HBASE-22735 : list_regions show basic info for region currently in transition with error handling

Author: virajjasani

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

@@ -79,7 +79,6 @@ def command(table_name, options = nil, cols = nil)
           raise "#{cols} must be an array of strings. Possible values are SERVER_NAME, REGION_NAME, START_KEY, END_KEY, SIZE, REQ, LOCALITY."
         end
 
-        error = false
         admin_instance = admin.instance_variable_get('@admin')
         conn_instance = admin_instance.getConnection
         cluster_status = org.apache.hadoop.hbase.ClusterStatus.new(admin_instance.getClusterMetrics)
@@ -105,17 +104,20 @@ def command(table_name, options = nil, cols = nil)
           regions.each do |hregion|
             hregion_info = hregion.getRegion
             server_name = hregion.getServerName
-            region_load_map = cluster_status.getLoad(server_name).getRegionsLoad
+            server_load = cluster_status.getLoad(server_name)
+            if server_load.nil?
+              region_load_map = java.util.HashMap.new
+            else
+              region_load_map = server_load.getRegionsLoad
+            end
             region_load = region_load_map.get(hregion_info.getRegionName)
 
             if region_load.nil?
-              puts "Can not find region: #{hregion_info.getRegionName} , it may be disabled or in transition\n"
-              error = true
-              break
+              puts "Can not find all details for region: #{hregion_info.getRegionNameAsString.strip} , it may be disabled or in transition\n"
+            else
+              # Ignore regions which exceed our locality threshold
+              next unless accept_region_for_locality? region_load.getDataLocality, locality_threshold
             end
-
-            # Ignore regions which exceed our locality threshold
-            next unless accept_region_for_locality? region_load.getDataLocality, locality_threshold
             result_hash = {}
 
             if size_hash.key?('SERVER_NAME')
@@ -141,19 +143,31 @@ def command(table_name, options = nil, cols = nil)
             end
 
             if size_hash.key?('SIZE')
-              region_store_file_size = region_load.getStorefileSizeMB.to_s.strip
+              if region_load.nil?
+                region_store_file_size = ''
+              else
+                region_store_file_size = region_load.getStorefileSizeMB.to_s.strip
+              end
               result_hash.store('SIZE', region_store_file_size)
               size_hash['SIZE'] = [size_hash['SIZE'], region_store_file_size.length].max
             end
 
             if size_hash.key?('REQ')
-              region_requests = region_load.getRequestsCount.to_s.strip
+              if region_load.nil?
+                region_requests = ''
+              else
+                region_requests = region_load.getRequestsCount.to_s.strip
+              end
               result_hash.store('REQ', region_requests)
               size_hash['REQ'] = [size_hash['REQ'], region_requests.length].max
             end
 
             if size_hash.key?('LOCALITY')
-              locality = region_load.getDataLocality.to_s.strip
+              if region_load.nil?
+                locality = ''
+              else
+                locality = region_load.getDataLocality.to_s.strip
+              end
               result_hash.store('LOCALITY', locality)
               size_hash['LOCALITY'] = [size_hash['LOCALITY'], locality.length].max
             end
@@ -166,8 +180,6 @@ def command(table_name, options = nil, cols = nil)
 
         @end_time = Time.now
 
-        return if error
-
         size_hash.each do |param, length|
           printf(" %#{length}s |", param)
         end