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
