UTF8MB4 Support Issues With Apache Doris/Starrocks In N8n

by Alex Johnson 58 views

Introduction

When working with databases like Apache Doris or Starrocks, character encoding can sometimes present challenges, especially when dealing with Unicode characters such as emojis. The utf8mb4 character set is designed to support a wide range of characters, including these emojis, by using four bytes per character. However, issues can arise if the application or connector used to interact with the database does not fully support utf8mb4. This article delves into a specific problem encountered while using n8n, an open-source workflow automation platform, to query Apache Doris or Starrocks databases. Specifically, the issue revolves around the incorrect display of emojis when retrieved via n8n's MySQL node, compared to other database clients like DBeaver. We will explore the problem, the steps to reproduce it, the expected behavior, and potential solutions or workarounds.

The correct handling of character encoding is crucial for ensuring data integrity and readability across different systems and applications. In the context of modern databases, utf8mb4 has become the standard for supporting a comprehensive set of characters, including those beyond the Basic Multilingual Plane (BMP). When an application fails to properly handle utf8mb4, it can lead to display issues such as question marks or other unexpected characters appearing in place of the intended emojis or special characters. This not only affects the user experience but can also have implications for data processing and analysis. Therefore, understanding the nuances of utf8mb4 support in various tools and platforms is essential for developers and database administrators.

This article aims to provide a detailed exploration of the utf8mb4 support issue in n8n when interacting with Apache Doris or Starrocks. By examining the problem's context, reproduction steps, and potential solutions, we hope to offer valuable insights for those facing similar challenges. Furthermore, this discussion highlights the importance of character encoding considerations in database interactions and the need for robust support in workflow automation platforms like n8n. Whether you are a developer, database administrator, or a user of n8n, this article will equip you with the knowledge to troubleshoot and address utf8mb4-related issues effectively.

Bug Description

A user reported an issue when using the MySQL node in n8n to query Apache Doris or Starrocks databases. The problem arises when the database contains four-character emojis; these emojis are not displayed correctly in n8n but appear as “����”. When querying the same database using DBeaver, a popular database management tool, the emojis are displayed correctly. This discrepancy indicates a potential issue with how n8n handles utf8mb4 character encoding in its MySQL node.

The user noted that the n8n UI does not allow setting the connection string with parameters like ?charset=utf8mb4&characterEncoding=utf8mb4. This option is typically used to explicitly specify the character encoding for the database connection. Without the ability to set these parameters, it's difficult to test whether explicitly setting the character encoding would resolve the issue. The absence of this configuration option in n8n's UI limits the user's ability to troubleshoot and address the problem directly.

As a temporary workaround, the user implemented a solution involving Base64 encoding and decoding. They query the database using TO_BASE64(text) as text_b64, which encodes the text data in Base64 format. Then, within a Code node in n8n, they decode the Base64-encoded text back to UTF-8 using Buffer.from(item.json.name_b64, 'base64').toString('utf8'). While this workaround allows the user to correctly display the emojis, it adds complexity to the workflow and is not an ideal long-term solution. The need for such a workaround underscores the importance of addressing the underlying utf8mb4 support issue in n8n's MySQL node.

The user's detailed description of the problem, along with the provided workaround, offers valuable insights into the issue. It highlights the specific scenario where the problem occurs (querying emojis with four characters), the limitations of n8n's UI in configuring character encoding, and a temporary solution that adds complexity to the workflow. This information sets the stage for further investigation and potential fixes to ensure proper utf8mb4 support in n8n when interacting with Apache Doris and Starrocks databases.

Steps to Reproduce

To reproduce the issue, the following steps can be taken:

  1. Create a database in either Apache Doris or Starrocks with utf8mb4 character set.

    CREATE DATABASE test2 DEFAULT CHARACTER SET utf8mb4;

    This SQL command creates a new database named test2 with the default character set set to utf8mb4. This is a crucial step because it ensures that the database is configured to store Unicode characters, including emojis, correctly.

  2. Create a table within the database that can store text, including emojis.

    create table test2.test(
	test TEXT
)
DUPLICATE KEY(test);

    This command creates a table named test inside the test2 database. The table has a single column named test with the TEXT data type, which is suitable for storing variable-length character strings. The DUPLICATE KEY(test) clause is specific to Starrocks and Apache Doris, indicating that the test column is used for duplicate key handling, which is relevant for data updates and insertions.

