[
https://issues.apache.org/jira/browse/BEAM-12824?focusedWorklogId=667568&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-667568
]
ASF GitHub Bot logged work on BEAM-12824:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 20/Oct/21 09:11
Start Date: 20/Oct/21 09:11
Worklog Time Spent: 10m
Work Description: mbenenso commented on a change in pull request #15434:
URL: https://github.com/apache/beam/pull/15434#discussion_r732569473
##########
File path:
sdks/java/io/deltalake/src/main/java/org/apache/beam/sdk/io/DeltaFileIO.java
##########
@@ -0,0 +1,653 @@
+package org.apache.beam.sdk.io;
+
+import com.google.auto.value.AutoValue;
+import io.delta.standalone.DeltaLog;
+import io.delta.standalone.Snapshot;
+import io.delta.standalone.actions.AddFile;
+import org.apache.beam.sdk.coders.StringUtf8Coder;
+import org.apache.beam.sdk.io.FileIO.ReadableFile;
+import org.apache.beam.sdk.io.fs.EmptyMatchTreatment;
+import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.options.ValueProvider;
+import org.apache.beam.sdk.options.ValueProvider.StaticValueProvider;
+import org.apache.beam.sdk.transforms.Contextful;
+import org.apache.beam.sdk.transforms.Create;
+import org.apache.beam.sdk.transforms.DoFn;
+import org.apache.beam.sdk.transforms.PTransform;
+import org.apache.beam.sdk.transforms.ParDo;
+import org.apache.beam.sdk.transforms.Requirements;
+import org.apache.beam.sdk.transforms.Reshuffle;
+import org.apache.beam.sdk.transforms.SerializableFunction;
+import org.apache.beam.sdk.transforms.Values;
+import org.apache.beam.sdk.transforms.Watch;
+import org.apache.beam.sdk.transforms.Watch.Growth.PollFn;
+import org.apache.beam.sdk.transforms.Watch.Growth.TerminationCondition;
+import org.apache.beam.sdk.transforms.display.DisplayData;
+import org.apache.beam.sdk.transforms.display.HasDisplayData;
+import org.apache.beam.sdk.values.PBegin;
+import org.apache.beam.sdk.values.PCollection;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.beam.sdk.io.hadoop.SerializableConfiguration;
+import org.joda.time.Duration;
+import org.joda.time.Instant;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.Nullable;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import static
org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Transforms for accessing Delta Lake files: listing files (matching) and
reading.
+ *
+ * <h2>Getting snapshot</h2>
+ *
+ * <p>{@link #snapshot} and {@link #matchAll} match filepatterns (respectively
either a single
+ * filepattern or a {@link PCollection} thereof) and return the files that
match them as {@link
+ * PCollection PCollections} of {@link MatchResult.Metadata}. Configuration
options for them are in
+ * {@link MatchConfiguration} and include features such as treatment of
filepatterns that don't
+ * match anything and continuous incremental matching of filepatterns
(watching for new files).
+ *
+ * <h3>Example: Watching a Delta Lake for new files</h3>
+ *
+ * <p>This example matches a single filepattern repeatedly every 30 seconds,
continuously returns
+ * new matched files as an unbounded {@code PCollection<Metadata>} and stops
if no new files appear
+ * for 1 hour.
+ *
+ * <pre>{@code
+ * PCollection<Metadata> matches = p.apply(DeltaFileIO.match()
+ * .filepattern("...")
+ * .continuously(
+ * Duration.standardSeconds(30),
afterTimeSinceNewOutput(Duration.standardHours(1))));
+ * }</pre>
+ *
+ * <h3>Example: Matching a Delta Lake directory for a specific version </h3>
+ *
+ * <p>This example reads Delta Lake parquet files for a version 5.
+ *
+ * <pre>{@code
+ * PCollection<Metadata> matches = p.apply(DeltaFileIO.match()
+ * .filepattern("...")
