Starrocks Data Loading

StarRocks Data Loading

Load data into StarRocks tables via the four loading methods, with column mapping, status checks, and failure troubleshooting.

When to Use

• Ingesting data from applications, object storage, or Kafka
• Choosing a loading method (Stream / Broker / Routine Load / INSERT)
• Mapping or transforming columns during load
• Checking load job status or canceling loads
• Diagnosing data load failures

Method selection:

• Stream Load — real-time, small/medium batches (<10GB), direct from applications
• Broker Load — large batch (>10GB) from S3/HDFS, scheduled ETL
• Routine Load — continuous streaming from Kafka
• INSERT INTO — small loads and ETL transformations within StarRocks

Related skills: [starrocks-table-design] for the target schema; [starrocks-etl-and-tasks] for ETL pipelines and async/scheduled execution.

1. Stream Load (HTTP-based, Real-time)

Use for: Real-time ingestion, small to medium batches (<10GB), direct from applications

Basic Stream Load:

curl --location-trusted -u user:password \
    -H "label:load_$(date +%Y%m%d_%H%M%S)" \
    -H "column_separator:," \
    -T data.csv \
    http://fe_host:8030/api/database/table/_stream_load

Stream Load with Column Mapping:

curl --location-trusted -u user:password \
    -H "label:load_label_001" \
    -H "column_separator:," \
    -H "columns: col1, col2, col3, col4=col1*100, col5=now()" \
    -H "where: col1 > 0" \
    -T data.csv \
    http://fe_host:8030/api/database/table/_stream_load

Stream Load JSON:

curl --location-trusted -u user:password \
    -H "label:json_load_$(date +%s)" \
    -H "format:json" \
    -H "jsonpaths:[\"$.id\", \"$.name\", \"$.amount\"]" \
    -H "strip_outer_array:true" \
    -T data.json \
    http://fe_host:8030/api/database/table/_stream_load

Stream Load Parquet:

curl --location-trusted -u user:password \
    -H "label:parquet_load_001" \
    -H "format:parquet" \
    -T data.parquet \
    http://fe_host:8030/api/database/table/_stream_load

Check Stream Load Status:

Stream Load returns its result synchronously in the HTTP response JSON. It is not queryable via SHOW LOAD (that covers Broker Load, INSERT, and Spark Load only). Use the response, or the get_load_state endpoint:

curl --location-trusted -u user:password \
    http://fe_host:8030/api/database/get_load_state?label=load_label_001

2. Broker Load (Batch from Object Storage)

Use for: Large batch loads (>10GB), data from S3/HDFS, scheduled ETL

Load from S3 (Parquet):

LOAD LABEL mydb.load_20240101_s3
(
    DATA INFILE("s3://bucket/path/data_*.parquet")
    INTO TABLE target_table
    FORMAT AS "parquet"
    (col1, col2, col3)
    SET (
        col4 = col1 * 100,
        col5 = FROM_UNIXTIME(col3)
    )
)
WITH BROKER
(
    "aws.s3.access_key" = "ACCESS_KEY",
    "aws.s3.secret_key" = "SECRET_KEY",
    "aws.s3.region" = "us-east-1",
    "aws.s3.use_instance_profile" = "false"
)
PROPERTIES (
    "timeout" = "3600",
    "max_filter_ratio" = "0.1",
    "strict_mode" = "false"
);

Load from S3 (CSV with Partition):

LOAD LABEL mydb.load_partition_20240101
(
    DATA INFILE("s3://bucket/year=2024/month=01/day=01/*.csv")
    INTO TABLE events
    COLUMNS TERMINATED BY ","
    FORMAT AS "csv"
    (event_id, user_id, event_type, created_at)
    PARTITION (p20240101)
)
WITH BROKER
(
    "aws.s3.access_key" = "ACCESS_KEY",
    "aws.s3.secret_key" = "SECRET_KEY",
    "aws.s3.region" = "us-east-1"
)
PROPERTIES (
    "timeout" = "7200"
);

Check Broker Load Status:

