

Mysos – MySQL on Mesos - _jomo
https://github.com/twitter/mysos

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chrissnell
How does Mysos handle the spin-up of new slaves? One of the pain points of our
current Chef-driven environment is the provisioning of new slaves. We use Chef
to install and configure MySQL but to get a slave up and running, we use
xtrabackup to dump the master's DBs to disk, then rsync them to the slave,
then use xtrabackup to restore the dump. Once that's done, we point the new
slave at the master and start it slaving. It's totally manual and takes around
15 minutes each time. How does Mysos automate this?

~~~
gpapilion
Looking at to code, it pulls from a backup and restores the state. It manages
the cluster slave and master states via zookeeper. When the master fails a
slave is promoted.

So, in order to run this you need zookeeper, hdfs, and mesos. Its a great
solution, but not for everyone.

~~~
jpgvm
To be fair, if you have Mesos it's highly likely you already have HDFS, ZK is
a dependency of Mesos.

Though it's not strictly necessary to run HDFS a lot of Mesos native
applications and frameworks already expect it.

The thing is you can often run HDFS on your Mesos slaves so it ends up
stacking up quite nicely, atleast in small deployments.

~~~
merb
How is HDFS quite nicely in small environments? I mean a minimal HA deployment
of HDFS contains at least 5 nodes. 2x Namenode, 3x Data Nodes. Sorry but for
"starting out small" this is definitely too much.

~~~
jpgvm
I don't see how Mesos is going to be useful to you with less than 5 servers.

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fi788
This is really interesting, specially if it really reduces the burden of
running Mysql with failover or multiple slave databases. This is similar to
what is currently available on AWS - RDS, but requires separate database
instances and is very tricky to implement on development environments or local
infrastructure.

I'd be interested in knowing if any of you have tried it or inspected the code
in detail.

~~~
stephenr
I'd imagine percona cluster would work for your use case?

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justinsb
Looks well designed. I wish someone would do this for MongoDB!

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dijit
we're still using mysql?

it's still relevant? I never suggest to people who are starting a project to
use mysql. (even percona, although I know they do good work).

if there is a case for using mysql can someone explain it to me? it feels like
a toy in comparison to postgresql, oracle or mssql.. and is too "warty" for
small systems either (where sqlite dominates).

from what I can tell the only real advocates of mysql seem to be those
unwilling to adopt new technology.. but this is all my experience and I'm
genuinely curious if anyone sees it differently.

~~~
SEJeff
Twitter
([https://github.com/twitter/mysos](https://github.com/twitter/mysos)),
Facebook
([https://github.com/facebook/mysql-5.6](https://github.com/facebook/mysql-5.6)),
Youtube
([https://github.com/youtube/vitess](https://github.com/youtube/vitess)), just
to name a few large users.

For everyone saying MySQL isn't "web scale", there are some absolute web
titans that seem to be using it quite happily.

~~~
xu
Yup, Twitter totally use MySQL extensively. This the recent blog post has more
details: [https://blog.twitter.com/2015/another-look-at-mysql-at-
twitt...](https://blog.twitter.com/2015/another-look-at-mysql-at-twitter-and-
incubating-mysos)

