MySQL Bugs: #79922: valid query_cache_size value being adjusted to 4294966272 even on 64 bit systems

Bug #79922	valid query_cache_size value being adjusted to 4294966272 even on 64 bit systems
Submitted:	12 Jan 2016 0:36	Modified:	7 Jul 2017 9:09
Reporter:	Charlie Sain	Email Updates:
Status:	Won't fix	Impact on me:	None
Category:	MySQL Server: Query Cache	Severity:	S2 (Serious)
Version:	5.1,5.5, 5.6,5.7,8.0	OS:	Windows (Windows 10 (hyper-v instance))
Assigned to:		CPU Architecture:	Any
Tags:	query_cache_size adjusted to 4294966272

Description:
Large, but valid, query_cache_size values are being adjusted down when MySQL server 5.7.10 starts. 

Exact error log message for my instance:
[Warning] option 'query_cache_size': unsigned value 17179869184 adjusted to 4294966272

This value, and larger values, run under 5.6x without issue.

How to repeat:
Set query_cache_size value in a large value in the .ini file and start server.

thanks for the report.  Verified on windows.

[Warning] option 'query_cache_size': unsigned value 12884901888 adjusted to 4294966272
Version: '5.7.11'  socket: ''  port: 3306  MySQL Community Server (GPL)

5.1.73, 5.5.47, 5.6.28, 5.7.11, 5.8.0 are all affected here.

for what it's worth, having a query cache larger than 4GB is not recommended for most installations.

Posted by developer:
 
Reported version value updated to reflect release name change from 5.8 to 8.0

MySQL will no longer invest in the query cache, see:

http://mysqlserverteam.com/mysql-8-0-retiring-support-for-the-query-cache/

https://bugs.mysql.com/bug.php?id=93385 marked as duplicate of this one.

don't have a solution ?

i have big number of websites with myisam with static queries, 192GB of ram to use on query cache, and simple: Oracle not will fix the BUG ?

Charlie,

>This value, and larger values, run under 5.6x without issue.

what's mysql 5.6x version you have running more than 4GB on query_cache_size ?