diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/external/ExternalIndexingOperations.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/external/ExternalIndexingOperations.java
index c8a9566..5df687a 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/external/ExternalIndexingOperations.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/app/external/ExternalIndexingOperations.java
@@ -38,7 +38,6 @@
 import org.apache.asterix.common.ioopcallbacks.LSMBTreeIOOperationCallbackFactory;
 import org.apache.asterix.common.ioopcallbacks.LSMBTreeWithBuddyIOOperationCallbackFactory;
 import org.apache.asterix.common.ioopcallbacks.LSMRTreeIOOperationCallbackFactory;
-import org.apache.asterix.runtime.util.AsterixRuntimeComponentsProvider;
 import org.apache.asterix.dataflow.data.nontagged.valueproviders.AqlPrimitiveValueProviderFactory;
 import org.apache.asterix.external.api.IAdapterFactory;
 import org.apache.asterix.external.indexing.ExternalFile;
@@ -71,6 +70,7 @@
 import org.apache.asterix.om.types.IAType;
 import org.apache.asterix.om.util.NonTaggedFormatUtil;
 import org.apache.asterix.runtime.util.AsterixAppContextInfo;
+import org.apache.asterix.runtime.util.AsterixRuntimeComponentsProvider;
 import org.apache.asterix.transaction.management.opcallbacks.SecondaryIndexOperationTrackerProvider;
 import org.apache.asterix.transaction.management.resource.ExternalBTreeLocalResourceMetadata;
 import org.apache.asterix.transaction.management.resource.PersistentLocalResourceFactoryProvider;
@@ -90,6 +90,7 @@
 import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
 import org.apache.hyracks.api.dataflow.value.ITypeTraits;
 import org.apache.hyracks.api.dataflow.value.RecordDescriptor;
+import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.api.job.JobSpecification;
 import org.apache.hyracks.dataflow.std.file.IFileSplitProvider;
 import org.apache.hyracks.storage.am.common.api.IPrimitiveValueProviderFactory;
@@ -255,13 +256,15 @@
      * @param files
      * @param indexerDesc
      * @return
-     * @throws AsterixException
+     * @throws AlgebricksException
+     * @throws HyracksDataException
      * @throws Exception
      */
     private static Pair<ExternalDataScanOperatorDescriptor, AlgebricksPartitionConstraint>
             getExternalDataIndexingOperator(
                     AqlMetadataProvider metadataProvider, JobSpecification jobSpec, IAType itemType, Dataset dataset,
-                    List<ExternalFile> files, RecordDescriptor indexerDesc) throws AsterixException {
+                    List<ExternalFile> files, RecordDescriptor indexerDesc)
+                    throws HyracksDataException, AlgebricksException {
         ExternalDatasetDetails externalDatasetDetails = (ExternalDatasetDetails) dataset.getDatasetDetails();
         Map<String, String> configuration = externalDatasetDetails.getProperties();
         IAdapterFactory adapterFactory = AdapterFactoryProvider.getIndexingAdapterFactory(
@@ -273,7 +276,7 @@
 
     public static Pair<ExternalDataScanOperatorDescriptor, AlgebricksPartitionConstraint> createExternalIndexingOp(
             JobSpecification spec, AqlMetadataProvider metadataProvider, Dataset dataset, ARecordType itemType,
-            RecordDescriptor indexerDesc, List<ExternalFile> files) throws AsterixException {
+            RecordDescriptor indexerDesc, List<ExternalFile> files) throws HyracksDataException, AlgebricksException {
         if (files == null) {
             files = MetadataManager.INSTANCE.getDatasetExternalFiles(metadataProvider.getMetadataTxnContext(), dataset);
         }
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/GenericAdapterFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/GenericAdapterFactory.java
index c7bed8d9..275825b 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/GenericAdapterFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/GenericAdapterFactory.java
@@ -22,7 +22,6 @@
 import java.util.Map;
 
 import org.apache.asterix.common.api.IAsterixAppRuntimeContext;
-import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.common.library.ILibraryManager;
 import org.apache.asterix.external.api.IAdapterFactory;
 import org.apache.asterix.external.api.IDataFlowController;
@@ -45,6 +44,7 @@
 import org.apache.asterix.external.util.FeedUtils;
 import org.apache.asterix.om.types.ARecordType;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.dataflow.std.file.FileSplit;
@@ -75,7 +75,8 @@
     }
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AsterixException {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint()
+            throws HyracksDataException, AlgebricksException {
         return dataSourceFactory.getPartitionConstraint();
     }
 
