[Solved] Fatal error: Uncaught CredisException: Connection to Redis 127.0.0.1:6379 failed. Last Error : (111) Connection refused

Error:- Fatal error: Uncaught CredisException: Connection to Redis 127.0.0.1:6379 failed after 2 failures.Last Error : (111) Connection refused in /home/the-d2/public_html/vendor/colinmollenhour/credis/Client.php:463 Stack trace: #0 /home/the-d2/public_html/vendor/colinmollenhour/credis/Client.php(459): Credis_Client->connect() #1 /home/the-d2/public_html/vendor/colinmollenhour/credis/Client.php(792): Credis_Client->connect() #2 /home/the-d2/public_html/vendor/colinmollenhour/cache-backend-redis/Cm/Cache/Backend/Redis.php(432): Credis_Client->__call(‘hGet’, Array) #3 /home/the-d2/public_html/vendor/magento/zendframework1/library/Zend/Cache/Core.php(306): Cm_Cache_Backend_Redis->load(’33d_GLOBAL__DIC…’, false) #4 /home/the-d2/public_html/vendor/magento/framework/Cache/Frontend/Adapter/Zend.php(39): Zend_Cache_Core->load(’33d_GLOBAL__DIC…’) #5 /home/the-d2/public_html/vendor/magento/framework/Cache/Frontend/Decorator/Bare.php(65): Magento\Framework\Cache\Frontend\Adapter\Z in /home/the-d2/public_html/vendor/colinmollenhour/credis/Client.php on line 463

Solution:- Try restarting the redis service and flush redis cache.
# service redis restart
# redis-cli flushall

[Solved] certificate verification failed for untrusted issuer /OU=GlobalSign Root CA

Error:-

Nov 11 17:09:43 server postfix/smtp[30572]: certificate verification failed for aspmx.l.google.com[74.125.200.26]:25: untrusted issuer /OU=GlobalSign Root CA – R2/O=GlobalSign/CN=GlobalSign
Nov 11 17:14:31 server postfix/smtp[3332]: certificate verification failed for in.hes.trendmicro.com[54.219.191.21]:25: untrusted issuer /C=BE/O=GlobalSign nv-sa/OU=Root CA/CN=GlobalSign Root CA
Nov 11 17:19:32 server postfix/smtp[5333]: certificate verification failed for mx6.mail.icloud.com[17.133.229.15]:25: untrusted issuer /C=US/O=GeoTrust Inc./CN=GeoTrust Global CA
Nov 11 17:19:35 server postfix/smtp[5333]: certificate verification failed for mx5.mail.icloud.com[17.133.229.14]:25: untrusted issuer /C=US/O=GeoTrust Inc./CN=GeoTrust Global CA

Solution:-

You need to mention the SSL CA file path, For me it was letsencrypt SSL and i gave it the complete chain, It worked.
Added below line in /etc/postfix/main.cf and restarted postfix

smtp_tls_CAfile = /etc/letsencrypt/live/the-d2.com/fullchain.pem

service postfix restart

[Solved] Error getting authority: PolicyKit1′: timed out (g-dbus-error-quark, 20)

Error:-

Error getting authority: Error initializing authority: Error calling StartServiceByName for org.freedesktop.PolicyKit1: GDBus.Error:org.freedesktop.DBus.Error.TimedOut: Failed to activate service ‘org.freedesktop.PolicyKit1’: timed out (g-dbus-error-quark, 20)

Troubleshooting:-

systemctl status polkit
● polkit.service – Authorization Manager
Loaded: loaded (/usr/lib/systemd/system/polkit.service; static; vendor preset: enabled)
Active: failed (Result: exit-code) since Sat 2019-11-16 09:02:02 EST; 1min 58s ago
Docs: man:polkit(8)
Process: 11321 ExecStart=/usr/lib/polkit-1/polkitd –no-debug (code=exited, status=1/FAILURE)
Main PID: 11321 (code=exited, status=1/FAILURE)

systemctl start polkit
Error getting authority: Error initializing authority: Error calling StartServiceByName for org.freedesktop.PolicyKit1: Timeout was reached (g-io-error-quark, 24)
Failed to start polkit.service: Connection timed out
See system logs and ‘systemctl status polkit.service’ for details.