+ * .withVersion(5L)
+ * }</pre>
+ *
+ * <h2>Reading files</h2>
+ *
+ * <p>{@link #readMatches} converts each result of {@link #snapshot} or {@link
#matchAll} to a {@link
+ * ReadableFile} that is convenient for reading a file's contents, optionally
decompressing it.
+ *
+ * <h3>Example: Returning filenames of parquet files from the latest snapshot
in Delta Lake</h3>
+ * *
+ * <pre>{@code
+ pipeline
+ .apply("Get Snapshot",
+ DeltaFileIO.snapshot()
+ .filepattern(filePattern)
+ .withEmptyMatchTreatment(EmptyMatchTreatment.ALLOW)
+ )
+ .apply("Read matched files",
+ DeltaFileIO.readMatches()
+ )
+ .apply("Read parquet files",
+ ParquetIO.readFiles(<SCHEMA>)
+ )
+ * }</pre>
+ *
+ */
+
+@SuppressWarnings({
+ "nullness" // TODO(https://issues.apache.org/jira/browse/BEAM-10402)
+})
+public class DeltaFileIO
+{
+ private static final Logger LOG = LoggerFactory.getLogger(DeltaFileIO.class);
+
+ /**
+ * Process a filepattern using DeltaLake Standalone and produces a
collection of parquet files
+ * as {@link MatchResult.Metadata}.
+ *
+ * <p>By default, matches the filepattern once and produces a bounded {@link
PCollection}. To
+ * continuously watch the filepattern for new matches, use {@link
MatchAll#continuously(Duration,
+ * TerminationCondition)} - this will produce an unbounded {@link
PCollection}.
+ *
+ * <p>By default, a filepattern matching no resources is treated according
to {@link
+ * EmptyMatchTreatment#DISALLOW}. To configure this behavior, use {@link
+ * Match#withEmptyMatchTreatment}.
+ *
+ * <p>Returned {@link MatchResult.Metadata} are deduplicated by filename.
For example, if this
+ * transform observes a file with the same name several times with different
metadata (e.g.
+ * because the file is growing), it will emit the metadata the first time
this file is observed,
+ * and will ignore future changes to this file.
+ */
+ public static Match snapshot() {
+ return new AutoValue_DeltaFileIO_Match.Builder()
+
.setConfiguration(MatchConfiguration.create(EmptyMatchTreatment.DISALLOW))
+ .build();
+ }
+
+ /**
+ * Like {@link #snapshot}, but matches each filepattern in a collection of
filepatterns.
+ *
+ * <p>Resources are not deduplicated between filepatterns, i.e. if the same
resource matches
+ * multiple filepatterns, it will be produced multiple times.
+ *
+ * <p>By default, a filepattern matching no resources is treated according
to {@link
+ * EmptyMatchTreatment#ALLOW_IF_WILDCARD}. To configure this behavior, use
{@link
+ * MatchAll#withEmptyMatchTreatment}.
+ */
+ public static MatchAll matchAll() {
+ return new AutoValue_DeltaFileIO_MatchAll.Builder()
+
.setConfiguration(MatchConfiguration.create(EmptyMatchTreatment.ALLOW_IF_WILDCARD))
+ .build();
+ }
+
+ /**
+ * Converts each result of {@link #snapshot} or {@link #matchAll} to a
{@link ReadableFile} which can
+ * be used to read the contents of each file, optionally decompressing it.
+ */
+ public static ReadMatches readMatches() {
+ return new AutoValue_DeltaFileIO_ReadMatches.Builder()
+ .setCompression(Compression.AUTO)
+ .setDirectoryTreatment(ReadMatches.DirectoryTreatment.SKIP)
+ .build();
+ }
+
+
+ /**
+ * Describes configuration for matching filepatterns, such as {@link
EmptyMatchTreatment} and
+ * continuous watching for matching files.
