Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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None
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None
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None
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Reviewed
Description
We discovered this in our work on upgrading from ~1.2.0 to 2.4.6. A 1.2.0 client will submit an Increment, without specifying a timestamp. This should be translated as LATEST_TIMESTAMP, but an hbase 2 server will store it with a timestamp of 0.
This is because the QualifierValue timestamp proto field is optional, and is not set in branch-1 MutationProtos: https://github.com/apache/hbase/blob/branch-1/hbase-client/src/main/java/org/apache/hadoop/hbase/protobuf/RequestConverter.java#L218-L219. In branch-1, the timestamp is actually ignored entirely: https://github.com/apache/hbase/blob/branch-1/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L8435-L8456. So this is not an issue there.
As of HBASE-18546, the timestamp is no longer ignored, but the usage of QualiferValue.getTimestamp() in deserialization is not wrapped in a .hasTimestamp() call: https://github.com/apache/hbase/blob/7d8dc3524981a04e82ff236bb3dc18d36ebc82b4/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java#L886-L909. The default value for non-present optionals is defined by the underlying primitive, so for longs that is 0. Since the Increment's timestamp is now respected by HRegion, it causes the erroneous 0 value to be stored: https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java#L4180 (updateLatestStamp only overwrites the cell timestamp if it's LATEST_TIMESTAMP, which in this case it has been deserialized as 0)
I think this might only apply to clients who do not use a KeyValueCodec.