… evs.send_window and evs.user_send_window could trigger cluster crash under high load. Bug fixed #1080539 (Teemu Ollakka). Standard MySQL port… could lead to unresolved replication conflict and leave a slave hanging. Bug fixed #1130888 (Seppo Jaakola). If MySQL replication threads were started before…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… moving from async to synchronous replication is right for their application or not. Facts about Galera replication There’s a lot of… has no effect on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’s actually much worse… up to several hundred. This really will open a large window where rows won’t be able to be updated more…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… to Galera is existence of a replication feedback mechanism, unlike anything you find in standard async MySQL replication. It is my belief that…_reads. It minimizes the expense of certification by keeping the window between new transactions being committed and the oldest unapplied transaction…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… post is about the way MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with… with other databases, at least not in the same way. Windows in particular has had excellent threading support practically forever; Linux…, it wouldn’t be a great OLTP web database too. MySQL replication is one of the core, fundamental features — and it’s…
Post: Finding your MySQL High-Availability solution – Replication
November 13, 2009 By 6 Comments
… MySQL, replication. High Availability solution for MySQL: Replication This HA solution is the easiest to implement and to manage. You basically need to setup MySQL replication… updated before returning after a commit statement. There is a window in time where it is possible that a fully committed…
Post: Finding your MySQL High-Availability solution – The questions
October 16, 2009 By 36 Comments
… a window of time where data loss is possible. If you can afford to lose some data, you can consider “MySQL replication” and… table below. Expertise level MySQL replication Typical, average MySQL DBA + some Sysadmin skills Master-Master with MMM manager Good, average MySQL DBA + good Sysadmin…
Post: Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
… is handy when you have this tool running in several windows on several nodes. cmt This is the wsrep_local_state… outbound replication. This generally increases when some other node is having difficulty receiving replication events. The ‘Dn’ (down) queue is inbound replication. Positive… to detect replication lag, and this really just tells you if multi-threaded replication could help improve replication speed at all. Conflct Replication conflicts…
Comment: Impact of the number of idle connections in MySQL
February 23, 2011 By 21 Comments
hi, i m using mysql 5.1 on windows platform, and i want to know how many slave is possible of master in replication process in mysql. what is maximum number to generate slaves in mysql replication
Post: Quickly finding unused indexes (and estimating their size)
December 5, 2012 By 2 Comments
… to run this several days, or just sample different short windows during your normal production peak. In either case, you may… just a slave somewhere (just be careful not to break replication!). mysql> create schema index_analysis; If our index_statistics are collecting… droppable_indexes view to use that information: mysql> drop view if exists droppable_indexes; mysql> create view droppable_indexes as select all…
Post: MySQL Crash Recovery
July 30, 2006 By 30 Comments
… only problem as we’ll see. MySQL has angel process mysqld_safe which will restart MySQL Server in most cases. It is… out of sync with database content. This will sometimes break replication but if you’re just planning on using binary log… MySQL to fail with wierd error messages. In MySQL 4.1 sync_frm option was added which reduces this problem as time window…
