rg's memory_limit value

[Wenru Yan]

Hello, everyone. After we redesign the memory control of resource group, we set rg’s memory_limit as the rg’s max available memory. And there is a controversy about the memory_limit’s value. Currently I have set memory_limit ‘s value default to -1 for resource groups which doesn’t set memory_limit when create or system resource groups, and in this case we will simply use statement_mem as the query’s memory limit, it’s just like the resourece queue. 

Is it ok? Or we should set a specified value (such as like 1000mb) as the memory_limit’s default value?

the pr link: https://github.com/greenplum-db/gpdb/pull/15030

show memory_limit information in gp_toolkit.gp_resgroup_config view by yanwr1 · Pull Request #15030 · greenplum-db/gpdb since commit c25db0c support resgroup with memory_limit, adds it to gp_resgroup_config view. Here are some reminders before you submit the pull request Add tests for the change Document changes ... github.com

[Ivan Novick]

My perception is we will not encourage customers to use -1 and statement_mem, but leave that option as an override just in case they want to use it that why. 

Another option is to make memory_limit mandatory setting when creating a resource group, to force the user to consider a reasonable value.  What do you think on that idea?

Ivan

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Sent: Thursday, March 2, 2023 6:12 PM
To: gpdb...@greenplum.org <gpdb...@greenplum.org>
Subject: rg's memory_limit value

 

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