[Improvement][AQE] Sort MapId before the data are flushed about incubator-uniffle HOT 17 CLOSED

Do we need to sort data by MapID of one partition before flushing data for all jobs? I think no. This will bring unused cost for those non-AQE optimized stages. Maybe we could sort the partition data by MapId when AQE's specified ShufflePartitionSpec is applied in first time.

from incubator-uniffle.

You are right.

from incubator-uniffle.

Do u have implemented this in your internal version? If not, I'm interested on this. @jerqi

from incubator-uniffle.

No. You can go ahead.

from incubator-uniffle.

I propose the design of this issue. https://docs.google.com/document/d/1G0cOFVJbYLf2oX1fiadh7zi2M6DlEcjTQTh4kSkb0LA/edit?usp=sharing

PTAL @jerqi

from incubator-uniffle.

It's better to sort MapId before the data are flushed.It won't bring too much cost for non-AQE optimized stages.

from incubator-uniffle.

It's better to sort MapId before the data are flushed.It won't bring too much cost for non-AQE optimized stages.

Does data need to sort by mapId?

from incubator-uniffle.

It's better to sort MapId before the data are flushed.It won't bring too much cost for non-AQE optimized stages.

Does data need to sort by mapId?

Yes, we only need local order. If we have local order, we can filter much data effectively.

from incubator-uniffle.

It's better to sort MapId before the data are flushed.It won't bring too much cost for non-AQE optimized stages.

Does data need to sort by mapId?

Yes, we only need local order. If we have local order, we can filter much data effectively.

Emm... I remember you prefer only sort the index-file instead of data-file, which is mentioned in offline meeting. Do i misunderstand you?

from incubator-uniffle.

It's better to sort MapId before the data are flushed.It won't bring too much cost for non-AQE optimized stages.

Does data need to sort by mapId?

Yes, we only need local order. If we have local order, we can filter much data effectively.

Emm... I remember you prefer only sort the index-file instead of data-file, which is mentioned in offline meeting. Do i misunderstand you?

Give an example:
We have three buffers to flush, they taskId 1 block, taskId 2 block, taskId 3 block. We should sort them to taskId 1 block, taskId 2 block, taskId 3 block. And then we can flush them to disks.Then we receive taskId 2 block, taskId 6 block, taskId 1 block, we sort them and flush them, so currently the data on the disk should be
taskId 1 block , taskId 2 block, taskId 3 block, taskId 1 block, taskId 2 block, taskId 6 block.
The data only have local order.

from incubator-uniffle.

taskId-1 block , taskId-2 block, taskId-3 block, taskId-1 block, taskId-2 block, taskId-6 block.

If one reader want the data from taskId=1, so it still want to read the data segment from taskId-1 block , taskId-2 block, taskId-3 block, taskId-1 block. The data of taskId-2 block, taskId-3 block is unnecessary for this reader. Right?

from incubator-uniffle.

taskId-1 block , taskId-2 block, taskId-3 block, taskId-1 block, taskId-2 block, taskId-6 block.

If one reader want the data from taskId=1, so it still want to read the data segment from taskId-1 block , taskId-2 block, taskId-3 block, taskId-1 block. The data of taskId-2 block, taskId-3 block is unnecessary for this reader. Right?

Yes.

from incubator-uniffle.

This looks ineffective and it's the same with the original block filter.

from incubator-uniffle.

This looks ineffective and it's the same with the original block filter.

Actually considering random io, It will cost the same time when you read 3 records or 2 records.

from incubator-uniffle.

This looks ineffective and it's the same with the original block filter.

Actually considering random io, It will cost the same time when you read 3 records or 2 records.

Yes. According to the problems mentioned by proposal design motivation section, the key point is a lot of data read by multiple times which depends on split number optimized by AQE. From this view, we should sort the data file.

from incubator-uniffle.

This looks ineffective and it's the same with the original block filter.

Actually considering random io, It will cost the same time when you read 3 records or 2 records.

Yes. According to the problems mentioned by proposal design motivation section, the key point is a lot of data read by multiple times which depends on split number optimized by AQE. From this view, we should sort the data file.

We don't need global order, local order should be enough.

from incubator-uniffle.

#293

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