+ */
+ @AutoValue
+ public abstract static class MatchConfiguration implements HasDisplayData,
Serializable {
+ /** Creates a {@link MatchConfiguration} with the given {@link
EmptyMatchTreatment}. */
+ public static MatchConfiguration create(EmptyMatchTreatment
emptyMatchTreatment) {
+ return new AutoValue_DeltaFileIO_MatchConfiguration.Builder()
+ .setEmptyMatchTreatment(emptyMatchTreatment)
+ .build();
+ }
+
+ public abstract EmptyMatchTreatment getEmptyMatchTreatment();
+
+ public abstract @Nullable Duration getWatchInterval();
+
+ abstract @Nullable TerminationCondition<String, ?>
getWatchTerminationCondition();
+
+ abstract @Nullable Long getVersion();
+
+ abstract @Nullable Long getTimestamp();
+
+ abstract @Nullable SerializableConfiguration getHadoopConfiguration();
+
+ abstract Builder toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder {
+ abstract Builder setEmptyMatchTreatment(EmptyMatchTreatment treatment);
+
+ abstract Builder setWatchInterval(Duration watchInterval);
+
+ abstract Builder
setWatchTerminationCondition(TerminationCondition<String, ?> condition);
+
+ abstract Builder setVersion(Long version);
+
+ abstract Builder setTimestamp(Long timestamp);
+
+ abstract Builder setHadoopConfiguration(SerializableConfiguration
hadoopConfiguration);
+
+ abstract MatchConfiguration build();
+ }
+
+ /** Sets the {@link EmptyMatchTreatment}. */
+ public MatchConfiguration withEmptyMatchTreatment(EmptyMatchTreatment
treatment) {
+ return toBuilder().setEmptyMatchTreatment(treatment).build();
+ }
+
+ public MatchConfiguration withVersion(Long version) {
+ return toBuilder().setVersion(version).build();
+ }
+
+ public MatchConfiguration withTimestamp(Long timestamp) {
+ return toBuilder().setTimestamp(timestamp).build();
+ }
+
+ public MatchConfiguration
withHadoopConfiguration(SerializableConfiguration hadoopConfiguration) {
+ return toBuilder().setHadoopConfiguration(hadoopConfiguration).build();
+ }
+
+ /**
+ * Continuously watches for new files at the given interval until the
given termination
+ * condition is reached, where the input to the condition is the
filepattern.
+ */
+ public MatchConfiguration continuously(
+ Duration interval, TerminationCondition<String, ?> condition) {
+ return
toBuilder().setWatchInterval(interval).setWatchTerminationCondition(condition).build();
+ }
+
+ @Override
+ public void populateDisplayData(DisplayData.Builder builder) {
+ builder
+ .add(
+ DisplayData.item("emptyMatchTreatment",
getEmptyMatchTreatment().toString())
+ .withLabel("Treatment of filepatterns that match no files"))
+ .addIfNotNull(
+ DisplayData.item("watchForNewFilesInterval", getWatchInterval())
+ .withLabel("Interval to watch for new files"));
+ }
+ }
+
+ /** Implementation of {@link #snapshot}. */
+ @AutoValue
+ public abstract static class Match extends PTransform<PBegin,
PCollection<MatchResult.Metadata>>
+ {
+ abstract @Nullable ValueProvider<String> getFilepattern();
+
+ abstract MatchConfiguration getConfiguration();
+
+ abstract Builder toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder {
