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Posted to commits@metamodel.apache.org by ka...@apache.org on 2017/07/23 05:41:39 UTC
[2/2] metamodel-membrane git commit: Added initial codebase, adapted from MetaModel REST service branch

Added initial codebase, adapted from MetaModel REST service branch

Project: http://git-wip-us.apache.org/repos/asf/metamodel-membrane/repo
Commit: http://git-wip-us.apache.org/repos/asf/metamodel-membrane/commit/6492107d
Tree: http://git-wip-us.apache.org/repos/asf/metamodel-membrane/tree/6492107d
Diff: http://git-wip-us.apache.org/repos/asf/metamodel-membrane/diff/6492107d

Branch: refs/heads/initial-codebase
Commit: 6492107d501b475c873cdf31a6a70b312b2fa198
Parents: 8d6636a
Author: Kasper Sørensen <i....@gmail.com>
Authored: Sat Jul 22 22:22:41 2017 -0700
Committer: Kasper Sørensen <i....@gmail.com>
Committed: Sat Jul 22 22:41:23 2017 -0700

----------------------------------------------------------------------
 README.md                                       |  18 +-
 core/pom.xml                                    | 104 ++++
 .../app/CachedDataSourceRegistryWrapper.java    | 109 ++++
 .../membrane/app/DataContextSupplier.java       |  48 ++
 .../membrane/app/DataContextTraverser.java      |  67 +++
 .../membrane/app/DataSourceDefinition.java      |  28 +
 .../membrane/app/DataSourceRegistry.java        |  48 ++
 .../app/InMemoryDataSourceRegistry.java         |  65 +++
 .../membrane/app/InMemoryTenantContext.java     |  45 ++
 .../membrane/app/InMemoryTenantRegistry.java    |  79 +++
 .../metamodel/membrane/app/TenantContext.java   |  31 ++
 .../metamodel/membrane/app/TenantRegistry.java  |  38 ++
 .../AbstractIdentifierNamingException.java      |  40 ++
 .../DataSourceAlreadyExistException.java        |  28 +
 .../DataSourceNotUpdateableException.java       |  37 ++
 .../app/exceptions/NoSuchColumnException.java   |  29 +
 .../exceptions/NoSuchDataSourceException.java   |  29 +
 .../app/exceptions/NoSuchSchemaException.java   |  29 +
 .../app/exceptions/NoSuchTableException.java    |  29 +
 .../app/exceptions/NoSuchTenantException.java   |  28 +
 .../exceptions/TenantAlreadyExistException.java |  28 +
 .../membrane/controllers/ColumnController.java  |  86 +++
 .../controllers/DataSourceController.java       | 104 ++++
 .../membrane/controllers/QueryController.java   |  85 +++
 .../membrane/controllers/RestErrorHandler.java  | 160 ++++++
 .../controllers/RootInformationController.java  | 102 ++++
 .../membrane/controllers/SchemaController.java  |  80 +++
 .../controllers/SwaggerSpecController.java      |  64 +++
 .../membrane/controllers/TableController.java   |  85 +++
 .../controllers/TableDataController.java        | 115 ++++
 .../membrane/controllers/TenantController.java  |  94 ++++
 .../model/RestDataSourceDefinition.java         |  55 ++
 .../controllers/model/RestErrorResponse.java    |  80 +++
 .../membrane/controllers/model/RestLink.java    |  60 +++
 .../resources/context/application-context.xml   |  34 ++
 .../resources/context/dispatcher-servlet.xml    |  59 ++
 core/src/main/resources/logback.xml             |  33 ++
 core/src/main/resources/swagger.yaml            | 538 +++++++++++++++++++
 .../RootInformationControllerTest.java          |  62 +++
 .../TenantInteractionScenarioTest.java          | 202 +++++++
 docker-compose.yml                              |  26 +
 pom.xml                                         |  48 +-
 undertow/Dockerfile                             |  22 +
 undertow/pom.xml                                |  80 +++
 undertow/src/main/docker/swagger-ui/index.html  | 112 ++++
 .../metamodel/membrane/server/WebServer.java    |  92 ++++
 war/pom.xml                                     |  42 ++
 war/src/main/webapp/WEB-INF/web.xml             |  74 +++
 48 files changed, 3534 insertions(+), 17 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/README.md
----------------------------------------------------------------------
diff --git a/README.md b/README.md
index b3586ae..8af263a 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,22 @@ Data Federation as a RESTful service. A subproject of [Apache MetaModel](http://
 <img src="http://metamodel.apache.org/img/logo.png" style="float: right; margin-left: 20px;" alt="MetaModel logo" />
 </div>
 
+### Building and running
+
+Make sure you have [Apache Maven](http://maven.apache.org/), then build by invoking:
+
+```
+mvn clean install
+```
+
+After building the Java archives and executables, you can use [Docker](https://www.docker.com/) and [Docker compose](https://docs.docker.com/compose/) to run Membrane easily, like this:
+
+```
+docker-compose up --build
+```
+
+Now Membrane should be running on port `8080` of your Docker host. Typically that's either http://localhost:8080 (if you have a native Docker install) or http://192.168.99.100:8080 (if you use Docker toolbox).
+
 ### Mailing lists
 
 Membrane uses the same development infrastructure as the main Apache MetaModel project:
@@ -16,4 +32,4 @@ Membrane uses the same development infrastructure as the main Apache MetaModel p
 
 ### Contributing
 
-Please see [CONTRIBUTE.md from Apache MetaModel](https://github.com/apache/metamodel/blob/master/CONTRIBUTE.md)
+Please see [CONTRIBUTE.md from Apache MetaModel](https://github.com/apache/metamodel/blob/master/CONTRIBUTE.md) which also apply to the Membrane contribution guidelines.

