… between master and slave in a standard replication setup. The client was using Maatkit’s mk-table-checksum to check his slave data was… of that of the master. mk-table-checksum –algorithm=BIT_XOR h=hostname.local,u=root,p=xxx –replicate=checksum.checksum –emptyrepltbl –chunksize=500000 –databases mydb…
Post: Why audit logging with triggers in MySQL is bad for replication
September 29, 2008 By 10 Comments
Post: The story of one MySQL Upgrade
October 8, 2010 By 8 Comments
… to avoid false positives. mk-table-checksum is a tool to do it. It turned out replication indeed had an issue replicating triggers. The problem… at the same position and used mk-table-checksum to ensure the data is in sync. mk-table-checksum can use replication to check consistency but comparing…
Comment: Resyncing table on MySQL Slave
July 1, 2008 By 11 Comments
… issues you discover through replication errors; or perhaps you use mk-table-sync or mk-table-checksum, or MySQL’s built-in CHECKSUM() function. At any rate, if it’s a small table, mk-table-sync is…
Post: Troubleshooting Relay Log Corruption in MySQL
August 2, 2008 By 7 Comments
… and indeed because there is little validation (ie no checksums) in the replication there are multiple reasons for bad event to show… what could cause it – it could be network (especially if replicating over unreliable long distance networks), MySQL bugs on master or… described and when use Maatkit mk-table-checksum to check what tables are out of sync and when use mk-table-sync to resync them. Last…
Comment: Is DRBD the right choice for me?
July 8, 2009 By 18 Comments
…… Replication is a risk here. The monitoring for replication of course must be in place as well as regular checks with mk-table-checksum. In general for most applications replication can…
Post: MongoDB Approach to database synchronization
April 30, 2010 By 5 Comments
… it from the slave or use mk-table-checksum to find inconsistencies and re-sync them with mk-table-sync. Both of these operations can be very expensive for large databases. MongoDB approach used in Replication Sets is… the great presentation on MongoDB Replication by Dwight Merriman as well as previously looking at how replication done in Redis I should…
Post: Upgrading MySQL
January 5, 2010 By 24 Comments
… MySQL Replication for upgrade. Once you have setup slave with new version and made it to caught up you can use mk-table-checksum… master. Older slaves may have issues unable to interpret new replication stream correctly. If this is the problem for you can try Tungsten Replicator which claims to work in both directions (though I have…
Comment: Is DRBD the right choice for me?
July 8, 2009 By 18 Comments
… solutions for the consistency problems that tend to break MySQL replication (your point #2). These include global transaction IDs for safe…, and built-in consistency checks similar to mk-table-checksum. Also, we will be introducing parallel replication during the next quarter, which is one…
Comment: Is DRBD the right choice for me?
July 7, 2009 By 18 Comments
I think with mk-table-checksum things got a whole deal better – now it is much … of any tool implementing it) to use MySQL replication with DRBD used for replication of binary log. In this case in case… able to catch up the events from the binary log replicated by DRBD before promoting the slave to the master.
Comment: Disaster: LVM Performance in Snapshot Mode
February 24, 2011 By 55 Comments
… ensure you’re checking your replication is in sync with mk-table-checksum or other tools. There are many reasons replication may go silently our…