-- Check load job status
SHOW LOAD WHERE label = 'load_20240101_s3';

-- Cancel if needed
CANCEL LOAD FROM mydb WHERE label = 'load_20240101_s3';

3. Routine Load (Kafka Continuous)

Use for: Continuous streaming from Kafka, real-time pipelines

Create Routine Load:

CREATE ROUTINE LOAD mydb.routine_load_events ON events
COLUMNS(event_id, user_id, event_type, event_time, properties)
PROPERTIES (
    "desired_concurrent_number" = "3",
    "max_batch_interval" = "20",
    "max_batch_rows" = "250000",
    "format" = "json",
    "jsonpaths" = "[\"$.event_id\",\"$.user_id\",\"$.type\",\"$.timestamp\",\"$.data\"]"
)
FROM KAFKA (
    "kafka_broker_list" = "broker1:9092,broker2:9092,broker3:9092",
    "kafka_topic" = "events_topic",
    "kafka_partitions" = "0,1,2,3,4,5,6,7",
    "property.group.id" = "starrocks_consumer_group",
    "property.kafka_default_offsets" = "OFFSET_BEGINNING"
);

Manage Routine Load:

-- Show routine load jobs
SHOW ROUTINE LOAD FOR mydb.routine_load_events;

-- Pause routine load
PAUSE ROUTINE LOAD FOR mydb.routine_load_events;

-- Resume routine load
RESUME ROUTINE LOAD FOR mydb.routine_load_events;

-- Stop routine load (cannot resume)
STOP ROUTINE LOAD FOR mydb.routine_load_events;

-- Show error details
SHOW ROUTINE LOAD TASK WHERE JobName = 'routine_load_events';

4. INSERT INTO (Direct SQL)

Use for: Small data loads, ETL transformations within StarRocks

Basic INSERT:

INSERT INTO target_table (col1, col2, col3)
VALUES (1, 'value1', 100.5),
       (2, 'value2', 200.3);

INSERT from SELECT (ETL):

INSERT INTO target_table (date, user_id, total_amount, event_count)
SELECT
    DATE(event_time) as date,
    user_id,
    SUM(amount) as total_amount,
    COUNT(*) as event_count
FROM source_table
WHERE event_time >= '2024-01-01'
GROUP BY DATE(event_time), user_id;

INSERT OVERWRITE (Replace partition):

INSERT OVERWRITE target_table PARTITION (p20240101)
SELECT col1, col2, col3
FROM source_table
WHERE date_col = '2024-01-01';

Multi-statement Transaction:

Version/cluster caveats: Explicit SQL transactions require v3.5+ and support INSERT only on shared-nothing clusters. UPDATE/DELETE inside a transaction need a shared-data cluster on v4.0+, must target a Primary Key table, and must appear before any INSERT on the same table (one UPDATE/DELETE per table).

BEGIN;

-- DELETE/UPDATE must come before INSERT on the same table (PK table, shared-data v4.0+)
DELETE FROM staging_pk_table WHERE load_date < '2024-01-01';

INSERT INTO staging_pk_table (id, value)
SELECT id, value FROM source_table WHERE status = 'active';

COMMIT;

Troubleshooting Data Load Failures

Check error message:

SHOW LOAD WHERE label = 'load_label' \G
-- Look at ErrorMsg field

Common errors:

Retry failed load:

-- Check which files failed
SHOW LOAD WHERE label = 'load_label' \G

-- Resubmit with same label (idempotent)
LOAD LABEL mydb.load_label ...

Quick checks when a load fails:

1. Check error message: SHOW LOAD WHERE label = 'your_label'
2. Verify data format matches column definitions
3. Check broker connectivity (for Broker Load)
4. Verify resource availability: SHOW PROC '/backends'

Anti-Patterns to Avoid

❌ No load labels — always set a label so loads are trackable and duplicate-safe:

-- BAD: No label, cannot track or prevent duplicates
curl ... -T data.csv http://fe:8030/api/db/table/_stream_load

-- GOOD: With label
curl ... -H "label:load_20240101_001" -T data.csv http://...