On Tuesday 16 January 2001 07:20, Alexander Aulbach wrote:
>Hi, this is not a bug but an important issue for us. We have the problem
>that mysql replikation (a really great feature of mysql!) cannot work,
>when you want to replicate a running replacation. E.g.
First, for future reference, this discussion belongs to the internals list.
bugs is only for repeatable bugs ( with a test case we can run).
>
> Master -> Slave 1 (runs since December 2000)
>
>now we need
> -> Slave 2 (should be setup now)
>
>
>The problem is, that we must stop the replication completly on the master
>to load the tables from master. But during this time there could be some
>updates on the master. I will not completly declare, what happens (think
>you know it already). I think it's clear, that we have had some problems
>with it, to bring all members into synchronization again, mainly if
>during synchronization (LOAD TABLE FROM MASTER) the tables has to be
>updated. This is a case, which cannot be atomized.
>
>There should be an option, that a slave should keep an eye on his
>synchronizition by itself. If a slave isn't synchron any more it should
>load all tables again by itself and tracks all updates during this by
>itself.
The full solution for this will be in 4.0, when we will have the
functionallity to take a consistent snapshot without holding a lock on the
whole database the entire time. We may implement SLAVE SYNC in 3.23, but I do
not see a clean and quick way of doing it without a read lock on the whole
database on the master. We should probably just spend our time/efforts on
getting 4.0 out and fixing it there.
>
>Another thing is, that we have a replication through a firewall:
>
> Master <--tcp--> Firewall <--tcp--> Slave
>
>The firewall is configured, that it will loose the TCP-connection after 15
>minutes of no action on this connection. The firewall dosn't belong to us,
>so we cannot adjust it in another way. It would be a fine feature, if the
>slave could look every minute if the master is still there (and
>synchron?). Any traffic on the connection will reset the timer. It should
>be done by the slave itself, not via cron, cause to handle the problem,
>when the connection is closed nevertheless.
If the slave loses connection, it will try to reconnect. Does it not happen
on your setup? If not, this is a bug that needs to be fixed.
--
MySQL Development Team
__ ___ ___ ____ __
/ |/ /_ __/ __/ __ \/ / Sasha Pachev <sasha@stripped>
/ /|_/ / // /\ \/ /_/ / /__ MySQL AB, http://www.mysql.com/
/_/ /_/\_, /___/\___\_\___/ Provo, Utah, USA
<___/