+ abstract Builder setFilepattern(ValueProvider<String> filepattern);
+
+ abstract Builder setConfiguration(MatchConfiguration configuration);
+
+ abstract Match build();
+ }
+
+ /** Matches the given filepattern. */
+ public Match filepattern(String filepattern) {
+ return this.filepattern(StaticValueProvider.of(filepattern));
+ }
+
+ /** Like {@link #filepattern(String)} but using a {@link ValueProvider}. */
+ public Match filepattern(ValueProvider<String> filepattern) {
+ return toBuilder().setFilepattern(filepattern).build();
+ }
+
+ /** Sets the {@link MatchConfiguration}. */
+ public Match withConfiguration(MatchConfiguration configuration) {
+ return toBuilder().setConfiguration(configuration).build();
+ }
+
+ /** See {@link
MatchConfiguration#withEmptyMatchTreatment(EmptyMatchTreatment)}. */
+ public Match withEmptyMatchTreatment(EmptyMatchTreatment treatment) {
+ return
withConfiguration(getConfiguration().withEmptyMatchTreatment(treatment));
+ }
+
+ public Match withVersion(Long version) {
+ return withConfiguration(getConfiguration().withVersion(version));
+ }
+
+ public Match withTimestamp(Long timestamp) {
+ return withConfiguration(getConfiguration().withTimestamp(timestamp));
+ }
+
+ public Match withHadoopConfiguration(Configuration hadoopConfiguration) {
+ return withConfiguration(getConfiguration()
+ .withHadoopConfiguration(new
SerializableConfiguration(hadoopConfiguration)));
+ }
+
+ /**
+ * See {@link MatchConfiguration#continuously}. The returned {@link
PCollection} is unbounded.
+ *
+ * <p>This works only in runners supporting splittable {@link
+ * org.apache.beam.sdk.transforms.DoFn}.
+ */
+ public Match continuously(
+ Duration pollInterval, TerminationCondition<String, ?>
terminationCondition) {
+ return withConfiguration(getConfiguration().continuously(pollInterval,
terminationCondition));
+ }
+
+ @Override
+ public PCollection<MatchResult.Metadata> expand(PBegin input) {
+ return input
+ .apply("Delta Create Filepattern",
+ Create.ofProvider(getFilepattern(), StringUtf8Coder.of())
+ )
+ .apply("Delta Via MatchAll",
+ matchAll().withConfiguration(getConfiguration())
+ )
+ ;
+ }
+
+ @Override
+ public void populateDisplayData(DisplayData.Builder builder) {
+ super.populateDisplayData(builder);
+ builder
+ .addIfNotNull(
+ DisplayData.item("filePattern",
getFilepattern()).withLabel("Input File Pattern"))
+ .include("configuration", getConfiguration());
+ }
+ }
+
+ /** Implementation of {@link #matchAll}. */
+ @AutoValue
+ public abstract static class MatchAll
+ extends PTransform<PCollection<String>,
PCollection<MatchResult.Metadata>>
+ {
+ private static final Logger logger =
LoggerFactory.getLogger(MatchAll.class);
+
+ abstract MatchConfiguration getConfiguration();
+
+ abstract Builder toBuilder();
+
+ @AutoValue.Builder
+ abstract static class Builder {
+ abstract Builder setConfiguration(MatchConfiguration configuration);
+
+ abstract MatchAll build();
+ }
+
+ /** Like {@link Match#withConfiguration}. */
+ public MatchAll withConfiguration(MatchConfiguration configuration) {
