In this blog, I will discuss about warnings that users might face if they are trying to purge active/in_use binary log which are introduced in MySQL-5.6.12/MySQL-5.7.2 releases.  Before jumping directly to that, I will be covering few basic things about PURGE BINARY LOGS command, about safe way to purge the binary logs on a replication forum. If you are good at basics on "PURGE BINARY LOGS" , you can choose to directly move to the section (at the end of the blog) where I was talking about these new warnings.

Introduction:
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A binary log file contains “events” that describe database changes occurred on a MySQL Server (typically called Master) that enabled binary logging using --log-bin. On a Master server, the files that are related to binary logging are binary log files (files with binlog_base_name.6_digit serial_number) and a binary log index file (file with …

Do you know if your production MySQL servers will come back up when restarted? A recent support episode illustrates a number of best practices. The task looked trivial: Update a production MySQL server (replication master) with a configuration tuned and tested on a development server. Clean shutdown, change configuration, restart. Unfortunately, the MySQL daemon did not just ‘come back’, leaving 2 sites offline. Thus begins an illuminating debugging story. First place to look is the daemon error log, which revealed that the server was segfaulting, seemingly at the end of or just after InnoDB recovery. Reverting to the previous configuration did not help, nor did changing the InnoDB recovery mode. Working with the client, we performed a failover to a replication slave, while I got a second opinion from a fellow engineer to work out what had gone wrong on the server. Since debug symbols weren’t shown in the stack trace, we needed …