Allow primary metastore to have prefix

CHANGELOG.md

@@ -1,3 +1,7 @@
+## TBD
+### Changed
+* Allow primary metastore to have a prefix. See [#152](https://github.com/HotelsDotCom/waggle-dance/issues/152).
+
 ## [3.2.0] - 2019-03-27
 ### Added
 * Configurable `latency` for each metastore in a Waggle Dance configuration.

README.md

@@ -141,7 +141,7 @@ The table below describes all the available configuration values for Waggle Danc
 | `primary-meta-store`                                    | No       | Primary MetaStore config. Can be empty but it is advised to configure it. |
 | `primary-meta-store.remote-meta-store-uris`             | Yes      | Thrift URIs of the federated read-only metastore. |
 | `primary-meta-store.name`                               | Yes      | Database name that uniquely identifies this metastore. Used internally. Cannot be empty. |
-| `primary-meta-store.database-prefix`                    | No       | This will be ignored for the primary metastore and an empty string will always be used instead. |
+| `primary-meta-store.database-prefix`                    | No       | Prefix used to access this particular metastore and differentiate databases in it from databases in another metastore. The default prefix (i.e. if this value isn't explicitly set) is empty string.|
 | `primary-meta-store.access-control-type`                | No       | Sets how the client access controls should be handled. Default is `READ_ONLY` Other options `READ_AND_WRITE_AND_CREATE`, `READ_AND_WRITE_ON_DATABASE_WHITELIST` and `READ_AND_WRITE_AND_CREATE_ON_DATABASE_WHITELIST` see Access Control section below. |
 | `primary-meta-store.writable-database-white-list`       | No       | White-list of databases used to verify write access used in conjunction with `primary-meta-store.access-control-type`. The list of databases should be listed without any `primary-meta-store.database-prefix`. This property supports both full database names and (case-insensitive) [Java RegEx patterns](https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html).|
 | `primary-meta-store.metastore-tunnel`                   | No       | See metastore tunnel configuration values below. |
@@ -356,7 +356,7 @@ database is encountered that is not prefixed then the primary metastore is used
       remote-meta-store-uris: thrift://primaryLocalMetastore:9083
     federated-meta-stores:
       - name: federated
-        prefix: waggle_prod_
+        database-prefix: waggle_prod_
         remote-meta-store-uris: thrift://federatedProdMetastore:9083
 
 Note: When choosing a prefix ensure that it does not match the start of _any_ existing database names in any of the configured metastores. To illustrate the problem this would cause, 
@@ -378,7 +378,7 @@ In `PREFIXED` mode any databases that are created while Waggle Dance is running
       remote-meta-store-uris: thrift://primaryLocalMetastore:9083
     federated-meta-stores:
       - name: federated
-        prefix: waggle_prod_
+        database-prefix: waggle_prod_
         remote-meta-store-uris: thrift://federatedProdMetastore:9083
         mapped-databases:
         - etldata

waggle-dance-api/src/main/java/com/hotels/bdp/waggledance/api/model/FederatedMetaStore.java

@@ -18,10 +18,9 @@
 import java.util.Collections;
 import java.util.List;
 
+import javax.validation.constraints.NotBlank;
 import javax.validation.constraints.NotNull;
 
-import org.hibernate.validator.constraints.NotBlank;
-
 public class FederatedMetaStore extends AbstractMetaStore {
 
   private @NotNull List<String> mappedDatabases = Collections.emptyList();

waggle-dance-api/src/main/java/com/hotels/bdp/waggledance/api/model/PrimaryMetaStore.java

@@ -15,19 +15,13 @@
  */
 package com.hotels.bdp.waggledance.api.model;
 
-import javax.validation.constraints.NotNull;
-import javax.validation.constraints.Size;
-
 import java.util.Arrays;
 import java.util.List;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import javax.validation.constraints.NotNull;
 
 public class PrimaryMetaStore extends AbstractMetaStore {
 
-  private final static Logger LOG = LoggerFactory.getLogger(PrimaryMetaStore.class);
-
   private static final String EMPTY_PREFIX = "";
 
   public PrimaryMetaStore() {}
@@ -53,17 +47,14 @@ public FederationType getFederationType() {
     return FederationType.PRIMARY;
   }
 
-  @Size(min = 0, max = 0)
   @NotNull
   @Override
   public String getDatabasePrefix() {
-    // primary is always empty
-    return EMPTY_PREFIX;
+    String prefix = super.getDatabasePrefix();
+    if (prefix == null) {
+      prefix = EMPTY_PREFIX;
+    }
+    return prefix;
   }
 
-  @Override
-  public void setDatabasePrefix(String databasePrefix) {
-    LOG.warn("Ignoring attempt to set prefix to '{}', the prefix for a primary metastore is always empty",
-        databasePrefix);
-  }
 }

waggle-dance-api/src/test/java/com/hotels/bdp/waggledance/api/model/PrimaryMetaStoreTest.java

@@ -80,11 +80,11 @@ public void nullDatabasePrefix() {
 
   @Test
   public void nonEmptyDatabasePrefix() {
-    metaStore.setDatabasePrefix("abc");
+    String prefix = "abc";
+    metaStore.setDatabasePrefix(prefix);
     Set<ConstraintViolation<PrimaryMetaStore>> violations = validator.validate(metaStore);
-    // Violation is not triggered cause EMPTY STRING is always returned. Warning is logged instead
     assertThat(violations.size(), is(0));
-    assertThat(metaStore.getDatabasePrefix(), is(""));
+    assertThat(metaStore.getDatabasePrefix(), is(prefix));
   }
 