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/pom.xml
----------------------------------------------------------------------
diff --git a/core/pom.xml b/core/pom.xml
new file mode 100644
index 0000000..ad0ccb3
--- /dev/null
+++ b/core/pom.xml
@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<groupId>org.apache.metamodel.membrane</groupId>
+		<artifactId>Membrane-parent</artifactId>
+		<version>0.1-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+	<artifactId>Membrane-core</artifactId>
+	<packaging>jar</packaging>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.apache.metamodel</groupId>
+			<artifactId>MetaModel-spring</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.metamodel</groupId>
+			<artifactId>MetaModel-full</artifactId>
+			<exclusions>
+				<exclusion>
+					<groupId>org.slf4j</groupId>
+					<artifactId>slf4j-log4j12</artifactId>
+				</exclusion>
+				<exclusion>
+					<groupId>javax.servlet</groupId>
+					<artifactId>servlet-api</artifactId>
+				</exclusion>
+				<exclusion>
+					<groupId>log4j</groupId>
+					<artifactId>log4j</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.dataformat</groupId>
+			<artifactId>jackson-dataformat-yaml</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.google.guava</groupId>
+			<artifactId>guava</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>ch.qos.logback</groupId>
+			<artifactId>logback-classic</artifactId>
+			<version>1.1.7</version>
+		</dependency>
+		<dependency>
+			<groupId>org.hibernate</groupId>
+			<artifactId>hibernate-validator</artifactId>
+			<version>5.2.4.Final</version>
+		</dependency>
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>jcl-over-slf4j</artifactId>
+		</dependency>
+
+		<!-- Provided -->
+		<dependency>
+			<groupId>javax.servlet</groupId>
+			<artifactId>javax.servlet-api</artifactId>
+			<scope>provided</scope>
+		</dependency>
+
+		<!-- Test -->
+		<dependency>
+			<groupId>junit</groupId>
+			<artifactId>junit</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+</project>
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/CachedDataSourceRegistryWrapper.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/CachedDataSourceRegistryWrapper.java b/core/src/main/java/org/apache/metamodel/membrane/app/CachedDataSourceRegistryWrapper.java
new file mode 100644
index 0000000..f09fbca
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/CachedDataSourceRegistryWrapper.java
@@ -0,0 +1,109 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.List;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.MetaModelException;
+import org.apache.metamodel.factory.DataContextProperties;
+import org.apache.metamodel.membrane.app.exceptions.DataSourceAlreadyExistException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchDataSourceException;
+import org.apache.metamodel.util.FileHelper;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+import com.google.common.cache.RemovalListener;
+import com.google.common.cache.RemovalNotification;
+
+/**
+ * A wrapper that adds a cache around a {@link DataSourceRegistry} in order to
+ * prevent re-connecting all the time to the same data source.
+ */
+public class CachedDataSourceRegistryWrapper implements DataSourceRegistry {
+
+    /**
+     * The default timeout (in seconds) before the cache evicts and closes the
+     * created {@link DataContext}s.
+     */
+    public static final int DEFAULT_TIMEOUT_SECONDS = 60;
+
+    private final DataSourceRegistry delegate;
+    private final LoadingCache<String, DataContext> loadingCache;
+
+    public CachedDataSourceRegistryWrapper(DataSourceRegistry delegate) {
+        this(delegate, DEFAULT_TIMEOUT_SECONDS, TimeUnit.SECONDS);
+    }
+
+    public CachedDataSourceRegistryWrapper(DataSourceRegistry delegate, long cacheTimeout, TimeUnit cacheTimeoutUnit) {
+        this.delegate = delegate;
+        this.loadingCache = CacheBuilder.newBuilder().expireAfterAccess(cacheTimeout, cacheTimeoutUnit).removalListener(
+                createRemovalListener()).build(createCacheLoader());
+    }
+
+    private RemovalListener<String, DataContext> createRemovalListener() {
+        return new RemovalListener<String, DataContext>() {
+            @Override
+            public void onRemoval(RemovalNotification<String, DataContext> notification) {
+                final DataContext dataContext = notification.getValue();
+                // some DataContexts are closeable - attempt closing it here
+                FileHelper.safeClose(dataContext);
+            }
+        };
+    }
+
+    private CacheLoader<String, DataContext> createCacheLoader() {
+        return new CacheLoader<String, DataContext>() {
+            @Override
+            public DataContext load(String key) throws Exception {
+                return delegate.openDataContext(key);
+            }
+        };
+    }
+
+    @Override
+    public List<String> getDataSourceNames() {
+        return delegate.getDataSourceNames();
+    }
+
+    @Override
+    public String registerDataSource(String dataContextName, DataContextProperties dataContextProperties)
+            throws DataSourceAlreadyExistException {
+        loadingCache.invalidate(dataContextName);
+        return delegate.registerDataSource(dataContextName, dataContextProperties);
+    }
+
+    @Override
+    public DataContext openDataContext(String dataSourceName) throws NoSuchDataSourceException {
+        try {
+            return loadingCache.get(dataSourceName);
+        } catch (ExecutionException e) {
+            final Throwable cause = e.getCause();
+            if (cause instanceof RuntimeException) {
+                throw (RuntimeException) cause;
+            }
+            throw new MetaModelException("Unexpected error happened while getting DataContext '" + dataSourceName
+                    + "' from cache", e);
+        }
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/DataContextSupplier.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/DataContextSupplier.java b/core/src/main/java/org/apache/metamodel/membrane/app/DataContextSupplier.java
new file mode 100644
index 0000000..7ce0cc0
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/DataContextSupplier.java
@@ -0,0 +1,48 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.function.Supplier;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.factory.DataContextFactoryRegistryImpl;
+import org.apache.metamodel.factory.DataContextProperties;
+
+public class DataContextSupplier implements Supplier<DataContext> {
+
+    private final String dataSourceName;
+    private final DataContextProperties dataContextProperties;
+
+    public DataContextSupplier(String dataSourceName, DataContextProperties dataContextProperties) {
+        this.dataSourceName = dataSourceName;
+        this.dataContextProperties = dataContextProperties;
+    }
+
+    @Override
+    public DataContext get() {
+        final DataContext dataContext = DataContextFactoryRegistryImpl.getDefaultInstance().createDataContext(
+                dataContextProperties);
+        return dataContext;
+    }
+
+    @Override
+    public String toString() {
+        return "DataContextSupplier[" + dataSourceName + "]";
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/DataContextTraverser.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/DataContextTraverser.java b/core/src/main/java/org/apache/metamodel/membrane/app/DataContextTraverser.java
new file mode 100644
index 0000000..ee22171
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/DataContextTraverser.java
@@ -0,0 +1,67 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchColumnException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchSchemaException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchTableException;
+import org.apache.metamodel.schema.Column;
+import org.apache.metamodel.schema.Schema;
+import org.apache.metamodel.schema.Table;
+
+/**
+ * Utility object responsible for traversing the schema/table/column structures
+ * of a {@link DataContext} based on String identifiers and names.
