[FLINK-13503][API] Add contract in `LookupableTableSource` to specify the behavior when lookupKeys contains null. #9335

beyond1920 · 2019-08-02T08:16:58Z

What is the purpose of the change

Add contract in LookupableTableSource to specify the behavior when lookupKeys contains null.
And update existed connector to comply with this contract.

Brief change log

Add contract in LookupableTableSource to specify the behavior when lookupKeys contains null.
Update HBase lookupFunction
Update JDBC lookupFunction

Verifying this change

existed IT.

Does this pull request potentially affect one of the following parts:

Dependencies (does it add or upgrade a dependency): no
The public API, i.e., is any changed class annotated with @Public(Evolving): yes
The serializers: no
The runtime per-record code paths (performance sensitive): no
Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: no
The S3 file system connector: no

Documentation

Does this pull request introduce a new feature? no
If yes, how is the feature documented? not applicable

beyond1920 · 2019-08-02T08:18:23Z

cc @JingsongLi @wuchong @lincoln-lil

flinkbot · 2019-08-02T08:18:56Z

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flinkbot · 2019-08-02T08:28:49Z

CI report:

3d97f63 : CANCELED Build
d23affc : CANCELED Build
6efd9ce : CANCELED Build
e84da4e : FAILURE Build
e134e61 : FAILURE Build

lincoln-lil · 2019-08-02T08:50:29Z

If I understand this issue correctly, should it just convert the null key into xx is null clause for JDBCLookupFunction instead of is not distinct from clause or other variant?

beyond1920 · 2019-08-02T09:00:11Z

@lincoln-lil The issue aims to specify the behavior when the lookupKeys contains null value. It has no relationship with is not distinct from clause.

lincoln-lil · 2019-08-02T09:32:37Z

...onnectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java

@@ -101,7 +105,7 @@ public JDBCLookupFunction(
 		this.maxRetryTimes = lookupOptions.getMaxRetryTimes();
 		this.keySqlTypes = Arrays.stream(keyTypes).mapToInt(JDBCTypeUtil::typeInformationToSqlType).toArray();
 		this.outputSqlTypes = Arrays.stream(fieldTypes).mapToInt(JDBCTypeUtil::typeInformationToSqlType).toArray();
-		this.query = options.getDialect().getSelectFromStatement(
+		this.query = options.getDialect().getSelectNotDistinctFromStatement(


Will this query performance poor against the older one?

Good question, I would add two prepareStatement with two query template, if arguments does not contain any null value, it using original query template; else use the new one. Ok?

lincoln-lil · 2019-08-02T10:02:00Z

...e/flink-table-common/src/main/java/org/apache/flink/table/sources/LookupableTableSource.java

 	 * @param lookupKeys the chosen field names as lookup keys, it is in the defined order
+	 *
+	 * <p>IMPORTANT:
+	 * If the returned {@link TableFunction} receives a lookup request with null value in lookup keys, expect


Give more detailed comments here maybe more clearly for understanding,

lookupKeys are nullable

should carefully deal with null value lookup in each concrete store engine, e.g., in MySQL this can a is null query
...

OK, I'll try to explain more clearly in the comment

lincoln-lil

LGTM! Only minor comments here.

...onnectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java

...e/flink-table-common/src/main/java/org/apache/flink/table/sources/LookupableTableSource.java

...onnectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java

… the behavior when lookupKeys contains null.

…or to avoid illegalArgument exception when create Get object.

… when there is null value in input data of eval.

wuchong

Thanks @beyond1920 , I left some comments.

wuchong · 2019-08-05T06:19:47Z

...e/flink-table-common/src/main/java/org/apache/flink/table/sources/LookupableTableSource.java

+	 * name  |   STRING
+	 * -----------------
+	 * For the external system which does not support null value (E.g, HBase does not support null value on rowKey),
+	 * it could throw an exception or discard the request when receiving a request with null value on lookup key.


Please never throw an exception. We should discard the request because HBase don't have null rowkeys.

wuchong · 2019-08-05T06:20:04Z

...e/flink-table-common/src/main/java/org/apache/flink/table/sources/LookupableTableSource.java

 	 * @param lookupKeys the chosen field names as lookup keys, it is in the defined order
 	 */
 	TableFunction<T> getLookupFunction(String[] lookupKeys);

 	/**
 	 * Gets the {@link AsyncTableFunction} which supports async lookup one key at a time.
+	 *


Please update javadoc of this method too.

wuchong · 2019-08-05T06:22:59Z

...-connectors/flink-hbase/src/main/java/org/apache/flink/addons/hbase/HBaseLookupFunction.java

+		Get get;
+		try {
+			get = readHelper.createGet(row);
+		} catch (IllegalArgumentException e) {


We shouldn't use try catch to do this job in performance critical code. We can return if length of row is zero.

wuchong · 2019-08-05T06:23:16Z

...ctors/flink-hbase/src/main/java/org/apache/flink/addons/hbase/util/HBaseReadWriteHelper.java

+	 * @return serialize bytes.
+	 */
+	public byte[] serialize(Object rowKey) {
+		byte[] key = HBaseTypeUtils.serializeFromObject(


return HBaseTypeUtils.serializeFromObject(...

wuchong · 2019-08-08T03:22:49Z

...ctors/flink-hbase/src/main/java/org/apache/flink/addons/hbase/util/HBaseReadWriteHelper.java

-			rowKeyType,
-			charset);
-		Get get = new Get(rowkey);
+	public Get createGet(byte[] row) {


row -> rowkey

wuchong · 2019-08-08T03:38:26Z

...-connectors/flink-hbase/src/main/java/org/apache/flink/addons/hbase/HBaseLookupFunction.java

 import org.apache.hadoop.hbase.client.HTable;
+import org.apache.hadoop.hbase.client.Mutation;


useless import

wuchong · 2019-08-08T03:38:35Z

...-connectors/flink-hbase/src/main/java/org/apache/flink/addons/hbase/HBaseLookupFunction.java

