schedule: fix scheduler removes region leader (#1462) #1469
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* schedule: fix scheduler removes region leader Signed-off-by: disksing <i@disksing.com>
disksing
added
type/bug
|
/run-all-tests tidb=release-2.1 tikv=release-2.1 tidb-test=release-2.1 |
nolouch
approved these changes
Mar 20, 2019
rleungx
approved these changes
Mar 20, 2019
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What problem does this PR solve?
Normally, PD avoids removing leader directly when scheduling. When the leader needs to be removed, the PD inserts a transfer leader step. However, when the number of replica is set to 1, this scheme does not attempt to transfer the leader to the peer that will be created, resulting in the direct remove of the leader.
What is changed and how it works?
Constructs a list based on the current peers and the peer to be added, then looks for the target of the transferLeader in the list. If target is not found, it returns an error to cancel the schedule process.
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