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Migrating Facebook to MySQL 8.0

engineering.fb.com

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Re: Migrating Facebook to MySQL 8.0

#111

Post by tpetry »

PeterZaitsev wrote: post #106
tpetry wrote: post #87

Earlier quoted context omitted.

So there has not been any major improvement in MySQL for 3 years? There hasn‘t been released any minor version? Can someone explain the current state more?

No. MySQL 8 changed its engineering approach with features released in minor releases. In this regard it is like MacOS X or Windows 10, whatever you prefer where features are shipped without major version change

Sure, and this is great. But The newest release is 8.0.26, so there hasn‘t been any minor release yet - in 3 years. And i can‘t find anything about new MySQL features or planned features except the big 8.0 release.

Re: Migrating Facebook to MySQL 8.0

#112

Post by hodgesrm »

sltkr wrote: post #108
lucideer wrote: post #74

Earlier quoted context omitted.

That was the expectation but the Oracle camp surprised everyone by actually giving it some attention, and meanwhile MariaDB's promise of being a "100% compatible drop-in replacement" came with more and more caveats with each release (as is to be entirely expected with any fork). When you consider the network effect of all the stacks already heavily invested in MySQL, all Oracle really needed to do was put in a modicu…

I was curious so I looked up the differences here: https://mariadb.com/kb/en/mariadb-vs-mysql-compatibility/ It doesn't sound too bad. The incompabilities seem to be mostly stuff like not being able to generally use replication from MySQL to MariaDB or vice versa. But I would guess that's not a very common case anyway: most users are either developers that want their software to work with both MariaDB and MySQL (whic…

Binlog incompatibility makes migration a lot more difficult at scale.

Re: Migrating Facebook to MySQL 8.0

#113

Post by schuyler2d »

I'd be interested more in what features were in their (3):

> Non-MyRocks Server: Features in the mysqld server that were not related to our MyRocks storage engine were ported.

i.e. things that they haven't shared with the MySQL community but aren't related to the storage layer. Why would/should they keep those private? Considering that RocksDB is open-source, clearly it's unlikely it's because they're 'trade secrets'.

Re: Migrating Facebook to MySQL 8.0

#114

Post by capableweb »

imoverclocked wrote: post #90
ansible wrote: post #70

Earlier quoted context omitted.

Spanner paper: https://static.googleusercontent.com/media/research.google.c... It is designed from the ground-up to be globally distributed. Some other databases like FoundationDB (now owned and killed? by Apple) and CockroachDB were designed to scale across multiple datacenters. Correction: FoundationDB is alive as open-source again, yay!

AFAIK, FoundationDB is alive and well. What makes you think it's killed?

It was acquired by a huge company that sometimes kills products. Shortly after the acquisition, the downloads were removed from the website. It did go open source "recently" though which made it longer lasting, but I'd understand if someone would think it was dead by now.

- https://news.ycombinator.com/item?id=9259986 - Apple Acquires FoundationDB - March 24, 2015

- Comparison between March 25 and March 14, 2015 - https://web.archive.org/web/20150314231702/https://foundatio... (14th March) > https://web.archive.org/web/20150325003252/https://foundatio... (25th March)

Re: Migrating Facebook to MySQL 8.0

#115

Post by dvtrn »

PeterZaitsev wrote: post #82
cmrdporcupine wrote: post #4

My old-man brain still can't compute this statement: "MySQL, an open source database developed by Oracle" . I know this is now factually true, but late-90s me keeps looking over my shoulder and freaking out.

I think MySQL Engineering team does great job with Engineering, Do not want to deal with Oracle Sales ? I would invite you to talk to Percona for Commercial Support and Services Options Full disclosure - I'm CEO at Percona :)

Full disclosure - I'm CEO at Percona :)

oh hi. big fan of you all. xtrabackup and PMM are wonderful tools

Re: Migrating Facebook to MySQL 8.0

#116

Post by tapoxi »

munk-a wrote: post #96
lucideer wrote: post #74

Earlier quoted context omitted.

