A large query triggers oom, help

[lazzyfu]

hi:
When the query returns a large amount of data, it will trigger the system's OOM。The proxysql process will be killed。
This issue exists in the following versions.

• proxysql 1.4.15
• proxysql 2.0.3

This should be because proxysql receives data faster than the client consumes.
I executed a query with about 20 million data volumes.

As shown below：

I adjusted the parameter mysql-throttle_max_bytes_per_second_to_client and it didn't work.

I read the relevant questions, but did not solve them, ask for advice, thank you

[lazzyfu]

Online, thank you

[renecannao]

Is the query using binary protocol (prepared statement) or text protocol?

[lazzyfu]

hi.
He is a go program, should be using prepared statement，thanks.

[lazzyfu]

I am using this package
https://github.com/jmoiron/sqlx
thanks

[renecannao]

If the client is using prepared statements, currently proxysql cannot throttle traffic.
It will fetch all the resultset before sending it to the client.

I think we need to introduce a new variable to define how much data can be buffered before aborting the request.

[lazzyfu]

I am looking forward to this parameter, thanks.
Is there an improved plan?

It should be session level

[winmutt]

Can you clarify the limitation that requires the need to return the full dataset?