HoodieDeltaStreamer throws exception due to SqlSource return null checkpoint

When use SqlSource：

## Create hive source table

```sql
create database test location '/test';
create table test.test_source (
  id int,
  name string,
  price double,
  dt string,
  ts bigint
);
insert into test.test_source values (105,'hudi', 10.0,'2021-05-05',100);
```

## Use SqlSource

sql_source.properties
```
hoodie.datasource.write.recordkey.field=id
hoodie.datasource.write.partitionpath.field=dt
hoodie.deltastreamer.source.sql.sql.query = select * from test.test_source
hoodie.datasource.hive_sync.table=test_hudi_target
hoodie.datasource.hive_sync.database=hudi
hoodie.datasource.hive_sync.partition_fields=dt
hoodie.datasource.hive_sync.create_managed_table = true
hoodie.datasource.write.hive_style_partitioning=true
hoodie.datasource.write.keygenerator.class=org.apache.hudi.keygen.ComplexKeyGenerator
hoodie.datasource.hive_sync.use_jdbc=false
hoodie.datasource.hive_sync.partition_extractor_class=org.apache.hudi.hive.MultiPartKeysValueExtractor
```

```bash
spark-submit --conf "spark.sql.catalogImplementation=hive" \
--master yarn --deploy-mode client --executor-memory 2G --num-executors 3 --executor-cores 2 --driver-memory 4G --driver-cores 2 \
--principal spark/indata-10-110-105-163.indata.com@INDATA.COM --keytab /etc/security/keytabs/spark.service.keytab \
--class org.apache.hudi.utilities.deltastreamer.HoodieDeltaStreamer /usr/hdp/3.1.0.0-78/spark2/jars/hudi-utilities-bundle_2.11-0.12.0-SNAPSHOT.jar \
--props file:///opt/sql_source.properties  \
--target-base-path /hudi/test_hudi_target \
--target-table test_hudi_target \
--op BULK_INSERT \
--table-type COPY_ON_WRITE \
--source-ordering-field ts \
--source-class org.apache.hudi.utilities.sources.SqlSource \
--enable-sync  \
--checkpoint earliest \
--allow-commit-on-no-checkpoint-change
```
Once executed, the hive source table can be successfully written to the Hudi target table.
However, if it is executed multiple times, such as the second time, an exception will be thrown：
```
org.apache.hudi.utilities.exception.HoodieDeltaStreamerException: Unable to find previous checkpoint. Please double check if this table was indeed built via delta streamer. Last Commit :

"deltastreamer.checkpoint.reset_key" : "earliest"
```
The reason is that the value of `deltastreamer.checkpoint.reset_key` is `earliest`,but `deltastreamer.checkpoint.key` is null，
According to the logic of the method `getCheckpointToResume`,Will throw this exception.
I think since  the value of `deltastreamer.checkpoint.reset_key` is null, The value of `deltastreamer.checkpoint.key`should also be saved as null.This also avoids this exception according to the logic of the method `getCheckpointToResume`

 

 

org.apache.hudi.utilities.exception.HoodieDeltaStreamerException: Unable to find previous checkpoint. Please double check if this table was indeed built via delta streamer. Last Commit :Option{val=[20220519162403646__commit__COMPLETED]}, Instants :[[20220519162403646__commit__COMPLETED]], CommitMetadata={
  "partitionToWriteStats" : {
    "2016/03/15" : [

{       "fileId" : "6a1e0512-508a-4bdb-ad8f-200cda157ff0-0",       "path" : "2016/03/15/6a1e0512-508a-4bdb-ad8f-200cda157ff0-0_0-21-21_20220519162403646.parquet",       "prevCommit" : "null",       "numWrites" : 342,       "numDeletes" : 0,       "numUpdateWrites" : 0,       "numInserts" : 342,       "totalWriteBytes" : 481336,       "totalWriteErrors" : 0,       "tempPath" : null,       "partitionPath" : "2016/03/15",       "totalLogRecords" : 0,       "totalLogFilesCompacted" : 0,       "totalLogSizeCompacted" : 0,       "totalUpdatedRecordsCompacted" : 0,       "totalLogBlocks" : 0,       "totalCorruptLogBlock" : 0,       "totalRollbackBlocks" : 0,       "fileSizeInBytes" : 481336,       "minEventTime" : null,       "maxEventTime" : null     }

],
    "2015/03/16" : [

{       "fileId" : "f3371308-8809-4644-baf6-c65c3fb86c8e-0",       "path" : "2015/03/16/f3371308-8809-4644-baf6-c65c3fb86c8e-0_1-21-22_20220519162403646.parquet",       "prevCommit" : "null",       "numWrites" : 340,       "numDeletes" : 0,       "numUpdateWrites" : 0,       "numInserts" : 340,       "totalWriteBytes" : 481106,       "totalWriteErrors" : 0,       "tempPath" : null,       "partitionPath" : "2015/03/16",       "totalLogRecords" : 0,       "totalLogFilesCompacted" : 0,       "totalLogSizeCompacted" : 0,       "totalUpdatedRecordsCompacted" : 0,       "totalLogBlocks" : 0,       "totalCorruptLogBlock" : 0,       "totalRollbackBlocks" : 0,       "fileSizeInBytes" : 481106,       "minEventTime" : null,       "maxEventTime" : null     }