@@ -89,7 +90,7 @@
                 .getApplicationContext().getApplicationObject();
         try {
             restoreExternalObjects(runtimeCtx.getLibraryManager());
-        } catch (AsterixException e) {
+        } catch (Exception e) {
             throw new HyracksDataException(e);
         }
         if (isFeed) {
@@ -107,7 +108,8 @@
         }
     }
 
-    private void restoreExternalObjects(ILibraryManager libraryManager) throws AsterixException {
+    private void restoreExternalObjects(ILibraryManager libraryManager)
+            throws HyracksDataException, AlgebricksException {
         if (dataSourceFactory == null) {
             dataSourceFactory = DatasourceFactoryProvider.getExternalDataSourceFactory(libraryManager, configuration);
             // create and configure parser factory
@@ -126,7 +128,8 @@
     }
 
     @Override
-    public void configure(ILibraryManager libraryManager, Map<String, String> configuration) throws AsterixException {
+    public void configure(ILibraryManager libraryManager, Map<String, String> configuration)
+            throws HyracksDataException, AlgebricksException {
         this.configuration = configuration;
         ExternalDataUtils.validateDataSourceParameters(configuration);
         dataSourceFactory = DatasourceFactoryProvider.getExternalDataSourceFactory(libraryManager, configuration);
@@ -144,7 +147,7 @@
         nullifyExternalObjects();
     }
 
-    private void configureFeedLogManager() throws AsterixException {
+    private void configureFeedLogManager() throws HyracksDataException, AlgebricksException {
         this.isFeed = ExternalDataUtils.isFeed(configuration);
         if (isFeed) {
             feedLogFileSplits = FeedUtils.splitsForAdapter(ExternalDataUtils.getDataverse(configuration),
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/LookupAdapterFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/LookupAdapterFactory.java
index 01fcfc2..6b69d9c 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/LookupAdapterFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/adapter/factory/LookupAdapterFactory.java
@@ -21,7 +21,6 @@
 import java.io.Serializable;
 import java.util.Map;
 
-import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.common.library.ILibraryManager;
 import org.apache.asterix.external.api.ILookupReaderFactory;
 import org.apache.asterix.external.api.ILookupRecordReader;
@@ -34,6 +33,7 @@
 import org.apache.asterix.external.provider.LookupReaderFactoryProvider;
 import org.apache.asterix.external.provider.ParserFactoryProvider;
 import org.apache.asterix.om.types.ARecordType;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.comm.IFrameWriter;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.dataflow.value.IMissingWriterFactory;
@@ -77,7 +77,8 @@
         }
     }
 
-    public void configure(ILibraryManager libraryManager, Map<String, String> configuration) throws AsterixException {
+    public void configure(ILibraryManager libraryManager, Map<String, String> configuration)
+            throws HyracksDataException, AlgebricksException {
         this.configuration = configuration;
         readerFactory = LookupReaderFactoryProvider.getLookupReaderFactory(configuration);
         dataParserFactory = (IRecordDataParserFactory<T>) ParserFactoryProvider.getDataParserFactory(libraryManager,
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IAdapterFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IAdapterFactory.java
index 2d42ba9..3ea3bb1 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IAdapterFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IAdapterFactory.java
@@ -21,10 +21,10 @@
 import java.io.Serializable;
 import java.util.Map;
 
-import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.common.library.ILibraryManager;
 import org.apache.asterix.om.types.ARecordType;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 
@@ -52,8 +52,12 @@
      * constraint can be expressed as a node IP address or a node controller id.
      * In the former case, the IP address is translated to a node controller id
      * running on the node with the given IP address.
+     *
+     * @throws AlgebricksException
+     * @throws HyracksDataException
      */
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AsterixException;
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint()
+            throws HyracksDataException, AlgebricksException;
 
     /**
      * Creates an instance of IDatasourceAdapter.
@@ -68,9 +72,11 @@
     /**
      * @param libraryManager
      * @param configuration
-     * @throws Exception
+     * @throws AlgebricksException
+     * @throws HyracksDataException
      */
-    public void configure(ILibraryManager libraryManager, Map<String, String> configuration) throws AsterixException;
+    public void configure(ILibraryManager libraryManager, Map<String, String> configuration)
+            throws HyracksDataException, AlgebricksException;
 
     public void setOutputType(ARecordType outputType);
 