   @Test

waggle-dance-integration-tests/src/main/java/com/hotels/bdp/waggledance/WaggleDanceRunner.java

@@ -174,6 +174,11 @@ public Builder primary(
       return this;
     }
 
+    public Builder withPrimaryPrefix(String prefix) {
+      primaryMetaStore.setDatabasePrefix(prefix);
+      return this;
+    }
+
     public Builder graphite(String graphiteHost, int graphitePort, String graphitePrefix, long pollInterval) {
       graphiteConfiguration.setHost(graphiteHost);
       graphiteConfiguration.setPort(graphitePort);

waggle-dance-integration-tests/src/test/java/com/hotels/bdp/waggledance/WaggleDanceIntegrationTest.java

@@ -77,6 +77,7 @@
 import com.hotels.hcommon.hive.metastore.client.tunnelling.MetastoreTunnel;
 
 public class WaggleDanceIntegrationTest {
+
   private static final Logger LOG = LoggerFactory.getLogger(WaggleDanceIntegrationTest.class);
 
   private static final String LOCAL_DATABASE = "local_database";
@@ -157,7 +158,7 @@ private HiveMetaStoreClient getWaggleDanceClient() throws MetaException {
     return new HiveMetaStoreClient(conf);
   }
 
-  private void runWaggleDance(final WaggleDanceRunner runner) throws Exception {
+  private void runWaggleDance(WaggleDanceRunner runner) throws Exception {
     executor.submit(new Runnable() {
       @Override
       public void run() {
@@ -223,11 +224,42 @@ public void usePrefix() throws Exception {
     // Remote table
     String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
     assertTypicalRemoteTable(proxy, waggledRemoteDbName);
+  }
+
+  @Test
+  public void usePrimaryPrefix() throws Exception {
+    String primaryPrefix = "primary_";
+    runner = WaggleDanceRunner
+        .builder(configLocation)
+        .databaseResolution(DatabaseResolution.PREFIXED)
+        .primary("primary", localServer.getThriftConnectionUri(), READ_ONLY)
+        .withPrimaryPrefix(primaryPrefix)
+        .federate(SECONDARY_METASTORE_NAME, remoteServer.getThriftConnectionUri())
+        .build();
+
+    runWaggleDance(runner);
+    HiveMetaStoreClient proxy = getWaggleDanceClient();
 
+    // Local table
+    String waggledLocalDbName = primaryPrefix + LOCAL_DATABASE;
+    assertPrefixedLocalTable(proxy, waggledLocalDbName);
+
+    // Remote table
+    String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
+    assertTypicalRemoteTable(proxy, waggledRemoteDbName);
+  }
+
+  private void assertPrefixedLocalTable(HiveMetaStoreClient proxy, String waggledLocalDbName) throws TException {
+    Table localTable = localServer.client().getTable(LOCAL_DATABASE, LOCAL_TABLE);
+    Table waggledLocalTable = proxy.getTable(waggledLocalDbName, LOCAL_TABLE);
+    assertThat(waggledLocalTable.getDbName(), is(waggledLocalDbName));
+    assertThat(waggledLocalTable.getTableName(), is(localTable.getTableName()));
+    assertThat(waggledLocalTable.getSd(), is(localTable.getSd()));
+    assertThat(waggledLocalTable.getParameters(), is(localTable.getParameters()));
+    assertThat(waggledLocalTable.getPartitionKeys(), is(localTable.getPartitionKeys()));
   }
 
-  private void assertTypicalRemoteTable(HiveMetaStoreClient proxy, String waggledRemoteDbName)
-    throws MetaException, TException, NoSuchObjectException {
+  private void assertTypicalRemoteTable(HiveMetaStoreClient proxy, String waggledRemoteDbName) throws TException {
     Table remoteTable = remoteServer.client().getTable(REMOTE_DATABASE, REMOTE_TABLE);
     Table waggledRemoteTable = proxy.getTable(waggledRemoteDbName, REMOTE_TABLE);
     assertThat(waggledRemoteTable.getDbName(), is(waggledRemoteDbName));
@@ -349,7 +381,7 @@ public void federatedWritesSucceedIfReadAndWriteOnDatabaseWhiteListIsConfigured(
 
     HiveMetaStoreClient proxy = getWaggleDanceClient();
 
-    final String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
+    String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
 
     assertTypicalRemoteTable(proxy, waggledRemoteDbName);
 
@@ -379,7 +411,7 @@ public void federatedWritesFailIfReadAndWriteOnDatabaseWhiteListIsNotConfigured(
 
     HiveMetaStoreClient proxy = getWaggleDanceClient();
 
-    final String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
+    String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
 
     assertTypicalRemoteTable(proxy, waggledRemoteDbName);
 
@@ -409,7 +441,7 @@ public void federatedWritesFailIfReadAndWriteOnDatabaseWhiteListDoesNotIncludeDb
 
     HiveMetaStoreClient proxy = getWaggleDanceClient();
 
-    final String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
+    String waggledRemoteDbName = PREFIXED_REMOTE_DATABASE;
 
     assertTypicalRemoteTable(proxy, waggledRemoteDbName);
 
@@ -716,5 +748,4 @@ public void getDatabaseFromPatternPrefixed() throws Exception {
     List<String> expected = Lists.newArrayList("default", LOCAL_DATABASE, PREFIXED_REMOTE_DATABASE);
     assertThat(allDatabases, is(expected));
   }
-
 }