[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF subversion and git services (Jira)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17152975#comment-17152975
 ] 

ASF subversion and git services commented on NIFI-5213:
---

Commit f040c6aadbedb0fb5e778e7e13069d66cc97af45 in nifi's branch 
refs/heads/main from Matt Burgess
[ https://gitbox.apache.org/repos/asf?p=nifi.git;h=f040c6a ]

NIFI-5213: Allow AvroReader to process files w embedded schema even when the 
access strategy is explicit schema
NIFI-5213: Incorporated review comments

This closes #2718

Signed-off-by: Mike Thomsen 


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>  Time Spent: 20m
>  Remaining Estimate: 0h
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF subversion and git services (Jira)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17152976#comment-17152976
 ] 

ASF subversion and git services commented on NIFI-5213:
---

Commit f040c6aadbedb0fb5e778e7e13069d66cc97af45 in nifi's branch 
refs/heads/main from Matt Burgess
[ https://gitbox.apache.org/repos/asf?p=nifi.git;h=f040c6a ]

NIFI-5213: Allow AvroReader to process files w embedded schema even when the 
access strategy is explicit schema
NIFI-5213: Incorporated review comments

This closes #2718

Signed-off-by: Mike Thomsen 


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>  Time Spent: 20m
>  Remaining Estimate: 0h
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16510191#comment-16510191
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user mattyb149 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194885270
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
--- End diff --

I checked this, it's a bit messy but I wasn't sure how else to do it. 
`decoder` is only used when parsing a "raw" Avro file, one without an embedded 
schema. For these changes, there are two scenarios:

1) The input is a raw Avro file. Then line 55 will throw an IOException and 
`decoder` will be set as it used to be (but this time in the catch). Then in 
nextAvroRecord it will drop through the `dataFileStream != null` check and use 
decoder (which is not null).
2) The input is an Avro file with an embedded schema. Then `dataFileStream` 
will not be null and nextAvroRecord() will return at line 86, before `decoder` 
is used.


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16510183#comment-16510183
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user mattyb149 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194883172
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/avro/TestAvroReaderWithExplicitSchema.java
 ---
@@ -0,0 +1,62 @@
+/*
+ * 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.nifi.avro;
+
+import org.apache.avro.Schema;
+import org.apache.nifi.serialization.SimpleRecordSchema;
+import org.apache.nifi.serialization.record.RecordSchema;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class TestAvroReaderWithExplicitSchema {
+
+@Test
+public void testAvroExplicitReaderWithSchemalessFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_schemaless.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
+}
+
+@Test
+public void testAvroExplicitReaderWithEmbeddedSchemaFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_embed_schema.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
+}
+
+@Test(expected = IOException.class)
--- End diff --

No from the constructor. I updated the test to make that more clear, thanks!


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

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[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16509485#comment-16509485
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user MikeThomsen commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194695221
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
+} catch (IOException ioe) {
+// Carry on, hopefully a raw Avro file
+// Need to be able to re-read the bytes read so far, and the 
InputStream passed in doesn't support reset. Use the TeeInputStream in
+// conjunction with SequenceInputStream to glue the two 
streams back together for future reading
+ByteArrayInputStream bais = new 
ByteArrayInputStream(baos.toByteArray());
+SequenceInputStream sis = new SequenceInputStream(bais, in);
+decoder = DecoderFactory.get().binaryDecoder(sis, null);
+}
+if (dataFileStream != null) {
+// Verify the schemas are the same
+Schema embeddedSchema = dataFileStream.getSchema();
+if (!embeddedSchema.equals(avroSchema)) {
+throw new IOException("Explicit schema does not match 
embedded schema");
--- End diff --

I don't think it's a show stopper here. The point of bringing it up was 
just to see if you had any input on it.