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IExternalDataSourceFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IExternalDataSourceFactory.java
index e4f21a6..6a237c6 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IExternalDataSourceFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/api/IExternalDataSourceFactory.java
@@ -20,12 +20,16 @@
 
 import java.io.Serializable;
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.Map;
+import java.util.Set;
 
 import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.runtime.util.AsterixAppContextInfo;
 import org.apache.asterix.runtime.util.AsterixClusterProperties;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
+import org.apache.hyracks.api.exceptions.HyracksDataException;
 
 public interface IExternalDataSourceFactory extends Serializable {
 
@@ -49,7 +53,8 @@
      * @return
      * @throws AsterixException
      */
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AsterixException;
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint()
+            throws AlgebricksException, HyracksDataException;
 
     /**
      * Configure the data parser factory. The passed map contains key value pairs from the
@@ -58,7 +63,7 @@
      * @param configuration
      * @throws AsterixException
      */
-    public void configure(Map<String, String> configuration) throws AsterixException;
+    public void configure(Map<String, String> configuration) throws AlgebricksException, HyracksDataException;
 
     /**
      * Specify whether the external data source can be indexed
@@ -69,30 +74,42 @@
         return false;
     }
 
+    /**
+     * returns the passed partition constraints if not null, otherwise returns round robin absolute partition
+     * constraints that matches the count.
+     *
+     * @param constraints
+     * @param count
+     * @return
+     * @throws AlgebricksException
+     */
     public static AlgebricksAbsolutePartitionConstraint getPartitionConstraints(
-            AlgebricksAbsolutePartitionConstraint constraints, int count) {
+            AlgebricksAbsolutePartitionConstraint constraints, int count) throws AlgebricksException {
         if (constraints == null) {
-            ArrayList<String> locs = new ArrayList<String>();
-            Map<String, String[]> stores = AsterixAppContextInfo.INSTANCE.getMetadataProperties().getStores();
+            ArrayList<String> locs = new ArrayList<>();
+            Set<String> stores = AsterixAppContextInfo.INSTANCE.getMetadataProperties().getStores().keySet();
+            if (stores.isEmpty()) {
+                throw new AlgebricksException("Configurations don't have any stores");
+            }
             int i = 0;
-            while (i < count) {
-                for (String node : stores.keySet()) {
+            outer: while (i < count) {
+                Iterator<String> storeIt = stores.iterator();
+                while (storeIt.hasNext()) {
+                    String node = storeIt.next();
                     int numIODevices = AsterixClusterProperties.INSTANCE.getIODevices(node).length;
                     for (int k = 0; k < numIODevices; k++) {
                         locs.add(node);
                         i++;
                         if (i == count) {
-                            break;
+                            break outer;
                         }
                     }
-                    if (i == count) {
-                        break;
-                    }
+                }
+                if (i == 0) {
+                    throw new AlgebricksException("All stores have 0 IO devices");
                 }
             }
-            String[] cluster = new String[locs.size()];
-            cluster = locs.toArray(cluster);
-            constraints = new AlgebricksAbsolutePartitionConstraint(cluster);
+            return new AlgebricksAbsolutePartitionConstraint(locs.toArray(new String[locs.size()]));
         }
         return constraints;
     }
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/rss/RSSRecordReaderFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/rss/RSSRecordReaderFactory.java
index f9eedd1..2ded3fb 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/rss/RSSRecordReaderFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/rss/RSSRecordReaderFactory.java
@@ -28,6 +28,7 @@
 import org.apache.asterix.external.api.IRecordReaderFactory;
 import org.apache.asterix.external.util.ExternalDataConstants;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 
@@ -45,7 +46,7 @@
     }
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AlgebricksException {
         int count = urls.size();
         clusterLocations = IExternalDataSourceFactory.getPartitionConstraints(clusterLocations, count);
         return clusterLocations;
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/stream/StreamRecordReaderFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/stream/StreamRecordReaderFactory.java
index f743a3f..4649559 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/stream/StreamRecordReaderFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/stream/StreamRecordReaderFactory.java
@@ -20,13 +20,13 @@
 
 import java.util.Map;
 
