starrocks-connector-for-apache-flink

This is connector for Apache Flink®

Prerequisites

<dependency>
    <groupId>com.starrocks</groupId>
    <artifactId>flink-connector-starrocks</artifactId>
    <!-- for Apache Flink® 1.15 -->
    <version>x.x.x_flink-1.15</version>
    <!-- for Apache Flink® 1.14 -->
    <version>x.x.x_flink-1.14_2.11</version>
    <version>x.x.x_flink-1.14_2.12</version>
    <!-- for Apache Flink® 1.13 -->
    <version>x.x.x_flink-1.13_2.11</version>
    <version>x.x.x_flink-1.13_2.12</version>
    <!-- for Apache Flink® 1.12 -->
    <version>x.x.x_flink-1.12_2.11</version>
    <version>x.x.x_flink-1.12_2.12</version>
    <!-- for Apache Flink® 1.11 -->
    <version>x.x.x_flink-1.11_2.11</version>
    <version>x.x.x_flink-1.11_2.12</version>
</dependency>

Click HERE to get the latest version.

Apache Flink® source

StarRocksSourceOptions options = StarRocksSourceOptions.builder()
    .withProperty("scan-url", "fe_ip1:8030,fe_ip2:8030,fe_ip3:8030")
    .withProperty("jdbc-url", "jdbc:mysql://fe_ip:9030")
    .withProperty("username", "root")
    .withProperty("password", "")
    .withProperty("table-name", "flink_test")
    .withProperty("database-name", "test")
    .build();
TableSchema tableSchema = TableSchema.builder()
    .field("date_1", DataTypes.DATE())
    .field("datetime_1", DataTypes.TIMESTAMP(6))
    .field("char_1", DataTypes.CHAR(20))
    .field("varchar_1", DataTypes.STRING())
    .field("boolean_1", DataTypes.BOOLEAN())
    .field("tinyint_1", DataTypes.TINYINT())
    .field("smallint_1", DataTypes.SMALLINT())
    .field("int_1", DataTypes.INT())
    .field("bigint_1", DataTypes.BIGINT())
    .field("largeint_1", DataTypes.STRING())
    .field("float_1", DataTypes.FLOAT())
    .field("double_1", DataTypes.DOUBLE())
    .field("decimal_1", DataTypes.DECIMAL(27, 9))
    .build();
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.addSource(StarRocksSource.source(options, tableSchema)).setParallelism(5).print();
env.execute("StarRocks flink source");

OR

// create a table with `structure` and `properties`
CREATE TABLE flink_test (
    date_1 DATE,
    datetime_1 TIMESTAMP(6),
    char_1 CHAR(20),
    varchar_1 VARCHAR,
    boolean_1 BOOLEAN,
    tinyint_1 TINYINT,
    smallint_1 SMALLINT,
    int_1 INT,
    bigint_1 BIGINT,
    largeint_1 STRING,
    float_1 FLOAT,
    double_1 DOUBLE,
    decimal_1 DECIMAL(27,9)
) WITH (
   'connector'='starrocks',
   'scan-url'='fe_ip1:8030,fe_ip2:8030,fe_ip3:8030',
   'jdbc-url'='jdbc:mysql://fe_ip:9030',
   'username'='root',
   'password'='',
   'database-name'='flink_test',
   'table-name'='flink_test'
);

select date_1, smallint_1 from flink_test where char_1 <> 'A' and int_1 = -126

Source options

Option	Required	Default	Type	Description
connector	YES	NONE	String	starrocks
scan-url	YES	NONE	String	Hosts of the fe nodes like: fe_ip1:http_port,fe_ip2:http_port....
jdbc-url	YES	NONE	String	Hosts of the fe nodes like: fe_ip1:query_port,fe_ip2: query_port....
username	YES	NONE	String	StarRocks user name.
password	YES	NONE	String	StarRocks user password.
database-name	YES	NONE	String	Database name
table-name	YES	NONE	String	Table name
scan.connect.timeout-ms	NO	1000	String	Connect timeout
scan.params.keep-alive-min	NO	10	String	Max keep alive time min
scan.params.query-timeout-s	NO	600(5min)	String	Query timeout for a single query(The value of this parameter needs to be longer than the estimated period of the source)
scan.params.mem-limit-byte	NO	102410241024(1G)	String	Memory limit for a single query
scan.max-retries	NO	1	String	Max request retry times.

Source metrics

Name	Type	Description
totalScannedRows	counter	successfully collected data

Source type mappings

StarRocks	Flink
NULL	NULL
BOOLEAN	BOOLEAN
TINYINT	TINYINT
SMALLINT	SMALLINT
INT	INT
BIGINT	BIGINT
LARGEINT	STRING
FLOAT	FLOAT
DOUBLE	DOUBLE
DATE	DATE
DATETIME	TIMESTAMP
DECIMAL	DECIMAL
DECIMALV2	DECIMAL
DECIMAL32	DECIMAL
DECIMAL64	DECIMAL
DECIMAL128	DECIMAL
CHAR	CHAR
VARCHAR	STRING

Source tips

1. exactly-once semantic cannot be guaranteed in the case of a task failure.
2. Only SQLs without aggregation like select {*|columns|count(1)} from {table-name} where ... are supported.

