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https://issues.apache.org/jira/browse/BEAM-4359?focusedWorklogId=195056&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-195056
]
ASF GitHub Bot logged work on BEAM-4359:
----------------------------------------
Author: ASF GitHub Bot
Created on: 06/Feb/19 13:01
Start Date: 06/Feb/19 13:01
Worklog Time Spent: 10m
Work Description: nielm commented on pull request #7747: [BEAM-4359]
Check for null values when encoding Key columns.
URL: https://github.com/apache/beam/pull/7747#discussion_r254260659
##########
File path:
sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/spanner/MutationKeyEncoder.java
##########
@@ -77,7 +77,7 @@ private void encodeKey(OrderedCode orderedCode, Mutation m) {
Map<String, Value> mutationMap = mutationAsMap(m);
for (SpannerSchema.KeyPart part : schema.getKeyParts(m.getTable())) {
Value val = mutationMap.get(part.getField());
- if (val.isNull()) {
+ if (val == null || val.isNull()) {
Review comment:
The database engine considers missing values as NULL - this code is
mimicking the same behavior.
Note also that this code is only concerned with Primary Key columns, and the
encoded value is only used for sorting mutations in a bundle by table and
primary key -- the value encoded here is never written to the database.
NOT NULL constraints can be set on any column. If the Mutation is an insert
and does not specify a column which is NOT NULL (or sets it to NULL), then the
insert will fail, and the Mutation appended to a PCollection of failed
MutationGroups which is output by the SpannerIO.Write transform.
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Issue Time Tracking
-------------------
Worklog Id: (was: 195056)
Time Spent: 40m (was: 0.5h)
> String encoding for a spanner mutation assumes that string length equals
> bytes length
> -------------------------------------------------------------------------------------
>
> Key: BEAM-4359
> URL: https://issues.apache.org/jira/browse/BEAM-4359
> Project: Beam
> Issue Type: Bug
> Components: io-java-gcp
> Affects Versions: 2.4.0
> Reporter: Sivanand
> Assignee: Chamikara Jayalath
> Priority: Major
> Fix For: 2.7.0
>
> Time Spent: 40m
> Remaining Estimate: 0h
>
> The bug is here:
> [https://github.com/apache/beam/blob/3ba96003d31ce98a54c0c51c1c0a9cf7c06e2fa2/sdks/java/io/google-cloud-platform/src/main/java/org/apache/beam/sdk/io/gcp/spanner/MutationGroupEncoder.java#L231-L235]
> {code:java}
> case STRING: {
> String str = value.getString();
> VarInt.encode(str.length(), bos);
> bos.write(str.getBytes(StandardCharsets.UTF_8));
> break;
> }
> {code}
>
> The code assumes that the number of bytes used to represent a UTF-8 String
> equals the string length. This is not true because a UTF-8 character can be
> encoded using 1 - 4 bytes.
> From wikipedia: [https://en.wikipedia.org/wiki/UTF-8]
> {quote}UTF-8 is a variable width character encoding capable of encoding all
> 1,112,064 valid code points in Unicode using one to four 8-bit bytes
> {quote}
> Code to recreate the issue:
> {code:java}
> /*
> Schema in spanner
> CREATE TABLE test (
> id INT64,
> testString STRING(MAX),
> number INT64,
> ) PRIMARY KEY (id)
> */
> import com.google.cloud.spanner.Mutation;
> import com.google.common.collect.Lists;
> import org.apache.beam.runners.direct.DirectRunner;
> import org.apache.beam.sdk.io.gcp.spanner.SpannerIO;
> import org.apache.beam.sdk.testing.TestPipeline;
> import org.apache.beam.sdk.transforms.Create;
> import org.apache.beam.sdk.transforms.DoFn;
> import org.apache.beam.sdk.transforms.ParDo;
> import org.junit.Rule;
> import org.junit.Test;
>
> import java.io.Serializable;
> import java.util.List;
>
> public class BeamSpannerTest implements Serializable {
>
> @Rule
> public transient TestPipeline pipeline = TestPipeline.create();
>
> @Test
> public void testSpanner() {
> pipeline.getOptions().setRunner(DirectRunner.class);
>
> List<String> strdata = Lists.newArrayList("၃7");
>
>
> pipeline.apply(
> Create.of(strdata)
> ).apply(ParDo.of(new DoFn<String, Mutation>() {
> @ProcessElement
> public void processElement(ProcessContext c) {
> String value = c.element();
> c.output(Mutation.newInsertOrUpdateBuilder("test")
> .set("id").to(1)
> .set("testString").to(value)
> .set("number").to(10)
> .build());
> }
> })
> ).apply("Write to Spanner", SpannerIO.write()
> .withProjectId("my-project")
> .withInstanceId("spanner-instance")
> .withDatabaseId("test")
> );
>
> pipeline.run();
> }
> }
> {code}
> After running the code, the value in the column {{number}} will be {{7043}}
> and not {{10}} because the bytes from the previous column {{testString}} have
> spilled into the {{number}}
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