Changes between Initial Version and Version 1 of waue/2010/0128

Timestamp:

Jan 28, 2010, 9:22:21 PM (15 years ago)

Author:

waue

Comment:

--

waue/2010/0128

@@ +1 @@
+{{{
+#!html
+<div style="text-align: center; color:#151B8D"><big style="font-weight: bold;"><big><big>
+HBase Indexed Table
+</big></big></big></div> <div style="text-align: center; color:#7E2217"><big style="font-weight: bold;"><big>
+Using HBase TableIndexed from Thrift with unique keys
+</big></big></div>
+}}}
+[[PageOutline]]
+
+[http://kdpeterson.net/blog/2009/09/using-hbase-tableindexed-from-thrift-with-unique-keys.html]
+
+HBase is primarily a sorted distributed hash map, but it does support secondary keys through a contrib package called Transactional HBase. The secondary keys are provided by a component called TableIndexed.
+
+
+
+
+= Secondary indexes in HBase =
+[http://rajeev1982.blogspot.com/2009/06/secondary-indexes-in-hbase.html]
+
+{{{
+#!java
+import java.io.IOException;
+import java.util.Date;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.client.Scanner;
+import org.apache.hadoop.hbase.client.tableindexed.IndexSpecification;
+import org.apache.hadoop.hbase.client.tableindexed.IndexedTable;
+import org.apache.hadoop.hbase.client.tableindexed.IndexedTableAdmin;
+import org.apache.hadoop.hbase.filter.ColumnValueFilter;
+import org.apache.hadoop.hbase.filter.ColumnValueFilter.CompareOp;
+import org.apache.hadoop.hbase.io.BatchUpdate;
+import org.apache.hadoop.hbase.io.RowResult;
+import org.apache.hadoop.hbase.util.Bytes;
+
+public class SecondaryIndexTest {
+    public void writeToTable() throws IOException {
+        HBaseConfiguration conf = new HBaseConfiguration();
+        conf.addResource(new Path("/opt/hbase-0.19.3/conf/hbase-site.xml"));
+
+        IndexedTable table = new IndexedTable(conf, Bytes.toBytes("test_table"));
+
+        String row = "test_row";
+        BatchUpdate update = null;
+
+        for (int i = 0; i < 100; i++) {
+            update = new BatchUpdate(row + i);
+            update.put("columnfamily1:column1", Bytes.toBytes("value1-" + i));
+            update.put("columnfamily1:column2", Bytes.toBytes("value2-" + i));
+            table.commit(update);
+        }
+
+        table.close();
+    }
+
+    public void readAllRowsFromSecondaryIndex() throws IOException {
+        HBaseConfiguration conf = new HBaseConfiguration();
+        conf.addResource(new Path("/opt/hbase-0.19.3/conf/hbase-site.xml"));
+
+        IndexedTable table = new IndexedTable(conf, Bytes.toBytes("test_table"));
+
+        Scanner scanner = table.getIndexedScanner("column1",
+            HConstants.EMPTY_START_ROW, null, null, new byte[][] {
+            Bytes.toBytes("columnfamily1:column1"),
+                Bytes.toBytes("columnfamily1:column2") });
+
+        for (RowResult rowResult : scanner) {
+            System.out.println(Bytes.toString(
+                rowResult.get(Bytes.toBytes("columnfamily1:column1")).getValue())
+                + ", " + Bytes.toString(rowResult.get(
+                Bytes.toBytes("columnfamily1:column2")).getValue()
+                ));
+        }
+
+        table.close();
+    }
+
+    public void readFilteredRowsFromSecondaryIndex() throws IOException {
+        HBaseConfiguration conf = new HBaseConfiguration();
+        conf.addResource(new Path("/opt/hbase-0.19.3/conf/hbase-site.xml"));
+
+        IndexedTable table = new IndexedTable(conf, Bytes.toBytes("test_table"));
+
+        ColumnValueFilter filter = 
+            new ColumnValueFilter(Bytes.toBytes("columnfamily1:column1"), 
+            CompareOp.LESS, Bytes.toBytes("value1-40"));
+
+        Scanner scanner = table.getIndexedScanner("column1", 
+            HConstants.EMPTY_START_ROW, null, filter, 
+            new byte[][] { Bytes.toBytes("columnfamily1:column1"),
+                Bytes.toBytes("columnfamily1:column2")
+            });
+
+        for (RowResult rowResult : scanner) {
+            System.out.println(Bytes.toString(
+                rowResult.get(Bytes.toBytes("columnfamily1:column1")).getValue())
+                + ", " + Bytes.toString(rowResult.get(
+                Bytes.toBytes("columnfamily1:column2")).getValue()
+                ));
+        }
+
+        table.close();
+    }
+
+    public void createTableWithSecondaryIndexes() throws IOException {
+        HBaseConfiguration conf = new HBaseConfiguration();
+        conf.addResource(new Path("/opt/hbase-0.19.3/conf/hbase-site.xml"));
+
+        HTableDescriptor desc = new HTableDescriptor("test_table");
+
+        desc.addFamily(new HColumnDescriptor("columnfamily1:column1"));
+        desc.addFamily(new HColumnDescriptor("columnfamily1:column2"));
+
+        desc.addIndex(new IndexSpecification("column1",
+            Bytes.toBytes("columnfamily1:column1")));
+        desc.addIndex(new IndexSpecification("column2",
+            Bytes.toBytes("columnfamily1:column2")));
+
+        IndexedTableAdmin admin = null;
+        admin = new IndexedTableAdmin(conf);
+
+        if (admin.tableExists(Bytes.toBytes("test_table"))) {
+            if (admin.isTableEnabled("test_table")) {
+                admin.disableTable(Bytes.toBytes("test_table"));
+            }
+
+            admin.deleteTable(Bytes.toBytes("test_table"));
+        }
+
+        if (admin.tableExists(Bytes.toBytes("test_table-column1"))) {
+            if (admin.isTableEnabled("test_table-column1")) {
+                admin.disableTable(Bytes.toBytes("test_table-column1"));
+            }
+
+            admin.deleteTable(Bytes.toBytes("test_table-column1"));
+        }
+
+        admin.createTable(desc);
+    }
+
+    public void addSecondaryIndexToExistingTable() throws IOException {
+        HBaseConfiguration conf = new HBaseConfiguration();
+        conf.addResource(new Path("/opt/hbase-0.19.3/conf/hbase-site.xml"));
+
+        IndexedTableAdmin admin = null;
+        admin = new IndexedTableAdmin(conf);
+
+        admin.addIndex(Bytes.toBytes("test_table"), 
+            new IndexSpecification("column2", 
+            Bytes.toBytes("columnfamily1:column2")));
+    }
+
+    public void removeSecondaryIndexToExistingTable() throws IOException {
+        HBaseConfiguration conf = new HBaseConfiguration();
+        conf.addResource(new Path("/opt/hbase-0.19.3/conf/hbase-site.xml"));
+
+        IndexedTableAdmin admin = null;
+        admin = new IndexedTableAdmin(conf);
+
+        admin.removeIndex(Bytes.toBytes("test_table"), "column2");
+    }
+
+    public static void main(String[] args) throws IOException {
+        SecondaryIndexTest test = new SecondaryIndexTest();
+
+        test.createTableWithSecondaryIndexes();
+        test.writeToTable();
+        test.addSecondaryIndexToExistingTable();
+        test.removeSecondaryIndexToExistingTable();
+        test.readAllRowsFromSecondaryIndex();
+        test.readFilteredRowsFromSecondaryIndex();
+
+        System.out.println("Done!");
+    }
+}
+}}}