SERVER-6352 Add sh.removeTagRange

Adding the removeTagRange helper to match addTagRange with some informational warnings that do not stop the operation from happening.

Note: does not address the fact that no feedback is given to indicate work done, or lack of work done (must check config.tags manually for results).
      This is also the case for addTagRange.

Closes mongodb#709

Signed-off-by: Benety Goh <[email protected]>

Author: comerford

jstests/sharding/tag_range.js

@@ -0,0 +1,34 @@
+// tests to make sure that tag ranges are added/removed/updated successfully
+
+s = new ShardingTest( "tag_range" , 2 , 0 , 1 , { nopreallocj : true } );
+
+// this set up is not required but prevents warnings in the remove
+db = s.getDB( "tag_range" );
+
+s.adminCommand( { enableSharding : "test" } )
+s.adminCommand( { shardCollection : "test.tag_range" , key : { _id : 1 } } );
+
+assert.eq( 1 , s.config.chunks.count() );
+
+sh.addShardTag( "shard0000" , "a" )
+
+// add two ranges, verify the additions
+
+sh.addTagRange( "test.tag_range" , { _id : 5 } , { _id : 10 } , "a" );
+sh.addTagRange( "test.tag_range" , { _id : 10 } , { _id : 15 } , "b" );
+
+assert.eq( 2 , s.config.tags.count() , "tag ranges were not successfully added" );
+
+// remove the second range, should be left with one
+
+sh.removeTagRange( "test.tag_range" , { _id : 10 } , { _id : 15 } , "b" );
+
+assert.eq( 1 , s.config.tags.count() , "tag range not removed successfully" );
+
+// the additions are actually updates, so you can alter a range's max
+sh.addTagRange( "test.tag_range" , { _id : 5 } , { _id : 11 } , "a" );
+
+assert.eq( 11 , s.config.tags.findOne().max._id , "tag range not updated successfully" );
+
+s.stop();
+

src/mongo/shell/utils_sh.js

@@ -47,6 +47,7 @@ sh.help = function() {
     print( "\tsh.addShardTag(shard,tag)                 adds the tag to the shard" );
     print( "\tsh.removeShardTag(shard,tag)              removes the tag from the shard" );
     print( "\tsh.addTagRange(fullName,min,max,tag)      tags the specified range of the given collection" );
+    print( "\tsh.removeTagRange(fullName,min,max,tag)   removes the tagged range of the given collection" );
 
     print( "\tsh.status()                               prints a general overview of the cluster" )
 }
@@ -351,3 +352,19 @@ sh.addTagRange = function( ns, min, max, tag ) {
             true );
     sh._checkLastError( config );    
 }
+
+sh.removeTagRange = function( ns, min, max, tag ) {
+    var config = db.getSisterDB( "config" );
+    // warn if the namespace does not exist, even dropped
+    if ( config.collections.findOne( { _id : ns } ) == null ) {
+        print( "Warning: can't find the namespace: " + ns + " - collection likely never sharded" );
+    }
+    // warn if the tag being removed is still in use
+    if ( config.shards.findOne( { tags : tag } ) ) {
+        print( "Warning: tag still in use by at least one shard" );
+    }
+    // max and tag criteria not really needed, but including them avoids potentially unexpected
+    // behavior.
+    config.tags.remove( { _id : { ns : ns , min : min } , max : max , tag : tag } );
+    sh._checkLastError( config );
+}