  3. Insert data into the table, including a row with emojis.

    INSERT INTO test2.test VALUES ('😀 ✅OK');

    This command inserts a row into the test table. The value inserted includes a smiling face emoji (😀) and a checkmark emoji (✅), along with the text "OK". The presence of these emojis is key to reproducing the utf8mb4 issue.

  4. Query the table using DBeaver (or another database client that correctly supports utf8mb4) and verify that the emojis are displayed correctly.

    select * from test2.test; -- from DBeaver
=> 😀 ✅OK

    When this query is executed in DBeaver or a similar client, the expected output is the row with the emojis displayed correctly. This step serves as a baseline to confirm that the database itself is storing and serving the emojis correctly.

  5. Query the same table using the MySQL node in n8n.

    select * from test2.test; -- from N8N Mysql Node
=> ���� ✅OK

    When the same query is executed through the n8n MySQL node, the emojis are not displayed correctly. Instead, they appear as a series of replacement characters (����). This is the core of the issue, demonstrating that n8n's MySQL node is not correctly handling the utf8mb4 characters.

By following these steps, anyone can reproduce the utf8mb4 support issue in n8n when querying Apache Doris or Starrocks databases. The key observation is the discrepancy in emoji display between DBeaver (or another utf8mb4-compatible client) and n8n's MySQL node. This clear reproduction path helps in isolating the problem and focusing on the specific component (n8n's MySQL node) that requires attention.

Expected Behavior

The expected behavior when querying a database that supports utf8mb4 character encoding, such as Apache Doris or Starrocks, using a client like n8n, is that all characters, including emojis and other Unicode characters, should be displayed correctly. Specifically, when the database table contains emojis like “😀 ✅OK”, the query result in n8n should show the same characters without any corruption or replacement. The emojis should render as the intended graphical symbols, ensuring data integrity and readability.

In this scenario, the discrepancy between the output in DBeaver (or other database clients that correctly handle utf8mb4) and n8n's MySQL node highlights the deviation from the expected behavior. DBeaver, which properly supports utf8mb4, displays the emojis correctly, while n8n's MySQL node shows replacement characters (“����”) instead. This indicates that n8n is not processing the utf8mb4 characters as expected.

The correct handling of utf8mb4 is essential for applications that deal with diverse character sets, including emojis and special symbols. Emojis have become a common form of communication in digital platforms, and their accurate representation is crucial for maintaining the intended meaning of the text. When a system fails to display emojis correctly, it can lead to misinterpretations and a degraded user experience. Therefore, ensuring utf8mb4 support is vital for applications that aim to provide a seamless and accurate representation of text data.

Moreover, the expected behavior extends beyond just displaying emojis correctly. It also includes the ability to store and retrieve utf8mb4 characters without any data loss or corruption. The database should be able to store the emojis as they are, and the client application should be able to retrieve and display them accurately. Any deviation from this behavior, such as the replacement of emojis with other characters, indicates a potential issue with character encoding handling.

In summary, the expected behavior is that n8n's MySQL node should display utf8mb4 characters, including emojis, correctly, just like other database clients such as DBeaver. This ensures data integrity, accurate representation of text, and a consistent user experience. The observed issue, where emojis are replaced with other characters, signifies a bug that needs to be addressed to align with this expected behavior.

Debug Information

The debug information provided offers a comprehensive snapshot of the n8n instance and its environment, which is crucial for diagnosing the issue. Here's a breakdown of the key sections and their implications:

Core

  • n8nVersion: 1.120.3: This indicates the version of n8n being used. Knowing the version is important because it helps identify if the issue is specific to a particular version or if it has been addressed in later releases.
  • platform: docker (self-hosted): This shows that n8n is running in a Docker container in a self-hosted environment. Dockerization can introduce its own set of complexities, such as networking and environment variable configurations, which need to be considered during debugging.
  • nodeJsVersion: 22.21.0: The Node.js version is a critical piece of information, as n8n is built on Node.js. Compatibility issues between n8n and specific Node.js versions can sometimes arise. Version 22.21.0 is a relatively recent version, so it's less likely to be the cause, but it's still worth noting.
  • nodeEnv: production: This indicates that n8n is running in a production environment, which typically has different configurations and optimizations compared to a development environment.
  • database: postgres: The database used by n8n is PostgreSQL. This is important because n8n uses this database for its internal data storage, such as workflow definitions and execution history. However, the issue being discussed is related to the MySQL node querying Apache Doris/Starrocks, so the internal n8n database is likely not the direct cause of the problem.
  • executionMode: scaling (single-main): This specifies the execution mode of n8n, which affects how workflows are executed and scaled. The "scaling (single-main)" mode suggests a setup designed for handling multiple workflows, which could be relevant if the issue is related to resource contention or concurrency.
  • concurrency: -1: A concurrency value of -1 typically means that n8n is configured to use the maximum available concurrency, which could impact resource utilization and performance.
  • license: enterprise (production): This indicates that the n8n instance is running with an enterprise license, which might offer additional features or support options.
  • consumerId: bc91cd3a-b9ca-4562-9f6d-f9470500a187: This is a unique identifier for the n8n instance, which can be useful for tracking and support purposes.

