test(dm): fix using pgrep to check argument pattern

[lance6716]

Signed-off-by: lance6716 lance6716@gmail.com

What problem does this PR solve?

Issue Number: close #6526, close #5731, close #5287

What is changed and how it works?

• we use kill_process dm-worker1 in test script, and finally it will become pgrep dm-worker1. This is not right because dm-worker1 is in arguments and pgrep only check process name.
• old problems, same root cause but different case as flaking test ALTER TABLE shardddl.tb ADD COLUMN new_col1 INT DEFAULT -1 #5807
• after syncer processes RowsEvent, check_sync_diff will pass, but XIDEvent may have not been written to relay log. We retry checking for 5 seconds.

Check List

Tests

• Integration test
• Manual test (add detailed scripts or steps below)

# lance @ lance6716-nuc10i7fnh in ~/go/src/github.com/pingcap/tiflow on git:master o [14:31:49] 
$ pgrep -f dm-worker1     
467807

# lance @ lance6716-nuc10i7fnh in ~/go/src/github.com/pingcap/tiflow on git:master x [14:32:09] 
$ pgrep dm-worker1                                       

Questions

Will it cause performance regression or break compatibility?

Do you need to update user documentation, design documentation or monitoring documentation?

Release note

 `None`.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• D3Hunter
• GMHDBJD

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[lance6716]

/cc @GMHDBJD @buchuitoudegou @D3Hunter

[lance6716]

/check-issue-triage-complete

[lance6716]

/run-verify

[lance6716]

/run-dm-integration-test

[GMHDBJD]

LGTM

[lance6716]

/hold

[lance6716]

/run-dm-integration-test

[lance6716]

/unhold

[lance6716]

/run-dm-integration-test

[lance6716]

/merge

[ti-chi-bot]

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

Commit hash: e98b946

[lance6716]

/run-dm-integration-test

[ti-chi-bot]

@lance6716: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

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.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[lance6716]

/run-all-tests

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6584.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6585.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6586.

[ti-chi-bot]

In response to a cherrypick label: new pull request created: #6587.