Solution:-

yum reinstall polkit
OR
wget http://mirror.centos.org/centos/7/updates/x86_64/Packages/polkit-0.112-22.el7_7.1.x86_64.rpm
yum install polkit-0.112-22.el7_7.1.x86_64.rpm
It will install two other packages as well.
—> Package mozjs17.x86_64 0:17.0.0-20.el7 will be installed
—> Package polkit-pkla-compat.x86_64 0:0.1-4.el7 will be installed
Once installed, start service.
systemctl start polkit
systemctl status polkit
● polkit.service – Authorization Manager
Loaded: loaded (/usr/lib/systemd/system/polkit.service; static; vendor preset: enabled)
Active: active (running) since Sat 2019-11-16 09:20:53 EST; 4s ago
Docs: man:polkit(8)
Main PID: 8302 (polkitd)
CGroup: /system.slice/polkit.service
└─8302 /usr/lib/polkit-1/polkitd –no-debug

[Solved] MySQL service not starting – Job for mariadb.service failed because the control process exited with error code. journalctl -xe

Issue / Error:-

[[email protected] ~]# service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service
Job for mariadb.service failed because the control process exited with error code. See “systemctl status mariadb.service” and “journalctl -xe” for details.

MySQL error logs:-

[[email protected] ~]# cat /var/lib/mysql/server.the-d2.com.err
2019-10-20 10:12:56 1220654356911872 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2019-10-20 10:12:56 1220656458905792 [Note] InnoDB: Highest supported file format is Barracuda.
2019-10-20 10:12:56 1220656458905792 [Note] InnoDB: 128 out of 128 rollback segments are active.
2019-10-20 10:12:56 1220656458905792 [Note] InnoDB: Creating shared tablespace for temporary tables
2019-10-20 10:12:56 1220656458905792 [Note] InnoDB: Setting file ‘./ibtmp1’ size to 12 MB. Physically writing the file full; Please wait …
2019-10-20 10:12:56 1220656458905792 [ERROR] InnoDB: preallocating 12582912 bytes for file ./ibtmp1 failed with error 28
2019-10-20 10:12:56 1220656458905792 [ERROR] InnoDB: Could not set the file size of ‘./ibtmp1’. Probably out of disk space
2019-10-20 10:12:56 1220656458905792 [ERROR] InnoDB: Unable to create the shared innodb_temporary
2019-10-20 10:12:56 1220656458905792 [ERROR] InnoDB: Plugin initialization aborted with error Generic error
2019-10-20 10:13:01 1220656458905792 [Note] InnoDB: Starting shutdown…
2019-10-20 10:13:01 1220656458905792 [Note] InnoDB: Removed temporary tablespace data file: “ibtmp1”
2019-10-20 10:13:01 1220656458905792 [ERROR] Plugin ‘InnoDB’ init function returned error.
2019-10-20 10:13:01 1220656458905792 [ERROR] Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed.
2019-10-20 10:13:01 1220656458905792 [Note] Plugin ‘FEEDBACK’ is disabled.
2019-10-20 10:13:01 1220656458905792 [ERROR] Could not open mysql.plugin table. Some plugins may be not loaded
2019-10-20 10:13:01 1220656458905792 [ERROR] Unknown/unsupported storage engine: InnoDB
2019-10-20 10:13:01 1220656458905792 [ERROR] Aborting

Solution:-

Disk was full, deleted some data and mysql service started without any issue.

[[email protected] ~]# df -h
Filesystem – Size – Used – Avail – Use% Mounted on
devtmpfs – – 3.9G – 0 – 3.9G – 0% /dev
tmpfs – 3.9G – 0 – 3.9G – 0% /sys/fs/cgroup
/dev/xvda1 – 99G – 99G – 78M – 100% /
tmpfs – 783M – 0 – 783M – 0% /run/user/1000

[[email protected] ~]# service mysqld restart
Redirecting to /bin/systemctl restart mysqld.service
[[email protected] ~]#