There is a lot of discussions whenever running MySQL storing data on NFS is a good idea. There is a lot of things for and against this and this post is not about them. The fact is number of people run their databases on NetApp and other forms of NFS storage and this post is [...]
Debugging problems with row based replication
May 6, 2010 By 12 Comments
MySQL 5.1 introduces row based binary logging. In fact, the default binary logging format in GA versions of MySQL 5.1 is ‘MIXED’ STATEMENT*; The binlog_format variable can still be changed per sessions which means it is possible that some of your binary log entries will be written in a row-based fashion instead of the [...]
How to know if you’re updating Slave you should not ?
April 11, 2010 By 8 Comments
When replication runs out of sync first question you often ask is if someone could be writing to the slave. Of course there is read_only setting which is good to set in the slave but it is not set always and also users with SUPER privilege bypass it. Looking into binary log is obvious choice [...]
Maximal write througput in MySQL
February 28, 2010 By 10 Comments
I recently was asked what maximal amount transactions per second we can get using MySQL and XtraDB / InnoDB storage engine if we have high-end server. Good questions, though not easy to answer, as it depends on: – durability setting ( innodb_flush_log_at_trx_commit = 0 or 1 ) ? – do we use binary logs ( [...]
XtraDB storage engine release 1.0.2-3 (Spring edition) codename Sapporo
March 2, 2009 By 10 Comments
Today we announce release 1.0.2-3 of our XtraDB storage engine. Here is a list of enhancements: Move to MySQL 5.1.31 Scalability fix — ability to use several rollback segments Increasing the number of rseg may be helpful for CPU scale of write-intentional workloads. See benchmark results. Scalability fix — replaced page_hash mutex to page_hash read-write [...]
Beware: ext3 and sync-binlog do not play well together
January 21, 2009 By 19 Comments
One of our customers reported strange problem with MySQL having extremely poor performance when sync-binlog=1 is enabled, even though the system with RAID and BBU were expected to have much better performance. The problem could be repeated with SysBench as follows:
1 | ./sysbench --num-threads=2 --test=oltp --oltp-test-mode=complex --oltp-table-size=100000 --oltp-distinct-ranges=0 --oltp-order-ranges=0 --oltp-sum-ranges=0 --oltp-simple-ranges=0 --oltp-point-selects=0 --oltp-range-size=0 --mysql-table-engine=innodb --mysql-user=root --max-requests=0 --max-time=60 --mysql-db=test run |
New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
As you likely have seen Sun has posted the new SpecJAppServer Results More information from Tom Daly can be found here These results are quite interesting for me as I worked on some of the previous SpecJAppServer Benchmarks several years ago while being employed by MySQL. These are great results, plus they can be relevant [...]
Why audit logging with triggers in MySQL is bad for replication
September 29, 2008 By 10 Comments
Recently I was tasked with investigating slippage between master and slave in a standard replication setup. The client was using Maatkit’s mk-table-checksum to check his slave data was indeed a fair copy of that of the master.
Recovery beyond data restore
August 2, 2008 By 11 Comments
Quite frequently I see customers looking at recovery as on ability to restore data from backup which can be far from being enough to restore the whole system to operating state, especially for complex systems. Instead of looking just at data restore process you better look at the whole process which is required to bring [...]
Troubleshooting Relay Log Corruption in MySQL
August 2, 2008 By 7 Comments
Have you ever seen the replication stopped with message like this: Last_Error: Could not parse relay log event entry. The possible reasons are: the master’s binary log is corrupted (you can check this by running ‘mysqlbinlog’ on the binary log), the slave’s relay log is corrupted (you can check this by running ‘mysqlbinlog’ on the [...]
