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Bug 1646158

Summary: PHP Warning: mysqli::mysqli(): Server sent charset (255) unknown to the client.
Product: Red Hat Enterprise Linux 7 Reporter: Karel Volný <kvolny>
Component: phpAssignee: Remi Collet <rcollet>
Status: CLOSED CURRENTRELEASE QA Contact: RHEL Stacks Subsystem QE <rhel-stacks-subsystem-qe>
Severity: unspecified Docs Contact: Lenka Špačková <lkuprova>
Priority: unspecified    
Version: 7.6CC: jorton, lkuprova, pasik, rcollet
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Known Issue
Doc Text:
.The `php-mysqlnd` database connector does not work with MySQL 8.0 The default character set has been changed to `utf8mb4` in MySQL 8.0 but this character set is unsupported by the `php-mysqlnd` database connector. Consequently, `php-mysqlnd` fails to connect in the default configuration. To work around this problem, specify a known character set as a parameter of the MySQL server configuration. For example, modify the `/etc/opt/rh/rh-mysql80/my.cnf.d/mysql-server.cnf` file to read: ---- [mysqld] character-set-server=utf8 ----
 Story Points: ---
Clone Of: Environment:
Last Closed: 2020-06-17 11:05:47 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Karel Volný 2018-11-05 09:38:42 UTC 
Description of problem:
PHP mysql fails to connect to MySQL 8 in default configuration due to change of default charset to utf8mb4.

Version-Release number of selected component (if applicable):
php-mysqlnd-5.4.16-46.el7.x86_64

How reproducible:
always

Steps to Reproduce:
1. install rh-mysql80 collection and stock php-mysqlnd
2. start mysql server
3. try to connect to mysql from php via mysqli functions

Actual results:
PHP Warning:  mysqli::mysqli(): Server sent charset (255) unknown to the client. Please, report to the developers in /mnt/tests/CoreOS/mysql/Security/CVE-2010-1848-mysql-multiple-insufficient-table-name-checks/CVE-2010-1848-mysqli.php on line 11
PHP Warning:  mysqli::mysqli(): (HY000/2054): Server sent charset unknown to the client. Please, report to the developers in /mnt/tests/CoreOS/mysql/Security/CVE-2010-1848-mysql-multiple-insufficient-table-name-checks/CVE-2010-1848-mysqli.php on line 11
Failed to connect to DB: Server sent charset unknown to the client. Please, report to the developers

Expected results:
(no such problem)

Additional info:
see https://bugs.php.net/bug.php?id=74461
Comment 3 Remi Collet 2019-05-29 09:22:48 UTC 
doc text looks good to me, as this a the simple way.

BTW, charset can also be set from PHP using "mysqli_set_charset" function.
Comment 5 Joe Orton 2020-06-17 11:05:47 UTC 
This issue is resolved in PHP 7.x in RHEL8.