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Old 18th August 2010, 10:31
Mark_NL Mark_NL is offline
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Quote:
Originally Posted by scottrill2 View Post
Have a question about replication. I read this statement on MYsql's website:
"•Data security - because data is replicated to the slave, and the slave can pause the replication process, it is possible to run backup services on the slave without corrupting the corresponding master data. "
Question 1: Does this mean everytime a backup script is run in ispconfig 2 there is a chance I could corrupt my databases? Is it a minute possiblity or is it fairly common?
No, because you're just stopping the slave to get a consistent snapshot of the database at that exact moment. when you do that on a master, inserts/deletes still work so you could get incosistent data (corrupt).

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Question 2: I found a few different replication tutorials on HowToForge, one covering master-slave and one covering master-master. Is a master-master vulnerable to the same corruption? Is a master-slave scenario safer all the way around?
master-slave is much safer .. if you make one mistake with master-master you can mess up your complete database, besides that i'm not a fan of m-m setup's .. it can give you a lot of problems (think of collisions when writing the same data/record at the exact same time, no locking through replication) .. i rather have a mysql cluster when a master-slave is not enough.

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Question 3: In falko's tutorial "http://www.howtoforge.com/mysql5_master_master_replication_debian_etch" he mentions:

"The advantages of master-master replication over the traditional master-slave replication are that you don't have to modify your applications to make write accesses only to the master"

Does this mean if I use a master-slave replication I have to tell ISPConfig 2 to only wrtite to the master or something like that?
Yes, you make the slave read-only (my.cnf: 'read-only' setting)
now you tell your applications to shoot inserts, deletes, updates etc to the master, and selects to the slave .. or use your master for everything, and just keep your slave solely for backing up your data.


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Thanks as always folks,

Scott
Your welcome !
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