[Issue #4]: update docs.

README.md

@@ -1,23 +1,21 @@
 # pixels-trino
 The Pixels connector for Trino.
 
-**This project is under development, and not ready to be used.**
-
 ## Compatibility
-Pixels integration (connector & event listener) is currently compatible with Trino 374. 
+Pixels integration (connector & event listener) is currently compatible with Trino 375. 
 Other Trino versions that are compatible
-with the Connector SPI in Trino 374 should also work well with Pixels.
+with the Connector SPI in Trino 375 should also work well with Pixels.
 
 ## Build
 This project can be opened as a maven project in Intellij and built using maven.
 
-**Note** that Trino 374 requires Java 11, thus this project should be build by Jdk 11 (11.0.11 is tested).
+**Note** that Trino 375 requires Java 11, thus this project should be build by Jdk 11 (11.0.11 is tested).
 
 [Pixels](https://github.com/pixelsdb/pixels) is the parent of this project,
 therefore use `mvn install` to install Pixels modules into your local maven repository,
 before building this project.
 
 ## Use Pixels in Trino
 
-Ensure that Pixels and other prerequisites are installed following the instructions
-[here](https://github.com/pixelsdb/pixels#installation-in-aws).
+Follow the instructions
+[here](https://github.com/pixelsdb/pixels#installation-in-aws) to install Pixels and use it in Trino.

connector/src/main/java/io/pixelsdb/pixels/trino/PixelsConnector.java

@@ -25,7 +25,9 @@
 import io.pixelsdb.pixels.common.transaction.QueryTransInfo;
 import io.pixelsdb.pixels.common.transaction.TransContext;
 import io.pixelsdb.pixels.common.transaction.TransService;
+import io.pixelsdb.pixels.optimizer.queue.QueryQueues;
 import io.pixelsdb.pixels.trino.exception.PixelsErrorCode;
+import io.pixelsdb.pixels.trino.impl.PixelsMetadataProxy;
 import io.pixelsdb.pixels.trino.impl.PixelsTrinoConfig;
 import io.pixelsdb.pixels.trino.properties.PixelsSessionProperties;
 import io.pixelsdb.pixels.trino.properties.PixelsTableProperties;
@@ -36,13 +38,17 @@
 
 import javax.inject.Inject;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
+
 import static java.util.Objects.requireNonNull;
 
-public class PixelsConnector implements Connector {
+public class PixelsConnector implements Connector
+{
     private static final Logger logger = Logger.get(PixelsConnector.class);
 
+    private final PixelsConnectorId connectorId;
     private final LifeCycleManager lifeCycleManager;
-    private final PixelsMetadata metadata;
+    private final PixelsMetadataProxy metadataProxy;
     private final PixelsSplitManager splitManager;
     private final boolean recordCursorEnabled;
     private final PixelsPageSourceProvider pageSourceProvider;
@@ -54,16 +60,19 @@ public class PixelsConnector implements Connector {
 
     @Inject
     public PixelsConnector(
+            PixelsConnectorId connectorId,
             LifeCycleManager lifeCycleManager,
-            PixelsMetadata metadata,
+            PixelsMetadataProxy metadataProxy,
             PixelsSplitManager splitManager,
             PixelsTrinoConfig config,
             PixelsPageSourceProvider pageSourceProvider,
             PixelsRecordSetProvider recordSetProvider,
             PixelsSessionProperties sessionProperties,
-            PixelsTableProperties tableProperties) {
+            PixelsTableProperties tableProperties)
+    {
+        this.connectorId = requireNonNull(connectorId, "connectorId is null");
         this.lifeCycleManager = requireNonNull(lifeCycleManager, "lifeCycleManager is null");
-        this.metadata = requireNonNull(metadata, "metadata is null");
+        this.metadataProxy = requireNonNull(metadataProxy, "metadataProxy is null");
         this.splitManager = requireNonNull(splitManager, "splitManager is null");
         this.pageSourceProvider = requireNonNull(pageSourceProvider, "recordSetProvider is null");
         this.recordSetProvider = requireNonNull(recordSetProvider, "recordSetProvider is null");
@@ -93,7 +102,29 @@ public ConnectorTransactionHandle beginTransaction(IsolationLevel isolationLevel
             throw new TrinoException(PixelsErrorCode.PIXELS_TRANS_SERVICE_ERROR, e);
         }
         TransContext.Instance().beginQuery(info);
-        return new PixelsTransactionHandle(info.getQueryId(), info.getQueryTimestamp());
+        QueryQueues.ExecutorType executorType;
+        if (config.getLambdaSwitch() == PixelsTrinoConfig.LambdaSwitch.AUTO)
+        {
+            while ((executorType = QueryQueues.Instance().Enqueue(info.getQueryId())) == QueryQueues.ExecutorType.None)
+            {
+                try
+                {
+                    TimeUnit.SECONDS.sleep(1);
+                } catch (InterruptedException e)
+                {
+                    logger.error("Interrupted while waiting for enqueue the query id.");
+                }
+            }
+        }
+        else if (config.getLambdaSwitch() == PixelsTrinoConfig.LambdaSwitch.ON)
+        {
+            executorType = QueryQueues.ExecutorType.Lambda;
+        }
+        else
+        {
+            executorType = QueryQueues.ExecutorType.Cluster;
+        }
+        return new PixelsTransactionHandle(info.getQueryId(), info.getQueryTimestamp(), executorType);
     }
 
