[HBASE-3443] ICV optimization to look in memstore first and then store files (HBASE-3082) does not work when deletes are in the mix - ASF JIRA

Voters

Watch issue

Watchers

Create sub-task

Link

Clone

Update Comment Author

Replace String in Comment

Update Comment Visibility

Delete Comments

XML

Word

Printable

JSON

Details

Type: Bug
Status: Closed
Priority: Critical
Resolution: Fixed
Affects Version/s: 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: 0.94.0, 0.95.0
Component/s: regionserver
Labels:
- corruption

Hadoop Flags:

Reviewed
Release Note:

Hide
This is a correctness fix and will incur a 10-20% performance penalty for ICV and Increment operations. Other operations are not affected.

Show
This is a correctness fix and will incur a 10-20% performance penalty for ICV and Increment operations. Other operations are not affected.

Description

For incrementColumnValue() ~~HBASE-3082~~ adds an optimization to check memstores first, and only if not present in the memstore then check the store files. In the presence of deletes, the above optimization is not reliable.

If the column is marked as deleted in the memstore, one should not look further into the store files. But currently, the code does so.

Sample test code outline:

admin.createTable(desc)

table = HTable.new(conf, tableName)

table.incrementColumnValue(Bytes.toBytes("row"), cf1name, Bytes.toBytes("column"), 5);

admin.flush(tableName)
sleep(2)

del = Delete.new(Bytes.toBytes("row"))
table.delete(del)

table.incrementColumnValue(Bytes.toBytes("row"), cf1name, Bytes.toBytes("column"), 5);

get = Get.new(Bytes.toBytes("row"))
keyValues = table.get(get).raw()
keyValues.each do |keyValue|
  puts "Expect 5; Got Value=#{Bytes.toLong(keyValue.getValue())}";
end