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an 

[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16509022#comment-16509022
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user mattyb149 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194590103
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
+} catch (IOException ioe) {
+// Carry on, hopefully a raw Avro file
+// Need to be able to re-read the bytes read so far, and the 
InputStream passed in doesn't support reset. Use the TeeInputStream in
+// conjunction with SequenceInputStream to glue the two 
streams back together for future reading
+ByteArrayInputStream bais = new 
ByteArrayInputStream(baos.toByteArray());
+SequenceInputStream sis = new SequenceInputStream(bais, in);
+decoder = DecoderFactory.get().binaryDecoder(sis, null);
+}
+if (dataFileStream != null) {
+// Verify the schemas are the same
+Schema embeddedSchema = dataFileStream.getSchema();
+if (!embeddedSchema.equals(avroSchema)) {
+throw new IOException("Explicit schema does not match 
embedded schema");
--- End diff --

I thought schema evolution was supported in other ways such as including 
optional (possibly missing) fields to support a transition to/from 
additional/deleted fields, but I admit I don't have my mind wrapped around the 
whole thing. In this case it was driven by the Avro API, if the file has a 
schema, there is a much more fluent API to read the records than if it does 
not. That is not for the case when someone wants to impose a schema on a file 
that already has a schema; I'm not sure that's a case for schema evolution 
(i.e. the embedded schema is not correct?), the alternate API is for "raw" Avro 
files that don't have an embedded schema, and instead need an external one for 
processing. TBH I don't know how to parse an Avro file that has an embedded 
schema with their API by imposing an external one. This was the middle ground 
to allow it as long as the external schema matched the embedded one. Thoughts?


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: 

[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16509019#comment-16509019
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user mattyb149 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194589636
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
--- End diff --

Sounds about right :) I was playing around with gluing these together and 
as soon as it "worked" I stopped touching it. Will take a closer look, thanks!


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16509018#comment-16509018
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user mattyb149 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194589527
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/avro/TestAvroReaderWithExplicitSchema.java
 ---
@@ -0,0 +1,62 @@
+/*
+ * 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.nifi.avro;
+
+import org.apache.avro.Schema;
+import org.apache.nifi.serialization.SimpleRecordSchema;
+import org.apache.nifi.serialization.record.RecordSchema;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class TestAvroReaderWithExplicitSchema {
+
+@Test
+public void testAvroExplicitReaderWithSchemalessFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_schemaless.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
--- End diff --

Probably, I think I did too much copy-paste in the tests instead of 
validating the individual things


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16508944#comment-16508944
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user MikeThomsen commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194575493
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/avro/TestAvroReaderWithExplicitSchema.java
 ---
@@ -0,0 +1,62 @@
+/*
+ * 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.nifi.avro;
+
+import org.apache.avro.Schema;
+import org.apache.nifi.serialization.SimpleRecordSchema;
+import org.apache.nifi.serialization.record.RecordSchema;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class TestAvroReaderWithExplicitSchema {
+
+@Test
+public void testAvroExplicitReaderWithSchemalessFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_schemaless.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
--- End diff --

As-is, this wouldn't test anything that I can tell with that method because 
all of the errors are caught in that method. Should have some assertions around 
it IMO.


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16508942#comment-16508942
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user MikeThomsen commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194575528
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/avro/TestAvroReaderWithExplicitSchema.java
 ---
@@ -0,0 +1,62 @@
+/*
+ * 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.nifi.avro;
+
+import org.apache.avro.Schema;
+import org.apache.nifi.serialization.SimpleRecordSchema;
+import org.apache.nifi.serialization.record.RecordSchema;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class TestAvroReaderWithExplicitSchema {
+
+@Test
+public void testAvroExplicitReaderWithSchemalessFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_schemaless.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
+}
+
+@Test
+public void testAvroExplicitReaderWithEmbeddedSchemaFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_embed_schema.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
--- End diff --

Same deal.


