalctl -xe”。

然后，客户再次在nextcloud中获得空白页。当我运行命令并立即关闭终端时，客户端也可以访问，但5分钟后仍然丢失。

我尝试备份nextcloud，sql并运行apt-get purge --auto-remove mariadb- server。然后，通过导入备份sql而不是创建新的sql，再次运行本教程中的MariaDB安装步骤。并没有改变一切。

下一次尝试是update-rc.d mysql defaults和update-rc.d mysql enable。但是重新启动后，仅是空白页。通过启动服务手册，只能访问5分钟。

我也尝试了BUM-BootUpManager，但是该服务似乎已启用。我看到您也可以手动启动服务。因此，尝试使用mysql并感到惊讶：BUM刚刚挂断时，nextcloud可使用5分钟。

我也找到了mariadb.com/kb/zh-CN/mariadb/starting-and-stopping-mariadb-
automatic/，但没有尝试任何操作，因为似乎还有其他问题。

root@s1:~# systemctl status mariadb.service：

\u25cf mariadb.service - MariaDB database server
   Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: 
  Drop-In: /etc/systemd/system/mariadb.service.d
           \u2514\u2500migrated-from-my.cnf-settings.conf
   Active: failed (Result: timeout) since Di 2016-12-06 14:52:51 CET; 55s ago
  Process: 3565 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WS
  Process: 3415 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR
  Process: 3409 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START
  Process: 3405 ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/ru
 Main PID: 3565 (code=exited, status=0/SUCCESS)

Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 3067387712 [Note] /usr/sbin
Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 3067387712 [Note] Event Sch
Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 2147785536 [Note] InnoDB: F
Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 3067387712 [Note] InnoDB: S
Dez 06 14:52:49 s1 mysqld[3565]: 2016-12-06 14:52:49 3067387712 [Note] InnoDB: W
Dez 06 14:52:50 s1 mysqld[3565]: 2016-12-06 14:52:50 3067387712 [Note] InnoDB: S
Dez 06 14:52:50 s1 mysqld[3565]: 2016-12-06 14:52:50 3067387712 [Note] /usr/sbin
Dez 06 14:52:51 s1 systemd[1]: Failed to start MariaDB database server.
Dez 06 14:52:51 s1 systemd[1]: mariadb.service: Unit entered failed state.
Dez 06 14:52:51 s1 systemd[1]: mariadb.service: Failed with result 'timeout'.

root@s1:~# journalctl -xe：

Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 3067387712 [Note] Event Scheduler: Purging the queue. 0 events
Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 2147785536 [Note] InnoDB: FTS optimize thread exiting.
Dez 06 14:52:48 s1 mysqld[3565]: 2016-12-06 14:52:48 3067387712 [Note] InnoDB: Starting shutdown...
Dez 06 14:52:49 s1 mysqld[3565]: 2016-12-06 14:52:49 3067387712 [Note] InnoDB: Waiting for page_cleaner to finish flushing of buffer po
Dez 06 14:52:50 s1 mysqld[3565]: 2016-12-06 14:52:50 3067387712 [Note] InnoDB: Shutdown completed; log sequence number 111890806
Dez 06 14:52:50 s1 mysqld[3565]: 2016-12-06 14:52:50 3067387712 [Note] /usr/sbin/mysqld: Shutdown complete
Dez 06 14:52:50 s1 audit[3648]: AVC apparmor="DENIED" operation="sendmsg" info="Failed name lookup - disconnected path" error=-13 profi
Dez 06 14:52:50 s1 kernel: audit: type=1400 audit(1481032370.973:29): apparmor="DENIED" operation="sendmsg" info="Failed name lookup - 
Dez 06 14:52:50 s1 audit[3565]: AVC apparmor="DENIED" operation="sendmsg" info="Failed name lookup - disconnected path" error=-13 profi
Dez 06 14:52:50 s1 kernel: audit: type=1400 audit(1481032370.973:30): apparmor="DENIED" operation="sendmsg" info="Failed name lookup - 
Dez 06 14:52:51 s1 systemd[1]: Failed to start MariaDB database server.
-- Subject: Unit mariadb.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mariadb.service has failed.
-- 
-- The result is failed.
Dez 06 14:52:51 s1 systemd[1]: mariadb.service: Unit entered failed state.
Dez 06 14:52:51 s1 systemd[1]: mariadb.service: Failed with result 'timeout'.
Dez 06 14:54:54 s1 x11vnc[2665]: 06/12/2016 14:54:54 cursor_noshape_updates_clients: 1
Dez 06 14:55:16 s1 ntpd[1244]: 46.4.1.155 local addr 192.168.178.50 -> <null>
Dez 06 14:57:30 s1 ntpd[1244]: 89.238.66.98 local addr 192.168.178.50 -> <null>

