错误2002（HY000）：无法通过套接字'/var/run/mysqld/mysqld.sock'（2）连接到本地MySQL服务器

Question

While starting the MySql server I am continuously getting this error. The path for the sock file that is mentioned is /var/run/mysqld/mysqld.sock . I tried to find it in other ways to but the file is missing.

after running systemctl status mysql.service the output is given be

 ● mysql.service - MySQL Community Server Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled) Active: activating (start-post) (Result: exit-code) since Thu 2017-08-24 12:58:44 UTC; 26s ago Process: 19985 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE) Process: 19976 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS) Main PID: 19985 (code=exited, status=1/FAILURE); : 19986 (mysql-systemd-s) Tasks: 2 Memory: 328.0K CPU: 262ms CGroup: /system.slice/mysql.service └─control ├─19986 /bin/bash /usr/share/mysql/mysql-systemd-start post └─20068 sleep 1 Aug 24 12:58:44 ip-172-31-25-190 systemd[1]: mysql.service: Service hold-off time over, scheduling restart. Aug 24 12:58:44 ip-172-31-25-190 systemd[1]: Stopped MySQL Community Server. Aug 24 12:58:44 ip-172-31-25-190 systemd[1]: Starting MySQL Community Server... Aug 24 12:58:46 ip-172-31-25-190 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE 

After running journalctl -xe following output got generated.

 Aug 24 12:58:44 ip-172-31-25-190 systemd[1]: Starting MySQL Community Server... -- Subject: Unit mysql.service has begun start-up -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit mysql.service has begun starting up. Aug 24 12:58:44 ip-172-31-25-190 kernel: audit: type=1400 audit(1503579524.748:818): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/19985/sta Aug 24 12:58:44 ip-172-31-25-190 kernel: audit: type=1400 audit(1503579524.748:819): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/sy Aug 24 12:58:44 ip-172-31-25-190 kernel: audit: type=1400 audit(1503579524.748:820): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/19985/sta Aug 24 12:58:44 ip-172-31-25-190 audit[19985]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/19985/status" pid=19985 comm="mysqld" reque Aug 24 12:58:44 ip-172-31-25-190 audit[19985]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=19985 comm="mysqld Aug 24 12:58:44 ip-172-31-25-190 audit[19985]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/19985/status" pid=19985 comm="mysqld" reque Aug 24 12:58:46 ip-172-31-25-190 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE Aug 24 12:59:14 ip-172-31-25-190 systemd[1]: Failed to start MySQL Community Server. -- Subject: Unit mysql.service has failed -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit mysql.service has failed. -- -- The result is failed. Aug 24 12:59:14 ip-172-31-25-190 systemd[1]: mysql.service: Unit entered failed state. Aug 24 12:59:14 ip-172-31-25-190 systemd[1]: mysql.service: Failed with result 'exit-code'. Aug 24 12:59:14 ip-172-31-25-190 systemd[1]: mysql.service: Service hold-off time over, scheduling restart. Aug 24 12:59:14 ip-172-31-25-190 systemd[1]: Stopped MySQL Community Server. -- Subject: Unit mysql.service has finished shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit mysql.service has finished shutting down. Aug 24 12:59:14 ip-172-31-25-190 systemd[1]: Starting MySQL Community Server... -- Subject: Unit mysql.service has begun start-up -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit mysql.service has begun starting up. Aug 24 12:59:15 ip-172-31-25-190 kernel: audit: type=1400 audit(1503579555.004:821): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/20089/sta Aug 24 12:59:15 ip-172-31-25-190 audit[20089]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/20089/status" pid=20089 comm="mysqld" reque Aug 24 12:59:15 ip-172-31-25-190 audit[20089]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=20089 comm="mysqld Aug 24 12:59:15 ip-172-31-25-190 audit[20089]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/20089/status" pid=20089 comm="mysqld" reque Aug 24 12:59:15 ip-172-31-25-190 kernel: audit: type=1400 audit(1503579555.012:822): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/sy Aug 24 12:59:15 ip-172-31-25-190 kernel: audit: type=1400 audit(1503579555.012:823): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/20089/sta Aug 24 12:59:16 ip-172-31-25-190 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE 

This error code appearing whenever I am uncommenting the following lines in /etc/mysql/mysql.conf.d/mysqld.cnf

 general_log_file = /var/log/mysql/mysql.log general_log= 1 log_slow_queries = /var/log/mysql/mysql-slow.log long_query_time = 1 log-queries-not-using-indexes = 1 

What should be done to resolve the same?

Answer 1

Could be because of apparmor

AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld"

Found this comment on the same issue: https://bugs.launchpad.net/ubuntu/+source/mysql-5.7/+bug/1610765/comments/19

Fix should be:

# sudo nano /etc/apparmor.d/usr.sbin.mysqld

editing the system resource access section to:

# Allow system resource access
/sys/devices/system/cpu/ r,
/sys/devices/system/node/ r,
/sys/devices/system/node/** r,
/proc/** r,