Unable to parse unknown SET query: SET max_heap_table_size = 1024 * 1024 * 64

[lurkie]

When performing the query SET max_heap_table_size = 1024 * 1024 * 64 a warning message in the log appears:

2020-04-16 14:44:04 MySQL_Session.cpp:7204:unable_to_parse_set_statement(): [WARNING] Unable to parse unknown SET query from client 1.2.3.4:32958. Setting lock_hostgroup. Please report a bug for future enhancements:SET max_heap_table_size = 1024 * 1024 * 64

First, I thought it was due to the expression after the equals-sign, but replacing it with the calculated value does not prevent the warning. Also, using := or = does not differ.

ProxySQL version: 2.0.10
OS: Ubuntu 18.04.4

Reporting this as requested in the warning message. Although there are other issues reported regarding unable_to_parse_set_statement, I could not find issues related to this specific variable nor about assigning an expression.

[renecannao]

Thank you for the report.
I would like your feedback on this.
Which one would you prefer?
a) proxysql to not return any warning (or convert it into an INFO), and just disable multiplexing on that connection
b) proxysql to track max_heap_table_size , and ensure that each client/server connection has the value correctly set

Because max_heap_table_size is a variable rarely used by many application, I think the cost of option B is not justified, and we should implement A .

Thoughts?

[lurkie]

My use case is ETL with some long-running queries generating large temporary tables. For this process, I just want multiplexing disabled. Option A will be my choice as well. Personally, I am not interested in any message about this, so just removing the warning would be my preference.

After some fiddling yesterday, I can conclude that next to max_heap_table_size three other variables generate the same warning: tmp_table_size, group_concat_max_len, and long_query_time. I would like to remove the warning for these as well and just disable multiplexing.

[renecannao]

Thank you for the input.

• group_concat_max_len : I actually think this should be tracked
• long_query_time : this should be tracked too. Yet, proxysql's administrators should be able to filter this request

[ByJacob]

Hi,

Meaby issue is old, but i want add some set commands which give errors:

ProxySQL 2.5.5
Mariadb 10.4
Magento2 2.4.2

[ERROR] Unable to parse query. If correct, report it as a bug: SET SESSION max_heap_table_size = 21168000;
[ERROR] Unable to parse query. If correct, report it as a bug: SET SESSION tmp_table_size = 21168000;

[renecannao]

Hi @ByJacob .

ProxySQL is able to track both max_heap_table_size and tmp_table_size from quite long time.
The bug is related to trailing semicolon at the end of the SET statement:t herefore this issue is a duplicate of #4369, #4380 and #4453 , all solved in PR #4385 , and ProxySQL 2.6 will be released very soon.

Unless you have any objection, I will proceed closing this ticket.

[ByJacob]

In my opinion, you can close.

Just one question, when can we expect ProxySQL 2.6, because I am also waiting for another feature - #4137

[renecannao]

Thanks, closing.

2.6 will be released very soon, we are finalizing few more details