5 ms·
Go-live of a migration of three web apps and their DBs from AWS to Azure resulted in one of the hot customer facing APIs grinding to a halt during peak hours. C
by vimwizard 5y ago
Go-live of a migration of three web apps and their DBs from AWS to Azure resulted in one of the hot customer facing APIs grinding to a halt during peak hours. Compute and DB SKU specs were exactly the same but as it turns out, Azure DB PaaS performance is nowhere near that of AWS RDS. pg_bench reported about 4x more transactions completed in AWS, even though in Azure I had upgraded to postgres 11 enabling parallel query plans.
Another fun time was when a reboot of an ubuntu 14.04 VM previously migrated up to Azure from an on-prem VMware esxi decided it wanted to sit waiting for user input in grub. We had no extension installed to use the serial console for user input. Since it was hosting a production postgres db, I received a call at 12am and was up til 4am transplanting /var/lib/postgresql from the old OS disk onto a fresh ubuntu VM's disk.