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DataStream API 读写

除 FlinkSQL 外,Flink Doris Connector 还提供 DataStream API:通过 DorisSource 读取 Doris 表,通过 DorisSink 写入 Doris。配置项与 FlinkSQL 相同,分别见 读取 Doris 数据写入 Doris 数据

引入依赖

在项目中引入 Connector 的 Maven 依赖,方式见 安装方式

信息

Connector 内部已包含 HttpClient 4.5.13 版本,如果项目中有单独引用 HttpClient,需要确保版本一致。

DorisSource 读取

final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
DorisOptions option = DorisOptions.builder()
.setFenodes("127.0.0.1:8030")
.setTableIdentifier("test.student")
.setUsername("root")
.setPassword("")
.build();

DorisReadOptions readOptions = DorisReadOptions.builder().build();
DorisSource<List<?>> dorisSource = DorisSource.<List<?>>builder()
.setDorisOptions(option)
.setDorisReadOptions(readOptions)
.setDeserializer(new SimpleListDeserializationSchema())
.build();

env.fromSource(dorisSource, WatermarkStrategy.noWatermarks(), "doris source").print();
env.execute("Doris Source Test");

DorisSink 写入

通过 DataStream API 写入时,可使用不同的序列化方式将上游数据写入 Doris 表。

根据上游数据的格式选择序列化器:

上游数据序列化器
CSV 或 JSON 字符串SimpleStringSerializer
Flink 内部的 RowDataRowDataSerializer
Debezium JSON,如 Flink CDC 或 Kafka 中的 Debezium 格式数据JsonDebeziumSchemaSerializer,可同步上游 Schema Change
带库表信息的 RecordWithMetaRecordWithMetaSerializer,单个 Sink 写入多张表

写入模式 同样适用于 DataStream API,通过 DorisExecutionOptions.Builder.setBatchMode(true) 开启攒批写入。

普通 String 格式

当上游是 csv 或 json 数据格式时,可直接使用 SimpleStringSerializer 序列化数据。

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.enableCheckpointing(30000);
DorisSink.Builder<String> builder = DorisSink.builder();

DorisOptions dorisOptions = DorisOptions.builder()
.setFenodes("10.16.10.6:28737")
.setTableIdentifier("test.student")
.setUsername("root")
.setPassword("")
.build();

Properties properties = new Properties();
// 上游是 json 数据时,需要开启以下配置
properties.setProperty("read_json_by_line", "true");
properties.setProperty("format", "json");

// 上游是 csv 写入时,需要开启以下配置
// properties.setProperty("format", "csv");
// properties.setProperty("column_separator", ",");

DorisExecutionOptions executionOptions = DorisExecutionOptions.builder()
.setLabelPrefix("label-doris")
.setDeletable(false)
// .setBatchMode(true) 开启攒批写入
.setStreamLoadProp(properties)
.build();

builder.setDorisReadOptions(DorisReadOptions.builder().build())
.setDorisExecutionOptions(executionOptions)
.setSerializer(new SimpleStringSerializer())
.setDorisOptions(dorisOptions);

List<String> data = new ArrayList<>();
data.add("{\"id\":3,\"name\":\"Michael\",\"age\":28}");
data.add("{\"id\":4,\"name\":\"David\",\"age\":38}");

env.fromCollection(data).sinkTo(builder.build());
env.execute("doris test");

RowData 格式

RowData 是 Flink 内部格式,如果上游传入的是 RowData 格式,需要使用 RowDataSerializer 序列化数据。

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.enableCheckpointing(10000);
env.setParallelism(1);

DorisSink.Builder<RowData> builder = DorisSink.builder();

Properties properties = new Properties();
properties.setProperty("column_separator", ",");
properties.setProperty("line_delimiter", "\n");
properties.setProperty("format", "csv");
// 上游是 json 写入时,需要开启以下配置
// properties.setProperty("read_json_by_line", "true");
// properties.setProperty("format", "json");
DorisOptions.Builder dorisBuilder = DorisOptions.builder();
dorisBuilder
.setFenodes("10.16.10.6:28737")
.setTableIdentifier("test.student")
.setUsername("root")
.setPassword("");
DorisExecutionOptions.Builder executionBuilder = DorisExecutionOptions.builder();
executionBuilder.setLabelPrefix(UUID.randomUUID().toString()).setDeletable(false).setStreamLoadProp(properties);