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16508943#comment-16508943
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user MikeThomsen commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194575701
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/test/java/org/apache/nifi/avro/TestAvroReaderWithExplicitSchema.java
 ---
@@ -0,0 +1,62 @@
+/*
+ * 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.nifi.avro;
+
+import org.apache.avro.Schema;
+import org.apache.nifi.serialization.SimpleRecordSchema;
+import org.apache.nifi.serialization.record.RecordSchema;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+
+public class TestAvroReaderWithExplicitSchema {
+
+@Test
+public void testAvroExplicitReaderWithSchemalessFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_schemaless.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
+}
+
+@Test
+public void testAvroExplicitReaderWithEmbeddedSchemaFile() throws 
Exception {
+File avroFileWithEmbeddedSchema = new 
File("src/test/resources/avro/avro_embed_schema.avro");
+FileInputStream fileInputStream = new 
FileInputStream(avroFileWithEmbeddedSchema);
+Schema dataSchema = new Schema.Parser().parse(new 
File("src/test/resources/avro/avro_schemaless.avsc"));
+RecordSchema recordSchema = new 
SimpleRecordSchema(dataSchema.toString(), AvroTypeUtil.AVRO_SCHEMA_FORMAT, 
null);
+
+AvroReaderWithExplicitSchema avroReader = new 
AvroReaderWithExplicitSchema(fileInputStream, recordSchema, dataSchema);
+avroReader.nextAvroRecord();
+}
+
+@Test(expected = IOException.class)
--- End diff --

I assume that comes from this, right?

```
if (dataFileStream != null) {
return dataFileStream.hasNext() ? dataFileStream.next() : null;
}
```


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded 

[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16508941#comment-16508941
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user MikeThomsen commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194576777
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
--- End diff --

I don't see where `decoder` is initialized outside of the try block, but 
it's used in `nextAvroRecord`. Shouldn't you initialize it here so it's 
guaranteed to be properly initialized when `nextAvroRecord` is called or are 
you just relying on the first if statement in that method as a null check?


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16508920#comment-16508920
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user MikeThomsen commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r194572498
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
+} catch (IOException ioe) {
+// Carry on, hopefully a raw Avro file
+// Need to be able to re-read the bytes read so far, and the 
InputStream passed in doesn't support reset. Use the TeeInputStream in
+// conjunction with SequenceInputStream to glue the two 
streams back together for future reading
+ByteArrayInputStream bais = new 
ByteArrayInputStream(baos.toByteArray());
+SequenceInputStream sis = new SequenceInputStream(bais, in);
+decoder = DecoderFactory.get().binaryDecoder(sis, null);
+}
+if (dataFileStream != null) {
+// Verify the schemas are the same
+Schema embeddedSchema = dataFileStream.getSchema();
+if (!embeddedSchema.equals(avroSchema)) {
+throw new IOException("Explicit schema does not match 
embedded schema");
--- End diff --

@mattyb149 How does it handle schema evolution in this case? It's possible 
that the Kafka producer has `Corporate Schema v1` and NiFi is configured with 
`Corporate Schema v2` and v2 gracefully allows an upgrade from v1 via Avro 
schema evolution rules. Or am I missing something about that being not really a 
thing WRT the Record API?


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is 

[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16482556#comment-16482556
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user mattyb149 commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r189606932
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
+} catch (IOException ioe) {
+// Carry on, hopefully a raw Avro file
+// Need to be able to re-read the bytes read so far, and the 
InputStream passed in doesn't support reset. Use the TeeInputStream in
+// conjunction with SequenceInputStream to glue the two 
streams back together for future reading
+ByteArrayInputStream bais = new 
ByteArrayInputStream(baos.toByteArray());
+SequenceInputStream sis = new SequenceInputStream(bais, in);
+decoder = DecoderFactory.get().binaryDecoder(sis, null);
+}
+if (dataFileStream != null) {
+// Verify the schemas are the same
+Schema embeddedSchema = dataFileStream.getSchema();
+if (!embeddedSchema.equals(avroSchema)) {
+throw new IOException("Explicit schema does not match 
embedded schema");
--- End diff --

