June 19, 2013

Post: Choosing a MySQL HA Solution - Post-Webinar Q&A

June 7, 2013 By Leave a Comment

…allow you to stripe a TCP connection over multiple ports, and with a two-NIC bonded …libexec/mysqld: Incorrect information in file: ‘./mysql/servers.frm’ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm’ …-tables and insert a few rows into an InnoDB table, but trying to run a simple …

Filed Under: Insight for DBAs, Insight for Developers, MySQL, MySQL Webinars Tagged With: , , ,

Post: Analyzing the distribution of InnoDB log file writes

July 16, 2010 By 5 Comments

… about how the log file writes are distributed in terms of write size. InnoDB writes to the log files in multiples of 512 bytes. Mark Callaghan explained this and some of its performance implications here. How many big writes does InnoDB do, and how many small writes? First, I found out the file descriptor numbers of the log files: # lsof -p…

Filed Under: MySQL, Percona Software Tagged With:

Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2

May 3, 2011 By 13 Comments

… 5.6.2 one can have multiple dedicated purge threads. Percona Server 5.1 supports multiple purge threads too, although using more…=1900M innodb_flush_log_at_trx_commit=2 innodb_doublewrite=1 innodb_flush_method=O_DIRECT innodb_max_dirty_pages_pct=80 innodb_file_format=barracuda innodb_file…

Filed Under: MySQL

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

February 26, 2013 By 1 Comment

… index. I’m not entirely sure about the _STOPWORDS.ibd file just yet; I thought it might be somehow related to… dropping FT indexes, it’s entirely possible to DROP multiple FT indexes with InnoDB in the same ALTER TABLE statement, but it… setting innodb_optimize_fulltext_only = 1 and then running OPTIMIZE TABLE, and that we might have to run OPTIMIZE TABLE multiple times…

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Post: Can Innodb Read-Ahead reduce read performance ?

June 26, 2007 By 2 Comments

… outstanding IO requests to the disk. Lets look at SHOW INNODB STATUS: ——– FILE I/O ——– I/O thread 0 state: waiting for… requests. May be it is poor read-ahead performance plus multiple threads doing scattered O_DIRECT (so no OS read-ahead… Mark Callaghan patches to see what happens if we allow multiple read-ahead threads. I also can’t wait for Christoffer…

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Post: How to estimate time it takes Innodb to Recover ?

May 9, 2007 By 7 Comments

… normally set innodb_log_file_size large. We however usually recommend caution as it may significantly increase recovery time if Innodb needs to… 40 minutes or so with innodb_log_file_size=256MB. In other cases I know same log file time may have recovery time… do you estimate how long it takes Innodb to Recover ? Now you know there are multiple of variables which all may be…

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Post: Fix of InnoDB/XtraDB scalability of rollback segment

January 18, 2009 By 9 Comments

… transactions are serialized accessing to segment. Fortunately InnoDB internally has mechanism to support multiple rollback segments – and Yasufumi just made…innodb_file_per_table=1 innodb_flush_log_at_trx_commit=2 innodb_log_buffer_size=8M innodb_log_files_in_group=2 innodb_log_file_size=128M innodb…

Filed Under: Benchmarks, Percona Software Tagged With: ,

Post: Innodb Double Write

August 4, 2006 By 24 Comments

… log file allocated inside Innodb tablespace – it contains space for 100 pages. When Innodb flushes pages from Innodb buffer pool it does so by multiple…. It also allows Innodb to save on fsync()s – instead of calling fsync() for each page write Innodb submits multiple page writes and…

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Post: The Doom of Multiple Storage Engines

May 8, 2010 By 22 Comments

… have to write second binary log file when all transaction engines have their own ! Quality Assurance Multiple storage engines are much more… SQL level table locks and using Innodb internal data dictionary instead of Innodb files. We would use Innodb transactional log for replication (which could…

Filed Under: Insight for DBAs, MySQL

Post: SHOW INNODB STATUS walk through

July 17, 2006 By 40 Comments

… if connection is in “Sleep” stage – if it is multiple statement transaction. Innodb also will print OS thread_id and process id… are pending requests on buffer pool level. Innodb may merge multiple requests to one on file level so these are different. We can also see different types of IO submited by Innodb…

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