+ * 
+ * This class will throw the appropriate exceptions if needed which is more
+ * communicative than the usual NPEs that would otherwise be thrown.
+ */
+public class DataContextTraverser {
+
+    private final DataContext dataContext;
+
+    public DataContextTraverser(DataContext dataContext) {
+        this.dataContext = dataContext;
+    }
+
+    public Schema getSchema(String schemaName) {
+        final Schema schema = dataContext.getSchemaByName(schemaName);
+        if (schema == null) {
+            throw new NoSuchSchemaException(schemaName);
+        }
+        return schema;
+    }
+
+    public Table getTable(String schemaName, String tableName) {
+        final Table table = getSchema(schemaName).getTableByName(tableName);
+        if (table == null) {
+            throw new NoSuchTableException(tableName);
+        }
+        return table;
+    }
+
+    public Column getColumn(String schemaName, String tableName, String columnName) {
+        final Column column = getTable(schemaName, tableName).getColumnByName(columnName);
+        if (column == null) {
+            throw new NoSuchColumnException(columnName);
+        }
+        return column;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceDefinition.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceDefinition.java b/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceDefinition.java
new file mode 100644
index 0000000..d8df5f4
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceDefinition.java
@@ -0,0 +1,28 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.Map;
+
+public interface DataSourceDefinition {
+
+    public String getType();
+    
+    public Map<String, Object> getProperties();
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceRegistry.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceRegistry.java b/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceRegistry.java
new file mode 100644
index 0000000..4aa6f01
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/DataSourceRegistry.java
@@ -0,0 +1,48 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.List;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.UpdateableDataContext;
+import org.apache.metamodel.factory.DataContextProperties;
+import org.apache.metamodel.membrane.app.exceptions.DataSourceAlreadyExistException;
+import org.apache.metamodel.membrane.app.exceptions.DataSourceNotUpdateableException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchDataSourceException;
+
+/**
+ * Represents a user's/tenant's registry of {@link DataContext}s.
+ */
+public interface DataSourceRegistry {
+
+    public List<String> getDataSourceNames();
+
+    public String registerDataSource(String dataContextName, DataContextProperties dataContextProperties) throws DataSourceAlreadyExistException;
+
+    public DataContext openDataContext(String dataSourceName) throws NoSuchDataSourceException;
+
+    public default UpdateableDataContext openDataContextForUpdate(String dataSourceName) {
+        final DataContext dataContext = openDataContext(dataSourceName);
+        if (dataContext instanceof UpdateableDataContext) {
+            return (UpdateableDataContext) dataContext;
+        }
+        throw new DataSourceNotUpdateableException(dataSourceName);
+    };
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryDataSourceRegistry.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryDataSourceRegistry.java b/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryDataSourceRegistry.java
new file mode 100644
index 0000000..1272cee
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryDataSourceRegistry.java
@@ -0,0 +1,65 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.factory.DataContextProperties;
+import org.apache.metamodel.membrane.app.exceptions.DataSourceAlreadyExistException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchDataSourceException;
+
+public class InMemoryDataSourceRegistry implements DataSourceRegistry {
+
+    private final Map<String, Supplier<DataContext>> dataSources;
+
+    public InMemoryDataSourceRegistry() {
+        dataSources = new LinkedHashMap<>();
+    }
+
+    @Override
+    public String registerDataSource(final String name, final DataContextProperties dataContextProperties)
+            throws DataSourceAlreadyExistException {
+        if (dataSources.containsKey(name)) {
+            throw new DataSourceAlreadyExistException(name);
+        }
+
+        dataSources.put(name, new DataContextSupplier(name, dataContextProperties));
+        return name;
+    }
+
+    @Override
+    public List<String> getDataSourceNames() {
+        return dataSources.keySet().stream().collect(Collectors.toList());
+    }
+
+    @Override
+    public DataContext openDataContext(String name) {
+        final Supplier<DataContext> supplier = dataSources.get(name);
+        if (supplier == null) {
+            throw new NoSuchDataSourceException(name);
+        }
+        return supplier.get();
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantContext.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantContext.java b/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantContext.java
new file mode 100644
index 0000000..3ecb7fe
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantContext.java
@@ -0,0 +1,45 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+public class InMemoryTenantContext implements TenantContext {
+
+    private final String tenantIdentifier;
+    private final DataSourceRegistry dataContextRegistry;
+
+    public InMemoryTenantContext(String tenantIdentifier) {
+        this.tenantIdentifier = tenantIdentifier;
+        this.dataContextRegistry = new CachedDataSourceRegistryWrapper(new InMemoryDataSourceRegistry());
+    }
+
+    @Override
+    public String getTenantName() {
+        return tenantIdentifier;
+    }
+
+    @Override
+    public DataSourceRegistry getDataSourceRegistry() {
+        return dataContextRegistry;
+    }
+
+    @Override
+    public String toString() {
+        return "InMemoryTenantContext[" + tenantIdentifier + "]";
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantRegistry.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantRegistry.java b/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantRegistry.java
new file mode 100644
index 0000000..8665819
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/InMemoryTenantRegistry.java
@@ -0,0 +1,79 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.apache.metamodel.membrane.app.exceptions.NoSuchTenantException;
+import org.apache.metamodel.membrane.app.exceptions.TenantAlreadyExistException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * In-memory {@link TenantRegistry}. This is not particularly
+ * production-friendly as it is non-persistent, but it is useful for demo
+ * purposes.