Flink sink

// -------- sink with raw json string stream --------
fromElements(new String[]{
    "{\"score\": \"99\", \"name\": \"stephen\"}",
    "{\"score\": \"100\", \"name\": \"lebron\"}"
}).addSink(
    StarRocksSink.sink(
        // the sink options
        StarRocksSinkOptions.builder()
            .withProperty("jdbc-url", "jdbc:mysql://ip:port,ip:port?xxxxx")
            .withProperty("load-url", "ip:port;ip:port")
            .withProperty("username", "xxx")
            .withProperty("password", "xxx")
            .withProperty("table-name", "xxx")
            .withProperty("database-name", "xxx")
            .withProperty("sink.properties.format", "json")
            .withProperty("sink.properties.strip_outer_array", "true")
            .withProperty("sink.parallelism", "1")
            .build()
    )
);


// -------- sink with stream transformation --------
class RowData {
    public int score;
    public String name;
    public RowData(int score, String name) {
        ......
    }
}
fromElements(
    new RowData[]{
        new RowData(99, "stephen"),
        new RowData(100, "lebron")
    }
).addSink(
    StarRocksSink.sink(
        // the table structure
        TableSchema.builder()
            .field("score", DataTypes.INT())
            .field("name", DataTypes.VARCHAR(20))
            .build(),
        // the sink options
        StarRocksSinkOptions.builder()
            .withProperty("jdbc-url", "jdbc:mysql://ip:port,ip:port?xxxxx")
            .withProperty("load-url", "ip:port;ip:port")
            .withProperty("username", "xxx")
            .withProperty("password", "xxx")
            .withProperty("table-name", "xxx")
            .withProperty("database-name", "xxx")
            .withProperty("sink.properties.format", "json")
            .withProperty("sink.properties.strip_outer_array", "true")
            .withProperty("sink.parallelism", "1")
            .build(),
        // set the slots with streamRowData
        (slots, streamRowData) -> {
            slots[0] = streamRowData.score;
            slots[1] = streamRowData.name;
        }
    )
);

OR

// create a table with `structure` and `properties`
tEnv.executeSql(
    "CREATE TABLE USER_RESULT(" +
        "name VARCHAR," +
        "score BIGINT" +
    ") WITH ( " +
        "'connector' = 'starrocks'," +
        "'jdbc-url'='jdbc:mysql://ip:port,ip:port?xxxxx'," +
        "'load-url'='ip:port;ip:port'," +
        "'database-name' = 'xxx'," +
        "'table-name' = 'xxx'," +
        "'username' = 'xxx'," +
        "'password' = 'xxx'," +
        "'sink.buffer-flush.interval-ms' = '15000'," +
        "'sink.properties.format' = 'json'," +
        "'sink.properties.strip_outer_array' = 'true'," +
        "'sink.parallelism' = '1'," +
        "'sink.max-retries' = '10'," +
    ")"
);

Sink options

Option	Required	Default	Type	Description
connector	YES	NONE	String	starrocks
jdbc-url	YES	NONE	String	this will be used to execute queries in starrocks.
load-url	YES	NONE	String	fe_ip:http_port;fe_ip:http_port separated with ;, which would be used to do the batch sinking.
database-name	YES	NONE	String	starrocks database name
table-name	YES	NONE	String	starrocks table name
username	YES	NONE	String	starrocks connecting username
password	YES	NONE	String	starrocks connecting password
sink.semantic	NO	at-least-once	String	at-least-once or exactly-once(flush at checkpoint only and options like sink.buffer-flush.* won't work either).
sink.buffer-flush.max-bytes	NO	94371840(90M)	String	the max batching size of the serialized data, range: [64MB, 10GB].
sink.buffer-flush.max-rows	NO	500000	String	the max batching rows, range: [64,000, 5000,000].
sink.buffer-flush.interval-ms	NO	300000	String	the flushing time interval, range: [1000ms, 3600000ms].
sink.max-retries	NO	3	String	max retry times of the stream load request, range: [0, 1000].
sink.parallelism	NO	NULL	String	Specify the parallelism of the sink individually. Remove it if you want to follow the global parallelism settings.
sink.connect.timeout-ms	NO	1000	String	Timeout in millisecond for connecting to the load-url, range: [100, 60000].
sink.label-prefix	NO	NO	String	the prefix of the stream load label, available characters are within [-_A-Za-z0-9].
sink.properties.*	NO	NONE	String	the stream load properties like 'sink.properties.columns' = 'k1, v1'.

Sink metrics

Name	Type	Description
totalFlushBytes	counter	successfully flushed bytes.
totalFlushRows	counter	successfully flushed rows.
totalFlushSucceededTimes	counter	number of times that the data-batch been successfully flushed.
totalFlushFailedTimes	counter	number of times that the flushing been failed.

Sink type mappings

Flink type	StarRocks type
BOOLEAN	BOOLEAN
TINYINT	TINYINT
SMALLINT	SMALLINT
INTEGER	INTEGER
BIGINT	BIGINT
FLOAT	FLOAT
DOUBLE	DOUBLE
DECIMAL	DECIMAL
BINARY	INT
CHAR	JSON / STRING
VARCHAR	JSON / STRING
STRING	JSON / STRING
DATE	DATE
TIMESTAMP_WITHOUT_TIME_ZONE(N)	DATETIME
TIMESTAMP_WITH_LOCAL_TIME_ZONE(N)	DATETIME
ARRAY<T>	ARRAY<T>
MAP<KT,VT>	JSON / JSON STRING
ROW<arg T...>	JSON / JSON STRING

Sink tips

1. Flush action was triggered at-least-once when: cachedRows >= ${sink.buffer-flush.max-rows} || cachedBytes >= ${sink.buffer-flush.max-bytes} || idleTime >= ${sink.buffer-flush.interval-ms}
2. sink.buffer-flush.{max-rows|max-bytes|interval-ms} becomes invalid when it comes with the exactly-once semantic.