CDC Server support data-dir (#1879)

[ti-chi-bot]

This is an automated cherry-pick of #1879

What problem does this PR solve?

This PR makes TiCDC support --data-dir at the server level.

What is changed and how it works?

• --data-dir is supported at the server level, default to "", if not set, it will be set by conditions:
  • if there is no other changefeed, /tmp/cdc_data will be set as default data-dir
  • if there is any changefeed with the --sort-dir set, choose the valid one with the largest available space as data-dir.
    • if there are no candidates who meet the requirement, server start failed
• --sort-dir set at both server level and changefeed level won't take effect, and default to /tmp/sorter, this means it can not be changed by both command flag or config file
  • sort dir of the server and changefeed will be set as /{data-dir}/tmp/sorter
• during server running, if the available space is lower than 10% of the disk, serve running will fail, due to trying to consume disk space (create new sort temporary file)
• warning user when set data dir and space unavailable.

Check List

Tests

• Unit test

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation
• Need to update key monitor metrics in both TiCDC document and official document

Release note

[ben1009]

@3AceShowHand seems there are conflicts need taking care of

[CLAassistant]

All committers have signed the CLA.

[3AceShowHand]

/run-all-tests

[amyangfei]

/run-integration-tests

[3AceShowHand]

/run-all-tests

[3AceShowHand]

/run-all-tests

[3AceShowHand]

/run-integration-tests
/run-kafka-integration-tests

[codecov-commenter]

Codecov Report

Merging #2069 (da7fc0a) into release-4.0 (753073a) will decrease coverage by 1.0862%.
The diff coverage is 57.5713%.

@@                 Coverage Diff                 @@
##           release-4.0      #2069        +/-   ##
===================================================
- Coverage      53.7661%   52.6799%   -1.0862%     
===================================================
  Files              153        165        +12     
  Lines            15958      17631      +1673     
===================================================
+ Hits              8580       9288       +708     
- Misses            6475       7365       +890     
- Partials           903        978        +75     

[3AceShowHand]

/run-all-tests

[3AceShowHand]

/run-all-tests

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• amyangfei
• overvenus

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[amyangfei]

/merge

[ti-chi-bot]

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

Commit hash: ec0c9de

[3AceShowHand]

/run-unit-tests
/run-leak-tests
/run-kafka-tests