+ */
+public class InMemoryTenantRegistry implements TenantRegistry {
+
+    private static final Logger logger = LoggerFactory.getLogger(InMemoryTenantRegistry.class);
+    private final Map<String, TenantContext> tenants;
+
+    public InMemoryTenantRegistry() {
+        tenants = new LinkedHashMap<>();
+        logger.info("Initialized!");
+    }
+
+    @Override
+    public List<String> getTenantIdentifiers() {
+        return tenants.keySet().stream().collect(Collectors.toList());
+    }
+
+    @Override
+    public TenantContext getTenantContext(String tenantIdentifier) {
+        final TenantContext tenant = tenants.get(tenantIdentifier);
+        if (tenant == null) {
+            throw new NoSuchTenantException(tenantIdentifier);
+        }
+        return tenant;
+    }
+
+    @Override
+    public TenantContext createTenantContext(String tenantIdentifier) {
+        if (tenants.containsKey(tenantIdentifier)) {
+            throw new TenantAlreadyExistException(tenantIdentifier);
+        }
+        final InMemoryTenantContext tenantContext = new InMemoryTenantContext(tenantIdentifier);
+        tenants.put(tenantIdentifier, tenantContext);
+        logger.info("Created new tenant: {}", tenantContext);
+        return tenantContext;
+    }
+
+    @Override
+    public void deleteTenantContext(String tenantIdentifier) {
+        final TenantContext removedTenant = tenants.remove(tenantIdentifier);
+        if (removedTenant == null) {
+            throw new NoSuchTenantException(tenantIdentifier);
+        }
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/TenantContext.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/TenantContext.java b/core/src/main/java/org/apache/metamodel/membrane/app/TenantContext.java
new file mode 100644
index 0000000..491859f
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/TenantContext.java
@@ -0,0 +1,31 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+/**
+ * Represents a context-object containing all the information and services
+ * related to a particular tenant.
+ */
+public interface TenantContext {
+
+    public String getTenantName();
+
+    public DataSourceRegistry getDataSourceRegistry();
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/TenantRegistry.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/TenantRegistry.java b/core/src/main/java/org/apache/metamodel/membrane/app/TenantRegistry.java
new file mode 100644
index 0000000..625adb8
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/TenantRegistry.java
@@ -0,0 +1,38 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app;
+
+import java.util.List;
+
+import org.apache.metamodel.membrane.app.exceptions.NoSuchTenantException;
+import org.apache.metamodel.membrane.app.exceptions.TenantAlreadyExistException;
+
+/**
+ * Represents the application's central registry of tenants
+ */
+public interface TenantRegistry {
+
+    public List<String> getTenantIdentifiers();
+
+    public TenantContext getTenantContext(String tenantIdentifier) throws NoSuchTenantException;
+
+    public TenantContext createTenantContext(String tenantIdentifier) throws TenantAlreadyExistException;
+
+    public void deleteTenantContext(String tenantIdentifier) throws NoSuchTenantException;
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/AbstractIdentifierNamingException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/AbstractIdentifierNamingException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/AbstractIdentifierNamingException.java
new file mode 100644
index 0000000..06a58e4
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/AbstractIdentifierNamingException.java
@@ -0,0 +1,40 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+import org.apache.metamodel.MetaModelException;
+
+/**
+ * Exception super class for any exception that arises because an identifier
+ * (name, ID or such) is invalid for a specific context.
