Retry when store is down in high layer (#2710)

[ti-chi-bot]

This is an automated cherry-pick of #2710

What problem does this PR solve?

#2705

What is changed and how it works?

1. when the store is unreachable or null, invalid cache and retry.

This enhancement will fix this situation: voter down and TiSpark fail

2. catch the exception thrown by splitrange and retry

This enhancement will fix this situation: pd leader down and the region get from pd will be null then an exception will be thrown. According to the implementation of client-java, the switch leader needs to get members from pd, when it requests the down pd, it takes spark.tispark.grpc.timeout_in_sec(180s in default)*2 to retry, which may block the leader switch for spark.tispark.grpc.timeout_in_sec(180s in default)*2 s

Check List

Tests

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

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 the tidb-ansible repository
• Need to be included in the release note

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• shiyuhang0
• zhangyangyu

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[shiyuhang0]

/run-all-tests

[shiyuhang0]

/run-all-tests

[shiyuhang0]

/merge

[ti-chi-bot]

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

Commit hash: 64b45e2