@@ -20,6 +20,7 @@

 import org.apache.flink.addons.hbase.util.HBaseConfigurationUtil;
 import org.apache.flink.addons.hbase.util.HBaseReadWriteHelper;
+import org.apache.flink.addons.hbase.util.HBaseTypeUtils;


useless import

wuchong · 2019-08-08T03:41:02Z

...onnectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java

-					JDBCUtils.setField(statement, keySqlTypes[i], keys[i], i);
+					if (containsNull) {
+						JDBCUtils.setField(statement, keySqlTypes[i], keys[i], 2 * i);
+						JDBCUtils.setField(statement, keySqlTypes[i], keys[i], 2 * i + 1);


We can keep this special logic for now. But please open a JIRA to improve this. We can introduced a custom NamedPreparedStatement to pass each field only once. see https://www.javaworld.com/article/2077706/named-parameters-for-preparedstatement.html

wuchong · 2019-08-08T03:43:16Z

...onnectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java

@@ -101,7 +113,8 @@ public JDBCLookupFunction(
 		this.maxRetryTimes = lookupOptions.getMaxRetryTimes();
 		this.keySqlTypes = Arrays.stream(keyTypes).mapToInt(JDBCTypeUtil::typeInformationToSqlType).toArray();
 		this.outputSqlTypes = Arrays.stream(fieldTypes).mapToInt(JDBCTypeUtil::typeInformationToSqlType).toArray();
-		this.query = options.getDialect().getSelectFromStatement(
+		this.nonNullableQuery = options.getDialect().getSelectFromStatement(options.getTableName(), fieldNames, keyNames);
+		this.nullableQuery = options.getDialect().getSelectNotDistinctFromStatement(


If we have a consensus on the new methods of SqlDialect. we can call the field nullSafeQuery and nonNullableQuery -> nullUnsafeQuery.

wuchong · 2019-08-08T03:44:35Z

...onnectors/flink-jdbc/src/main/java/org/apache/flink/api/java/io/jdbc/JDBCLookupFunction.java

@@ -76,7 +87,8 @@
 	private final int maxRetryTimes;

 	private transient Connection dbConn;
-	private transient PreparedStatement statement;
+	private transient PreparedStatement fastStatement;
+	private transient PreparedStatement slowStatement;


If we have a consensus on the new methods of SqlDialect. We can rename these fields to nullSafeStatemen and nullUnsafeStatement, we can add comment on the fields that we should use nullUnsafeStatement as much as possible because it is faster.

rmetzger added the review=description? label Aug 2, 2019

rmetzger added component=Connectors/JDBC component=TableSQL/API labels Aug 2, 2019

lincoln-lil reviewed Aug 2, 2019

View reviewed changes

beyond1920 force-pushed the FLINK-13503 branch from 3d97f63 to d23affc Compare August 2, 2019 10:50

lincoln-lil reviewed Aug 2, 2019

View reviewed changes

beyond1920 force-pushed the FLINK-13503 branch from d23affc to 6efd9ce Compare August 2, 2019 11:22

beyond1920 added 3 commits August 2, 2019 19:33

[Blink-13503][API] Add contract in LookupableTableSource to specify…

30d4301

… the behavior when lookupKeys contains null.

[Blink-13503][HBase-connector] Update lookupFunction in HBASE connect…

a1da4e2

…or to avoid illegalArgument exception when create Get object.

[Blink-13503][JDBC-connector] Update lookupFunction in jbdc connector…

e84da4e

… when there is null value in input data of eval.

beyond1920 force-pushed the FLINK-13503 branch from 6efd9ce to e84da4e Compare August 2, 2019 11:34

beyond1920 mentioned this pull request Aug 7, 2019

[FLINK-13433][table-planner-blink] Do not fetch data from LookupableTableSource if the JoinKey in left side of LookupJoin contains null value. #9285

Closed

Fix compile error

e134e61

wuchong reviewed Aug 8, 2019

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beyond1920 closed this Mar 2, 2021

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[FLINK-13503][API] Add contract in `LookupableTableSource` to specify the behavior when lookupKeys contains null. #9335

[FLINK-13503][API] Add contract in `LookupableTableSource` to specify the behavior when lookupKeys contains null. #9335

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		import org.apache.hadoop.hbase.client.HTable;
		import org.apache.hadoop.hbase.client.Mutation;

[FLINK-13503][API] Add contract in LookupableTableSource to specify the behavior when lookupKeys contains null. #9335

[FLINK-13503][API] Add contract in LookupableTableSource to specify the behavior when lookupKeys contains null. #9335

Conversation

beyond1920 commented Aug 2, 2019

What is the purpose of the change

Brief change log

Verifying this change

Does this pull request potentially affect one of the following parts:

Documentation

beyond1920 commented Aug 2, 2019

flinkbot commented Aug 2, 2019 • edited

Automated Checks

Review Progress

flinkbot commented Aug 2, 2019 • edited

CI report:

lincoln-lil commented Aug 2, 2019

beyond1920 commented Aug 2, 2019 • edited

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[FLINK-13503][API] Add contract in `LookupableTableSource` to specify the behavior when lookupKeys contains null. #9335

[FLINK-13503][API] Add contract in `LookupableTableSource` to specify the behavior when lookupKeys contains null. #9335

flinkbot commented Aug 2, 2019 •

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flinkbot commented Aug 2, 2019 •

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beyond1920 commented Aug 2, 2019 •

edited