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bio website blog.9minutesnooze.com
location New York, United States
age
visits member for 5 years, 1 month
seen Jun 18 at 22:17

May
20
comment Determine if LUKS/dmcrypt key is present
Thanks for the response, Hauke. The reality that I've observed is that while it's only a few seconds to unlock the volume, it completely saturates a CPU during this operation which could prove problematic on a database in an OLTP scenario. Thanks for the alternatives, also.
Jul
10
comment MySQL Slow Writes
I think the query cache is completely separate from the storage engine. It basically serializes all write operations by forcing everything to go through and scan the query cache for queries to invalidate. I've never found a use case for it and it has always caused problems.
Jul
10
comment MySQL Slow Writes
query_cache_size is enormous, too. Every insert will require up to 6GB of cache to be flushed.
Jun
25
comment How to automatically kill slow MySQL queries after N seconds?
Why not use pt-kill?
Jun
25
comment How to automatically kill slow MySQL queries after N seconds?
pt-kill is very well tested and solves your exact problem. It takes like 10 minutes to figure out the command line parameters and get it running. What more do you want?
Apr
19
comment What is more important for a database server? Mem? Mem speed? Cores?
InnoDB Plugin can be installed easily in 5.1. Also, Percona Server 5.1 is based on InnoDB plugin.
Apr
19
comment What is more important for a database server? Mem? Mem speed? Cores?
Since MySQL was specifically mentioned, faster processors are usually a better choice than more (assuming you're not talking about just 1 or 2), as the speed of a single query is fundamentally limited by the speed of a single processor. Even the most recent MySQL versions don't scale as well as some other RDBMSes across multiple cores due to internal mutex and semaphore contention. I run several 24 core servers and I would give my left arm to trade them in for half as many cores that are 1.5x faster.
Mar
25
comment MySQL master-master replication between database running on 3 different server
I have some advice. Don't do it. You'll regret it later. This configuration is incredibly unstable and increases your points of failure.
Feb
2
comment HA Setup for MySQL/mostly MyISAM Tables
Sorry, i misread.
Jan
30
comment MySQL query caching - what happens if Server runs out of RAM?
You should confirm that you are using the right definition of free memory. The line that you generally care about is memory available for apps which is the free column on the -/+ buffers cache line. Nearly everyone I talk to doesn't understand how Linux utilizes memory.
Jan
29
comment How to migrate from regular MySQL to Percona Server in production?
You can just install Percona Server over MySQL. It is binary compatible.
Jan
23
comment High iowait on Amazon EC2 MySQL instance with EBS volume
Thanks, Baron! I will remove that statement.
Jan
15
comment Restore MySQL Databases from File backups, not MySQL Export
A list of the filenames that you restored would be helpful.
Dec
13
comment Copy MySQL to RAM as a poor man's memcached replacement?
The way that you use memcached for reads -> 1. client requests data. 2. client looks to see if it is in memcached 3. if it is in memcached, return the data, if not 4. read it from the database 5. return to client, 6. write data to memcached. For writes, you just write to both memcached and the database.
Dec
6
comment flush tables in the Locked state
What does the entire SHOW FULL PROCESSLIST look like while the locks are occurring? What you have shown above only shows SELECT statements, which, unless they are FOR UPDATE, won't lock anything and don't provide any insight. You have 128MB query cache but only a 100MB key buffer. How much memory is available on this server? What is the ratio of reads to writes? The query cache is almost never valuable. The biggest thing you can tune on a MyISAM workload is the key_buffer_size and you should make it as large as you can.
Dec
3
comment flush tables in the Locked state
What does the rest of the process list show? If tables are locked, there is something locking them, likely a long running insert, update, delete, insert select, or select for update. Also, please post your my.cnf settings. attack the cause (queries that are causing locking), not the symptom ( locked tables)
Nov
25
comment flush tables in the Locked state
You say you can't switch to InnoDB -- why?
Nov
15
comment Is EBS naturally CPU-hungry?
what does iostat -x 1 say while you are running the cpu intensive process. It sounds like you might just have high iowait time.
Nov
10
comment How do I quickly create new instances of complex MySQL database?
Fair enough. Legacy architecture is a pain.
Nov
9
comment How do I quickly create new instances of complex MySQL database?
This doesn't sound scalable at all. Every user gets their own database? How large could your user base potentially get?