… that while SSDs are a lot faster than regular spinning disk, a PCIe flash card is still massively faster than an… card, not Virident, but there’s a comparison in TPCC-MySQL performance between that card and a traditional SSD – the PCIe… or HDD RAID), I can write data out to spinning disk at a nice sustainable rate. @Mark- I don’t know…
Comment: TMP_TABLE_SIZE and MAX_HEAP_TABLE_SIZE
April 4, 2013 By 17 Comments
… and drupal, and i converted databases from MyISAM to InnoDB, mysql tunning script gives below results for temp table , server has… = 128 M Of 21559 temp tables, 44% were created on disk Perhaps you should increase your tmp_table_size and/or max_heap_table_size to reduce the number of disk-based temporary tables Note! BLOB and TEXT columns are not…
Post: The write cache: Swap insanity tome III
April 19, 2013 By 5 Comments
…, you need to interleave the allocation of memory for the MySQL process using the numactl utility, drop the file cache and… like: pt-stalk, vmstat, top, iostat, etc all saving to disk with the current time stamp in front of each line… S3. Why? The push to S3 was especially puzzling since MySQL was not involved. The server was running with nearly 7GB…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… a 4GiB buffer pool. The cache devices were flushed to disk immediately prior to and immediately following each test run. With…-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: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…, but InnoDB can’t make 5h run. After 3h the disk is full, and InnoDB data size is about 210GB with…=insert_roll.lua –oltp-table-size=10000 –mysql-user=root –oltp-tables-count=32 –mysql_table_engine=tokudb –oltp_auto_inc=on… = 10G myisam_repair_threads = 1 myisam_recover socket=/var/lib/mysql/mysql.sock user=root skip-grant-tables TokuDB-related options are…
Post: How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
… InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no… need the table id to find indexes of the table. mysql> select * from SYS_TABLES WHERE NAME=’sakila/actor’; +————–+—–+——–+——+——–+———+————–+——-+ | NAME | ID… of the dictionary tables into some MySQL server. Use LOAD DATA INFILE constraints_parser generates mysql>LOAD DATA INFILE ‘/path/to/SYS…
Comment: State of the art: Galera - synchronous replication for InnoDB
April 23, 2013 By 15 Comments
… see the same kind of disk i/o on it that I have seen when running mysql 5.1 or mariadb 5… write 100,000 queries in about 50-60 seconds to mysql 5.1 and in about 6-9 seconds on mariadb…=100000 MariaDB-Galera-server-5.5.29-1.x86_64 mysql-5.1.67-1.el6_3.x86_64 MariaDB-server…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
… (within a single connection) anywhere in any ‘free’ variant of MySQL. PARTITIONs are scanned one at a time. (Please provide specific… billion-row (non-partitioned) table will, at worst, hit the disk only 5 times. (Usually 4 of the 5 are cached… PARTITIONing. I go into more details (and code) here: http://mysql.rjweb.org/doc.php/partitionmaint The third use case for…
Post: Virident vCache vs. FlashCache: Part 1
May 16, 2013 By 3 Comments
… the MySQL working set is significantly larger than the InnoDB buffer pool (thus leading to a lot of buffer pool disk reads…
Post: Aligning IO on a hard disk RAID – the Theory
June 9, 2011 By 18 Comments
… doing the right thing. Say we have 6-disk RAID5 (so 5 bearing disks) with 64k stripe unit size and 4k file…’s no striping, with RAID0 number of bearing disks is actual number of disks (N), with RAID1+0 (RAID10) it’s N… of data that will be written to single disk before skipping to next disk in the array. This is also one of…