     @Override
@@ -102,6 +133,7 @@ public void commit(ConnectorTransactionHandle transactionHandle)
         if (transactionHandle instanceof PixelsTransactionHandle)
         {
             PixelsTransactionHandle handle = (PixelsTransactionHandle) transactionHandle;
+            QueryQueues.Instance().Dequeue(handle.getTransId(), handle.getExecutorType());
             TransContext.Instance().commitQuery(handle.getTransId());
             cleanIntermediatePathForQuery(handle.getTransId());
         } else
@@ -117,8 +149,12 @@ public void rollback(ConnectorTransactionHandle transactionHandle)
         if (transactionHandle instanceof PixelsTransactionHandle)
         {
             PixelsTransactionHandle handle = (PixelsTransactionHandle) transactionHandle;
+            QueryQueues.Instance().Dequeue(handle.getTransId(), handle.getExecutorType());
             TransContext.Instance().rollbackQuery(handle.getTransId());
-            cleanIntermediatePathForQuery(handle.getTransId());
+            if (handle.getExecutorType() == QueryQueues.ExecutorType.Lambda)
+            {
+                cleanIntermediatePathForQuery(handle.getTransId());
+            }
         } else
         {
             throw new TrinoException(PixelsErrorCode.PIXELS_TRANS_HANDLE_TYPE_ERROR,
@@ -128,26 +164,23 @@ public void rollback(ConnectorTransactionHandle transactionHandle)
 
     private void cleanIntermediatePathForQuery(long queryId)
     {
-        if (config.isLambdaEnabled())
+        try
         {
-            try
+            if (config.isCleanLocalResult())
             {
-                if (config.isCleanLocalResult())
-                {
-                    IntermediateFileCleaner.Instance().asyncDelete(config.getOutputFolderForQuery(queryId));
-                }
-            } catch (InterruptedException e)
-            {
-                throw new TrinoException(PixelsErrorCode.PIXELS_STORAGE_ERROR,
-                        "Failed to clean intermediate path for the query");
+                IntermediateFileCleaner.Instance().asyncDelete(config.getOutputFolderForQuery(queryId));
             }
+        } catch (InterruptedException e)
+        {
+            throw new TrinoException(PixelsErrorCode.PIXELS_STORAGE_ERROR,
+                    "Failed to clean intermediate path for the query");
         }
     }
 
     @Override
-    public ConnectorMetadata getMetadata(ConnectorSession session, ConnectorTransactionHandle transactionHandle)
+    public ConnectorMetadata getMetadata(ConnectorSession session, ConnectorTransactionHandle transHandle)
     {
-        return metadata;
+        return new PixelsMetadata(connectorId, metadataProxy, config, (PixelsTransactionHandle) transHandle);
     }
 
     @Override

connector/src/main/java/io/pixelsdb/pixels/trino/PixelsMetadata.java

@@ -33,6 +33,7 @@
 import io.pixelsdb.pixels.core.stats.StatsRecorder;
 import io.pixelsdb.pixels.executor.aggregation.FunctionType;
 import io.pixelsdb.pixels.optimizer.plan.Table;
+import io.pixelsdb.pixels.optimizer.queue.QueryQueues;
 import io.pixelsdb.pixels.trino.exception.PixelsErrorCode;
 import io.pixelsdb.pixels.trino.impl.PixelsMetadataProxy;
 import io.pixelsdb.pixels.trino.impl.PixelsTrinoConfig;
@@ -47,7 +48,6 @@
 import io.trino.spi.statistics.Estimate;
 import io.trino.spi.statistics.TableStatistics;
 
-import javax.inject.Inject;
 import java.nio.ByteBuffer;
 import java.util.*;
 