+ */
+public class AbstractIdentifierNamingException extends MetaModelException {
+
+    private static final long serialVersionUID = 1L;
+    private final String identifier;
+
+    public AbstractIdentifierNamingException(String identifier) {
+        super("Illegal value: " + identifier);
+        this.identifier = identifier;
+    }
+
+    public String getIdentifier() {
+        return identifier;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceAlreadyExistException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceAlreadyExistException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceAlreadyExistException.java
new file mode 100644
index 0000000..e284cd7
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceAlreadyExistException.java
@@ -0,0 +1,28 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class DataSourceAlreadyExistException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public DataSourceAlreadyExistException(String name) {
+        super(name);
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceNotUpdateableException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceNotUpdateableException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceNotUpdateableException.java
new file mode 100644
index 0000000..09003f9
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/DataSourceNotUpdateableException.java
@@ -0,0 +1,37 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+import org.apache.metamodel.MetaModelException;
+
+public class DataSourceNotUpdateableException extends MetaModelException {
+
+    private static final long serialVersionUID = 1L;
+
+    private final String dataSourceName;
+
+    public DataSourceNotUpdateableException(String dataSourceName) {
+        super(dataSourceName);
+        this.dataSourceName = dataSourceName;
+    }
+
+    public String getDataSourceName() {
+        return dataSourceName;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchColumnException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchColumnException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchColumnException.java
new file mode 100644
index 0000000..a161973
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchColumnException.java
@@ -0,0 +1,29 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class NoSuchColumnException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public NoSuchColumnException(String name) {
+        super(name);
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchDataSourceException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchDataSourceException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchDataSourceException.java
new file mode 100644
index 0000000..38421b0
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchDataSourceException.java
@@ -0,0 +1,29 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class NoSuchDataSourceException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public NoSuchDataSourceException(String name) {
+        super(name);
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchSchemaException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchSchemaException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchSchemaException.java
new file mode 100644
index 0000000..1810981
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchSchemaException.java
@@ -0,0 +1,29 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class NoSuchSchemaException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public NoSuchSchemaException(String name) {
+        super(name);
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTableException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTableException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTableException.java
new file mode 100644
index 0000000..42bf93c
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTableException.java
@@ -0,0 +1,29 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class NoSuchTableException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public NoSuchTableException(String name) {
+        super(name);
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTenantException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTenantException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTenantException.java
new file mode 100644
index 0000000..45cfa7a
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/NoSuchTenantException.java
@@ -0,0 +1,28 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class NoSuchTenantException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public NoSuchTenantException(String tenantIdentifier) {
+        super(tenantIdentifier);
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/TenantAlreadyExistException.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/TenantAlreadyExistException.java b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/TenantAlreadyExistException.java
new file mode 100644
index 0000000..364e166
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/app/exceptions/TenantAlreadyExistException.java
@@ -0,0 +1,28 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.app.exceptions;
+
+public class TenantAlreadyExistException extends AbstractIdentifierNamingException {
+
+    private static final long serialVersionUID = 1L;
+
+    public TenantAlreadyExistException(String tenantIdentifier) {
+        super(tenantIdentifier);
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/ColumnController.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/ColumnController.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/ColumnController.java
new file mode 100644
index 0000000..6e99371
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/ColumnController.java
@@ -0,0 +1,86 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.membrane.app.DataContextTraverser;
+import org.apache.metamodel.membrane.app.TenantContext;
+import org.apache.metamodel.membrane.app.TenantRegistry;
+import org.apache.metamodel.schema.Column;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping(value = { "/{tenant}/{dataContext}/schemas/{schema}/tables/{table}/columns/{column}",
+        "/{tenant}/{dataContext}/s/{schema}/t/{table}/c/{column}" }, produces = MediaType.APPLICATION_JSON_VALUE)
+public class ColumnController {
+
+    private final TenantRegistry tenantRegistry;
+
+    @Autowired
+    public ColumnController(TenantRegistry tenantRegistry) {
+        this.tenantRegistry = tenantRegistry;
+    }
+
+    @RequestMapping(method = RequestMethod.GET)
+    @ResponseBody
+    public Map<String, Object> get(@PathVariable("tenant") String tenantId,
+            @PathVariable("dataContext") String dataSourceName, @PathVariable("schema") String schemaId,
+            @PathVariable("table") String tableId, @PathVariable("column") String columnId) {
+        final TenantContext tenantContext = tenantRegistry.getTenantContext(tenantId);
+        final DataContext dataContext = tenantContext.getDataSourceRegistry().openDataContext(dataSourceName);
+
+        final DataContextTraverser traverser = new DataContextTraverser(dataContext);
+
+        final Column column = traverser.getColumn(schemaId, tableId, columnId);
+
+        final String tenantName = tenantContext.getTenantName();
+        final String tableName = column.getTable().getName();
+        final String schemaName = column.getTable().getSchema().getName();
+
+        final Map<String, Object> metadata = new LinkedHashMap<>();
+        metadata.put("number", column.getColumnNumber());
+        metadata.put("size", column.getColumnSize());
+        metadata.put("nullable", column.isNullable());
+        metadata.put("primary-key", column.isPrimaryKey());
+        metadata.put("indexed", column.isIndexed());
+        metadata.put("column-type", column.getType() == null ? null : column.getType().getName());
+        metadata.put("native-type", column.getNativeType());
+        metadata.put("remarks", column.getRemarks());
+
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("type", "column");
+        map.put("name", column.getName());
+        map.put("table", tableName);
+        map.put("schema", schemaName);
+        map.put("datasource", dataSourceName);
+        map.put("tenant", tenantName);
+        map.put("metadata", metadata);
+
+        return map;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/DataSourceController.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/DataSourceController.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/DataSourceController.java
new file mode 100644
index 0000000..c9df027
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/DataSourceController.java
@@ -0,0 +1,104 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import javax.validation.Valid;
+import javax.ws.rs.core.UriBuilder;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.UpdateableDataContext;
+import org.apache.metamodel.factory.DataContextProperties;
+import org.apache.metamodel.factory.DataContextPropertiesImpl;
+import org.apache.metamodel.membrane.app.TenantContext;
+import org.apache.metamodel.membrane.app.TenantRegistry;
+import org.apache.metamodel.membrane.controllers.model.RestDataSourceDefinition;
+import org.apache.metamodel.membrane.controllers.model.RestLink;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping(value = "/{tenant}/{datasource}", produces = MediaType.APPLICATION_JSON_VALUE)
+public class DataSourceController {
+
+    private final TenantRegistry tenantRegistry;
+
+    @Autowired
+    public DataSourceController(TenantRegistry tenantRegistry) {
+        this.tenantRegistry = tenantRegistry;
+    }
+
+    @RequestMapping(method = RequestMethod.PUT)
+    @ResponseBody
+    public Map<String, Object> put(@PathVariable("tenant") String tenantId,
+            @PathVariable("datasource") String dataSourceId,
+            @Valid @RequestBody RestDataSourceDefinition dataContextDefinition) {
+
+        final Map<String, Object> map = new HashMap<>();
+        map.putAll(dataContextDefinition.getProperties());
+        map.put(DataContextPropertiesImpl.PROPERTY_DATA_CONTEXT_TYPE, dataContextDefinition.getType());
+
+        if (!map.containsKey(DataContextPropertiesImpl.PROPERTY_DATABASE)) {
+            // add the data source ID as database name if it is not already set.