Storage

This section provides information about how n8n stores execution data and binary files.

  • success: all, error: all: This indicates that n8n is configured to store execution data for both successful and failed workflow runs.
  • progress: false: This suggests that n8n is not storing progress data, which could be relevant for debugging long-running workflows.
  • manual: true: This likely refers to manual executions, indicating that n8n is storing data for workflows triggered manually.
  • binaryMode: memory: The binary data is stored in memory. This is generally faster but can consume more memory resources.

Pruning

This section details the configuration for pruning (removing) old execution data.

  • enabled: true: Pruning is enabled, which is important for managing storage space.
  • maxAge: 336 hours: Execution data is kept for a maximum of 336 hours (14 days).
  • maxCount: 10000 executions: A maximum of 10,000 executions are stored.

Client

This section provides information about the client (web browser) used to access n8n.

  • userAgent: mozilla/5.0 (macintosh; intel mac os x 10_15_7) applewebkit/537.36 (khtml, like gecko) chrome/142.0.0.0 safari/537.36: This is the user agent string, which identifies the browser and operating system. It indicates that the user is using Chrome version 142 on macOS 10.15.7.
  • isTouchDevice: false: This confirms that the client is not a touch-enabled device.

General System Information

  • Operating System: Kubernetes + Helm: n8n is deployed on Kubernetes using Helm, which is a package manager for Kubernetes. This adds another layer of complexity to the deployment environment.
  • Database: PostgreSQL: This reiterates that n8n's internal database is PostgreSQL.
  • Execution mode: queue: The execution mode is queue, which is consistent with the "scaling (single-main)" mode mentioned earlier.
  • Hosting: self hosted: This confirms that n8n is self-hosted.

Analysis and Implications

Based on the debug information, several key points emerge:

  • The issue is likely not related to n8n's core functionality or its internal database (PostgreSQL) since the problem is specific to the MySQL node interacting with external databases (Apache Doris/Starrocks).
  • The Docker and Kubernetes deployment suggests that networking and environment configurations should be carefully examined.
  • The Node.js version is relatively recent, so it's less likely to be the root cause, but it's still a factor to consider.

The most relevant aspect of the debug information is the context it provides about the n8n environment. This information helps narrow down the potential causes of the utf8mb4 support issue and guides the troubleshooting process. For example, the Kubernetes deployment suggests that potential networking or configuration issues within the Kubernetes cluster could be contributing to the problem.

Potential Solutions and Workarounds

Addressing the utf8mb4 support issue in n8n when querying Apache Doris or Starrocks requires a multi-faceted approach. Here are several potential solutions and workarounds to consider:

1. Explicitly Set Character Encoding in Connection String

The most direct solution would be to allow users to explicitly set the character encoding in the connection string for the MySQL node. As the user noted, the n8n UI does not currently support adding parameters like ?charset=utf8mb4&characterEncoding=utf8mb4 to the connection string. Implementing this feature would enable users to specify the desired character encoding, potentially resolving the issue.

  • How to Implement: Update the n8n MySQL node to include an option for users to add custom parameters to the connection string. This could be a text input field where users can enter additional parameters, or a more structured UI element that allows specifying character encoding and other connection options.
  • Expected Outcome: By explicitly setting the character encoding to utf8mb4, the MySQL node should be able to correctly interpret and display emojis and other Unicode characters.

2. Update MySQL Connector Library

n8n's MySQL node likely uses a MySQL connector library to interact with MySQL-compatible databases. An outdated library might not fully support utf8mb4 character encoding. Updating the library to the latest version could include bug fixes and improvements related to character set handling.

