Re: Connections from mysql8.0 to mysql5.1 - bad handshake

Hi Jim,

On 10/31/2018 7:12 PM, Halaasz Saandor wrote:
> 2018/10/31 15:15 ... Jim:
>> Given the following bug report, what I am trying to do does not sound
>> hopeful:
>> https://bugs.mysql.com/bug.php?id=90994
>>
> ...
>>
>> Any thoughts or do I need to accept that what I'm attempting just
>> isn't going to work?
>
>  From the same bug report, id=90994:
>
> [24 Oct 20:17] Brad Jackson
>
> Version 8.0.13 was released on 10/22 and the change list says:
>
> "Support for MySQL 5.5 by MySQL Workbench 8.0 was removed. If you still
> need to use MySQL Workbench on a MySQL 5.5 server, you can use MySQL
> Workbench 6.3"
>
> I guess we're all stuck on the old version until we upgrade our servers.
>

Halaasz is on the right track.

As a client (which is what a replication slave really is), MySQL 8.0 
doesn't know how to login to a 5.1 server. Those old handshakes have 
been retired.

We only maintain connection compatibility with the "previous version" 
which, relative to 8.0, is 5.7 . Older versions may work, but it isn't 
guaranteed.

You could, potentially, set up replication chain like this....
5.1 -> (is a master of) 5.5 -> 5.6 -> 5.7 -> 8.0

But then you would need to worry if your table definitions (we have 
deprecated and removed some data types since 5.1 was the "current 
version") are even legal in 8.0.  Other language features, like command 
syntaxes, also evolve over time.

There's a lot of deprecation history you will need to worry about. 
Something that is legal to replicate from 5.1 -> 5.5 may no longer be 
legal between 5.5 and 5.6 because 5.5 may have been the last version for 
which that feature was supported.  You may be better off with a 
lift-and-shift upgrade to try to establish a copy of your non-system 
tables and other objects (like stored procedures or views) in an empty 
initialized 8.0 server.  Then you can use a set of 8.0 CREATE USER and 
GRANT commands (you can't use naked GRANT commands to create accounts 
any longer. That feature was deprecated and removed in earlier versions) 
to populate your 8.0 server with user accounts.

Once you reach that stage, you are ready to start testing copies of your 
applications against 8.0 to see what else will need to be updated (such 
as the library you use to connect to MySQL).  Moving from 5.1 to 8.0 is 
a big shift, you potentially have a lot of work ahead of you.


Yours,

-- 
Shawn Green
MySQL Senior Principal Technical Support Engineer
Oracle USA, Inc. - Integrated Cloud Applications & Platform Services
Office: Blountville, TN

Become certified in MySQL! Visit https://www.mysql.com/certification/ 
for details.

-- 
MySQL General Mailing List
For list archives: http://lists.mysql.com/mysql
To unsubscribe:    http://lists.mysql.com/mysql