> On Jul 24, 2015, at 9:17 AM, Leif Hedstrom <[email protected]> wrote:
>
>>
>> On Jul 24, 2015, at 9:11 AM, Leif Hedstrom <[email protected]> wrote:
>>
>>>
>>> On Jul 24, 2015, at 3:16 AM, Susan Hinrichs
>>> <[email protected]> wrote:
>>>
>>> Hello,
>>>
>>> Another latent cross-thread race condition has become very active in our
>>> environment (TS-3797). Given that we just spent time within the last month
>>> squashing another cross thread race condition (TS-3486) that was active in
>>> several environments, Alan and I would like to step back and try to reduce
>>> the cross thread impact of the global session pools.
>>>
>>> I wrote up our thoughts and plan for implementation. Given that threading
>>> and race conditions are always tricky, I'd appreciate more eyes looking for
>>> flaws in our approach or suggestions for alternatives.
>>>
>>> https://cwiki.apache.org/confluence/display/TS/Threading+Issues+And+NetVC+Migration
>>
>>
>>
>> My gut reaction to this is that this makes our efforts for NUMA / thread
>> affinity very, very difficult to achieve. The goal is to avoid memory
>> migrating cross NUMA sockets, to avoid QPI traffic. This would encourage the
>> opposite unless I misread it ? It also obviously violates the original
>> design goals, where VCs do *not* migrate.
>
>
> Also, William Bardwell made an attempt to do these VC migrations long ago,
> and it did not work well. That was in fact the reason why the per-thread
> session pools where implemented.
>
> See the patches / discussions on
>
> https://issues.apache.org/jira/browse/TS-880
And
https://issues.apache.org/jira/browse/TS-924
— Leif