-import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.external.api.IInputStreamFactory;
 import org.apache.asterix.external.api.IRecordReader;
 import org.apache.asterix.external.api.IRecordReaderFactory;
 import org.apache.asterix.external.provider.StreamRecordReaderProvider;
 import org.apache.asterix.external.provider.StreamRecordReaderProvider.Format;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 
@@ -52,12 +52,13 @@
     }
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AsterixException {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint()
+            throws HyracksDataException, AlgebricksException {
         return streamFactory.getPartitionConstraint();
     }
 
     @Override
-    public void configure(Map<String, String> configuration) throws AsterixException {
+    public void configure(Map<String, String> configuration) throws HyracksDataException, AlgebricksException {
         this.configuration = configuration;
         streamFactory.configure(configuration);
         format = StreamRecordReaderProvider.getReaderFormat(configuration);
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/twitter/TwitterRecordReaderFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/twitter/TwitterRecordReaderFactory.java
index 172b22b..73d1b39 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/twitter/TwitterRecordReaderFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/record/reader/twitter/TwitterRecordReaderFactory.java
@@ -31,11 +31,11 @@
 import org.apache.asterix.external.util.TwitterUtil.AuthenticationConstants;
 import org.apache.asterix.external.util.TwitterUtil.SearchAPIConstants;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 
 import twitter4j.FilterQuery;
-import twitter4j.Status;
 
 public class TwitterRecordReaderFactory implements IRecordReaderFactory<String> {
 
@@ -55,7 +55,7 @@
     }
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AlgebricksException {
         clusterLocations = IExternalDataSourceFactory.getPartitionConstraints(clusterLocations, INTAKE_CARDINALITY);
         return clusterLocations;
     }
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/factory/SocketClientInputStreamFactory.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/factory/SocketClientInputStreamFactory.java
index 1eb760e..8ab8ead 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/factory/SocketClientInputStreamFactory.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/input/stream/factory/SocketClientInputStreamFactory.java
@@ -33,6 +33,7 @@
 import org.apache.asterix.external.util.ExternalDataConstants;
 import org.apache.http.impl.conn.SystemDefaultDnsResolver;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.algebricks.common.utils.Pair;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
@@ -44,7 +45,7 @@
     private List<Pair<String, Integer>> sockets;
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AlgebricksException {
         clusterLocations = IExternalDataSourceFactory.getPartitionConstraints(clusterLocations, sockets.size());
         return clusterLocations;
     }
diff --git a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/provider/AdapterFactoryProvider.java b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/provider/AdapterFactoryProvider.java
index 4cc8e33..059de63 100644
--- a/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/provider/AdapterFactoryProvider.java
+++ b/asterixdb/asterix-external-data/src/main/java/org/apache/asterix/external/provider/AdapterFactoryProvider.java
@@ -21,7 +21,6 @@
 import java.util.List;
 import java.util.Map;
 
-import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.common.library.ILibraryManager;
 import org.apache.asterix.external.adapter.factory.GenericAdapterFactory;
 import org.apache.asterix.external.adapter.factory.LookupAdapterFactory;
@@ -30,7 +29,9 @@
 import org.apache.asterix.external.indexing.ExternalFile;
 import org.apache.asterix.external.util.ExternalDataCompatibilityUtils;
 import org.apache.asterix.om.types.ARecordType;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.dataflow.value.IMissingWriterFactory;
+import org.apache.hyracks.api.exceptions.HyracksDataException;
 
 /**
  * This class represents the entry point to all things adapters
@@ -39,7 +40,8 @@
 