// flink rowdata's schema
String[] fields = {"id", "name", "age"};
DataType[] types = {DataTypes.INT(), DataTypes.VARCHAR(256), DataTypes.INT()};

builder.setDorisExecutionOptions(executionBuilder.build())
.setSerializer(
RowDataSerializer.builder() // serialize according to rowdata
.setType(LoadConstants.CSV)
.setFieldDelimiter(",")
.setFieldNames(fields)
.setFieldType(types)
.build())
.setDorisOptions(dorisBuilder.build());

// mock rowdata source
DataStream<RowData> source =
env.fromElements("")
.flatMap(
new FlatMapFunction<String, RowData>() {
@Override
public void flatMap(String s, Collector<RowData> out)
throws Exception {
GenericRowData genericRowData = new GenericRowData(3);
genericRowData.setField(0, 1);
genericRowData.setField(1, StringData.fromString("Michael"));
genericRowData.setField(2, 18);
out.collect(genericRowData);

GenericRowData genericRowData2 = new GenericRowData(3);
genericRowData2.setField(0, 2);
genericRowData2.setField(1, StringData.fromString("David"));
genericRowData2.setField(2, 38);
out.collect(genericRowData2);
}
});

source.sinkTo(builder.build());
env.execute("doris test");

Debezium 格式

对于上游是 Debezium 数据格式的数据(如 Flink CDC 或 Kafka 中 Debezium 格式数据),可使用 JsonDebeziumSchemaSerializer 序列化。

// 启用 checkpoint
env.enableCheckpointing(10000);

Properties props = new Properties();
props.setProperty("format", "json");
props.setProperty("read_json_by_line", "true");
DorisOptions dorisOptions = DorisOptions.builder()
.setFenodes("127.0.0.1:8030")
.setTableIdentifier("test.student")
.setUsername("root")
.setPassword("").build();

DorisExecutionOptions.Builder executionBuilder = DorisExecutionOptions.builder();
executionBuilder.setLabelPrefix("label-prefix")
.setStreamLoadProp(props)
.setDeletable(true);

DorisSink.Builder<String> builder = DorisSink.builder();
builder.setDorisReadOptions(DorisReadOptions.builder().build())
.setDorisExecutionOptions(executionBuilder.build())
.setDorisOptions(dorisOptions)
.setSerializer(JsonDebeziumSchemaSerializer.builder().setDorisOptions(dorisOptions).build());

env.fromSource(mySqlSource, WatermarkStrategy.noWatermarks(), "MySQL Source")
.sinkTo(builder.build());

多表写入

DorisSink 支持单个 Sink 同步多张表,需要将数据以及库表一起传递给 Sink,使用 RecordWithMetaSerializer 序列化即可。

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.setParallelism(1);
DorisSink.Builder<RecordWithMeta> builder = DorisSink.builder();
Properties properties = new Properties();
properties.setProperty("column_separator", ",");
properties.setProperty("line_delimiter", "\n");
properties.setProperty("format", "csv");
DorisOptions.Builder dorisBuilder = DorisOptions.builder();
dorisBuilder
.setFenodes("10.16.10.6:28737")
.setTableIdentifier("")
.setUsername("root")
.setPassword("");

DorisExecutionOptions.Builder executionBuilder = DorisExecutionOptions.builder();

executionBuilder
.setLabelPrefix("label-doris")
.setStreamLoadProp(properties)
.setDeletable(false)
.setBatchMode(true);

builder.setDorisReadOptions(DorisReadOptions.builder().build())
.setDorisExecutionOptions(executionBuilder.build())
.setDorisOptions(dorisBuilder.build())
.setSerializer(new RecordWithMetaSerializer());

RecordWithMeta record = new RecordWithMeta("test", "student_1", "1,David,18");
RecordWithMeta record1 = new RecordWithMeta("test", "student_2", "1,Jack,28");
env.fromCollection(Arrays.asList(record, record1)).sinkTo(builder.build());