[MDEV-7481] Replace max_long_data_size functionality with max_allowed_packet Created: 2015-01-19  Updated: 2020-03-13  Resolved: 2019-09-28

Status: Closed
Project: MariaDB Server
Component/s: OTHER
Fix Version/s: 10.5.0

Type: Task Priority: Blocker
Reporter: Geoff Montee (Inactive) Assignee: Sergei Golubchik
Resolution: Fixed Votes: 2
Labels: 10.5-beta, upstream

Attachments: Text File mariadb_10_1_supersize_repl.txt    

 Description   

According to documentation, max_long_data_size is still present in MariaDB:

https://mariadb.com/kb/en/mariadb/documentation/managing-mariadb/optimization-and-tuning/system-variables/server-system-variables/#max_long_data_size

This variable was removed in Oracle's MySQL 5.6, and it's functionality was replaced with max_allowed_packet:

http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_max_long_data_size

Is there any reason to keep max_long_data_size in MariaDB? Some users think it should be removed.

 Comments   
Comment by Daniël van Eeden [ 2015-07-19 ]

I used this to test this:
https://github.com/dveeden/mysql_supersize/blob/master/C/supersize.c

max_allowed_packet can be 1GB
max_long_data_size can be 4GB

So if you want to insert (in chunks) more than 1G you need this variable.

Comment by Daniël van Eeden [ 2015-07-20 ]

Note that for max_allowed_packet < transaction < max_long_data_size this will break replication and point-in-time restore based on binlogs. So this setting is dangerous on systems with binlog enabled.

Comment by Daniël van Eeden [ 2015-07-20 ]

It happens both when master uses SBR and RBR:

                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'log event entry exceeded max_allowed_packet; Increase max_allowed_packet on master; the first event '.' at 4, the last event read from 'mysql-bin.000006' at 1000000917, the last byte read from 'mysql-bin.000006' at 1000000936.'
 

                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'log event entry exceeded max_allowed_packet; Increase max_allowed_packet on master; the first event 'mysql-bin.000001' at 312, the last event read from 'mysql-bin.000005' at 1000000898, the last byte read from 'mysql-bin.000005' at 1000000917.'

This is with master and slave with max_allowed_packet = 1G.

Comment by Ian Gilfillan [ 2016-07-21 ]

This is still listed as deprecated, and in practice set to max_allowed_packet, so perhaps 10.2 is a good time to remove it?

Comment by Daniel Black [ 2018-01-01 ]

As this deprecated option survived another full major release perhaps 10.3 is a time to remove it?

Generated at Thu Feb 08 07:19:55 UTC 2024 using Jira 8.20.16#820016-sha1:9d11dbea5f4be3d4cc21f03a88dd11d8c8687422.