+ return toBuilder().setConfiguration(configuration).build();
+ }
+
+ /** Like {@link Match#withEmptyMatchTreatment}. */
+ public MatchAll withEmptyMatchTreatment(EmptyMatchTreatment treatment) {
+ return
withConfiguration(getConfiguration().withEmptyMatchTreatment(treatment));
+ }
+
+ /** Like {@link Match#continuously}. */
+ public MatchAll continuously(
+ Duration pollInterval, TerminationCondition<String, ?>
terminationCondition) {
+ return withConfiguration(getConfiguration().continuously(pollInterval,
terminationCondition));
+ }
+
+ @Override
+ public PCollection<MatchResult.Metadata> expand(PCollection<String> input)
+ {
+ logger.info("matchAll config: {}", getConfiguration());
+
+ PCollection<MatchResult.Metadata> res;
+ if (getConfiguration().getWatchInterval() == null) {
+ res =
+ input.apply(
+ "Delta MatchAll FilePatterns",
+ ParDo.of(new MatchOnceFn(getConfiguration())));
+ } else {
+ res =
+ input.apply(
+ "Delta Continuously MatchAll filePatterns",
+ Watch.growthOf(
+ Contextful.of(new MatchPollFn(getConfiguration()),
Requirements.empty()),
+ new ExtractFilenameFn())
+
.withPollInterval(getConfiguration().getWatchInterval())
+
.withTerminationPerInput(getConfiguration().getWatchTerminationCondition()))
+ .apply(Values.create());
+ }
+ return res.apply("Delta Reshuffle files", Reshuffle.viaRandomKey());
+ }
+
+ @Override
+ public void populateDisplayData(DisplayData.Builder builder) {
+ super.populateDisplayData(builder);
+ builder.include("configuration", getConfiguration());
+ }
+
+ private static class MatchOnceFn extends DoFn<String, MatchResult.Metadata>
+ {
+ private final MatchConfiguration matchConfiguration;
+
+ MatchOnceFn(MatchConfiguration matchConfiguration) {
+ this.matchConfiguration = matchConfiguration;
+ }
+
+ @ProcessElement
+ public void process(ProcessContext c) throws Exception
+ {
+ LOG.info("DeltaFileIO:MatchOnceFn processing {}", matchConfiguration);
+
+ String filePattern = c.element();
+
+ Configuration hadoopConfiguration =
(matchConfiguration.getHadoopConfiguration() != null) ?
+ matchConfiguration.getHadoopConfiguration().get() : new
Configuration();
+
+ DeltaLog deltaLog = getDeltaLog(filePattern, hadoopConfiguration);
+ Snapshot deltaSnapshot = getDeltaSnapshot(deltaLog,
matchConfiguration);
+
+ List<AddFile> deltaFiles = deltaSnapshot.getAllFiles();
+
+ LOG.info("DeltaFileIO:MatchOnceFn DeltaLog.forTables: version={},
numberOfFiles={}",
+ deltaSnapshot.getVersion(), deltaFiles.size());
+
+ String separator = filePattern.endsWith("/") ? "" : "/";
+
+ for (AddFile file : deltaFiles) {
+ String fullPath = filePattern + separator + file.getPath();
+ MatchResult match = FileSystems.match(fullPath,
matchConfiguration.getEmptyMatchTreatment());
+ LOG.info("DeltaFileIO will process {}", match);
+ for (MatchResult.Metadata metadata : match.metadata()) {
+ c.output(metadata);
+ }
+ }
+ }
+ }
+
+ static DeltaLog getDeltaLog(String filePattern, Configuration
hadoopConfiguration)
+ {
+ // Delta standalone use Hadoop Filesystem, so need to replace s3 schema
+ String deltaFilePattern = (filePattern.startsWith("s3://")) ?