+            map.put(DataContextPropertiesImpl.PROPERTY_DATABASE, dataSourceId);
+        }
+
+        final DataContextProperties properties = new DataContextPropertiesImpl(map);
+
+        final String dataContextIdentifier = tenantRegistry.getTenantContext(tenantId).getDataSourceRegistry()
+                .registerDataSource(dataSourceId, properties);
+
+        return get(tenantId, dataContextIdentifier);
+    }
+
+    @RequestMapping(method = RequestMethod.GET)
+    @ResponseBody
+    public Map<String, Object> get(@PathVariable("tenant") String tenantId,
+            @PathVariable("datasource") String dataSourceName) {
+        final TenantContext tenantContext = tenantRegistry.getTenantContext(tenantId);
+        final DataContext dataContext = tenantContext.getDataSourceRegistry().openDataContext(dataSourceName);
+
+        final String tenantName = tenantContext.getTenantName();
+        final UriBuilder uriBuilder = UriBuilder.fromPath("/{tenant}/{dataContext}/s/{schema}");
+
+        final List<RestLink> schemaLinks = Arrays.stream(dataContext.getSchemaNames()).map(s -> new RestLink(s,
+                uriBuilder.build(tenantName, dataSourceName, s))).collect(Collectors.toList());
+
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("type", "datasource");
+        map.put("name", dataSourceName);
+        map.put("tenant", tenantName);
+        map.put("updateable", dataContext instanceof UpdateableDataContext);
+        map.put("query_uri", UriBuilder.fromPath("/{tenant}/{dataContext}/query").build(tenantName, dataSourceName));
+        map.put("schemas", schemaLinks);
+        return map;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/QueryController.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/QueryController.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/QueryController.java
new file mode 100644
index 0000000..1cd6ed6
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/QueryController.java
@@ -0,0 +1,85 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.util.Arrays;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.data.DataSet;
+import org.apache.metamodel.membrane.app.TenantContext;
+import org.apache.metamodel.membrane.app.TenantRegistry;
+import org.apache.metamodel.query.Query;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping(value = { "/{tenant}/{dataContext}/query",
+        "/{tenant}/{dataContext}/q" }, produces = MediaType.APPLICATION_JSON_VALUE)
+public class QueryController {
+
+    private final TenantRegistry tenantRegistry;
+
+    @Autowired
+    public QueryController(TenantRegistry tenantRegistry) {
+        this.tenantRegistry = tenantRegistry;
+    }
+
+    @RequestMapping(method = RequestMethod.GET)
+    @ResponseBody
+    public Map<String, Object> get(@PathVariable("tenant") String tenantId,
+            @PathVariable("dataContext") String dataSourceName,
+            @RequestParam(value = "sql", required = true) String queryString,
+            @RequestParam(value = "offset", required = false) Integer offset,
+            @RequestParam(value = "limit", required = false) Integer limit) {
+        final TenantContext tenantContext = tenantRegistry.getTenantContext(tenantId);
+        final DataContext dataContext = tenantContext.getDataSourceRegistry().openDataContext(dataSourceName);
+
+        final Query query = dataContext.parseQuery(queryString);
+        
+        return executeQuery(dataContext, query, offset, limit);
+    }
+
+    public static Map<String, Object> executeQuery(DataContext dataContext, Query query, Integer offset, Integer limit) {
+
+        if (offset != null) {
+            query.setFirstRow(offset);
+        }
+        if (limit != null) {
+            query.setMaxRows(limit);
+        }
+
+        final DataSet dataSet = dataContext.executeQuery(query);
+
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("type", "dataset");
+        map.put("header", Arrays.stream(dataSet.getSelectItems()).map((si) -> si.toString()).collect(Collectors
+                .toList()));
+        map.put("data", dataSet.toObjectArrays());
+        return map;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/RestErrorHandler.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/RestErrorHandler.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/RestErrorHandler.java
new file mode 100644
index 0000000..5d79f56
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/RestErrorHandler.java
@@ -0,0 +1,160 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.metamodel.membrane.app.exceptions.AbstractIdentifierNamingException;
+import org.apache.metamodel.membrane.app.exceptions.DataSourceAlreadyExistException;
+import org.apache.metamodel.membrane.app.exceptions.DataSourceNotUpdateableException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchColumnException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchDataSourceException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchSchemaException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchTableException;
+import org.apache.metamodel.membrane.app.exceptions.NoSuchTenantException;
+import org.apache.metamodel.membrane.app.exceptions.TenantAlreadyExistException;
+import org.apache.metamodel.membrane.controllers.model.RestErrorResponse;
+import org.apache.metamodel.query.parser.QueryParserException;
+import org.springframework.http.HttpStatus;
+import org.springframework.validation.BindingResult;
+import org.springframework.validation.FieldError;
+import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ControllerAdvice
+public class RestErrorHandler {
+
+    /**
+     * Method binding issues (raised by Spring framework) - mapped to
+     * BAD_REQUEST.
