[HBASE-3170] RegionServer confused about empty row keys

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.89.20100621, 0.89.20100924, 0.90.0, 0.90.1, 0.90.2, 0.90.3, 0.90.4, 0.90.5, 0.90.6, 0.92.0, 0.92.1
• Fix Version/s: 0.95.0
• Component/s: regionserver
• Hadoop Flags: Reviewed
• Release Note: If no row specified by a Get, we no longer return first row in the table. Now we fail.
• Assignee: Devaraj Das
• Reporter: Benoit Sigoure
• Created: 29/Oct/10 18:23
• Updated: 23/Sep/13 18:30
• Resolved: 21/Jan/13 20:12

Description

I'm no longer sure about the expected behavior when using an empty row key (e.g. a 0-byte long byte array). I assumed that this was a legitimate row key, just like having an empty column qualifier is allowed. But it seems that the RegionServer considers the empty row key to be whatever the first row key is.

Version: 0.89.20100830, r0da2890b242584a8a5648d83532742ca7243346b, Sat Sep 18 15:30:09 PDT 2010

hbase(main):001:0> scan 'tsdb-uid', {LIMIT => 1}
ROW                           COLUMN+CELL                                                                          
 \x00                         column=id:metrics, timestamp=1288375187699, value=foo      
 \x00                         column=id:tagk, timestamp=1287522021046, value=bar         
 \x00                         column=id:tagv, timestamp=1288111387685, value=qux      
1 row(s) in 0.4610 seconds

hbase(main):002:0> get 'tsdb-uid', ''
COLUMN                        CELL                                                                                 
 id:metrics                   timestamp=1288375187699, value=foo                         
 id:tagk                      timestamp=1287522021046, value=bar                         
 id:tagv                      timestamp=1288111387685, value=qux                      
3 row(s) in 0.0910 seconds

hbase(main):003:0> get 'tsdb-uid', "\000"
COLUMN                        CELL                                                                                 
 id:metrics                   timestamp=1288375187699, value=foo                         
 id:tagk                      timestamp=1287522021046, value=bar                         
 id:tagv                      timestamp=1288111387685, value=qux                      
3 row(s) in 0.0550 seconds

This isn't a parsing problem with the command-line of the shell. I can reproduce this behavior both with plain Java code and with my asynchbase client.

Since I don't actually have a row with an empty row key, I expected that the first get would return nothing.