],
    "2015/03/17" : [

{       "fileId" : "672dde90-af93-4f05-8519-fea783295aa6-0",       "path" : "2015/03/17/672dde90-af93-4f05-8519-fea783295aa6-0_2-21-23_20220519162403646.parquet",       "prevCommit" : "null",       "numWrites" : 318,       "numDeletes" : 0,       "numUpdateWrites" : 0,       "numInserts" : 318,       "totalWriteBytes" : 478586,       "totalWriteErrors" : 0,       "tempPath" : null,       "partitionPath" : "2015/03/17",       "totalLogRecords" : 0,       "totalLogFilesCompacted" : 0,       "totalLogSizeCompacted" : 0,       "totalUpdatedRecordsCompacted" : 0,       "totalLogBlocks" : 0,       "totalCorruptLogBlock" : 0,       "totalRollbackBlocks" : 0,       "fileSizeInBytes" : 478586,       "minEventTime" : null,       "maxEventTime" : null     }

]
  },
  "compacted" : false,
  "extraMetadata" : {
    "schema" : "{\"type\":\"record\",\"name\":\"hoodie_source\",\"namespace\":\"hoodie.source\",\"fields\":[

{\"name\":\"timestamp\",\"type\":[\"null\",\"long\"],\"default\":null}

,{\"name\":\"_row_key\",\"type\":[\"null\",\"string\"],\"default\":null},{\"name\":\"partition_path\",\"type\":[\"null\",\"string\"],\"default\":null},{\"name\":\"rider\",\"type\":[\"null\",\"string\"],\"default\":null},{\"name\":\"driver\",\"type\":[\"null\",\"string\"],\"default\":null},{\"name\":\"begin_lat\",\"type\":[\"null\",\"double\"],\"default\":null},{\"name\":\"begin_lon\",\"type\":[\"null\",\"double\"],\"default\":null},{\"name\":\"end_lat\",\"type\":[\"null\",\"double\"],\"default\":null},{\"name\":\"end_lon\",\"type\":[\"null\",\"double\"],\"default\":null},{\"name\":\"distance_in_meters\",\"type\":[\"null\",\"int\"],\"default\":null},{\"name\":\"seconds_since_epoch\",\"type\":[\"null\",\"long\"],\"default\":null},{\"name\":\"weight\",\"type\":[\"null\",\"float\"],\"default\":null},{\"name\":\"nation\",\"type\":[\"null\",\"bytes\"],\"default\":null},{\"name\":\"current_date\",\"type\":[\"null\",

{\"type\":\"int\",\"logicalType\":\"date\"}

],\"default\":null},{\"name\":\"current_ts\",\"type\":[\"null\",\"long\"],\"default\":null},{\"name\":\"height\",\"type\":[\"null\",

{\"type\":\"fixed\",\"name\":\"fixed\",\"namespace\":\"hoodie.source.hoodie_source.height\",\"size\":5,\"logicalType\":\"decimal\",\"precision\":10,\"scale\":6}

],\"default\":null},{\"name\":\"city_to_state\",\"type\":[\"null\",

{\"type\":\"map\",\"values\":[\"string\",\"null\"]}

],\"default\":null},{\"name\":\"fare\",\"type\":[\"null\",{\"type\":\"record\",\"name\":\"fare\",\"namespace\":\"hoodie.source.hoodie_source\",\"fields\":[

{\"name\":\"amount\",\"type\":[\"null\",\"double\"],\"default\":null}

,{\"name\":\"currency\",\"type\":[\"null\",\"string\"],\"default\":null}]}],\"default\":null},{\"name\":\"tip_history\",\"type\":[\"null\",{\"type\":\"array\",\"items\":[{\"type\":\"record\",\"name\":\"tip_history\",\"namespace\":\"hoodie.source.hoodie_source\",\"fields\":[

{\"name\":\"amount\",\"type\":[\"null\",\"double\"],\"default\":null}

,{\"name\":\"currency\",\"type\":[\"null\",\"string\"],\"default\":null}]},\"null\"]}],\"default\":null},{\"name\":\"_hoodie_is_deleted\",\"type\":[\"null\",\"boolean\"],\"default\":null}]}",
    "deltastreamer.checkpoint.reset_key" : "earliest"
  },
  "operationType" : "INSERT",
  "fileIdAndRelativePaths" :

{     "672dde90-af93-4f05-8519-fea783295aa6-0" : "2015/03/17/672dde90-af93-4f05-8519-fea783295aa6-0_2-21-23_20220519162403646.parquet",     "6a1e0512-508a-4bdb-ad8f-200cda157ff0-0" : "2016/03/15/6a1e0512-508a-4bdb-ad8f-200cda157ff0-0_0-21-21_20220519162403646.parquet",     "f3371308-8809-4644-baf6-c65c3fb86c8e-0" : "2015/03/16/f3371308-8809-4644-baf6-c65c3fb86c8e-0_1-21-22_20220519162403646.parquet"   }

