BlobStore support multipath.

[jiaqizho]

What problem does this PR solve?

Issue Number: ref #3594

Problem Summary:

What is changed and how it works?

• support multipath in blobstore.

I'm not sure if multipath needs to be supported in this way. What I mean is that the upper layer may change the table storage or DT may combine log/meta/data into single PageStorage.

But if we still do multipathing in the old way, this PR is fine. Just need to wait for #3908 merged and change some details of this PR.

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• JaySon-Huang
• lidezhu

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[jiaqizho]

@JaySon-Huang @lidezhu PTAL

[JaySon-Huang]

some small comments

[JaySon-Huang]

LGTM with some small polish https://github.com/jiaqizho/tiflash/pull/10

[lidezhu]

LGTM

[jiaqizho]

/merge

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@jiaqizho: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

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[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 38eb316

[jiaqizho]

/merge

[ti-chi-bot]

@jiaqizho: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and if the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 2cea4bb

[sre-bot]

Coverage for changed files

Filename                                            Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Storages/Page/V3/BlobFile.cpp                            29                10    65.52%           6                 1    83.33%          84                27    67.86%          16                 8    50.00%
Storages/Page/V3/BlobFile.h                               2                 0   100.00%           2                 0   100.00%           6                 0   100.00%           0                 0         -
Storages/Page/V3/BlobStore.cpp                          374               113    69.79%          39                 3    92.31%         818               209    74.45%         240                90    62.50%
Storages/Page/V3/BlobStore.h                              7                 1    85.71%           7                 1    85.71%          25                10    60.00%           0                 0         -
Storages/Page/V3/PageStorageImpl.cpp                     80                22    72.50%          21                 7    66.67%         194                62    68.04%          44                23    47.73%
Storages/Page/V3/tests/gtest_blob_store.cpp            3589               596    83.39%          17                 0   100.00%         694                 0   100.00%        1114               525    52.87%
Storages/Page/V3/tests/gtest_page_directory.cpp        8833              1575    82.17%          50                 0   100.00%        1635                 7    99.57%        2774              1405    49.35%
Storages/PathPool.cpp                                   370               144    61.08%          77                28    63.64%         744               250    66.40%         214               103    51.87%
Storages/PathPool.h                                      14                 3    78.57%          14                 3    78.57%          16                 3    81.25%           0                 0         -
Storages/tests/gtest_path_pool.cpp                     1371               208    84.83%          13                 0   100.00%         358                 9    97.49%         466               203    56.44%
TestUtils/MockDiskDelegator.h                            22                 6    72.73%          20                 5    75.00%          59                12    79.66%           2                 1    50.00%
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                 14691              2678    81.77%         266                48    81.95%        4633               589    87.29%        4870              2358    51.58%

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
17069      9587             43.83%    192089  97178        49.41%

full coverage report (for internal network access only)

[lidezhu]

It seems we need to pass parent_path instead of path when call functions like addPageFileUsedSize in PageStorage V3, otherwise it's hard to make PSDiskDelegatorRaft compatible for both V2 and V3. @jiaqizho /cc @JaySon-Huang

[JaySon-Huang]

Yes, I found this bug and fix it in my branch

[JaySon-Huang]

It seems we need to pass parent_path instead of path when call functions like addPageFileUsedSize in PageStorage V3, otherwise it's hard to make PSDiskDelegatorRaft compatible for both V2 and V3.

will be fixed in #4540