… reloading the data will be a very IO intense operation (redo logs, binlogs, etc) as well further …sure that the files are owned by mysql: chown mysql:mysql /var/lib/mysql/orig_old/* For each table, run… allow remote users to compare on a live system without needed to grant access to another “backup” …
Post: Webinar: Best Practices for MySQL Scalability on May 1
April 30, 2013 By Leave a Comment
…-level look at the components of MySQL scalability: application architecture, MySQL version and configuration, choosing hardware and operating systems. For each area we’ll… the Webinar! *** More info: MySQL scalability depends on getting many things right including the architecture, hardware, operating system, MySQL version, MySQL configuration, schema design and…
Post: Rotating MySQL slow logs safely
April 18, 2013 By 7 Comments
… log writes. Truncation can block MySQL because the OS serializes access to the inode during the truncate operation. This problem is particularly evident when using the ext3 file system (instead of xfs). Use FLUSH LOGS instead of sending SIGHUP When copytruncate is disabled, MySQL must be told…
Post: Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL now available
April 17, 2013 By 2 Comments
…when appending exclusive key for cascading delete operation. Bug fixed #1089490 (Seppo Jaakola). Parallel …hanging. Bug fixed #1130888 (Seppo Jaakola). If MySQL replication threads were started before running wsrep … please report them to our bug tracking system. UPDATE[18-04-2013]: There was a…
Post: Why MySQL Performance at Low Concurrency is Important
March 27, 2013 By 8 Comments
… jobs are written to be single-threaded. MySQL replication is single-thread too, and MySQL 5.6 brings some abilities of parallel… or less, at least the system is performing well, pointing to rather low concurrency in the normal system operation. Much higher concurrency in most cases is seen when the system is overloaded and suffering. So…
Post: MySQL 5.6 - InnoDB Memcached Plugin as a caching layer
March 29, 2013 By 10 Comments
… nutshell, here is how one would start the memcached plugin: mysql> install plugin daemon_memcached soname ‘libmemcached.so’; In an effort…: InnoDB store operation was 280% higher (~1.73 ms/op) InnoDB fetch operation was 20% higher (~.06 ms/op) MySQL Select showed 27… both operations, there are some tradeoffs to consider: Cost of additional memcached hardware Cost of operations time to maintain an additional system Impact…
Post: MySQL 5.6 Compatible Percona Toolkit 2.2 Released
March 25, 2013 By 2 Comments
… pt-osc 2.1 only retries certain operations, pt-osc 2.2 retries every critical operation, and its tries and wait time… (introduced in MySQL 5.5) for metadata locks. Now –set-vars is used to set both of these (or any) system variables… are certain versions of MySQL that have critical bugs. Version check will warn you about these if your system is running them…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…device. EXT4 is the filesystem, and CentOS 6.4 the operating system, although the pre-release modules I received from Virident required…time=7200 –max-requests=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=innodb \ –oltp-read-only=off run…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… a six-hour tutorial about Percona XtraDB Cluster (PXC) for MySQL. I actually had more material than I covered (by design… find in standard async MySQL replication. It is my belief that the lack of understanding of this system, or even that it… must be taken that your application or some other maintenance operation (like a backup) doesn’t inadvertently cause flow control on…
Post: Testing the Micron P320h
April 16, 2013 By 7 Comments
… tests were also performed using the Cisco UCS C250. The operating system in use was CentOS 6.3, and for the sysbench… latency just over 3ms. How well does it perform with MySQL? Exact results vary, depending upon the usual factors (read/write… compare the performance of the P320h on a standard TPCC-MySQL test to the original FusionIO and the Intel i910 with…
