Constraint

Data synchronization

• A single data record cannot exceed 8 MB.
• The fields in time format support down-to-second precision.
• A table name cannot contain hyphens (-) or number signs (#).
• Modifying table structures after a task is started leads to task failure. In this case, restart the task.
• The destination does not support tables whose mapping fields are all primary keys.
• Only at-least-once delivery is supported; exactly-once delivery is not, meaning data may be duplicated. To ensure data consistency, a primary key and target system capabilities are required.
• Up to 800 MB of files can be collected by concurrent tasks.
  NOTE:

  This constraint applies only to OBS, FTP, and MRS HDFS data sources. For example, if two OBS tasks and two FTP tasks are concurrently executed, the total size of files to be collected from the four tasks cannot exceed 800 MB.

FTP data source

If parsing is enabled, each file cannot exceed 200 MB (files exceeding 200 MB will be automatically skipped) and up to 1,500,000 data records can be parsed. If parsing is disabled, each file cannot exceed 6 MB and up to 20,000 files can be collected.

OBS data source

If parsing is enabled, total files cannot exceed 200 MB for each scheduling (files exceeding 200 MB will be automatically skipped). If parsing is disabled, each file cannot exceed 6 MB and the total size of files cannot exceed 200 MB.

MRS data source

• Only MRS clusters authenticated by Kerberos can be connected.
• Only structured data is supported.

MRS Hive data source

• Hive supports only RCFile and TEXTFILE read and write.
• When MRS Hive serves as the source, only tables of up to 1 million records can be synchronized.

API data source

• If the server does not respond in 60 seconds, an error is reported during task execution.
• When the API serves as the source, every request can read up to 20 MB data. Otherwise, paging must be enabled.
• When the API serves as the source, only constant parameters are supported. Dynamic parameter transfer is not supported.
• When the API serves as the destination, the source data cannot be mapped to the destination headers.

Kafka data source

SASL can be used only to connect ROMA Connect MQS. The Kafka service developed by users themselves supports only plaintext connection.

Oracle database

• Only the following field types are supported. Fields support only uppercase letters.

  CHAR, VARCHAR, DATE, NUMBER, FLOAT, LONG, NCHAR, NVARCHAR2, RAW, TIMESTAMP

• The system time difference between the Oracle system and the ROMA Connect server must be less than 2 minutes.

SQL Server database

Only the following field types are supported:

BIT, CHAR, DATE, DATETIME, DECIMAL, FLOAT, IMAGE, INT, MONEY, NUMERIC

MySQL database

Only the following field types are supported:

INT, BIGINT, TINYINT, MEDIUMINT, FLOAT, DOUBLE, DECIMAL, CHAR, VARCHAR, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT, DATETIME, TIMESTAMP, SMALLINT, YEAR, BINARY, JSON

PostgreSQL/DWS database

Only the following field types are supported:

BOOL, CIDR, CIRCLE, DATE, NUMERIC, FLOAT4, FLOAT8, MONEY, PATH, POINT, INT, TIMESTAMP, TIMETZ, UUID, VARBIT, VARCHAR

For better write performance, destination data sources do not support the batch number and constant features by default. To enable these two features, contact technical support.

Redis database

When the Redis data source is at the destination, to write a time field (datetime/date) into the yyyy-MM-dd HH:mm:ss format, set the destination field type to string

DIS database

Each channel supports only one task to collect source data.

WebSocket database

When you create a data integration task and set Parse to Yes, Parsing Path in Metadata must be configured. Otherwise, the task will fail.

Relational database

A maximum of 10 million data records can be synchronized.

Composite task (CDC)

• Source

  Scheduled: MySQL, Oracle, SQL Server, PostgreSQL, and HANA.

  Real-time: MySQL, Oracle, and SQL Server

• Destination

  Scheduled: MySQL, Oracle, PostgreSQL, SQL Server, and HANA

  Real-time: MySQL, Oracle, PostgreSQL, Kafka, and SQL Server

• The destination table must have a primary key. Otherwise, data synchronization will be affected.
• The Oracle data source at the source can contain only tables with uppercase table names and field names.
• The Oracle data source at the destination cannot contain tables with lowercase field names.
• When you modify a composite task and add a source table to it, the source table must contain data.
• Each table name can include up to 64 characters for composite tasks.
• Automatic tasks map the first 2,000 source/destination tables and will fail if delayed over 1 minute by performance, load, or network issues. If that happens, try manual mapping.
• Binary fields are not supported when defining real-time composite tasks.
• A MySQL schema task supports a maximum of 10 groups of mappings, and a maximum of 2,000 tables are supported.

Flow task

• Destination tables cannot be cleared each time a task is executed.
• Constants cannot be specified for the destination fields.
• When you create a task with multiple destinations, the value of Batch Number Format of the first connection applies to all the connections. For example, if UUID is set for the first connection while yyyyMMddHHmmss is set for the second and the third, UUID is used for all the three connections.

Data API response body size

The data body returned by a data API cannot exceed 10 MB.

Number of data records returned by a data API

By default, a data API obtains 2,000 records from the database. The excessive records cannot be returned.

Paging of data API results

When paging is enabled, a maximum of 2,000 data records can be obtained at a time.

Custom backend header

X-Apig-Mode is taken up and not recommended for services.

Request body size of a hosting API for transparent transmission

The request body of a hosting API cannot exceed 2 GB.

Function API HTTP Client request timeout

The maximum timeout period is 30s and cannot be changed.

Cross-domain request

If the OPTIONS request is accessed using an IP address, the inbound IP address of ROMA Connect cannot be mapped. To map the inbound IP address, domain name access is required.

Signature authentication request body size

The size of the request body can be configured in the instance configurations, ranging from 1 to 9536 MB. However, during App authentication development, only requests whose body does not exceed 12 MB can be accessed. Otherwise, the signature will fail.

Sandbox memory calculation

The APIC sandbox memory size cannot be accurately calculated due to the underlying JVM. It is an approximate value.

New and modified resources

It takes 5 to 10 seconds for a new or modified APIC resource to take effect.

Message size

The maximum size is 10 MB.

Faulty node

If some nodes in the instance are faulty, topic management (such as creation and deletion) cannot be performed.

Topic import

• Only XLSX, XLS, and CSV files can be imported.
• The description in the files to be imported cannot start with an equal sign (=). Newline characters contained in the description will be escaped.
• The number of topics in a file to be imported cannot exceed 100.

Topic export

Only XLSX, XLS, and CSV files can be exported.

Number of messages to be queried

A maximum of 500 messages can be queried at a time.

Number of connections of each IP address

A maximum of 1,000 connections can be created for each client IP address through private networks, and the same constraint applies to each instance through public networks.

Topic aging time

When you create or modify a topic on the console, the maximum aging time is 168 hours.

Maximum size of a message reported by a device

512 KB

Maximum size of a message delivered by a command

File types supported by device import and export

CSV

File types supported by product import and export

File types supported by rule import and export

Maximum size of a device import file

200 MB

Maximum size of a product import file

Maximum size of a rule import file

Server MQTT QoS levels

Only QoS 0 and QoS 1 are supported. QoS 2 is not supported.

Modbus device usage

Command delivery is not supported.

Device access protocol

Only MQTT, OPC UA, and Modbus are supported.