+     * 
+     * @param ex
+     * @return
+     */
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ResponseBody
+    public RestErrorResponse processValidationError(MethodArgumentNotValidException ex) {
+        final BindingResult result = ex.getBindingResult();
+
+        final Map<String, Object> globalErrorsMap = new LinkedHashMap<>();
+        final List<ObjectError> globalErrors = result.getGlobalErrors();
+        for (ObjectError objectError : globalErrors) {
+            globalErrorsMap.put(objectError.getObjectName(), objectError.getDefaultMessage());
+        }
+
+        final List<FieldError> fieldErrors = result.getFieldErrors();
+        final Map<String, Object> fieldErrorsMap = new LinkedHashMap<>();
+        for (FieldError fieldError : fieldErrors) {
+            fieldErrorsMap.put(fieldError.getObjectName() + '.' + fieldError.getField(), fieldError
+                    .getDefaultMessage());
+        }
+
+        final Map<String, Object> additionalDetails = new LinkedHashMap<>();
+        if (!globalErrorsMap.isEmpty()) {
+            additionalDetails.put("global-errors", globalErrorsMap);
+        }
+        if (!fieldErrorsMap.isEmpty()) {
+            additionalDetails.put("field-errors", fieldErrorsMap);
+        }
+        final RestErrorResponse errorResponse = new RestErrorResponse(HttpStatus.BAD_REQUEST.value(),
+                "Failed to validate request");
+        if (!additionalDetails.isEmpty()) {
+            errorResponse.setAdditionalDetails(additionalDetails);
+        }
+        return errorResponse;
+    }
+
+    /**
+     * No such [Entity] exception handler method - mapped to NOT_FOUND.
+     * 
+     * @param ex
+     * @return
+     */
+    @ExceptionHandler({ NoSuchTenantException.class, NoSuchDataSourceException.class, NoSuchSchemaException.class,
+            NoSuchTableException.class, NoSuchColumnException.class })
+    @ResponseStatus(HttpStatus.NOT_FOUND)
+    @ResponseBody
+    public RestErrorResponse processNoSuchEntity(AbstractIdentifierNamingException ex) {
+        return new RestErrorResponse(HttpStatus.NOT_FOUND.value(), "Not found: " + ex.getIdentifier());
+    }
+
+    /**
+     * [Entity] already exist exception handler method - mapped to CONFLICT.
+     * 
+     * @param ex
+     * @return
+     */
+    @ExceptionHandler({ TenantAlreadyExistException.class, DataSourceAlreadyExistException.class })
+    @ResponseStatus(HttpStatus.CONFLICT)
+    @ResponseBody
+    public RestErrorResponse processEntityAlreadyExist(AbstractIdentifierNamingException ex) {
+        return new RestErrorResponse(HttpStatus.CONFLICT.value(), "Already exist: " + ex.getIdentifier());
+    }
+
+    /**
+     * DataSource not updateable exception handler method - mapped to
+     * BAD_REQUEST.
+     * 
+     * @param ex
+     * @return
+     */
+    @ExceptionHandler(DataSourceNotUpdateableException.class)
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ResponseBody
+    public RestErrorResponse processDataSourceNotUpdateable(DataSourceNotUpdateableException ex) {
+        return new RestErrorResponse(HttpStatus.BAD_REQUEST.value(), "DataSource not updateable: " + ex
+                .getDataSourceName());
+    }
+
+    /**
+     * Query parsing exception - mapped to BAD_REQUEST.
+     * 
+     * @param ex
+     * @return
+     */
+    @ExceptionHandler(QueryParserException.class)
+    @ResponseStatus(HttpStatus.BAD_REQUEST)
+    @ResponseBody
+    public RestErrorResponse processQueryParsingError(QueryParserException ex) {
+        return new RestErrorResponse(HttpStatus.BAD_REQUEST.value(), ex.getMessage());
+    }
+
+    /**
+     * Catch-all exception handler method - mapped to INTERNAL_SERVER_ERROR.
+     * 
+     * @param ex
+     * @return
+     */
+    @ExceptionHandler(Exception.class)
+    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+    @ResponseBody
+    public RestErrorResponse processAnyException(Exception ex) {
+        final Map<String, Object> additionalDetails = new HashMap<>();
+        additionalDetails.put("exception_type", ex.getClass().getName());
+        return new RestErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR.value(), ex.getMessage(), additionalDetails);
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/RootInformationController.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/RootInformationController.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/RootInformationController.java
new file mode 100644
index 0000000..0a624aa
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/RootInformationController.java
@@ -0,0 +1,102 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.io.InputStream;
+import java.net.InetAddress;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.Date;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Properties;
+
+import javax.servlet.ServletContext;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class RootInformationController {
+
+    private static final Logger logger = LoggerFactory.getLogger(RootInformationController.class);
+
+    @Autowired
+    ServletContext servletContext;
+
+    @RequestMapping(method = RequestMethod.GET, value = "/", produces = MediaType.APPLICATION_JSON_VALUE)
+    @ResponseBody
+    public Map<String, Object> index() {
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("ping", "pong!");
+        map.put("application", "Apache MetaModel Membrane");
+        map.put("version", getVersion());
+        map.put("server-time", getServerTime());
+        try {
+            map.put("canonical-hostname", InetAddress.getLocalHost().getCanonicalHostName());
+        } catch (Exception e) {
+            logger.info("Failed to get canonical-hostname", e);
+        }
+        map.put("open-api", getOpenApi());
+        return map;
+    }
+
+    private Map<String, Object> getOpenApi() {
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("spec", servletContext.getContextPath() + "/swagger.json");
+        return map;
+    }
+
+    private Map<String, Object> getServerTime() {
+        final ZonedDateTime now = ZonedDateTime.now();
+        final String dateFormatted = now.format(DateTimeFormatter.ISO_INSTANT);
+
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("timestamp", new Date().getTime());
+        map.put("iso8601", dateFormatted);
+        return map;
+    }
+
+    /**
+     * Does the slightly tedious task of reading the software version from
+     * META-INF based on maven metadata.