@@ -71,13 +71,15 @@ public class PixelsMetadata implements ConnectorMetadata
     private final String connectorId;
     private final PixelsMetadataProxy metadataProxy;
     private final PixelsTrinoConfig config;
+    private final PixelsTransactionHandle transHandle;
 
-    @Inject
-    public PixelsMetadata(PixelsConnectorId connectorId, PixelsMetadataProxy metadataProxy, PixelsTrinoConfig config)
+    public PixelsMetadata(PixelsConnectorId connectorId, PixelsMetadataProxy metadataProxy,
+                          PixelsTrinoConfig config, PixelsTransactionHandle transHandle)
     {
         this.connectorId = requireNonNull(connectorId, "connectorId is null").toString();
         this.metadataProxy = requireNonNull(metadataProxy, "metadataProxy is null");
         this.config = requireNonNull(config, "config is null");
+        this.transHandle = requireNonNull(transHandle, "transHandle is null");
     }
 
     @Override
@@ -541,7 +543,7 @@ public Optional<AggregationApplicationResult<ConnectorTableHandle>> applyAggrega
             ConnectorSession session, ConnectorTableHandle handle, List<AggregateFunction> aggregates,
             Map<String, ColumnHandle> assignments, List<List<ColumnHandle>> groupingSets)
     {
-        if (!config.isLambdaEnabled())
+        if (transHandle.getExecutorType() != QueryQueues.ExecutorType.Lambda)
         {
             return Optional.empty();
         }
@@ -664,7 +666,7 @@ public Optional<JoinApplicationResult<ConnectorTableHandle>> applyJoin(
             Map<String, ColumnHandle> rightAssignments,
             JoinStatistics statistics)
     {
-        if (!config.isLambdaEnabled())
+        if (transHandle.getExecutorType() != QueryQueues.ExecutorType.Lambda)
         {
             return Optional.empty();
         }

connector/src/main/java/io/pixelsdb/pixels/trino/PixelsModule.java

@@ -47,7 +47,6 @@ public void configure(Binder binder) {
         binder.bind(PixelsConnector.class).in(Scopes.SINGLETON);
         binder.bind(PixelsConnectorId.class).toInstance(new PixelsConnectorId(connectorId));
         binder.bind(PixelsTypeParser.class).in(Scopes.SINGLETON);
-        binder.bind(PixelsMetadata.class).in(Scopes.SINGLETON);
         binder.bind(PixelsMetadataProxy.class).in(Scopes.SINGLETON);
         binder.bind(PixelsSplitManager.class).in(Scopes.SINGLETON);
         binder.bind(PixelsPageSourceProvider.class).in(Scopes.SINGLETON);

connector/src/main/java/io/pixelsdb/pixels/trino/PixelsPageSourceProvider.java

@@ -40,6 +40,7 @@
 import io.pixelsdb.pixels.executor.lambda.output.ScanOutput;
 import io.pixelsdb.pixels.executor.predicate.TableScanFilter;
 import io.pixelsdb.pixels.optimizer.plan.Table;
+import io.pixelsdb.pixels.optimizer.queue.QueryQueues;
 import io.pixelsdb.pixels.trino.exception.PixelsErrorCode;
 import io.pixelsdb.pixels.trino.impl.PixelsTrinoConfig;
 import io.trino.spi.TrinoException;
@@ -142,7 +143,9 @@ else if (config.getOutputScheme() == Storage.Scheme.redis)
             {
                 // perform scan push down.
                 List<PixelsColumnHandle> withFilterColumns = getIncludeColumns(pixelsColumns, tableHandle);
-                if (config.isLambdaEnabled() && this.localSplitCounter.get() >= config.getLocalScanConcurrency())
+                PixelsTransactionHandle transHandle = (PixelsTransactionHandle) transactionHandle;
+                if (transHandle.getExecutorType() == QueryQueues.ExecutorType.Lambda &&
+                        this.localSplitCounter.get() >= config.getLocalScanConcurrency())
                 {
                     String[] columnsToRead = new String[withFilterColumns.size()];
                     boolean[] projection = new boolean[withFilterColumns.size()];

