--- title: "Cloud DB for MySQL troubleshooting" slug: "clouddbformysql-troubleshoot" updated: 2026-10-08T06:43:12Z published: 2026-10-08T06:43:12Z canonical: "guide.ncloud-docs.com/clouddbformysql-troubleshoot" --- > ## Documentation Index > Fetch the complete documentation index at: https://guide.ncloud-docs.com/llms.txt > Use this file to discover all available pages before exploring further. # Cloud DB for MySQL troubleshooting Available in Classic and VPC Learn how to resolve issues with Cloud DB for MySQL. Click any error for detailed troubleshooting steps. ## Troubleshoot common issues The following are examples of common errors you might encounter: [Individual start and stop of MySQL Server](/docs/en/clouddbformysql-troubleshoot-common#MySQLServer%EC%9D%98%EA%B0%9C%EB%B3%84%EC%8B%9C%EC%9E%91%EB%B0%8F%EC%A0%95%EC%A7%80) Unable to start and stop MySQL Server individually. [MySQL Server connection error](/docs/en/clouddbformysql-troubleshoot-common#MySQLServer%EC%A0%91%EC%86%8D%EC%98%A4%EB%A5%98) Error occurs when accessing the MySQL Server. Currently using SSL VPN but cannot connect to Cloud DB for MySQL. [Failover when restarting Master Server](/docs/en/clouddbformysql-troubleshoot-common#MasterServer%EC%9E%AC%EC%8B%9C%EC%9E%91%EC%8B%9CFailover) Failover not executed when restarting Master Server. [Execute Failover](/docs/en/clouddbformysql-troubleshoot-common#Failover%EC%88%98%ED%96%89) You need to reproduce a Master Server failover situation prior to service launch to proactively verify that applications remain unaffected during such incidents. [Deleted data recovery](/docs/en/clouddbformysql-troubleshoot-common#%EC%82%AD%EC%A0%9C%EB%90%9C%EB%8D%B0%EC%9D%B4%ED%84%B0%EB%B3%B5%EA%B5%AC) Recovery of deleted data is needed. [Create database](/docs/en/clouddbformysql-troubleshoot-common#%EB%8D%B0%EC%9D%B4%ED%84%B0%EB%B2%A0%EC%9D%B4%EC%8A%A4%EC%83%9D%EC%84%B1) Direct database creation is needed. [Notifications on exceeding MySQL Server threshold](/docs/en/clouddbformysql-troubleshoot-common#MySQLServer%EC%9D%98%EC%9E%84%EA%B3%84%EA%B0%92%EC%B4%88%EA%B3%BC%EC%95%8C%EB%A6%BC) Unable to receive an event notification on exceeding MySQL Server threshold. [Replication error](/docs/en/clouddbformysql-troubleshoot-common#Replication%EC%98%A4%EB%A5%98) Replication error occurs and replication stopped. [Mitigate Replication delay](/docs/en/clouddbformysql-troubleshoot-common#Replication%EC%A7%80%EC%97%B0%EC%99%84%ED%99%94) Replication delay occurs. [mysqldump utility error](/docs/en/clouddbformysql-troubleshoot-common#mysqldump%EC%9C%A0%ED%8B%B8%EB%A6%AC%ED%8B%B0%EC%98%A4%EB%A5%98) An error occurs when performing a backup or restore using the mysqldump utility. [Unknown status](/docs/en/clouddbformysql-troubleshoot-common#Unknown%EC%83%81%ED%83%9C) The server status is displayed as Unknown. [Unsupported engine table creation restriction](/docs/en/clouddbformysql-troubleshoot-common#%EB%AF%B8%EC%A7%80%EC%9B%90%EC%97%94%EC%A7%84%ED%85%8C%EC%9D%B4%EB%B8%94%EC%83%9D%EC%84%B1%EC%A0%9C%ED%95%9C) Tables using the MyISAM, BLACKHOLE, FEDERATED, ARCHIVE, or MEMORY engine cannot be created. [Error notifications in the console](/docs/en/clouddbformysql-troubleshoot-common#%EC%BD%98%EC%86%94%EB%82%B4%EC%98%A4%EB%A5%98%EC%95%8C%EB%A6%BC) The