+     * 
+     * @return
+     */
+    private String getVersion() {
+        final String groupId = "org.apache.metamodel.membrane";
+        final String artifactId = "Membrane-core";
+        final String resourcePath = "/META-INF/maven/" + groupId + "/" + artifactId + "/pom.properties";
+        final Properties properties = new Properties();
+        try (final InputStream inputStream = RootInformationController.class.getResourceAsStream(resourcePath)) {
+            properties.load(inputStream);
+        } catch (Exception e) {
+            logger.error("Failed to load version from manifest: " + e.getMessage());
+        }
+
+        final String version = properties.getProperty("version", "UNKNOWN");
+        return version;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/SchemaController.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/SchemaController.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/SchemaController.java
new file mode 100644
index 0000000..0332138
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/SchemaController.java
@@ -0,0 +1,80 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.util.Arrays;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import javax.ws.rs.core.UriBuilder;
+
+import org.apache.metamodel.DataContext;
+import org.apache.metamodel.membrane.app.DataContextTraverser;
+import org.apache.metamodel.membrane.app.TenantContext;
+import org.apache.metamodel.membrane.app.TenantRegistry;
+import org.apache.metamodel.membrane.controllers.model.RestLink;
+import org.apache.metamodel.schema.Schema;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping(value = { "/{tenant}/{dataContext}/schemas/{schema}",
+        "/{tenant}/{dataContext}/s/{schema}" }, produces = MediaType.APPLICATION_JSON_VALUE)
+public class SchemaController {
+
+    private final TenantRegistry tenantRegistry;
+
+    @Autowired
+    public SchemaController(TenantRegistry tenantRegistry) {
+        this.tenantRegistry = tenantRegistry;
+    }
+
+    @RequestMapping(method = RequestMethod.GET)
+    @ResponseBody
+    public Map<String, Object> get(@PathVariable("tenant") String tenantId,
+            @PathVariable("dataContext") String dataSourceName, @PathVariable("schema") String schemaId) {
+        final TenantContext tenantContext = tenantRegistry.getTenantContext(tenantId);
+        final DataContext dataContext = tenantContext.getDataSourceRegistry().openDataContext(dataSourceName);
+
+        final DataContextTraverser traverser = new DataContextTraverser(dataContext);
+
+        final Schema schema = traverser.getSchema(schemaId);
+        final String tenantName = tenantContext.getTenantName();
+        final UriBuilder uriBuilder = UriBuilder.fromPath("/{tenant}/{dataContext}/s/{schema}/t/{table}");
+
+        final String schemaName = schema.getName();
+        final List<RestLink> tableLinks = Arrays.stream(schema.getTableNames()).map(t -> new RestLink(String.valueOf(t),
+                uriBuilder.build(tenantName, dataSourceName, schemaName, t))).collect(Collectors.toList());
+
+        final Map<String, Object> map = new LinkedHashMap<>();
+        map.put("type", "schema");
+        map.put("name", schemaName);
+        map.put("datasource", dataSourceName);
+        map.put("tenant", tenantName);
+        map.put("tables", tableLinks);
+        return map;
+    }
+}

http://git-wip-us.apache.org/repos/asf/metamodel-membrane/blob/6492107d/core/src/main/java/org/apache/metamodel/membrane/controllers/SwaggerSpecController.java
----------------------------------------------------------------------
diff --git a/core/src/main/java/org/apache/metamodel/membrane/controllers/SwaggerSpecController.java b/core/src/main/java/org/apache/metamodel/membrane/controllers/SwaggerSpecController.java
new file mode 100644
index 0000000..a01ef2f
--- /dev/null
+++ b/core/src/main/java/org/apache/metamodel/membrane/controllers/SwaggerSpecController.java
@@ -0,0 +1,64 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.metamodel.membrane.controllers;
+
+import java.io.InputStream;
+import java.util.Arrays;
+import java.util.Map;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+
+import org.apache.metamodel.util.FileHelper;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+
+@RestController
+public class SwaggerSpecController {
+
+    @Autowired
+    ServletContext servletContext;
+    
+    @RequestMapping(method = RequestMethod.GET, value = "/swagger.json", produces = MediaType.APPLICATION_JSON_VALUE)
+    @ResponseBody
+    public Map<String, Object> getSwaggerJson(HttpServletRequest req) throws Exception {
+        final String yaml;
+        try (final InputStream resource = getClass().getResourceAsStream("/swagger.yaml")) {
+            yaml = FileHelper.readInputStreamAsString(resource, FileHelper.UTF_8_ENCODING);
+        }
+
+        final ObjectMapper yamlReader = new ObjectMapper(new YAMLFactory());
+        @SuppressWarnings("unchecked")
+        final Map<String, Object> map = yamlReader.readValue(yaml, Map.class);
+
+        // add the base path, scheme and host
+        map.put("basePath", servletContext.getContextPath());
+        map.put("host", req.getServerName() + ":" + req.getServerPort());
+        map.put("schemes", Arrays.asList(req.getScheme()));
+
+        return map;
+    }
+}