… SAN snapshotting that was unsafe. In a nutshell, the client used SAN block-level replication to maintain a standby/failover MySQL… errors on the filesystem level. From InnoDB’s point of view, though, it was still completely corrupted. The “InnoDB file” contained… is true no matter what type of replication is being used. In this case it’s block-level SAN replication. DRBD…
Post: Using MySQL as a Queue, and Free Percona Live Tickets
September 15, 2011 By Leave a Comment
… Engine Yard blog: 5 subtle ways you’re using MySQL as a queue, and why it’ll bite you. Go there to… a great design pattern from the developer’s point of view, they know it’s often hard to implement well in…
Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
… [Warning] WSREP: Ignoring possible split-brain (allowed by configuration) from view: view(view_id(REG,7e6d285b-d56d-11e1-0800-2491595e99bb,2) memb { 7e6d285b…-f7c4916d8330, } joined { 7e6d285b-d56d-11e1-0800-2491595e99bb, } left { } partitioned { }) to view: view(view_id(TRANS,7e6d285b-d56d-11e1-0800-2491595e99bb,2) memb { 86928728… is why two node clusters is not recommended at all. Now if you have only storage for 2 nodes, using the galera…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… just said repeatedly that SQL doesn’t work on rows! Why would you break this paradigm by passing around rows instead… view over a union of all the already joined and aggregated data from all the nodes. A single temporary table is used… aggregation get a second distributed reduce using UPSERTs into the coordination node when maintaining the “materialized view” of the results. Finally, a…
Post: Implementing efficient counters with MySQL
July 1, 2007 By 16 Comments
… given object – blog post, forum thread, image, movie etc was viewed. This is sometimes handy feature but it can be rather expensive from performance point of view. The nasty thing with counters as they are implemented the… “counter” columns. Using separate table for updates already solves the problem in a lot of cases, and here is why. Assume you…
Post: MySQL opening .frm even when table is in table definition cache
November 21, 2011 By 8 Comments
…open(“./db/t4.frm”, O_RDONLY) = 32 <0.000013> So, why is this? It turns out that this triggered a …code paths in the server: DROP TABLE RENAME TABLE DROP VIEW open table filling INFORMATION_SCHEMA tables (I think it …’t look closely) An example of how this is used is that in the DROP TABLE code path, …
Post: Commodity Hardware, Commodity Software and Commodity People
June 15, 2007 By 9 Comments
…with clustering) with support of partitioning stored procedures views and a lot of stuff. Think how much… projects starts with retrieving data from storage engine using HTTP Protocol and I expect it would …storage engines out where are for MySQL but why could not one develop smaller and lighter top …
Comment: Implementing efficient counters with MySQL
July 2, 2007 By 16 Comments
…-realtime counters just access logs are not enough this is why you can find realtime updates to memcache in my solution… do not care or you can use data specific optimization, for example if there are 0 views in total you may want… as skipping it would be too visible, while if the view count is already 123400 skipping few updates will be unnoticed…
Post: ClickAider - Track Adsense Clicks and much more
July 9, 2007 By 17 Comments
…typically it is compatible with advertisers terms of service. Why did we decide to do it ? Most PPC …all reports by any fields. For example you can view information about clicks for users which came to …and mostly Innodb storage engines. Initially we tried to use PBXT for log storage but it had some …
Post: Percona Toolkit Webinar followup Q&A
December 19, 2012 By 1 Comment
…, and it tries to use the same credentials used in the DSN specified for the master. This is why I recommended having consistent… selected from the timestamp list (the timestamp list is the view you get when first running pt-sift). Q: For pt… is only a way to get a bird’s eye view of a capture (or a set of captures) obtained with…
