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From:Gerald Clark Date:July 13 2001 6:44pm
Subject:Re: HA Setup for MySQL
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I don't believe NFS locking is reliable enough to allow two
servers to serve the same databases.

Shon Stephens wrote:

> I recently started experimenting with a way to setup MySQL to be 
> load-balanced. I installed 2 servers with MySQL, NFS mounted the 
> /mysql/var directory, then moved the grant tables to /mysql/grant, and 
> created a symbolic link from /mysql/var/mysql to /mysql/grant. This 
> appeared to work correctly, however, my tables soon began to show 
> corruptions, and sometimes when an insert was made, and then immediately 
> following a select statement was made against that data, it would not be 
> found. I figured this was due to memory cache not being flushed to disk 
> before the select statement. So the other server would have no record of 
> the data. I adjusted the server settings so that data was always written 
> to disk. This solved that problem 99.99% of  the time. However, I was 
> wondering if perhaps the server doesn't always try and select from the 
> table on disk, but rather the table in memory. So that if server 1 
> inserts data into the table and writes it to disk, then server 2 selects 
> data but only from the table it has loaded into memory it won't be able 
> to select the new data?
> Has anyone ever tried something like this?
> Also, I want to try setting up replication such as A -> B -> A. I want 
> to be able to put both system behind a load-balancing switch. If an 
> insert is done on server A, then server B is updated, then server B 
> sends an update to server A, will server A know to ignore it since it 
> originated from server A?
> Thanks,
> Shon Stephens
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Gerald L. Clark

HA Setup for MySQLShon Stephens13 Jul
  • Re: HA Setup for MySQLGerald Clark13 Jul
    • Re: HA Setup for MySQLShon Stephens14 Jul