inconsistent behaviour with GetApproximateSizes ?

[benoitc]

GetApproximateSizes can return from time to time "0", when expected size is > 6000 bytes for 1 range when including both files and memtables. I'm passing to the function an array of ranges:

 uint64_t sizes[num_ranges];
 db_ptr->m_Db->GetApproximateSizes(column_family, ranges, num_ranges, sizes, flag);

where ranges have been initialised like this:

rocksdb::Range *ranges = new rocksdb::Range[num_ranges];
    while (...)
    {
      ...
            ranges[j].start = start;
            ranges[j].limit = limit;
            j++;
       ...
    }

Full code : https://gitlab.com/barrel-db/erlang-rocksdb/blob/master/c_src/erocksdb_db.cc#L1301-1381

The test is doing similar to the one in db_test.cc . Is this expected?

[benoitc]

Current theory is that the data has been written in SST files. But then i'm confused about what means include_files there. Shouldn't it return also the size?

The unit test is actually a port of the ApproximateSizesMemTable test in db_tests.cc in erlang. I am not sure what I'm missing.

Full ticket related : https://gitlab.com/barrel-db/erlang-rocksdb/issues/72

[benoitc]

is there anything i should check? This error comes often dring our unit tests, and it's not good to restart them to fix it...

[benoitc]

closing issue as it's not enough described IMO. I will reopen a more descriptive one.