Re: [Tarantool-patches] [PATCH v3] memtx: fix out of memory handling for rtree

[Olga Arkhangelskaia <arkholga@tarantool.org>]

On 19/12/2019 17:14, Konstantin Osipov wrote:
> * Olga Arkhangelskaia <arkholga@tarantool.org> [19/12/19 16:44]:
>> When tarantool tries to recover rtree from a snapshot and memtx_memory value
>> is lower than it has been when the snapshot was created, server suffers from
>> segmentation fault. This happens because there is no out of memory error
>> handling in rtree lib. In another words, we do not check the result of
>> malloc operation.
>> The execution flow in case of recovery uses different way and the secondary
>> keys are build in batches. There is no separate implementations for rtree of
>> build_next function. And the way with no checks and reservation is used
>> (insex_replace). The patch adds memtx_rtree_build_next implementation to
>> check and insert keys. Although this gives us no additional optimization as in
>> case of memtx_tree, the memory reservation prevents tarantool from segmentation
>> fault.
>> If there is not enough memory to be reserved - server will fail
>> gently with the "Failed to allocate" error message.
> Why not add memtx_index_extent_reserve() to
> generic_index_build_next(), this would be a shorter version which
> does the same thing?
>
>
I can't agree - everything that has memtx_ should be in memtx, because 
generic is used by vinyl, and sysview.

And the only way I see do it generic - is to use index_reserve? Did you 
mean index_reserve, that has  memtx_index_extent_reserve( inside?

In this case it is not shorter.