My understanding is... * There is a "permanent" connection (TCP/IP socket) between the Master and each Slave. This is opened by the Slave when the slave starts (or restarts or recovers from a network glitch).
* Master writes to binlog _and_ to that connection whenever there is a 'write' operation. (I do not know whether the binlog is written/flushed before or after or simultaneous with writing to the Slave(s).) * If the connection is interrupted, the Slave will reconnect and ask the Master for "old" info. This comes from the binlog. Otherwise, the Master's binlog file is not part of the flow of data from Master to Slave. * Semi-sync (5.5) adds some chatter from Slave to Master so that the Master can wait for at least one Slave to have written to its relay log. * Percona Cluster, Galera, etc., add more complexity to the replication traffic. > -----Original Message----- > From: Keith Murphy [mailto:bmur...@paragon-cs.com] > Sent: Thursday, July 26, 2012 9:45 AM > To: Zhigang Zhang > Cc: mysql@lists.mysql.com > Subject: Re: How often the slave to pull data from master? > > Yes, the slave pulls from the master. The slave io thread reads the > information effectively as soon as it is written to the master's binary > log. > > Keith > On Jul 26, 2012 4:17 AM, "Zhigang Zhang" <zzgang2...@gmail.com> wrote: > > > Hello: > > > > > > > > I haven't read the source code of mysql ,but as I know ,the slave get > > data from master server, rather than the master push data to slave. > > > > > > > > I think there is a timer to do this. > > > > > > > > Who can tell me the interval about the replication----how often the > > slave to pull data from master? > > > > > > > > Thanks! > > > > > > > > Zhigang Zhang > > > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