  • How to Implement: Identify the MySQL connector library used by n8n and check for newer versions. Update the library within the n8n codebase and redeploy the application.
  • Expected Outcome: A newer connector library is more likely to have robust utf8mb4 support, resolving the display issues.

3. Investigate Default Character Set Configuration

It's possible that the default character set configuration in n8n or the MySQL connector is not set to utf8mb4. Even if the database and tables are configured for utf8mb4, the connection might be using a different default character set. Investigating and adjusting the default character set configuration could address the problem.

  • How to Implement: Check the n8n codebase and the MySQL connector library's documentation for default character set settings. Ensure that the default character set is set to utf8mb4 or that it can be overridden by the connection string parameters.
  • Expected Outcome: Correcting the default character set configuration ensures that the connection uses utf8mb4 unless explicitly overridden, leading to proper emoji display.

4. Review n8n's Internal Character Encoding Handling

There might be an issue with how n8n internally handles character encoding for data retrieved from the database. It's possible that the data is being incorrectly converted or processed, leading to the display issues. Reviewing n8n's codebase for character encoding handling logic could reveal potential bugs.

  • How to Implement: Analyze the n8n codebase, particularly the MySQL node and related data processing functions, for character encoding handling. Look for any potential issues in data conversion or processing.
  • Expected Outcome: Identifying and fixing any bugs in n8n's internal character encoding handling should ensure that data is processed and displayed correctly.

5. Base64 Encoding/Decoding Workaround (Temporary)

As the user already discovered, using Base64 encoding and decoding can serve as a temporary workaround. This involves encoding the text data in Base64 format when querying the database and then decoding it back to UTF-8 within n8n.

  • How to Implement: Modify the SQL query to use TO_BASE64(text) as text_b64 to encode the data. Then, use a Code node in n8n with Buffer.from(item.json.name_b64, 'base64').toString('utf8') to decode the data.
  • Expected Outcome: Emojis should be displayed correctly after decoding, but this is a workaround and not a permanent solution.

6. Direct Database Client Node (If Available)

If n8n has a direct database client node for Apache Doris or Starrocks, using that node instead of the MySQL node might bypass the utf8mb4 support issue. Direct database client nodes are often optimized for specific databases and may have better support for their features, including character encoding.

  • How to Implement: Check if n8n has a direct database client node for Apache Doris or Starrocks. If so, try using that node instead of the MySQL node.
  • Expected Outcome: The direct database client node might handle utf8mb4 characters correctly, resolving the display issues.

7. Community Contributions and Feature Requests

If none of the above solutions work, consider reaching out to the n8n community for assistance. Filing a feature request to explicitly support utf8mb4 configuration in the MySQL node can also help prioritize this issue for future development.

  • How to Implement: Post the issue on the n8n community forum or GitHub repository. File a feature request for utf8mb4 support in the MySQL node.
  • Expected Outcome: Community members might offer additional insights or solutions. A feature request can help prioritize the issue for the n8n development team.

By exploring these potential solutions and workarounds, users can systematically address the utf8mb4 support issue in n8n when querying Apache Doris or Starrocks. Addressing this issue will ensure accurate data representation and enhance the overall user experience.

Conclusion

The issue of utf8mb4 support in n8n's MySQL node when querying Apache Doris or Starrocks highlights the importance of proper character encoding handling in modern applications. The discrepancy in emoji display between n8n and other database clients like DBeaver underscores the need for robust utf8mb4 support to ensure data integrity and accurate representation of text. While the Base64 encoding/decoding workaround provides a temporary solution, it adds complexity to workflows and is not a sustainable long-term fix.

The potential solutions discussed, such as explicitly setting character encoding in the connection string, updating the MySQL connector library, and reviewing n8n's internal character encoding handling, offer a path towards resolving this issue. By implementing these solutions, n8n can enhance its compatibility with databases like Apache Doris and Starrocks, providing a seamless experience for users working with diverse character sets, including emojis.

The debug information provided by the user offers valuable insights into the n8n environment, including the version, platform, Node.js version, and database configurations. This information helps narrow down the potential causes of the issue and guides the troubleshooting process. The Kubernetes deployment, in particular, suggests that networking and configuration within the cluster should be carefully examined.

Ultimately, addressing the utf8mb4 support issue in n8n will not only improve the user experience but also enhance the platform's capabilities in handling a wide range of data types and character sets. This is crucial for n8n's continued growth and adoption as a versatile workflow automation tool.

For further information on character encoding and utf8mb4, you can visit the MySQL documentation on character sets.