Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=”//platform.twitter.com/widgets.js”;fjs.parentNode.insertBefore(js,fjs);}}(document,”script”,”twitter-wjs”); When running replication, two new files appear in your data directory: master.info and relay-log.info. MySQL uses these files to save information about your replication state, and they’re used when MySQL starts up, if they’re available. Caution MySQL considers the information contained in the master.info and relay-log.info filebefore looking for settings in the [...]

Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=”//platform.twitter.com/widgets.js”;fjs.parentNode.insertBefore(js,fjs);}}(document,”script”,”twitter-wjs”); Now that you’re familiar with the binary log, and we’ve hinted at how the binary log might beused in replication, let’s look at the steps that happen when data is replicated to another server: INSERT, UPDATE, DELETE or some other data-changing query is issued to the masterdatabase. The query is parsed, executed, [...]

Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=”//platform.twitter.com/widgets.js”;fjs.parentNode.insertBefore(js,fjs);}}(document,”script”,”twitter-wjs”); Some of our specific challenges of the denormalization process were: 1. Dozens of legacy data formats that evolved over years. Peter Ondruška, a Facebook summer intern, defined a custom language to concisely express our data format conversion rules and wrote a compiler to turn this into runnable PHP. Three “data archeologists” wrote the conversion [...]