[IMPALA-5720] FunctionContext::*Allocate*() should use TryAllocate() instead of Allocate().

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: Impala 2.10.0
• Component/s: Backend
• Labels: incompatibility resource-management
• Target Version: Product Backlog
• Epic Color: ghx-label-7
• Assignee: Unassigned
• Reporter: Tim Armstrong
• Created: 25/Jul/17 18:41
• Updated: 09/Apr/18 01:54

Description

Currently the UDF interface uses Allocate(), which only returns NULL if malloc() fails. We should switch it to use TryAllocate() instead so that the query stays within the memory limit.

We should consider this a breaking change because existing UDFs and UDAs may not tolerate Allocate() returning NULL very well, and this would make it more frequent.

I would like to get this in soon, but put it behind a flag so that it can optionally be enabled.

Issue Links

• is related to: IMPALA-3304 Aggregations do not always spill when exprs use large amount of memory