It could be, if SchemaValidationException extended IOException instead of 
RuntimeException. The processors that end up creating this reader handle 
IOException but often handle a runtime exception with rollback (I couldn't find 
anything that explicitly catches SchemaValidationException. Also, although 
Javadoc is missing for that class, in RecordReader there is Javadoc for a 
parameter that says:

`throws SchemaValidationException if a Record contains a field that 
violates the schema and cannot be coerced into the appropriate field type.`

That's not exactly what's going on here, so I thought to keep it an 
IOException which may be handled by routing to failure rather than a rollback 
(which would prevent a flow from continuing if an Avro file showed up with an 
embedded that didn't exactly match the explicit one. It's still best practice 
to Use Embedded Schema instead of an explicit one, this was just supposed to 
make it a little easier on the user if they configured it differently.


> Allow AvroReader with explicit schema to read files with embedded schema
> 

[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16481426#comment-16481426
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

Github user bdesert commented on a diff in the pull request:

https://github.com/apache/nifi/pull/2718#discussion_r189422180
  
--- Diff: 
nifi-nar-bundles/nifi-standard-services/nifi-record-serialization-services-bundle/nifi-record-serialization-services/src/main/java/org/apache/nifi/avro/AvroReaderWithExplicitSchema.java
 ---
@@ -17,33 +17,61 @@
 
 package org.apache.nifi.avro;
 
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.SequenceInputStream;
 
 import org.apache.avro.Schema;
+import org.apache.avro.file.DataFileStream;
 import org.apache.avro.generic.GenericDatumReader;
 import org.apache.avro.generic.GenericRecord;
 import org.apache.avro.io.BinaryDecoder;
 import org.apache.avro.io.DatumReader;
 import org.apache.avro.io.DecoderFactory;
-import org.apache.nifi.schema.access.SchemaNotFoundException;
+import org.apache.commons.io.input.TeeInputStream;
 import org.apache.nifi.serialization.MalformedRecordException;
 import org.apache.nifi.serialization.record.RecordSchema;
 
 public class AvroReaderWithExplicitSchema extends AvroRecordReader {
 private final InputStream in;
 private final RecordSchema recordSchema;
 private final DatumReader datumReader;
-private final BinaryDecoder decoder;
+private BinaryDecoder decoder;
 private GenericRecord genericRecord;
+private DataFileStream dataFileStream;
 
-public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException, 
SchemaNotFoundException {
+public AvroReaderWithExplicitSchema(final InputStream in, final 
RecordSchema recordSchema, final Schema avroSchema) throws IOException {
 this.in = in;
 this.recordSchema = recordSchema;
 
-datumReader = new GenericDatumReader(avroSchema);
-decoder = DecoderFactory.get().binaryDecoder(in, null);
+datumReader = new GenericDatumReader<>(avroSchema);
+ByteArrayOutputStream baos = new ByteArrayOutputStream();
+TeeInputStream teeInputStream = new TeeInputStream(in, baos);
+// Try to parse as a DataFileStream, if it works, glue the streams 
back together and delegate calls to the DataFileStream
+try {
+dataFileStream = new DataFileStream<>(teeInputStream, new 
GenericDatumReader<>());
+} catch (IOException ioe) {
+// Carry on, hopefully a raw Avro file
+// Need to be able to re-read the bytes read so far, and the 
InputStream passed in doesn't support reset. Use the TeeInputStream in
+// conjunction with SequenceInputStream to glue the two 
streams back together for future reading
+ByteArrayInputStream bais = new 
ByteArrayInputStream(baos.toByteArray());
+SequenceInputStream sis = new SequenceInputStream(bais, in);
+decoder = DecoderFactory.get().binaryDecoder(sis, null);
+}
+if (dataFileStream != null) {
+// Verify the schemas are the same
+Schema embeddedSchema = dataFileStream.getSchema();
+if (!embeddedSchema.equals(avroSchema)) {
+throw new IOException("Explicit schema does not match 
embedded schema");
--- End diff --

Would it be better to throw SchemaValidationException - makes more sense 
than IOException?


> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> 

[jira] [Commented] (NIFI-5213) Allow AvroReader with explicit schema to read files with embedded schema

[ASF GitHub Bot (JIRA)]

[ 
https://issues.apache.org/jira/browse/NIFI-5213?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16480125#comment-16480125
 ] 

ASF GitHub Bot commented on NIFI-5213:
--

GitHub user mattyb149 opened a pull request:

https://github.com/apache/nifi/pull/2718

NIFI-5213: Allow AvroReader to process files w embedded schema even when 
the access strategy is explicit schema

Thank you for submitting a contribution to Apache NiFi.

In order to streamline the review of the contribution we ask you
to ensure the following steps have been taken:

### For all changes:
- [x] Is there a JIRA ticket associated with this PR? Is it referenced 
 in the commit message?

- [x] Does your PR title start with NIFI- where  is the JIRA number 
you are trying to resolve? Pay particular attention to the hyphen "-" character.

- [x] Has your PR been rebased against the latest commit within the target 
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- [x] Is your initial contribution a single, squashed commit?

### For code changes:
- [x] Have you ensured that the full suite of tests is executed via mvn 
-Pcontrib-check clean install at the root nifi folder?
- [x] Have you written or updated unit tests to verify your changes?
- [ ] If adding new dependencies to the code, are these dependencies 
licensed in a way that is compatible for inclusion under [ASF 
2.0](http://www.apache.org/legal/resolved.html#category-a)? 
- [ ] If applicable, have you updated the LICENSE file, including the main 
LICENSE file under nifi-assembly?
- [ ] If applicable, have you updated the NOTICE file, including the main 
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- [ ] If adding new Properties, have you added .displayName in addition to 
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- [ ] Have you ensured that format looks appropriate for the output in 
which it is rendered?

### Note:
Please ensure that once the PR is submitted, you check travis-ci for build 
issues and submit an update to your PR as soon as possible.


You can merge this pull request into a Git repository by running:

$ git pull https://github.com/mattyb149/nifi NIFI-5213

Alternatively you can review and apply these changes as the patch at:

https://github.com/apache/nifi/pull/2718.patch

To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:

This closes #2718


commit 40b9e110abadf802780e2d697aeab336b50094b9
Author: Matthew Burgess 
Date:   2018-05-18T04:29:52Z

NIFI-5213: Allow AvroReader to process files w embedded schema even when 
the access strategy is explicit schema




> Allow AvroReader with explicit schema to read files with embedded schema
> 
>
> Key: NIFI-5213
> URL: https://issues.apache.org/jira/browse/NIFI-5213
> Project: Apache NiFi
>  Issue Type: Improvement
>  Components: Extensions
>Reporter: Matt Burgess
>Assignee: Matt Burgess
>Priority: Minor
>
> AvroReader allows the choice of schema access strategy from such options as 
> Use Embedded Schema, Use Schema Name, Use Schema Text, etc. If the incoming 
> Avro files will have embedded schemas, then Use Embedded Schema is best 
> practice for the Avro Reader. However it is not intuitive that if the same 
> schema that is embedded in the file is specified by name (using a schema 
> registry) or explicitly via Schema Text, that errors can occur. This has been 
> noticed in QueryRecord for example, and the error is also not intuitive or 
> descriptive (it is often an ArrayIndexOutOfBoundsException).
> To provide a better user experience, it would be an improvement for 
> AvroReader to be able to successfully process Avro files with embedded 
> schemas, even when the Schema Access Strategy is not "Use Embedded Schema". 
> Of course, the explicit schema would have to match the embedded schema, or an 
> error would be reported (and rightfully so).



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