[SegmentV2] Change the default storage format to SegmentV2

[morningman]

Proposed changes

Since the Segment V2 has been released for a long time, we should make it as default storage format for newly created table.

This CL mainly changes:

1. For all newly created tables, their default storage format is Segment V2.
2. For all already exist tablets, their storage format remain unchanged.
3. Fix bugs described in Fix [Bug][SparkLoad] Spark load will create rowset with incorrect rowset type #4384 and Fix [Bug] tablet type in tablet meta is wrong #4385

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• I have create an issue on (Fix [SegmentV2] Change the default storage format to SegmentV2  #4386), and have described the bug/feature there in detail
• Compiling and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• If this change need a document change, I have updated the document
• Any dependent changes have been merged

Further comments

We should provide a more friendly way to check the conversion progress of Segment V2

[yangzhg]

Why not change the default value of config default_rowset_type in common/config.h to BETA

[morningman]

Why not change the default value of config default_rowset_type in common/config.h to BETA

Modifying this config will cause BE to automatically convert all existing data.
In fact, this is a very bad design because it is completely uncontrollable. . .
But since we have released this feature in version 0.12, even if we make changes, we cannot change the status quo.

I will add some explain in document.

[yangzhg]

Why not change the default value of config default_rowset_type in common/config.h to BETA

Modifying this config will cause BE to automatically convert all existing data.
In fact, this is a very bad design because it is completely uncontrollable. . .
But since we have released this feature in version 0.12, even if we make changes, we cannot change the status quo.

I will add some explain in document.

We will change it to BETA in 0.13？
the real default is BETA but the value in config says default is ALPHA this it too werid

[morningman]

Why not change the default value of config default_rowset_type in common/config.h to BETA

Modifying this config will cause BE to automatically convert all existing data.
In fact, this is a very bad design because it is completely uncontrollable. . .
But since we have released this feature in version 0.12, even if we make changes, we cannot change the status quo.
I will add some explain in document.

We will change it to BETA in 0.13？
the real default is BETA but the value in config says default is ALPHA this it too werid

yes, but I can't find a good way to solve it. I think we can just leave it and explain it in document.

[EmmyMiao87]

Should we remove the config of storage format in BE?

[morningman]

Should we remove the config of storage format in BE?

Can not. Because some user already use it.

[EmmyMiao87]

LGTM