PostgreSQL的XID wraparound坑了一波又一波

这次中招的是Mailchimp，恢复花了40多个小时。

Bryan Cantrill有感而发呀，毕竟他所任职的Joyent当年也被坑过

Mailchimp: https://mailchimp.com/what-we-learned-from-the-recent-mandrill-outage

Joyent: https://www.joyent.com/blog/manta-postmortem-7-27-2015

Sentry: https://blog.sentry.io/2015/07/23/transaction-id-wraparound-in-postgres

值得欣慰的是PG12已经开始在做这方面的工作了https://commitfest.postgresql.org/22/1718