That was the expectation but the Oracle camp surprised everyone by actually giving it some attention, and meanwhile MariaDB's promise of being a "100% compatible drop-in replacement" came with more and more caveats with each release (as is to be entirely expected with any fork). When you consider the network effect of all the stacks already heavily invested in MySQL, all Oracle really needed to do was put in a modicu…

I carried out a (quite ill-advised in retrospect) migration from MySQL to Postgres on a mature codebase with absolutely no automated test coverage and it went pretty smoothly. We had some bumpy performance directly after the production migration but we were able to reach parity after about two months of observing and adding targeted indices. I absolutely adore Postgres's tweaks to the SQL language, that dialect is am…

We also did a MySQL 5.7 to PG 9.6 migration (thanks to https://pgloader.io/) and we got some pretty immediate speed improvements (2-5x).

We shot ourselves in the foot a few weeks later with some poorly written RLS policies, but it was overall a smooth experience.

Re: Migrating Facebook to MySQL 8.0

#117

Post by hellcow »

sltkr wrote: post #108
lucideer wrote: post #74

Earlier quoted context omitted.

That was the expectation but the Oracle camp surprised everyone by actually giving it some attention, and meanwhile MariaDB's promise of being a "100% compatible drop-in replacement" came with more and more caveats with each release (as is to be entirely expected with any fork). When you consider the network effect of all the stacks already heavily invested in MySQL, all Oracle really needed to do was put in a modicu…

I was curious so I looked up the differences here: https://mariadb.com/kb/en/mariadb-vs-mysql-compatibility/ It doesn't sound too bad. The incompabilities seem to be mostly stuff like not being able to generally use replication from MySQL to MariaDB or vice versa. But I would guess that's not a very common case anyway: most users are either developers that want their software to work with both MariaDB and MySQL (whic…

The issues I encountered while using MariaDB in place of MySQL were subtle -- most things worked as expected, which makes the issues so much more unexpected. But at the end of the day, the same migrations produced a different schema.

Arguably MariaDB made the correct decision to fix some MySQL 5.7 bugs that we were unwittingly relying upon, but the different behavior caused issues for us all the same.

Rather than worry about MySQL vs MariaDB and whether the one I need is packaged and available for my distro/OS of choice, I reach for Postgres on new projects.

Re: Migrating Facebook to MySQL 8.0

#118

Post by ahiknsr »

andrewmcwatters wrote: post #86
datavirtue wrote: post #25

Earlier quoted context omitted.

Like everyone else?

I didn't downvote you, but you were downvoted for this. So maybe I'll explain further, instead, to stir conversation. As you deal with more and more rows, it becomes imperative that all of your where clauses hit indexes/indices, but even beyond that, with large enough row sizes, it's not enough to provide fast responses. I suspect they deal with this in the form of some sort of caching outside of MySQL, but I haven't…

> I suspect they deal with this in the form of some sort of caching outside of MySQL, but I haven't read into it.

It is handled by TAO, https://engineering.fb.com/2013/06/25/core-data/tao-the-powe...

Re: Migrating Facebook to MySQL 8.0

#119

Post by hodgesrm »

alberth wrote: post #3

It's interesting to see FB migrating so much over to Oracle. 2 weeks ago was FB use of GraalVM (from Oracle). And now this. https://news.ycombinator.com/item?id=27782475

The MySQL 8.0 upgrade is not a migration to Oracle. Facebook has run MySQL for many years at this point and, as the article describes, operates on a private fork. They have employed some of the leading engineers in the MySQL community to support their version of MySQL.

Re: Migrating Facebook to MySQL 8.0

#120

Post by lazide »

linspace wrote: post #76
jacquesm wrote: post #47

Earlier quoted context omitted.

Because there is a substantial cost to such migrations. If it works don't fix it.

Does anything "just work"? Everything is constantly changing, new features always in demand, more users, more data.

And you need to support that for anything you have ON TOP of any migration work - which is huge, and also a similarly moving target
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