Hi all，
向社区求助一个HBase的scan异常导致RS宕机的问题，异常日志如下：
2023-01-19 03:19:06,986 ERROR
[RpcServer.default.RWQ.Fifo.scan.handler=226,queue=19,port=60020]
ipc.RpcServer: Unexpected throwable object
java.lang.RuntimeException: Cached block contents differ, which should not
have happened.cacheKey:bbec4ed53b6d475cbb8711f183556eb0_14145152
at
org.apache.hadoop.hbase.io.hfile.BlockCacheUtil.validateBlockAddition(BlockCacheUtil.java:205)
at
org.apache.hadoop.hbase.io.hfile.BlockCacheUtil.shouldReplaceExistingCacheBlock(BlockCacheUtil.java:237)
at
org.apache.hadoop.hbase.io.hfile.bucket.BucketCache.shouldReplaceExistingCacheBlock(BucketCache.java:432)
at
org.apache.hadoop.hbase.io.hfile.bucket.BucketCache.cacheBlockWithWait(BucketCache.java:417)
at
org.apache.hadoop.hbase.io.hfile.bucket.BucketCache.cacheBlock(BucketCache.java:403)
at
org.apache.hadoop.hbase.io.hfile.CombinedBlockCache.cacheBlock(CombinedBlockCache.java:68)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.lambda$readBlock$2(HFileReaderImpl.java:1528)
at java.util.Optional.ifPresent(Optional.java:159)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl.readBlock(HFileReaderImpl.java:1526)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl$HFileScannerImpl.readNextDataBlock(HFileReaderImpl.java:928)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl$HFileScannerImpl.isNextBlock(HFileReaderImpl.java:1061)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl$HFileScannerImpl.positionForNextBlock(HFileReaderImpl.java:1055)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl$HFileScannerImpl._next(HFileReaderImpl.java:1073)
at
org.apache.hadoop.hbase.io.hfile.HFileReaderImpl$HFileScannerImpl.next(HFileReaderImpl.java:1094)
at
org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseekAtOrAfter(StoreFileScanner.java:351)
at
org.apache.hadoop.hbase.regionserver.StoreFileScanner.reseek(StoreFileScanner.java:244)
at
org.apache.hadoop.hbase.regionserver.NonLazyKeyValueScanner.doRealSeek(NonLazyKeyValueScanner.java:55)
at
org.apache.hadoop.hbase.regionserver.KeyValueHeap.generalizedSeek(KeyValueHeap.java:324)
at
org.apache.hadoop.hbase.regionserver.KeyValueHeap.reseek(KeyValueHeap.java:267)
at
org.apache.hadoop.hbase.regionserver.StoreScanner.reseek(StoreScanner.java:1099)
at
org.apache.hadoop.hbase.regionserver.StoreScanner.seekAsDirection(StoreScanner.java:1088)
at
org.apache.hadoop.hbase.regionserver.StoreScanner.seekOrSkipToNextColumn(StoreScanner.java:823)
at
org.apache.hadoop.hbase.regionserver.StoreScanner.next(StoreScanner.java:730)
at
org.apache.hadoop.hbase.regionserver.KeyValueHeap.next(KeyValueHeap.java:157)
at
org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.populateResult(HRegion.java:6681)
at
org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextInternal(HRegion.java:6845)
at
org.apache.hadoop.hbase.regionserver.HRegion$RegionScannerImpl.nextRaw(HRegion.java:6615)
at
org.apache.hadoop.hbase.regionserver.RSRpcServices.scan(RSRpcServices.java:3238)
at
org.apache.hadoop.hbase.regionserver.RSRpcServices.scan(RSRpcServices.java:3483)
at
org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos$ClientService$2.callBlockingMethod(ClientProtos.java:42278)
at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:379)
at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:133)
at
org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:338)
at
org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:318)
对应的源码（2.2.6）：
public static int validateBlockAddition(Cacheable existing, Cacheable newBlock,
BlockCacheKey cacheKey) {
int comparison = compareCacheBlock(existing, newBlock, false);
if (comparison != 0) {
throw new RuntimeException(
"Cached block contents differ, which should not have happened."
+ "cacheKey:" + cacheKey);
}
if ((existing instanceof HFileBlock) && (newBlock instanceof HFileBlock)) {
comparison = ((HFileBlock) existing).getNextBlockOnDiskSize()
- ((HFileBlock) newBlock).getNextBlockOnDiskSize();
}
return comparison;
}
scan操作的缓存置换过程中，触发了一个未捕获的RunTime异常，导致RS突然宕机，请教一下，什么情况会触发此异常，然后如何避免此异常的发生呢？