     // Adapters
     public static IAdapterFactory getAdapterFactory(ILibraryManager libraryManager, String adapterName,
-            Map<String, String> configuration, ARecordType itemType, ARecordType metaType) throws AsterixException {
+            Map<String, String> configuration, ARecordType itemType, ARecordType metaType)
+            throws HyracksDataException, AlgebricksException {
         ExternalDataCompatibilityUtils.prepare(adapterName, configuration);
         GenericAdapterFactory adapterFactory = new GenericAdapterFactory();
         adapterFactory.setOutputType(itemType);
@@ -51,7 +53,7 @@
     // Indexing Adapters
     public static IIndexingAdapterFactory getIndexingAdapterFactory(ILibraryManager libraryManager, String adapterName,
             Map<String, String> configuration, ARecordType itemType, List<ExternalFile> snapshot, boolean indexingOp,
-            ARecordType metaType) throws AsterixException {
+            ARecordType metaType) throws HyracksDataException, AlgebricksException {
         ExternalDataCompatibilityUtils.prepare(adapterName, configuration);
         GenericAdapterFactory adapterFactory = new GenericAdapterFactory();
         adapterFactory.setOutputType(itemType);
@@ -64,7 +66,8 @@
     // Lookup Adapters
     public static LookupAdapterFactory<?> getLookupAdapterFactory(ILibraryManager libraryManager,
             Map<String, String> configuration, ARecordType recordType, int[] ridFields, boolean retainInput,
-            boolean retainMissing, IMissingWriterFactory missingWriterFactory) throws AsterixException {
+            boolean retainMissing, IMissingWriterFactory missingWriterFactory)
+            throws HyracksDataException, AlgebricksException {
         LookupAdapterFactory<?> adapterFactory = new LookupAdapterFactory<>(recordType, ridFields, retainInput,
                 retainMissing, missingWriterFactory);
         adapterFactory.configure(libraryManager, configuration);
diff --git a/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/input/record/reader/RecordWithPKTestReaderFactory.java b/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/input/record/reader/RecordWithPKTestReaderFactory.java
index 87c187a..3467411 100644
--- a/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/input/record/reader/RecordWithPKTestReaderFactory.java
+++ b/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/input/record/reader/RecordWithPKTestReaderFactory.java
@@ -25,6 +25,7 @@
 import org.apache.asterix.external.api.IRecordReaderFactory;
 import org.apache.asterix.external.input.record.RecordWithPK;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 
 public class RecordWithPKTestReaderFactory implements IRecordReaderFactory<RecordWithPK<char[]>> {
@@ -33,7 +34,7 @@
     private transient AlgebricksAbsolutePartitionConstraint clusterLocations;
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AlgebricksException {
         clusterLocations = IExternalDataSourceFactory.getPartitionConstraints(clusterLocations, 1);
         return clusterLocations;
     }
diff --git a/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/library/adapter/TestTypedAdapterFactory.java b/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/library/adapter/TestTypedAdapterFactory.java
index d45097a..20cb2bc 100644
--- a/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/library/adapter/TestTypedAdapterFactory.java
+++ b/asterixdb/asterix-external-data/src/test/java/org/apache/asterix/external/library/adapter/TestTypedAdapterFactory.java
@@ -24,7 +24,6 @@
 
 import org.apache.asterix.common.cluster.ClusterPartition;
 import org.apache.asterix.common.config.IAsterixPropertiesProvider;
-import org.apache.asterix.common.exceptions.AsterixException;
 import org.apache.asterix.common.library.ILibraryManager;
 import org.apache.asterix.external.api.IAdapterFactory;
 import org.apache.asterix.external.api.IDataSourceAdapter;
@@ -36,6 +35,7 @@
 import org.apache.asterix.external.util.FeedUtils;
 import org.apache.asterix.om.types.ARecordType;
 import org.apache.hyracks.algebricks.common.constraints.AlgebricksAbsolutePartitionConstraint;
+import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
 import org.apache.hyracks.api.comm.IFrameWriter;
 import org.apache.hyracks.api.context.IHyracksTaskContext;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
@@ -62,7 +62,7 @@
     }
 
     @Override
-    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AsterixException {
+    public AlgebricksAbsolutePartitionConstraint getPartitionConstraint() throws AlgebricksException {
         clusterLocations = IExternalDataSourceFactory.getPartitionConstraints(clusterLocations, 1);
         return clusterLocations;
     }
@@ -78,9 +78,11 @@
                 ADMDataParser parser;
                 ITupleForwarder forwarder;
                 ArrayTupleBuilder tb;
-                IAsterixPropertiesProvider propertiesProvider = (IAsterixPropertiesProvider) ((NodeControllerService) ctx
-                        .getJobletContext().getApplicationContext().getControllerService()).getApplicationContext()
-                                .getApplicationObject();
+                IAsterixPropertiesProvider propertiesProvider =
+                        (IAsterixPropertiesProvider) ((NodeControllerService) ctx
+                                .getJobletContext().getApplicationContext().getControllerService())
+                                        .getApplicationContext()
+                                        .getApplicationObject();
                 ClusterPartition nodePartition = propertiesProvider.getMetadataProperties().getNodePartitions()
                         .get(nodeId)[0];
                 parser = new ADMDataParser(outputType, true);
diff --git a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/util/LangRecordParseUtil.java b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/util/LangRecordParseUtil.java
index a604315..c46b0be 100644
--- a/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/util/LangRecordParseUtil.java
+++ b/asterixdb/asterix-lang-common/src/main/java/org/apache/asterix/lang/common/util/LangRecordParseUtil.java
@@ -19,6 +19,8 @@
 package org.apache.asterix.lang.common.util;
 