/ect/init.d中的内容（如果有用）：

#!/bin/bash
#
### BEGIN INIT INFO
# Provides:          mysql
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Should-Start:      $network $named $time
# Should-Stop:       $network $named $time
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start and stop the mysql database server daemon
# Description:       Controls the main MariaDB database server daemon "mysqld"
#                    and its wrapper script "mysqld_safe".
### END INIT INFO
#
set -e
set -u
${DEBIAN_SCRIPT_DEBUG:+ set -v -x}

test -x /usr/sbin/mysqld || exit 0

. /lib/lsb/init-functions

SELF=$(cd $(dirname $0); pwd -P)/$(basename $0)
CONF=/etc/mysql/my.cnf
MYADMIN="/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf"

# priority can be overriden and "-s" adds output to stderr
ERR_LOGGER="logger -p daemon.err -t /etc/init.d/mysql -i"

# Safeguard (relative paths, core dumps..)
cd /
umask 077

# mysqladmin likes to read /root/.my.cnf. This is usually not what I want
# as many admins e.g. only store a password without a username there and
# so break my scripts.
export HOME=/etc/mysql/

# Source default config file.
[ -r /etc/default/mariadb ] && . /etc/default/mariadb

## Fetch a particular option from mysql's invocation.
#
# Usage: void mysqld_get_param option
mysqld_get_param() {
    /usr/sbin/mysqld --print-defaults \
        | tr " " "\n" \
        | grep -- "--$1" \
        | tail -n 1 \
        | cut -d= -f2
}

## Do some sanity checks before even trying to start mysqld.
sanity_checks() {
  # check for config file
  if [ ! -r /etc/mysql/my.cnf ]; then
    log_warning_msg "$0: WARNING: /etc/mysql/my.cnf cannot be read. See README.Debian.gz"
    echo                "WARNING: /etc/mysql/my.cnf cannot be read. See README.Debian.gz" | $ERR_LOGGER
  fi

  # check for diskspace shortage
  datadir=`mysqld_get_param datadir`
  if LC_ALL=C BLOCKSIZE= df --portability $datadir/. | tail -n 1 | awk '{ exit ($4>4096) }'; then
    log_failure_msg "$0: ERROR: The partition with $datadir is too full!"
    echo                "ERROR: The partition with $datadir is too full!" | $ERR_LOGGER
    exit 1
  fi
}

## Checks if there is a server running and if so if it is accessible.
#
# check_alive insists on a pingable server
# check_dead also fails if there is a lost mysqld in the process list
#
# Usage: boolean mysqld_status [check_alive|check_dead] [warn|nowarn]
mysqld_status () {
    ping_output=`$MYADMIN ping 2>&1`; ping_alive=$(( ! $? ))

    ps_alive=0
    pidfile=`mysqld_get_param pid-file`
    if [ -f "$pidfile" ] && ps `cat $pidfile` >/dev/null 2>&1; then ps_alive=1; fi

    if [ "$1" = "check_alive"  -a  $ping_alive = 1 ] ||
       [ "$1" = "check_dead"   -a  $ping_alive = 0  -a  $ps_alive = 0 ]; then
    return 0 # EXIT_SUCCESS
    else
    if [ "$2" = "warn" ]; then
        echo -e "$ps_alive processes alive and '$MYADMIN ping' resulted in\n$ping_output\n" | $ERR_LOGGER -p daemon.debug
    fi
    return 1 # EXIT_FAILURE
    fi
}

