MySQL 5.7 upgrade process failed

I am getting error MySQL 5.7 upgrade. Please let me know this fix.

Code:

(XID kb2ypk) The system failed to connect to the “MySQL” database “mysql” because of an error: CR_CONNECTION_ERROR (Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)) at /usr/local/cpanel/Whostmgr/Mysql/Upgrade.pm line 234.
    Whostmgr::Mysql::Upgrade::__ANON__(Cpanel::Exception::Database::ConnectError=HASH(0x40184e8)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/Try/Tiny.pm line 120
    Try::Tiny::try(CODE(0x3aba8e8), Try::Tiny::Catch=REF(0x37d2e10)) called at /usr/local/cpanel/Whostmgr/Mysql/Upgrade.pm line 235
    Whostmgr::Mysql::Upgrade::upgrade_mysql_with_status(HASH(0x3602698)) called at /usr/local/cpanel/Whostmgr/Mysql/Upgrade.pm line 469
    Whostmgr::Mysql::Upgrade::_run_unattended_upgrade(HASH(0x3602698)) called at /usr/local/cpanel/Cpanel/ForkSync.pm line 50
    Cpanel::ForkSync::__ANON__() called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/Try/Tiny.pm line 99
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/Try/Tiny.pm line 90
    Try::Tiny::try(CODE(0x3d2a3f8), Try::Tiny::Catch=REF(0x3cb82d0)) called at /usr/local/cpanel/Cpanel/ForkSync.pm line 58
    Cpanel::ForkSync::__ANON__() called at /usr/local/cpanel/Cpanel/ForkAsync.pm line 67
    eval {...} called at /usr/local/cpanel/Cpanel/ForkAsync.pm line 67
    Cpanel::ForkAsync::do_in_child(CODE(0x29a3098)) called at /usr/local/cpanel/Cpanel/ForkSync.pm line 66
    Cpanel::ForkSync::new("Cpanel::ForkSync", CODE(0x3b02c80), HASH(0x3602698)) called at /usr/local/cpanel/Whostmgr/Mysql/Upgrade.pm line 383
    Whostmgr::Mysql::Upgrade::unattended_upgrade(HASH(0x3602698)) called at whostmgr/bin/whostmgr.pl line 6585
    main::__ANON__() called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/Try/Tiny.pm line 99
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/Try/Tiny.pm line 90
    Try::Tiny::try(CODE(0x3d2a500), Try::Tiny::Catch=REF(0x3ca4268)) called at whostmgr/bin/whostmgr.pl line 6589
    main::__ANON__(HASH(0x3602698)) called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/mysqlupgrade-unattended.tmpl line 10
    eval {...} called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/mysqlupgrade-unattended.tmpl line 10
    eval {...} called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/mysqlupgrade-unattended.tmpl line 7
    Template::Document::__ANON__(Template::Context=HASH(0x3c36868)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Context.pm line 354
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Context.pm line 327
    Template::Context::process(Template::Context=HASH(0x3c36868), "runner") called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/runner.tmpl line 30
    eval {...} called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/runner.tmpl line 7
    Template::Document::__ANON__(Template::Context=HASH(0x3c36868)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Document.pm line 163
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Document.pm line 161
    Template::Document::process(Template::Document=HASH(0x3d31490), Template::Context=HASH(0x3c36868)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Context.pm line 357
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Context.pm line 327
    Template::Context::process(Template::Context=HASH(0x3c36868), "mysqlupgrade/runner.tmpl") called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/mysqlupgrade-unattended.tmpl line 12
    eval {...} called at /usr/local/cpanel/whostmgr/docroot/templates/mysqlupgrade/mysqlupgrade-unattended.tmpl line 7
    Template::Document::__ANON__(Template::Context=HASH(0x3c36868)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Document.pm line 163
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Document.pm line 161
    Template::Document::process(Template::Document=HASH(0x3ca1080), Template::Context=HASH(0x3c36868)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Context.pm line 357
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Context.pm line 327
    Template::Context::process(Template::Context=HASH(0x3c36868), Template::Document=HASH(0x3ca1080)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Service.pm line 94
    eval {...} called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template/Service.pm line 91
    Template::Service::process(Template::Service=HASH(0x3c16c50), "mysqlupgrade/mysqlupgrade-unattended.tmpl", HASH(0x3a68d50)) called at /usr/local/cpanel/3rdparty/perl/526/lib64/perl5/cpanel_lib/x86_64-linux-64int/Template.pm line 64
    Template::process(Template=HASH(0x3c162a8), "mysqlupgrade/mysqlupgrade-unattended.tmpl", HASH(0x3a68d50)) called at /usr/local/cpanel/Cpanel/Template.pm line 512
    Cpanel::Template::process_template("whostmgr", HASH(0x3a68d50), HASH(0x3ad3b58)) called at /usr/local/cpanel/Cpanel/Template/Interactive.pm line 54
    Cpanel::Template::Interactive::process_template("whostmgr", HASH(0x3a68d50)) called at whostmgr/bin/whostmgr.pl line 6631
    main::mysqlupgrade("mysqlupgrade") called at /usr/local/cpanel/Whostmgr/Dispatch.pm line 216
    Whostmgr::Dispatch::_do_call("mysqlupgrade", HASH(0x35feb50), HASH(0x36025c0)) called at /usr/local/cpanel/Whostmgr/Dispatch.pm line 125
    Whostmgr::Dispatch::dispatch("mysqlupgrade", ARRAY(0x3601978)) called at whostmgr/bin/whostmgr.pl line 582

 

Now I do hit retry button then get The upgrade process completed successfully.

Code:

Log Messages
2018-02-06T10:05:13.055718Z 0 [Note] /usr/sbin/mysqld: ready for connections.
2018-02-06T10:05:12.659400Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
2018-02-06T10:05:11.048142Z 0 [Note] /usr/sbin/mysqld: ready for connections.

mysqld restarted successfully.
Obtained version information from system.
Proceeding with MySQL/MariaDB upgrade despite the following:
Normal: The selected MySQL version (5.7) is the same as the currently installed MySQL version (5.7). No upgrade will be performed at this time, though the normal upgrade steps will still be executed. This is only useful if a previous upgrade failed while partially completed.
Critical: MySQL enables "strict mode" by default as of version 5.7. Strict mode controls how MySQL handles invalid or missing values in data-change statements such as INSERT or UPDATE. Applications not built with strict mode enabled may cause undesired behavior; please verify applications using MySQL are compatible before upgrading. More information about strict mode is availablehere.
MySQL upgrade completed successfully
------------------------------------
Checking for Ruby update...
No Ruby update required.
------------------------------------

The upgrade process completed successfully.