svn commit: r1181545 - /hbase/branches/0.89/bin/region_status.rb

[ns...@apache.org]

Author: nspiegelberg
Date: Tue Oct 11 02:18:35 2011
New Revision: 1181545

URL: http://svn.apache.org/viewvc?rev=1181545&view=rev
Log:
List HBase Region availability

Summary:
One critical feature necessary to completely automate
production pushes is the ability to recognize when HBase has
successfully made all regions available for reads/writes (step prior to
HBCK).  Created script to display region availability status and stall
until all onlined regions are actually available.

Test Plan:
- bin/hbase org.jruby.Main bin/region_status.rb wait

Reviewed By: kannan
Reviewers: alasla, kannan
CC: , kannan, nspiegelberg
Differential Revision: 261179

Added:
    hbase/branches/0.89/bin/region_status.rb

Added: hbase/branches/0.89/bin/region_status.rb
URL: http://svn.apache.org/viewvc/hbase/branches/0.89/bin/region_status.rb?rev=1181545&view=auto
==============================================================================
--- hbase/branches/0.89/bin/region_status.rb (added)
+++ hbase/branches/0.89/bin/region_status.rb Tue Oct 11 02:18:35 2011
@@ -0,0 +1,96 @@
+# View the current status of all regions on an HBase cluster.  This is
+# predominantly used to determined if all the regions in META have been
+# onlined yet on startup.
+#
+# To use this script, run:
+#
+#  ${HBASE_HOME}/bin/hbase org.jruby.Main region_status.rb [wait]
+
+SHOULD_WAIT=ARGV[0] == 'wait'
+
+if ARGV[0] and not SHOULD_WAIT
+  print "USAGE: #{$0} [wait] \n"
+  exit 1
+end
+
+require 'java'
+
+import org.apache.hadoop.hbase.HBaseConfiguration
+import org.apache.hadoop.hbase.HConstants
+import org.apache.hadoop.hbase.MasterNotRunningException
+import org.apache.hadoop.hbase.client.HBaseAdmin
+import org.apache.hadoop.hbase.client.HTable
+import org.apache.hadoop.hbase.client.Scan
+import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter
+import org.apache.hadoop.hbase.util.Bytes
+import org.apache.hadoop.hbase.util.Writables
+
+# disable debug logging on this script for clarity
+log_level = org.apache.log4j.Level::ERROR
+org.apache.log4j.Logger.getLogger("org.apache.zookeeper").setLevel(log_level)
+org.apache.log4j.Logger.getLogger("org.apache.hadoop.hbase").setLevel(log_level)
+
+config = HBaseConfiguration.create
+config.set 'fs.default.name', config.get(HConstants::HBASE_DIR)
+
+# wait until the master is running
+admin = nil
+while true
+  begin
+    admin = HBaseAdmin.new config
+    break
+  rescue MasterNotRunningException => e
+    print 'Waiting for master to start...\n'
+    sleep 1
+  end
+end
+
+meta_count = 0
+server_count = 0
+
+# scan META to see how many regions we should have
+scan = Scan.new
+scan.cache_blocks = false
+scan.caching = 10
+scan.setFilter(FirstKeyOnlyFilter.new)
+INFO = 'info'.to_java_bytes
+REGION_INFO = 'regioninfo'.to_java_bytes
+scan.addColumn INFO, REGION_INFO
+table = nil
+iter = nil
+while true
+  begin
+    table = HTable.new config, '.META.'.to_java_bytes
+    scanner = table.getScanner(scan)
+    iter = scanner.iterator
+    break
+  rescue IOException => ioe
+    print "Exception trying to scan META: #{ioe}"
+    sleep 1
+  end
+end
+while iter.hasNext
+  row = iter.next
+  region = Writables.getHRegionInfo row.getValue(INFO, REGION_INFO)
+  if not region.isOffline
+    # only include regions that should be online
+    meta_count += 1
+  end
+end
+scanner.close
+# META count does not include the -ROOT- and .META. regions *doh*
+meta_count += 2
+
+# query the master to see how many regions are on region servers
+while true
+  server_count = admin.getClusterStatus().getRegionsCount()
+  print "Region Status: #{server_count} / #{meta_count}\n"
+  if SHOULD_WAIT and server_count < meta_count
+    #continue this loop until server & meta count match
+    sleep 10
+  else
+    break
+  end
+end
+
+exit server_count == meta_count ? 0 : 1