,
  "writePartitionPaths" : [ "2016/03/15", "2015/03/16", "2015/03/17" ],
  "totalLogRecordsCompacted" : 0,
  "totalLogFilesSize" : 0,
  "totalLogFilesCompacted" : 0,
  "totalUpsertTime" : 0,
  "totalCreateTime" : 0,
  "minAndMaxEventTime" : {
    "Optional.empty" :

{       "val" : null,       "present" : false     }

  },
  "totalRecordsDeleted" : 0,
  "totalCompactedRecordsUpdated" : 0,
  "totalScanTime" : 0,
  "writeStats" : [

{     "fileId" : "6a1e0512-508a-4bdb-ad8f-200cda157ff0-0",     "path" : "2016/03/15/6a1e0512-508a-4bdb-ad8f-200cda157ff0-0_0-21-21_20220519162403646.parquet",     "prevCommit" : "null",     "numWrites" : 342,     "numDeletes" : 0,     "numUpdateWrites" : 0,     "numInserts" : 342,     "totalWriteBytes" : 481336,     "totalWriteErrors" : 0,     "tempPath" : null,     "partitionPath" : "2016/03/15",     "totalLogRecords" : 0,     "totalLogFilesCompacted" : 0,     "totalLogSizeCompacted" : 0,     "totalUpdatedRecordsCompacted" : 0,     "totalLogBlocks" : 0,     "totalCorruptLogBlock" : 0,     "totalRollbackBlocks" : 0,     "fileSizeInBytes" : 481336,     "minEventTime" : null,     "maxEventTime" : null   }

,

{     "fileId" : "f3371308-8809-4644-baf6-c65c3fb86c8e-0",     "path" : "2015/03/16/f3371308-8809-4644-baf6-c65c3fb86c8e-0_1-21-22_20220519162403646.parquet",     "prevCommit" : "null",     "numWrites" : 340,     "numDeletes" : 0,     "numUpdateWrites" : 0,     "numInserts" : 340,     "totalWriteBytes" : 481106,     "totalWriteErrors" : 0,     "tempPath" : null,     "partitionPath" : "2015/03/16",     "totalLogRecords" : 0,     "totalLogFilesCompacted" : 0,     "totalLogSizeCompacted" : 0,     "totalUpdatedRecordsCompacted" : 0,     "totalLogBlocks" : 0,     "totalCorruptLogBlock" : 0,     "totalRollbackBlocks" : 0,     "fileSizeInBytes" : 481106,     "minEventTime" : null,     "maxEventTime" : null   }

,

{     "fileId" : "672dde90-af93-4f05-8519-fea783295aa6-0",     "path" : "2015/03/17/672dde90-af93-4f05-8519-fea783295aa6-0_2-21-23_20220519162403646.parquet",     "prevCommit" : "null",     "numWrites" : 318,     "numDeletes" : 0,     "numUpdateWrites" : 0,     "numInserts" : 318,     "totalWriteBytes" : 478586,     "totalWriteErrors" : 0,     "tempPath" : null,     "partitionPath" : "2015/03/17",     "totalLogRecords" : 0,     "totalLogFilesCompacted" : 0,     "totalLogSizeCompacted" : 0,     "totalUpdatedRecordsCompacted" : 0,     "totalLogBlocks" : 0,     "totalCorruptLogBlock" : 0,     "totalRollbackBlocks" : 0,     "fileSizeInBytes" : 478586,     "minEventTime" : null,     "maxEventTime" : null   }

]
}
    at org.apache.hudi.utilities.deltastreamer.DeltaSync.getCheckpointToResume(DeltaSync.java:527)
    at org.apache.hudi.utilities.deltastreamer.DeltaSync.readFromSource(DeltaSync.java:364)
    at org.apache.hudi.utilities.deltastreamer.DeltaSync.syncOnce(DeltaSync.java:302)
    at org.apache.hudi.utilities.deltastreamer.HoodieDeltaStreamer.lambda$sync$2(HoodieDeltaStreamer.java:201)
    at org.apache.hudi.common.util.Option.ifPresent(Option.java:97)
    at org.apache.hudi.utilities.deltastreamer.HoodieDeltaStreamer.sync(HoodieDeltaStreamer.java:199)
    at org.apache.hudi.utilities.functional.TestHoodieDeltaStreamer.testSqlSourceSource(TestHoodieDeltaStreamer.java:1962)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
    at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
    at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:212)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:208)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:137)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:71)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:107)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:87)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:53)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:66)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:51)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:87)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:66)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
    at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)

## JIRA info

- Link: https://issues.apache.org/jira/browse/HUDI-4123
- Type: Bug
- Fix version(s):
- 0.16.0