It's also strange that the first two rows have the same value for c79.
That is extremely unlikely.  I can dig in more tomorrow.

- Dan

On Mon, Oct 3, 2016 at 10:53 PM, Dan Burkert <[email protected]> wrote:

> The first three rows (including the out of order row) all fall in the same
> range partition, so the issue is likely that the intra-tablet scan returned
> out of order results (as opposed to the client scanning tablets out of
> order). I'm under the same impression about SetFaultTolerant(), which is
> why the test explicitly sets it.  How often is this happening? Back when
> this test was committed a few months ago I ran it a few thousand times and
> never saw anything like this.
>
> On Mon, Oct 3, 2016 at 10:35 PM, Todd Lipcon <[email protected]> wrote:
>
>> Hey Dan (+CC dev in case anyone else knows about this too)
>>
>> I'm debugging some flakiness in alter_table-randomized-test, and ti seems
>> like it's failing because the verification scan is returning some out of
>> order rows, despite using "SetFaultTolerant()". Granted, fault tolerance
>> isn't publicly guaranteed to return rows in order, but I was under the
>> impression that, with range partitioned tablets, it would always do so.
>>
>> The scan result I'm seeing has the following sequence within it:
>>
>> (int32 key=537424064, int32 c945=NULL, int32 c79=234639860, int32
>> c990=NULL)
>> >>>> OUT OF ORDER ROW
>> (int32 key=552025439, int32 c945=NULL, int32 c79=234639860, int32
>> c990=NULL)
>> >>>> BACK TO NORMAL ORDER
>> (int32 key=539314778, int32 c945=1708089980, int32 c79=-878787336, int32
>> c990=829302644)
>> (int32 key=541817227, int32 c945=2064952224, int32 c79=2064952224, int32
>> c990=NULL)
>> (int32 key=546056206, int32 c945=26527696, int32 c79=26527696, int32
>> c990=26527696)
>> (int32 key=601960253, int32 c945=NULL, int32 c79=1088757503, int32
>> c990=NULL)
>> (int32 key=677154987, int32 c945=823764490, int32 c79=823764490, int32
>> c990=823764490)
>>
>> The prior alter was:
>> I1004 05:17:48.192611 28113 alter_table-randomized-test.cc:481] Dropping
>> range partition: [805306356, 872415219) resulting partitions: (134217726,
>> 201326589], (268435452, 335544315], (335544315, 402653178], (402653178,
>> 469762041], (536870904, 603979767], (671088630, 738197493], (738197493,
>> 805306356], (939524082, 1006632945], (1006632945, 1073741808], (1275068397,
>> 1342177260], (1342177260, 1409286123], (1409286123, 1476394986],
>> (1610612712, 1677721575], (1879048164, 1946157027], (2013265890,
>> 2080374753], (2080374753, 2147483616)
>> I1004 05:17:48.193013 28113 alter_table-randomized-test.cc:406]
>> Committing Alterations
>>
>> The whole log is available here:
>> https://gist.githubusercontent.com/toddlipcon/466976caf973f4
>> 96885da9efc2f7246c/raw/f9baf418dad4ad07f33961b131c86e8480381
>> 5a8/alter_table-randomized-test.txt
>>
>> Any ideas what might be causing this out-of-order result? Is the test
>> making some incorrect assumptions or might we have a bug?
>>
>> -Todd
>>
>>
>>
>>
>>
>>
>> --
>> Todd Lipcon
>> Software Engineer, Cloudera
>>
>
>

Reply via email to