[
https://issues.apache.org/jira/browse/DRILL-5660?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16127167#comment-16127167
]
ASF GitHub Bot commented on DRILL-5660:
---------------------------------------
Github user arina-ielchiieva commented on a diff in the pull request:
https://github.com/apache/drill/pull/877#discussion_r133177759
--- Diff:
exec/java-exec/src/main/java/org/apache/drill/exec/store/parquet/Metadata.java
---
@@ -543,78 +584,72 @@ private void readBlockMeta(String path,
mapper.registerModule(serialModule);
mapper.registerModule(module);
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,
false);
- FSDataInputStream is = fs.open(p);
-
- boolean alreadyCheckedModification = false;
- boolean newMetadata = false;
-
- if (metaContext != null) {
- alreadyCheckedModification = metaContext.getStatus(parentDirString);
- }
-
- if (dirsOnly) {
- parquetTableMetadataDirs = mapper.readValue(is,
ParquetTableMetadataDirs.class);
- logger.info("Took {} ms to read directories from directory cache
file", timer.elapsed(TimeUnit.MILLISECONDS));
- timer.stop();
- parquetTableMetadataDirs.updateRelativePaths(parentDirString);
- if (!alreadyCheckedModification &&
tableModified(parquetTableMetadataDirs.getDirectories(), p, parentDir,
metaContext)) {
- parquetTableMetadataDirs =
-
(createMetaFilesRecursively(Path.getPathWithoutSchemeAndAuthority(p.getParent()).toString())).getRight();
- newMetadata = true;
- }
- } else {
- parquetTableMetadata = mapper.readValue(is,
ParquetTableMetadataBase.class);
- logger.info("Took {} ms to read metadata from cache file",
timer.elapsed(TimeUnit.MILLISECONDS));
- timer.stop();
- if (parquetTableMetadata instanceof ParquetTableMetadata_v3) {
- ((ParquetTableMetadata_v3)
parquetTableMetadata).updateRelativePaths(parentDirString);
- }
- if (!alreadyCheckedModification &&
tableModified(parquetTableMetadata.getDirectories(), p, parentDir,
metaContext)) {
- parquetTableMetadata =
-
(createMetaFilesRecursively(Path.getPathWithoutSchemeAndAuthority(p.getParent()).toString())).getLeft();
- newMetadata = true;
- }
+ try (FSDataInputStream is = fs.open(path)) {
+ boolean alreadyCheckedModification = false;
+ boolean newMetadata = false;
+ alreadyCheckedModification =
metaContext.getStatus(metadataParentDirPath);
+
+ if (dirsOnly) {
+ parquetTableMetadataDirs = mapper.readValue(is,
ParquetTableMetadataDirs.class);
+ logger.info("Took {} ms to read directories from directory cache
file", timer.elapsed(TimeUnit.MILLISECONDS));
+ timer.stop();
+
parquetTableMetadataDirs.updateRelativePaths(metadataParentDirPath);
+ if (!alreadyCheckedModification &&
tableModified(parquetTableMetadataDirs.getDirectories(), path,
metadataParentDir, metaContext)) {
+ parquetTableMetadataDirs =
+
(createMetaFilesRecursively(Path.getPathWithoutSchemeAndAuthority(path.getParent()).toString())).getRight();
+ newMetadata = true;
+ }
+ } else {
+ parquetTableMetadata = mapper.readValue(is,
ParquetTableMetadataBase.class);
+ logger.info("Took {} ms to read metadata from cache file",
timer.elapsed(TimeUnit.MILLISECONDS));
+ timer.stop();
+ if (new
MetadataVersion(parquetTableMetadata.getMetadataVersion()).compareTo(new
MetadataVersion(3, 0)) >= 0) {
+ ((ParquetTableMetadata_v3)
parquetTableMetadata).updateRelativePaths(metadataParentDirPath);
+ }
+ if (!alreadyCheckedModification &&
tableModified(parquetTableMetadata.getDirectories(), path, metadataParentDir,
metaContext)) {
+ parquetTableMetadata =
+
(createMetaFilesRecursively(Path.getPathWithoutSchemeAndAuthority(path.getParent()).toString())).getLeft();
+ newMetadata = true;
+ }
- // DRILL-5009: Remove the RowGroup if it is empty
- List<? extends ParquetFileMetadata> files =
parquetTableMetadata.getFiles();
- for (ParquetFileMetadata file : files) {
- List<? extends RowGroupMetadata> rowGroups = file.getRowGroups();
- for (Iterator<? extends RowGroupMetadata> iter =
rowGroups.iterator(); iter.hasNext(); ) {
- RowGroupMetadata r = iter.next();
- if (r.getRowCount() == 0) {
- iter.remove();
+ // DRILL-5009: Remove the RowGroup if it is empty
+ List<? extends ParquetFileMetadata> files =
parquetTableMetadata.getFiles();
+ for (ParquetFileMetadata file : files) {
+ List<? extends RowGroupMetadata> rowGroups = file.getRowGroups();
+ for (Iterator<? extends RowGroupMetadata> iter =
rowGroups.iterator(); iter.hasNext(); ) {
+ RowGroupMetadata r = iter.next();
+ if (r.getRowCount() == 0) {
+ iter.remove();
+ }
}
}
- }
-
- }
- if (newMetadata && metaContext != null) {
- // if new metadata files were created, invalidate the existing
metadata context
- metaContext.clear();
+ }
+ if (newMetadata) {
+ // if new metadata files were created, invalidate the existing
metadata context
+ metaContext.clear();
+ }
+ } catch (IOException e) {
+ logger.error("Failed to read '{}' metadata file", path, e);
+ metaContext.setMetadataCacheCorrupted(true);
}
-
}
/**
* Check if the parquet metadata needs to be updated by comparing the
modification time of the directories with
* the modification time of the metadata file
*
- * @param directories
- * @param metaFilePath
- * @return
- * @throws IOException
+ * @param directories List of directories
+ * @param metaFilePath path of parquet metadata cache file
+ * @return true if metadata needs to be updated, false otherwise
+ * @throws IOException if some resources are not accessible
*/
- private boolean tableModified(List<String> directories, Path
metaFilePath,
- Path parentDir,
- MetadataContext metaContext)
+ private boolean tableModified(List<String> directories, Path
metaFilePath, Path parentDir, MetadataContext metaContext)
throws IOException {
Stopwatch timer = Stopwatch.createStarted();
- if (metaContext != null) {
- metaContext.setStatus(parentDir.toString());
- }
+ metaContext.setStatus(parentDir.toString());
--- End diff --
`parentDir.toUri().getPath()`?