+ filePattern.replaceFirst("s3://", "s3a://") : filePattern;
+ LOG.info("DeltaFileIO trying DeltaLog.forTables for pattern {}",
deltaFilePattern);
+
+ DeltaLog deltaLog = DeltaLog.forTable(hadoopConfiguration,
deltaFilePattern);
+ return deltaLog;
+ }
+
+ static Snapshot getDeltaSnapshot(DeltaLog deltaLog, MatchConfiguration
matchConfiguration)
+ {
+ Snapshot deltaSnapshot;
+
+ if (matchConfiguration.getVersion() != null) {
+ logger.info("DeltaFileIO creating snapshot for version {}",
matchConfiguration.getVersion());
+ deltaSnapshot =
deltaLog.getSnapshotForVersionAsOf(matchConfiguration.getVersion());
+ } else if (matchConfiguration.getTimestamp() != null) {
+ logger.info("DeltaFileIO creating snapshot for timestamp {}",
matchConfiguration.getTimestamp());
+ deltaSnapshot =
deltaLog.getSnapshotForTimestampAsOf(matchConfiguration.getTimestamp());
+ } else {
+ logger.info("DeltaFileIO creating snapshot the latest version");
+ deltaSnapshot = deltaLog.snapshot();
+ }
+
+ return deltaSnapshot;
+ }
+
+ private static class MatchPollFn extends PollFn<String,
MatchResult.Metadata>
+ {
+ private final MatchConfiguration matchConfiguration;
+ private final long pollDutationMs;
+
+ private transient DeltaLog deltaLog = null;
+ private transient long deltaSnapshotVersion = -1;
+
+ MatchPollFn(MatchConfiguration matchConfiguration) {
+ this.matchConfiguration = matchConfiguration;
+ pollDutationMs =
matchConfiguration.getWatchInterval().getStandardSeconds() * 1000L;
+ LOG.info("DeltaFileIO.MatchPollFn created, pollDutationMs=" +
pollDutationMs);
+ }
+
+ @Override
+ public Watch.Growth.PollResult<MatchResult.Metadata> apply(String
filePattern, Context c) throws Exception
+ {
+ Instant now = Instant.now();
+
+ List<MatchResult.Metadata> filesMetadata;
+
+ Snapshot deltaSnapshot;
+ if (deltaLog == null) {
+ Configuration hadoopConfiguration =
(matchConfiguration.getHadoopConfiguration() != null) ?
+ matchConfiguration.getHadoopConfiguration().get() : new
Configuration();
+ deltaLog = getDeltaLog(filePattern, hadoopConfiguration);
+
+ deltaSnapshot = getDeltaSnapshot(deltaLog, matchConfiguration);
+ } else {
+ deltaSnapshot = deltaLog.update();
+ }
+
+ if (deltaSnapshot.getVersion() == deltaSnapshotVersion) {
+ // LOG.info("DeltaFileIO.MatchPollFn: No update for
deltaSnapshotVersion={}", deltaSnapshotVersion);
+ filesMetadata = Collections.EMPTY_LIST;
+ } else {
+ List<AddFile> deltaFiles = deltaSnapshot.getAllFiles();
+ LOG.info("DeltaFileIO.MatchPollFn: DeltaLog.updates, version={},
numberOfFiles={}",
+ deltaSnapshot.getVersion(), deltaFiles.size());
+
+ String separator = filePattern.endsWith("/") ? "" : "/";
+ filesMetadata = new ArrayList<>();
+ for (AddFile file : deltaFiles) {
+ String fullPath = filePattern + separator + file.getPath();
+ MatchResult match = FileSystems.match(fullPath,
matchConfiguration.getEmptyMatchTreatment());
+ // LOG.info("DeltaFileIO.MatchPollFn will process {}", match);
+ for (MatchResult.Metadata metadata : match.metadata()) {
+ filesMetadata.add(metadata);
+ }
+ }
+
+ deltaSnapshotVersion = deltaSnapshot.getVersion();
+ LOG.info("DeltaFileIO.MatchPollFn: for deltaSnapshotVersion={}
updating filesMetadata.size={}",
Review comment:
changed
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 667568)
Time Spent: 4h 40m (was: 4.5h)
> Beam Connector for Reading Data from Delta Lake
> -----------------------------------------------
>
> Key: BEAM-12824
> URL: https://issues.apache.org/jira/browse/BEAM-12824
> Project: Beam
> Issue Type: New Feature
> Components: sdk-java-core
> Affects Versions: 2.29.0
> Reporter: Michael
> Assignee: Michael
> Priority: P2
> Labels: features
> Time Spent: 4h 40m
> Remaining Estimate: 0h
>
> Beam Connector for Reading Data from Delta Lake
> Initial version is in [https://github.com/mbenenso/beam-deltalake] for the
> connector & [https://github.com/mbenenso/beam-deltalake-example] for the
> usage example.
>
> Consider to add it to the Beam repository
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
