HBASE-18412 [Shell] Support unset of list of configuration for a table (Yun Zhao)

hbase-shell/src/main/ruby/hbase/admin.rb

@@ -657,6 +657,23 @@ module Hbase
               htd.remove(name)
             end
             hasTableUpdate = true
+          # Unset table configuration
+          elsif method == 'table_conf_unset'
+            raise(ArgumentError, 'NAME parameter missing for table_conf_unset method') unless name
+            if name.is_a?(Array)
+              name.each do |key|
+                if htd.getConfigurationValue(key).nil?
+                  raise ArgumentError, "Could not find configuration: #{key}"
+                end
+                htd.removeConfiguration(key)
+              end
+            else
+              if htd.getConfigurationValue(name).nil?
+                raise ArgumentError, "Could not find configuration: #{name}"
+              end
+              htd.removeConfiguration(name)
+            end
+            hasTableUpdate = true
           # Unknown method
           else
             raise ArgumentError, "Unknown method: #{method}"

hbase-shell/src/main/ruby/shell/commands/alter.rb

@@ -71,6 +71,10 @@ You can also set configuration settings specific to this table or column family:
   hbase> alter 't1', CONFIGURATION => {'hbase.hregion.scan.loadColumnFamiliesOnDemand' => 'true'}
   hbase> alter 't1', {NAME => 'f2', CONFIGURATION => {'hbase.hstore.blockingStoreFiles' => '10'}}
 
+You can also unset configuration settings specific to this table:
+
+  hbase> alter 't1', METHOD => 'table_conf_unset', NAME => 'hbase.hregion.majorcompaction'
+
 You can also remove a table-scope attribute:
 
   hbase> alter 't1', METHOD => 'table_att_unset', NAME => 'MAX_FILESIZE'

hbase-shell/src/test/ruby/hbase/admin_test.rb

@@ -480,6 +480,36 @@ module Hbase
       assert_no_match(eval("/" + key_2 + "/"), admin.describe(@test_name))
     end
 
+    define_test "alter should be able to remove a table configuration" do
+      drop_test_table(@test_name)
+      create_test_table(@test_name)
+
+      key = "TestConf"
+      command(:alter, @test_name, CONFIGURATION => {key => 1})
+
+      # eval() is used to convert a string to regex
+      assert_match(eval("/" + key + "/"), admin.describe(@test_name))
+
+      command(:alter, @test_name, 'METHOD' => 'table_conf_unset', 'NAME' => key)
+      assert_no_match(eval("/" + key + "/"), admin.describe(@test_name))
+    end
+
+    define_test "alter should be able to remove a list of table configuration" do
+      drop_test_table(@test_name)
+
+      key_1 = "TestConf1"
+      key_2 = "TestConf2"
+      command(:create, @test_name, { NAME => 'i'}, CONFIGURATION => { key_1 => 1, key_2 => 2 })
+
+      # eval() is used to convert a string to regex
+      assert_match(eval("/" + key_1 + "/"), admin.describe(@test_name))
+      assert_match(eval("/" + key_2 + "/"), admin.describe(@test_name))
+
+      command(:alter, @test_name, 'METHOD' => 'table_conf_unset', 'NAME' => [ key_1, key_2 ])
+      assert_no_match(eval("/" + key_1 + "/"), admin.describe(@test_name))
+      assert_no_match(eval("/" + key_2 + "/"), admin.describe(@test_name))
+    end
+
     define_test "get_table should get a real table" do
       drop_test_table(@test_name)
       create_test_table(@test_name)