> Drill 1.10 queries fail due to Parquet Metadata "corruption" from DRILL-3867
> ----------------------------------------------------------------------------
>
> Key: DRILL-5660
> URL: https://issues.apache.org/jira/browse/DRILL-5660
> Project: Apache Drill
> Issue Type: Bug
> Affects Versions: 1.11.0
> Reporter: Paul Rogers
> Assignee: Vitalii Diravka
> Labels: doc-impacting
> Fix For: 1.12.0
>
>
> Drill recently accepted a PR for the following bug:
> DRILL-3867: Store relative paths in metadata file
> This PR turned out to have a flaw which affects version compatibility.
> The DRILL-3867 PR changed the format of Parquet metadata files to store
> relative paths. All Drill servers after that PR create files with relative
> paths. But, the version number of the file is unchanged, so that older
> Drillbits don't know that they can't understand the file.
> Instead, if an older Drill tries to read the file, queries fail left and
> right. Drill will resolve the paths, but does so relative to the user's HDFS
> home directory, which is wrong.
> What should have happened is that we should have bumped the parquet metadata
> file version number so that older Drillbits can’t read the file. This ticket
> requests that we do that.
> Now, one could argue that the lack of version number change is fine. Once a
> user upgrades Drill, they won't use an old Drillbit. But, things are not that
> simple:
> * A developer tests a branch based on a pre-DRILL-3867 build on a cluster in
> which metadata files have been created by a post-DRILL-3867 build. (This has
> already occurred multiple times in our shop.)
> * A user tries to upgrade to Drill 1.11, finds an issue, and needs to roll
> back to Drill 1.10. Doing so will cause queries to fail due to
> seemingly-corrupt metadata files.
> * A user tries to do a rolling upgrade: running 1.11 on some servers, 1.10 on
> others. Once a 1.11 server is installed, the metadata is updated ("corrupted"
> from the perspective of 1.10) and queries fail.
> Standard practice in this scenario is to:
> * Bump the file version number when the file format changes, and
> * Software refuses to read files with a version newer than the software was
> designed for.
> Of course, it is highly desirable that newer servers read old files, but that
> is not the issue here.
> *Main technical points of working of parquet metadata caching for now.*
> Only process of reading the parquet metadata is changed (the process of
> writing isn't changed):
> +1. Metadata files are valid:+
> Metadata objects are created by deserialization of parquet metadata files in
> the process of creating ParquetGroupScan physical operator.
> All supported versions are stored in the "MetadataVersion.Constants" class
> and in the Jackson annotations for Metadata.ParquetTableMetadataBase class.
> +2. Metadata files version isn't supported (created by newer Drill version).
> Drill table has at least one metadata file of unsupported version:+
> JsonMappingException is obtained and swallowed without creating metadata
> object. Error message is logged. The state is stored in MetadataContext,
> therefore further there will be no attempt to deserialize metadata file again
> in context of performing current query. The physical plan will be created
> without using parquet metadata caching. Warning message is logged for every
> further check "is metadata corrupted".
> +3. Drill table has at least one corrupted metadata file, which can't be
> deserialized:+
> JsonParseException is obtained. Then the same behaviour as for the
> unsupported version files.
> +4. The metadata file was removed by other process:+
> FileNotFound is obtained. Then the same behaviour as for the unsupported
> version files.
> The new versions of metadata should be added in such manner:
> 1. Increasing of the metadata major version if metadata structure is changed.
> 2. Increasing of the metadata minor version if only metadata content is
> changed, but metadata structure is the same.
> For the first case a new metadata structure (class) should be created
> (possible an improvement of deserializing metadata files of any version into
> one strucure by using special converting)
> For the second case only annotation for the last metadata structure can be
> updated.
> *Summary*
> 1. Drill will read and use metadata files if files are valid, all present and
> supported. Under supported we mean that files were created before and under
> current Drill version.
> 2. Drill will ignore reading metadata files if at least one file is missing,
> empty, corrupted or unsupported. Under unsupported we mean files created
> after current Drill version. When metadata files are not used, warning
> message will be written to the logs.
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