运行 PyFlink 示例时出现"pyflink.util.exceptions.TableException: findAndCreateTableSource failed."

Question

我正在运行PyFlink程序(从https://ci.apache.org/projects/flink/flink-docs-release-1.12/dev/python/table_api_tutorial.html)

from pyflink.dataset import ExecutionEnvironment
from pyflink.table import TableConfig, DataTypes, BatchTableEnvironment
from pyflink.table.descriptors import Schema, OldCsv, FileSystem
from pyflink.table.expressions import lit
exec_env = ExecutionEnvironment.get_execution_environment()
exec_env.set_parallelism(1)
t_config = TableConfig()
t_env = BatchTableEnvironment.create(exec_env, t_config)
t_env.connect(FileSystem().path('/tmp/input')) 
.with_format(OldCsv()
.field('word', DataTypes.STRING())) 
.with_schema(Schema()
.field('word', DataTypes.STRING())) 
.create_temporary_table('mySource')
t_env.connect(FileSystem().path('/tmp/output')) 
.with_format(OldCsv()
.field_delimiter('t')
.field('word', DataTypes.STRING())
.field('count', DataTypes.BIGINT())) 
.with_schema(Schema()
.field('word', DataTypes.STRING())
.field('count', DataTypes.BIGINT())) 
.create_temporary_table('mySink')
tab = t_env.from_path('mySource')
tab.group_by(tab.word) 
.select(tab.word, lit(1).count) 
.execute_insert('mySink').wait()

为了验证它的有效性，我按顺序做了以下操作：

1. 运行echo -e "flinknpyflinknflink" > /tmp/input
2. 运行python WordCount.py
3. 运行cat /tmp/out并查找预期输出

然后我更改了PyFlink程序，使其更喜欢SQL而不是Table API，但我发现它不起作用。

from pyflink.dataset import ExecutionEnvironment
from pyflink.table import TableConfig, DataTypes, BatchTableEnvironment
from pyflink.table.descriptors import Schema, OldCsv, FileSystem
from pyflink.table.expressions import lit
exec_env = ExecutionEnvironment.get_execution_environment()
exec_env.set_parallelism(1)
t_config = TableConfig()
t_env = BatchTableEnvironment.create(exec_env, t_config)
my_source_ddl = """
create table mySource (
word VARCHAR
) with (
'connector' = 'filesystem',
'format' = 'csv',
'path' = '/tmp/input'
)
"""
my_sink_ddl = """
create table mySink (
word VARCHAR,
`count` BIGINT
) with (
'connector' = 'filesystem',
'format' = 'csv',
'path' = '/tmp/output'
)
"""
t_env.sql_update(my_source_ddl)
t_env.sql_update(my_sink_ddl)
tab = t_env.from_path('mySource')
tab.group_by(tab.word) 
.select(tab.word, lit(1).count) 
.execute_insert('mySink').wait()

错误如下：

Traceback (most recent call last):
File "WordCount.py", line 38, in <module>
.execute_insert('mySink').wait()
File "/usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/pyflink/table/table.py", line 864, in execute_insert
return TableResult(self._j_table.executeInsert(table_path, overwrite))
File "/usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/py4j/java_gateway.py", line 1286, in __call__
answer, self.gateway_client, self.target_id, self.name)
File "/usr/local/anaconda3/envs/pyflink-quickstart/lib/python3.7/site-packages/pyflink/util/exceptions.py", line 162, in deco
raise java_exception
pyflink.util.exceptions.TableException: findAndCreateTableSink failed.
at org.apache.flink.table.factories.TableFactoryUtil.findAndCreateTableSink(TableFactoryUtil.java:87)
at org.apache.flink.table.api.internal.TableEnvImpl.getTableSink(TableEnvImpl.scala:1097)
at org.apache.flink.table.api.internal.TableEnvImpl.org$apache$flink$table$api$internal$TableEnvImpl$$writeToSinkAndTranslate(TableEnvImpl.scala:929)
at org.apache.flink.table.api.internal.TableEnvImpl$$anonfun$1.apply(TableEnvImpl.scala:556)
at org.apache.flink.table.api.internal.TableEnvImpl$$anonfun$1.apply(TableEnvImpl.scala:554)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.Iterator$class.foreach(Iterator.scala:891)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1334)
at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.AbstractTraversable.map(Traversable.scala:104)
at org.apache.flink.table.api.internal.TableEnvImpl.executeInternal(TableEnvImpl.scala:554)
at org.apache.flink.table.api.internal.TableImpl.executeInsert(TableImpl.java:572)
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.apache.flink.api.python.shaded.py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
at org.apache.flink.api.python.shaded.py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
at org.apache.flink.api.python.shaded.py4j.Gateway.invoke(Gateway.java:282)
at org.apache.flink.api.python.shaded.py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
at org.apache.flink.api.python.shaded.py4j.commands.CallCommand.execute(CallCommand.java:79)
at org.apache.flink.api.python.shaded.py4j.GatewayConnection.run(GatewayConnection.java:238)
at java.lang.Thread.run(Thread.java:748)

我想知道我的新程序出了什么问题？

Answer 1

问题是您正在使用的旧数据集不支持您声明的FileSystem连接器。您可以使用blink Planner来满足您的需求。

t_env = BatchTableEnvironment.create(
environment_settings=EnvironmentSettings.new_instance()
.in_batch_mode().use_blink_planner().build())
t_env._j_tenv.getPlanner().getExecEnv().setParallelism(1)
my_source_ddl = """
create table mySource (
word VARCHAR
) with (
'connector' = 'filesystem',
'format' = 'csv',
'path' = '/tmp/input'
)
"""
my_sink_ddl = """
create table mySink (
word VARCHAR,
`count` BIGINT
) with (
'connector' = 'filesystem',
'format' = 'csv',
'path' = '/tmp/output'
)
"""
t_env.execute_sql(my_source_ddl)
t_env.execute_sql(my_sink_ddl)
tab = t_env.from_path('mySource')
tab.group_by(tab.word) 
.select(tab.word, lit(1).count) 
.execute_insert('mySink').wait()