Notes on Importing mysqldump

Background: I have multiple 200GB+ MySQL dumps to import. It takes a lot of time. pv shows you the progress so you have the idea how long will the import take. Pipe the dump.sql.gz file to gunzip instead of unzipping it then import. Saves much disk read and write, not to mention the time and effort. e.g. pv dump.sql.gz | gunzip -c | mysql grep is slow for a large file.

Migrating MySQL to Amazon RDS from Azure

I have recently migrated to Amazon RDS from MySQL on Azure VM. This percona article about migrating to RDS is actually very helpful. I have a few things to add though. Setup My setup is a self-hosted MySQL 5.6 server in VM on Azure and a new Amazon RDS for MySQL 5.6. AWS DMS I have tried AWS Database Migration Service (DMS). It is reasonably fast. The main problem is it does not look like mature technology at all.

Python & MySQL Interrupted System Call & pyinstrument

Background My Python application cannot connect to MySQL. The error message looks like this: Can’t connect to MySQL server on ‘’ (4) Error 4 means Interrupted system call. I am using mysqlclient, the C wrapper MySQL connector. The error happens on both MySQL 5.6 and 5.7. It can be reproduced consistently. It seems that PyMySQL doesn’t have this problem. Also I am using gevent but it is not much related in this case.