 import java.io.Serializable;
+import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
 
 import org.apache.asterix.builders.OrderedListBuilder;
@@ -39,6 +41,7 @@
 import org.apache.asterix.om.base.AString;
 import org.apache.asterix.om.types.ARecordType;
 import org.apache.asterix.om.types.BuiltinType;
+import org.apache.hyracks.algebricks.common.utils.Pair;
 import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
 import org.apache.hyracks.api.exceptions.HyracksDataException;
 import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
@@ -68,7 +71,7 @@
                 parseLiteral((LiteralExpr) expr, serialized);
                 break;
             case RECORD_CONSTRUCTOR_EXPRESSION:
-                parseRecord((RecordConstructor) expr, serialized, true);
+                parseRecord((RecordConstructor) expr, serialized, true, Collections.emptyList());
                 break;
             case LIST_CONSTRUCTOR_EXPRESSION:
                 parseList((ListConstructor) expr, serialized);
@@ -82,7 +85,8 @@
         }
     }
 
-    public static void parseRecord(RecordConstructor recordValue, ArrayBackedValueStorage serialized, boolean tagged)
+    public static void parseRecord(RecordConstructor recordValue, ArrayBackedValueStorage serialized, boolean tagged,
+            List<Pair<String, String>> defaults)
             throws HyracksDataException {
         AMutableString fieldNameString = new AMutableString(null);
         ArrayBackedValueStorage fieldName = new ArrayBackedValueStorage();
@@ -91,30 +95,48 @@
         recordBuilder.reset(ARecordType.FULLY_OPEN_RECORD_TYPE);
         recordBuilder.init();
         List<FieldBinding> fbList = recordValue.getFbList();
+        HashSet<String> fieldNames = new HashSet<>();
         for (FieldBinding fb : fbList) {
             fieldName.reset();
             fieldValue.reset();
             // get key
-            Expression keyExpr = fb.getLeftExpr();
-            if (keyExpr.getKind() != Expression.Kind.LITERAL_EXPRESSION) {
-                throw new HyracksDataException(ErrorCode.ASTERIX, ErrorCode.ERROR_PARSE_ERROR,
-                        "JSON key can only be of type %1$s", Expression.Kind.LITERAL_EXPRESSION);
+            fieldNameString.setValue(exprToStringLiteral(fb.getLeftExpr()).getStringValue());
+            if (!fieldNames.add(fieldNameString.getStringValue())) {
+                throw new HyracksDataException(
+                        "Field " + fieldNameString.getStringValue() + " was specified multiple times");
             }
-            LiteralExpr keyLiteralExpr = (LiteralExpr) keyExpr;
-            Literal keyLiteral = keyLiteralExpr.getValue();
-            if (keyLiteral.getLiteralType() != Literal.Type.STRING) {
-                throw new HyracksDataException(ErrorCode.ASTERIX, ErrorCode.ERROR_PARSE_ERROR,
-                        "JSON key can only be of type %1$s", Literal.Type.STRING);
-            }
-            fieldNameString.setValue(keyLiteral.getStringValue());
             stringSerde.serialize(fieldNameString, fieldName.getDataOutput());
             // get value
             parseExpression(fb.getRightExpr(), fieldValue);
             recordBuilder.addField(fieldName, fieldValue);
         }
+        // defaults
+        for (Pair<String, String> kv : defaults) {
+            if (!fieldNames.contains(kv.first)) {
+                fieldName.reset();
+                fieldValue.reset();
+                stringSerde.serialize(new AString(kv.first), fieldName.getDataOutput());
+                stringSerde.serialize(new AString(kv.second), fieldValue.getDataOutput());
+                recordBuilder.addField(fieldName, fieldValue);
+            }
+        }
         recordBuilder.write(serialized.getDataOutput(), tagged);
     }
 
