Updated trigger example

patch by Mike Adamson; reviewed by Aleksey Yeschenko for CASSANDRA-10257

CHANGES.txt

@@ -1,4 +1,5 @@
 3.0.1
+ * Updated trigger example (CASSANDRA-10257)
 Merged from 2.2:
  * (Hadoop) ensure that Cluster instances are always closed (CASSANDRA-10058)
 Merged from 2.1:

examples/triggers/README.txt

@@ -1,11 +1,8 @@
-Cassandra Trigger's Example:
-=========================
+Cassandra Trigger Example:
+==========================
 
-InvertedIndex class will create a inverted index of 
-RowKey:ColumnName:Value to Value:ColumnName:RowKey
-
-NOTE: This example is limited to append-only workloads, 
-	  doesn't delete indexes on deletes. 
+The AuditTrigger class will create a basic audit of
+activity on a table.
 
 Installation:
 ============
@@ -13,9 +10,27 @@ change directory to <cassandra_src_dir>/examples/triggers
 run "ant jar"
 Copy build/trigger-example.jar to <cassandra_conf>/triggers/
 Copy conf/* to <cassandra_home>/conf/
-Create column family configured in InvertedIndex.properties 
-    Example: Keyspace1.InvertedIndex as configured in InvertedIndex.properties
-Configure trigger on the table.
-    Example: CREATE TRIGGER test1 ON "Keyspace1"."Standard1"
-                 USING 'org.apache.cassandra.triggers.InvertedIndex';
-Start inserting data to the column family which has the triggers. 
+
+Create the keyspace and table configured in AuditTrigger.properties:
+    CREATE KEYSPACE test WITH REPLICATION =
+        { 'class' : 'SimpleStrategy', 'replication_factor' : '1' };
+    CREATE TABLE test.audit (key timeuuid, keyspace_name text,
+        table_name text, primary_key text, PRIMARY KEY(key));
+
+Create a table to add the trigger to:
+    CREATE TABLE test.test (key text, value text, PRIMARY KEY(key));
+    Note: The example currently only handles non-composite partition keys
+
+Configure the trigger on the table:
+    CREATE TRIGGER test1 ON test.test
+        USING 'org.apache.cassandra.triggers.AuditTrigger';
+
+Start inserting data to the table that has the trigger. For each
+partition added to the table an entry should appear in the 'audit' table:
+    INSERT INTO test.test (key, value) values ('1', '1');
+    SELECT * FROM test.audit;
+
+    key                                  | keyspace_name | primary_key | table_name
+   --------------------------------------+---------------+-------------+------------
+    7dc75b60-770f-11e5-9019-033d8af33e6f |          test |           1 |       test
+

examples/triggers/conf/AuditTrigger.properties

@@ -15,5 +15,5 @@
 # specific language governing permissions and limitations
 # under the License.
 
-keyspace=Keyspace1
-table=InvertedIndex
+keyspace=test
+table=audit

examples/triggers/src/org/apache/cassandra/triggers/AuditTrigger.java

@@ -18,49 +18,42 @@
 package org.apache.cassandra.triggers;
 
 import java.io.InputStream;
-import java.nio.ByteBuffer;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
+import java.util.Collections;
 import java.util.Properties;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import org.apache.cassandra.db.Cell;
-import org.apache.cassandra.db.ColumnFamily;
+import org.apache.cassandra.config.Schema;
 import org.apache.cassandra.db.Mutation;
+import org.apache.cassandra.db.RowUpdateBuilder;
+import org.apache.cassandra.db.partitions.Partition;
 import org.apache.cassandra.io.util.FileUtils;
+import org.apache.cassandra.utils.FBUtilities;
+import org.apache.cassandra.utils.UUIDGen;
 
-public class InvertedIndex implements ITrigger
+public class AuditTrigger implements ITrigger
 {
-    private static final Logger logger = LoggerFactory.getLogger(InvertedIndex.class);
     private Properties properties = loadProperties();
 
-    public Collection<Mutation> augment(ByteBuffer key, ColumnFamily update)
+    public Collection<Mutation> augment(Partition update)
     {
-        List<Mutation> mutations = new ArrayList<>(update.getColumnCount());
+        String auditKeyspace = properties.getProperty("keyspace");
+        String auditTable = properties.getProperty("table");
 
-        String indexKeySpace = properties.getProperty("keyspace");
-        String indexColumnFamily = properties.getProperty("table");
-        for (Cell cell : update)
-        {
-            // Skip the row marker and other empty values, since they lead to an empty key.
-            if (cell.value().remaining() > 0)
-            {
-                Mutation mutation = new Mutation(indexKeySpace, cell.value());
-                mutation.add(indexColumnFamily, cell.name(), key, System.currentTimeMillis());
-                mutations.add(mutation);
-            }
-        }
+        RowUpdateBuilder audit = new RowUpdateBuilder(Schema.instance.getCFMetaData(auditKeyspace, auditTable),
+                                                      FBUtilities.timestampMicros(),
+                                                      UUIDGen.getTimeUUID());
 
-        return mutations;
+        audit.add("keyspace_name", update.metadata().ksName);
+        audit.add("table_name", update.metadata().cfName);
+        audit.add("primary_key", update.metadata().getKeyValidator().getString(update.partitionKey().getKey()));
+
+        return Collections.singletonList(audit.build());
     }
 
     private static Properties loadProperties()
     {
         Properties properties = new Properties();
-        InputStream stream = InvertedIndex.class.getClassLoader().getResourceAsStream("InvertedIndex.properties");
+        InputStream stream = AuditTrigger.class.getClassLoader().getResourceAsStream("AuditTrigger.properties");
         try
         {
             properties.load(stream);
@@ -73,7 +66,6 @@ public class InvertedIndex implements ITrigger
         {
             FileUtils.closeQuietly(stream);
         }
-        logger.info("loaded property file, InvertedIndex.properties");
         return properties;
     }
 }