connector/src/main/java/io/pixelsdb/pixels/trino/PixelsRecordSetProvider.java

@@ -24,6 +24,7 @@
 import io.pixelsdb.pixels.common.physical.Storage;
 import io.pixelsdb.pixels.common.physical.StorageFactory;
 import io.pixelsdb.pixels.core.PixelsFooterCache;
+import io.pixelsdb.pixels.optimizer.queue.QueryQueues;
 import io.pixelsdb.pixels.trino.exception.PixelsErrorCode;
 import io.pixelsdb.pixels.trino.impl.PixelsTrinoConfig;
 import io.trino.spi.TrinoException;
@@ -75,7 +76,7 @@ public PixelsRecordSetProvider(PixelsConnectorId connectorId, PixelsTrinoConfig
     public RecordSet getRecordSet(ConnectorTransactionHandle transaction, ConnectorSession session,
                                   ConnectorSplit split, ConnectorTableHandle table, List<? extends ColumnHandle> columns)
     {
-        if (config.isLambdaEnabled())
+        if (((PixelsTransactionHandle) transaction).getExecutorType() == QueryQueues.ExecutorType.Lambda)
         {
             throw new TrinoException(PixelsErrorCode.PIXELS_CONFIG_ERROR,
                     "PixelsRecordSet does not support lambda coprocessor.");

connector/src/main/java/io/pixelsdb/pixels/trino/PixelsTransactionHandle.java

@@ -21,32 +21,41 @@
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import io.pixelsdb.pixels.optimizer.queue.QueryQueues;
 import io.trino.spi.connector.ConnectorTransactionHandle;
 
 public class PixelsTransactionHandle implements ConnectorTransactionHandle
 {
-    public static final PixelsTransactionHandle Default = new PixelsTransactionHandle(-1, -1);
+    public static final PixelsTransactionHandle Default = new PixelsTransactionHandle(
+            -1, -1, QueryQueues.ExecutorType.None);
 
     /**
-     * transId is also the query id, as each query is a single-statement read-only transaction.
+     * transId is also the query id in Pixels, as each query is a single-statement read-only transaction.
      */
     private final long transId;
     /**
      * The timestamp that is used to get a read snapshot of the query.
      */
     private final long timestamp;
+    /**
+     * The type of executor to execute this query.
+     */
+    private final QueryQueues.ExecutorType executorType;
 
     /**
      * Create a transaction handle.
-     * @param transId is also the queryId as a query is a single-statement read-only transaction.
+     * @param transId is also the query id in Pixels, as a query is a single-statement read-only transaction.
      * @param timestamp the timestamp of a transaction.
+     * @param executorType the type of executor to execute this query.
      */
     @JsonCreator
     public PixelsTransactionHandle(@JsonProperty("transId") long transId,
-                                   @JsonProperty("timestamp") long timestamp)
+                                   @JsonProperty("timestamp") long timestamp,
+                                   @JsonProperty("executorType")QueryQueues.ExecutorType executorType)
     {
         this.transId = transId;
         this.timestamp = timestamp;
+        this.executorType = executorType;
     }
 
     @JsonProperty
@@ -60,4 +69,10 @@ public long getTimestamp()
     {
         return this.timestamp;
     }
+
+    @JsonProperty
+    public QueryQueues.ExecutorType getExecutorType()
+    {
+        return this.executorType;
+    }
 }

connector/src/main/java/io/pixelsdb/pixels/trino/impl/PixelsTrinoConfig.java

@@ -47,8 +47,10 @@ public static int getBatchSize()
         return BatchSize;
     }
 
+    public enum LambdaSwitch { ON, OFF, AUTO }
+
     private String pixelsConfig = null;
-    private boolean lambdaEnabled = false;
+    private LambdaSwitch lambdaSwitch = LambdaSwitch.AUTO;
     private boolean cleanLocalResult = true;
     private int localScanConcurrency = -1;
     private Storage.Scheme outputScheme = null;
@@ -124,10 +126,10 @@ public PixelsTrinoConfig setPixelsConfig (String pixelsConfig)
         return this;
     }
 
-    @Config("lambda.enabled")
-    public PixelsTrinoConfig setLambdaEnabled(boolean enabled)
+    @Config("lambda.switch")
+    public PixelsTrinoConfig setLambdaSwitch(String lambdaSwitch)
     {
-        this.lambdaEnabled = enabled;
+        this.lambdaSwitch = LambdaSwitch.valueOf(lambdaSwitch.toUpperCase());
         return this;
     }
 
@@ -190,9 +192,10 @@ public String getPixelsConfig ()
         return this.pixelsConfig;
     }
 
-    public boolean isLambdaEnabled()
+    @NotNull
+    public LambdaSwitch getLambdaSwitch()
     {
-        return lambdaEnabled;
+        return lambdaSwitch;
     }
 
     public int getLocalScanConcurrency()

connector/src/main/resources/pixels.properties

@@ -8,7 +8,8 @@ connector.name=pixels
 pixels.config=/home/pixels/opt/pixels/pixels.properties
 
 # serverless config
-lambda.enabled=false
+# lambda.switch can be on, off, auto
+lambda.switch=auto
 local.scan.concurrency=40
 clean.local.result=true
 output.scheme=output-scheme-dummy