server: fix data race in RaftCluster #1272
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Would you explain more details of what's wrong before and how does this PR fix it? |
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Do we need to backport it to 2.1 and 2.0 branch? |
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@disksing I‘m not sure how much impact it will cause, since it happens rarely. |
nolouch
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Oct 16, 2018
| @@ -27,6 +27,8 @@ import ( | |||
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| // HandleRegionHeartbeat processes RegionInfo reports from client. | |||
| func (c *RaftCluster) HandleRegionHeartbeat(region *core.RegionInfo) error { | |||
| c.RLock() | |||
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this lock is in the hot path, can we bench it or remove it?
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@disksing After running a benchmark, it doesn't have much impact on performance. |
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What problem does this PR solve?
When the leader drops which could be caused by some reasons (e.g. cannot read from disk), it will elect a new leader which will call
createRaftClusterto reassigncachedCluster,coordinatorandrunninginRaftCluster. At that time, if we readRaftClusterwithout lock, the data race may happens. This PR closes #1270.What is changed and how it works?
This PR adds some locks when reading from
cachedClusterandcoordinatorin order to prevent reading and writingRaftClusterat the same time.Check List
Tests
Related changes