#
# main()
#

case "${1:-''}" in
  'start')
    sanity_checks;
    # Start daemon
    log_daemon_msg "Starting MariaDB database server" "mysqld"
    if mysqld_status check_alive nowarn; then
       log_progress_msg "already running"
       log_end_msg 0
    else
        # Could be removed during boot
        test -e /var/run/mysqld || install -m 755 -o mysql -g root -d /var/run/mysqld

        # Start MariaDB! 
        /usr/bin/mysqld_safe "${@:2}" > /dev/null 2>&1 &

        # 6s was reported in #352070 to be too little
        for i in $(seq 1 "${MYSQLD_STARTUP_TIMEOUT:-60}"); do
                sleep 1
            if mysqld_status check_alive nowarn ; then break; fi
        log_progress_msg "."
        done
        if mysqld_status check_alive warn; then
                log_end_msg 0
            # Now start mysqlcheck or whatever the admin wants.
            output=$(/etc/mysql/debian-start)
        [ -n "$output" ] && log_action_msg "$output"
        else
            log_end_msg 1
        log_failure_msg "Please take a look at the syslog"
        fi
    fi
    ;;

  'stop')
    # * As a passwordless mysqladmin (e.g. via ~/.my.cnf) must be possible
    # at least for cron, we can rely on it here, too. (although we have 
    # to specify it explicit as e.g. sudo environments points to the normal
    # users home and not /root)
    log_daemon_msg "Stopping MariaDB database server" "mysqld"
    if ! mysqld_status check_dead nowarn; then
      set +e
      shutdown_out=`$MYADMIN shutdown 2>&1`; r=$?
      set -e
      if [ "$r" -ne 0 ]; then
        log_end_msg 1
        [ "$VERBOSE" != "no" ] && log_failure_msg "Error: $shutdown_out"
        log_daemon_msg "Killing MariaDB database server by signal" "mysqld"
        killall -15 mysqld
            server_down=
        for i in `seq 1 600`; do
              sleep 1
              if mysqld_status check_dead nowarn; then server_down=1; break; fi
            done
          if test -z "$server_down"; then killall -9 mysqld; fi
      fi
        fi

        if ! mysqld_status check_dead warn; then
      log_end_msg 1
      log_failure_msg "Please stop MariaDB manually and read /usr/share/doc/mariadb-server-10.1/README.Debian.gz!"
      exit -1
    else
      log_end_msg 0
        fi
    ;;

  'restart')
    set +e; $SELF stop; set -e
    $SELF start 
    ;;

  'reload'|'force-reload')
    log_daemon_msg "Reloading MariaDB database server" "mysqld"
    $MYADMIN reload
    log_end_msg 0
    ;;

  'status')
    if mysqld_status check_alive nowarn; then
      log_action_msg "$($MYADMIN version)"
    else
      log_action_msg "MariaDB is stopped."
      exit 3
    fi
    ;;

  'bootstrap')
    # Bootstrap the cluster, start the first node
    # that initiates the cluster
    log_daemon_msg "Bootstrapping the cluster" "mysqld"
    $SELF start "${@:2}" --wsrep-new-cluster
    ;;

  *)
    echo "Usage: $SELF start|stop|restart|reload|force-reload|status|bootstrap"
    exit 1
    ;;
esac

不幸的是，Google无法帮助我。我尽了最大的努力来解释，也许这可以帮助您。非常感谢！

Answer 1

漫长的问题无话可做…从来没有听说过AppArmor，但这是原因。答案在这里解决了。不用担心apparmor的错误，配置文件将不存在。

sudo aa-status向您显示保镖正在做什么；实际具有强制执行的政策，而不是仅仅抱怨的内容。

sudo apt-get install apparmor-utils 添加了一些使apparmor配置文件更易于处理的命令，例如…

sudo aa-complain /usr/sbin/mysqld将个人资料从“强制”转为投诉。（aa-enforce将其返回。）

完成此操作后，sudo service apparmor reload重新启动apparmor，然后瞧……就sudo /etc/init.d/mysql start可以了，服务器保持启动状态。