+    public static Literal exprToStringLiteral(Expression expr) throws HyracksDataException {
+        if (expr.getKind() != Expression.Kind.LITERAL_EXPRESSION) {
+            throw new HyracksDataException(ErrorCode.ASTERIX, ErrorCode.ERROR_PARSE_ERROR,
+                    "Expected expression can only be of type %1$s", Expression.Kind.LITERAL_EXPRESSION);
+        }
+        LiteralExpr keyLiteralExpr = (LiteralExpr) expr;
+        Literal keyLiteral = keyLiteralExpr.getValue();
+        if (keyLiteral.getLiteralType() != Literal.Type.STRING) {
+            throw new HyracksDataException(ErrorCode.ASTERIX, ErrorCode.ERROR_PARSE_ERROR,
+                    "Expected Literal can only be of type %1$s", Literal.Type.STRING);
+        }
+        return keyLiteral;
+    }
+
     private static void parseList(ListConstructor valueExpr, ArrayBackedValueStorage serialized)
             throws HyracksDataException {
         if (valueExpr.getType() != ListConstructor.Type.ORDERED_LIST_CONSTRUCTOR) {
diff --git a/asterixdb/asterix-om/src/main/java/org/apache/asterix/dataflow/data/nontagged/serde/ARecordSerializerDeserializer.java b/asterixdb/asterix-om/src/main/java/org/apache/asterix/dataflow/data/nontagged/serde/ARecordSerializerDeserializer.java
index c69c89e..55c9d13 100644
--- a/asterixdb/asterix-om/src/main/java/org/apache/asterix/dataflow/data/nontagged/serde/ARecordSerializerDeserializer.java
+++ b/asterixdb/asterix-om/src/main/java/org/apache/asterix/dataflow/data/nontagged/serde/ARecordSerializerDeserializer.java
@@ -21,6 +21,7 @@
 import java.io.DataInput;
 import java.io.DataOutput;
 import java.io.IOException;
+import java.util.List;
 
 import org.apache.asterix.builders.IARecordBuilder;
 import org.apache.asterix.builders.RecordBuilder;
@@ -39,6 +40,7 @@
 import org.apache.asterix.om.types.BuiltinType;
 import org.apache.asterix.om.types.IAType;
 import org.apache.asterix.om.util.NonTaggedFormatUtil;
+import org.apache.hyracks.algebricks.common.utils.Pair;
 import org.apache.hyracks.api.dataflow.value.IBinaryComparator;
 import org.apache.hyracks.api.dataflow.value.IBinaryHashFunction;
 import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
@@ -210,6 +212,26 @@
         confRecordBuilder.write(dataOutput, writeTypeTag);
     }
 
+    @SuppressWarnings("unchecked")
+    public static void serializeSimpleSchemalessRecord(List<Pair<String, String>> record, DataOutput dataOutput,
+            boolean writeTypeTag)
+            throws HyracksDataException {
+        ISerializerDeserializer<AString> stringSerde = AqlSerializerDeserializerProvider.INSTANCE
+                .getSerializerDeserializer(BuiltinType.ASTRING);
+        RecordBuilder confRecordBuilder = new RecordBuilder();
+        confRecordBuilder.reset(ARecordType.FULLY_OPEN_RECORD_TYPE);
+        ArrayBackedValueStorage fieldNameBytes = new ArrayBackedValueStorage();
+        ArrayBackedValueStorage fieldValueBytes = new ArrayBackedValueStorage();
+        for (int i = 0; i < record.size(); i++) {
+            fieldValueBytes.reset();
+            fieldNameBytes.reset();
+            stringSerde.serialize(new AString(record.get(i).first), fieldNameBytes.getDataOutput());
+            stringSerde.serialize(new AString(record.get(i).second), fieldValueBytes.getDataOutput());
+            confRecordBuilder.addField(fieldNameBytes, fieldValueBytes);
+        }
+        confRecordBuilder.write(dataOutput, writeTypeTag);
+    }
+
     private IAObject[] mergeFields(IAObject[] closedFields, IAObject[] openFields) {
         IAObject[] fields = new IAObject[closedFields.length + openFields.length];
         int i = 0;