[HBASE-10321] CellCodec has broken the 96 client to 98 server compatibility

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.98.0
• Fix Version/s: 0.98.0, 0.99.0
• Hadoop Flags: Reviewed
• Release Note: A new Codec CellCodecV2 is added which can do all the work of CellCodec plus writing/reading Tags. CellCodec will not be able to handle tags. When one wants to use CellCodec and tags need to use CellCodecV2.
• Assignee: Anoop Sam John
• Reporter: Anoop Sam John
• Created: 12/Jan/14 06:46
• Updated: 21/Feb/15 23:31
• Resolved: 13/Jan/14 17:32

Description

The write/read tags added in CellCodec has broken the 96 client to 98 server compatibility (and 98 client to 96 server)
When 96 client CellCodec writes cell, it won't write tags part at all. But the server expects a tag part, at least a 0 tag length. This tag length read will make a read of some bytes from next cell!

I suggest we can remove the tag part from CellCodec. This codec is not used by default and I don't think some one will change to CellCodec from the default KVCodec now. ..

This makes tags not supported via CellCodec..Tag support can be added to CellCodec once we have Connection negotiation in place