following error notifications occur in the console. - CASE 1: MySQL replication is in a delayed state. Try again after all delays have been resolved. - CASE 2: Master DB failover cannot be performed due to unstable communication with the DB server. Try again after a short while. - CASE 3: Work cannot be performed before or after the backup time. To proceed with the work, adjust the backup time. - CASE 4: A backup is currently in progress. Proceed with the work after the backup has been completed. The backup duration increases in proportion to the size of user data. ## Troubleshoot usage and performance issues The following are examples of resource errors you might encounter: [Data storage size decreased after restarting MySQL Server (VPC)](/docs/en/clouddbformysql-troubleshoot-resource#MySQLServer%EC%9E%AC%EC%8B%9C%EC%9E%91%ED%9B%84%EB%8D%B0%EC%9D%B4%ED%84%B0%EC%8A%A4%ED%86%A0%EB%A6%AC%EC%A7%80%ED%81%AC%EA%B8%B0%EA%B0%90%EC%86%8CVPC) The size of data storage decreased after restarting MySQL Server. [Data storage size decreased after restarting MySQL Server (Classic)](/docs/en/clouddbformysql-troubleshoot-resource#MySQLServer%EC%9E%AC%EC%8B%9C%EC%9E%91%ED%9B%84%EB%8D%B0%EC%9D%B4%ED%84%B0%EC%8A%A4%ED%86%A0%EB%A6%AC%EC%A7%80%ED%81%AC%EA%B8%B0%EA%B0%90%EC%86%8CVPC) The size of data storage decreased after restarting MySQL Server. [Memory usage increased](/docs/en/clouddbformysql-troubleshoot-resource#%EB%A9%94%EB%AA%A8%EB%A6%AC%EC%82%AC%EC%9A%A9%EB%9F%89%EC%A6%9D%EA%B0%80) Memory usage keeps increasing. [DB performance issues and response delays](/docs/en/clouddbformysql-troubleshoot-resource#DB%EC%84%B1%EB%8A%A5%EB%AC%B8%EC%A0%9C%EB%B0%8F%EC%9D%91%EB%8B%B5%EC%A7%80%EC%97%B0) Issue in DB performance occurs. There is a delay in DB response. [High CPU usage](/docs/en/clouddbformysql-troubleshoot-resource#CPU%EC%82%AC%EC%9A%A9%EB%9F%89%EC%9D%B4%EB%86%92%EC%9D%8C) CPU usage is high. ## Learning resources We offer various materials for you to explore. To learn more about Cloud DB for MySQL, check out these helpful links: - FAQs: [Get answers to common Cloud DB for MySQL questions](https://www.ncloud.com/support/faq/prod?categoryCode2=DB&categoryCode3=SV_0027&page=1) - NAVER Cloud Platform blog: [MySQL major version upgrade (MySQL 5 → MySQL 8) — NAVER Cloud Platform Cloud DB for MySQL practice](https://blog.naver.com/n_cloudplatform/223293357482?trackingCode=blog_bloghome_searchlist) - NAVER Cloud Platform blog: [Data migration from Cloud DB for MySQL to Cloud Hadoop with Sqoop](https://blog.naver.com/n_cloudplatform/222183167971?trackingCode=blog_bloghome_searchlist) - NAVER Cloud Platform blog: [Deliver APIs without an application server using Cloud Functions service and Cloud DB_Part 1](https://blog.naver.com/n_cloudplatform/222156401842) - NAVER Cloud Platform blog: [Deliver APIs without an application server using Cloud Functions service and Cloud DB_Part 2](https://blog.naver.com/n_cloudplatform/222159923255?trackingCode=blog_bloghome_searchlist) Note If you're still having trouble finding what you need, click on the feedback icon and send us your thoughts and requests. 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