svn commit: r1181922 - /hbase/branches/0.89/bin/remove_table_from_meta.rb

[ns...@apache.org]

Author: nspiegelberg
Date: Tue Oct 11 17:42:08 2011
New Revision: 1181922

URL: http://svn.apache.org/viewvc?rev=1181922&view=rev
Log:
Checking in Kannan's script clean_meta.rb as remove_table_from_meta.rb

Summary: We need Kannan's clean_meta.rb script for our HBase DR recovery
workflow. I renamed it to remove_table_from_meta.rb for clarity, since it only
removes one table.
Test Plan: Run it on a 5-node cluster.
Reviewed By: nspiegelberg
Reviewers: kranganathan, madhuvaidya, nspiegelberg
Commenters: madhuvaidya
CC: , hbase@lists, bhiller, madhuvaidya, nspiegelberg, mbautin
Revert Plan: OK
Differential Revision: 297233

Added:
    hbase/branches/0.89/bin/remove_table_from_meta.rb   (with props)

Added: hbase/branches/0.89/bin/remove_table_from_meta.rb
URL: http://svn.apache.org/viewvc/hbase/branches/0.89/bin/remove_table_from_meta.rb?rev=1181922&view=auto
==============================================================================
--- hbase/branches/0.89/bin/remove_table_from_meta.rb (added)
+++ hbase/branches/0.89/bin/remove_table_from_meta.rb Tue Oct 11 17:42:08 2011
@@ -0,0 +1,116 @@
+#!/usr/bin/env hbase-jruby
+#
+# Copyright 2011 The Apache Software Foundation
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Script adds a table back to a running hbase.
+# Currently only works on if table data is in place.
+#
+# To see usage for this script, run:
+#
+#  ${HBASE_HOME}/bin/hbase org.jruby.Main remove_table_from_meta.rb
+#
+
+include Java
+import org.apache.hadoop.hbase.util.Bytes
+import org.apache.hadoop.hbase.HConstants
+import org.apache.hadoop.hbase.regionserver.HRegion
+import org.apache.hadoop.hbase.HRegionInfo
+import org.apache.hadoop.hbase.client.HTable
+import org.apache.hadoop.hbase.client.Delete
+import org.apache.hadoop.hbase.client.Put
+import org.apache.hadoop.hbase.client.Scan
+import org.apache.hadoop.hbase.HTableDescriptor
+import org.apache.hadoop.hbase.HBaseConfiguration
+import org.apache.hadoop.hbase.util.FSUtils
+import org.apache.hadoop.hbase.util.Writables
+import org.apache.hadoop.fs.Path
+import org.apache.hadoop.fs.FileSystem
+import org.apache.commons.logging.LogFactory
+
+# Name of this script
+NAME = "remove_table_from_meta"
+
+# Print usage for this script
+def usage
+  puts 'Usage: %s.rb TABLE_NAME' % NAME
+  puts
+  puts 'CAUTION: this script is extremely dangerous!'
+  puts
+  puts 'This script deletes all mentions of the given table name from the'
+  puts 'META table. Make sure to disable the table before running this'
+  puts 'script. Disabling the table, running this script, and removing the'
+  puts 'table directory from HDFS effectively drops the table.'
+  exit!
+end
+
+# Get configuration to use.
+c = HBaseConfiguration.new()
+
+# Set hadoop filesystem configuration using the hbase.rootdir.
+# Otherwise, we'll always use localhost though the hbase.rootdir
+# might be pointing at hdfs location.
+c.set("fs.default.name", c.get(HConstants::HBASE_DIR))
+fs = FileSystem.get(c)
+
+# Get a logger and a metautils instance.
+LOG = LogFactory.getLog(NAME)
+
+# Check arguments
+if ARGV.size != 1
+  usage
+end
+
+# Get table name
+tableName = ARGV[0]
+
+HTableDescriptor.isLegalTableName(tableName.to_java_bytes)
+
+puts 'Assuming the table has been disabled. If not, do not proceed.'
+puts ('Delete all occurrences of the table ' + tableName +
+      ' from .META.? [y/N]')
+answer = STDIN.gets().strip()
+if answer != 'y' && answer != 'Y'
+  exit!
+end
+
+# Clean mentions of table from .META.
+# Scan the .META. and remove all lines that begin with tablename
+LOG.info("Deleting mention of " + tableName + " from .META.")
+metaTable = HTable.new(c, HConstants::META_TABLE_NAME)
+tableNameMetaPrefix = tableName + HConstants::META_ROW_DELIMITER.chr
+scan = Scan.new((tableNameMetaPrefix +
+                HConstants::META_ROW_DELIMITER.chr).to_java_bytes)
+scanner = metaTable.getScanner(scan)
+
+# Use java.lang.String doing compares.  Ruby String is a bit odd.
+tableNameStr = java.lang.String.new(tableName)
+while (result = scanner.next())
+  rowid = Bytes.toString(result.getRow())
+  rowidStr = java.lang.String.new(rowid)
+  if not rowidStr.startsWith(tableNameMetaPrefix)
+    # Gone too far, break
+    break
+  end
+  LOG.info("Found row in catalog: " + rowid)
+  LOG.info("Deleting row from catalog: " + rowid);
+  d = Delete.new(result.getRow())
+  metaTable.delete(d)
+end
+
+scanner.close()

Propchange: hbase/branches/0.89/bin/remove_table_from_meta.rb
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