Website backup

[neo_sluf]

Everytime i visit this website.After many minutes it creates a timer that says BAC UP within a given time and after the time expires this website is not reachable?

-is there a problem on this site?

 

[Magtheridon96]

No.
That's perfectly normal.
The site is backing up it's data in-case something goes wrong.
If something were to go wrong, we wouldn't lose a ton of data because then we could simply restore from the last backup.

It takes time because the site's database is about 100GB.
The server has to read 100GB of data and write it to another disk.

 

[Ralle]

Actually. The MySQL database is about 1.5 GB and it does a dump of that which is what makes the site be down for 2-3 minutes.
The rest of the database is backed up every 4 hours or so, which does not make any downtime.

 

[Dr Super Good]

It is not possible to backup the SQL database without taking the site down?

 

[The Reborn Devil]

I guess that could cause complications. I don't know much about how these servers work, nor do I know anything about MySQL (other than it being used for databases and stuff). However, I assume that you wouldn't want any writing to the SQL database while backing it up. Basically, some of the data relies on other data, or at least requires synchronization with it, and so if some values change while backing up, a desynchronization could occur (as already backup data would not be updated).

Just my guess though.

 

[Ralle]

There is something called binary replication, where every edit to the database is logged to a binary log which is then synced to slave servers. Then you can stop the slave server from syncing and dump its contents without affecting the master. I may set this up at one point. We had it until this server went unstable. The problem is that basically every time it crashes, the binary log would be corrupt. This means you have to re-sync the databases (dump the main, copy over to slave, load the file, start syncing), which is a very painful process.

There also exists something called mysqlhotcopy which takes a copy of the database without locking anything. This means you could potentially backup a recent thread but not the first post and race conditions like that. It is not pretty.