[英]Apache Flink: How to sink stream to Google Cloud Storage File System
[英]flink sink to parquet file with AvroParquetWriter is not writing data to file
我正在嘗試使用AvroParquetWriter將鑲木地板文件寫入接收器。 已創建文件,但長度為0(未寫入數據)。 難道我做錯了什么 ? 不知道是什么問題
import io.eels.component.parquet.ParquetWriterConfig
import org.apache.avro.Schema
import org.apache.avro.generic.{GenericData, GenericRecord}
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.hadoop.fs.Path
import org.apache.parquet.avro.AvroParquetWriter
import org.apache.parquet.hadoop.{ParquetFileWriter, ParquetWriter}
import org.apache.parquet.hadoop.metadata.CompressionCodecName
import scala.io.Source
import org.apache.flink.streaming.api.scala._
object Tester extends App {
val env = StreamExecutionEnvironment.getExecutionEnvironment
def now = System.currentTimeMillis()
val path = new Path(s"/tmp/test-$now.parquet")
val schemaString = Source.fromURL(getClass.getResource("/request_schema.avsc")).mkString
val schema: Schema = new Schema.Parser().parse(schemaString)
val compressionCodecName = CompressionCodecName.SNAPPY
val config = ParquetWriterConfig()
val genericReocrd: GenericRecord = new GenericData.Record(schema)
genericReocrd.put("name", "test_b")
genericReocrd.put("code", "NoError")
genericReocrd.put("ts", 100L)
val stream = env.fromElements(genericReocrd)
val writer: ParquetWriter[GenericRecord] = AvroParquetWriter.builder[GenericRecord](path)
.withSchema(schema)
.withCompressionCodec(compressionCodecName)
.withPageSize(config.pageSize)
.withRowGroupSize(config.blockSize)
.withDictionaryEncoding(config.enableDictionary)
.withWriteMode(ParquetFileWriter.Mode.OVERWRITE)
.withValidation(config.validating)
.build()
writer.write(genericReocrd)
stream.addSink{r =>
writer.write(r)
}
env.execute()
問題是您沒有關閉ParquetWriter
。 這對於將掛起的元素刷新到磁盤是必需的。 您可以通過定義自己的RichSinkFunction
來解決問題,您可以在其中使用close
方法關閉ParquetWriter
:
class ParquetWriterSink(val path: String, val schema: String, val compressionCodecName: CompressionCodecName, val config: ParquetWriterConfig) extends RichSinkFunction[GenericRecord] {
var parquetWriter: ParquetWriter[GenericRecord] = null
override def open(parameters: Configuration): Unit = {
parquetWriter = AvroParquetWriter.builder[GenericRecord](new Path(path))
.withSchema(new Schema.Parser().parse(schema))
.withCompressionCodec(compressionCodecName)
.withPageSize(config.pageSize)
.withRowGroupSize(config.blockSize)
.withDictionaryEncoding(config.enableDictionary)
.withWriteMode(ParquetFileWriter.Mode.OVERWRITE)
.withValidation(config.validating)
.build()
}
override def close(): Unit = {
parquetWriter.close()
}
override def invoke(value: GenericRecord, context: SinkFunction.Context[_]): Unit = {
parquetWriter.write(value)
}
}
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