… of production database servers and will perform the backups. The write load is not excessive so a single server can easily… snapshot, like LVM but… since it is a copy on write filesystem, the snapshots are free, no performance penalty. You can… from the other drive in the mirror. Better availability and disk usage On purpose, I allocated mirror pairs using drives from…
Post: The write cache: Swap insanity tome III
April 19, 2013 By 5 Comments
… like: pt-stalk, vmstat, top, iostat, etc all saving to disk with the current time stamp in front of each line… (~150MB/s) but doing very little physical writes. The writes were cached and the write cache was causing the problem. It happened that… to 20 on a 48GB server, allowing nearly 10GB of “write cache”. A quick survey of the servers I have access…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… the original node where the transaction is committed) Galera prevents writing conflicts to these pending transactions while they are inflight in… to persist after a crash, it has to get to disk. This has no effect on standard MySQL replication from this… more latency waiting for a write to go through, and possibly some poor user experience. batch writes Instead of updating global counters…
Comment: Virident vCache vs. FlashCache: Part 1
May 17, 2013 By 3 Comments
… to help me when I need to start writing massive amounts of data to disk. I could go out and buy a… a Samsung 830 in the laptop I’m using to write this comment on. It’s pretty fast. But it’s… a regular SSD or HDD RAID), I can write data out to spinning disk at a nice sustainable rate. @Mark- I don…
Comment: Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
…Joshua, writing every query to disk can be very expensive. At Groupon, we write slow logs to a different disk array on our large…
Post: MySQL 5.6 - InnoDB Memcached Plugin as a caching layer
March 29, 2013 By 10 Comments
…, stop/start plugin). As expected, there is a slowdown for write operations when using the InnoDB version. But there is also… buffer pool, so there are no reads from disk. However, there is write activity stemming from the fact that this is using… additional system Impact of warmup time to application Cost of disk space on database server Now, there are definitely other NoSQL…
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…, the baseline configuration plus: innodb_read_io_threads = 16 innodb_write_io_threads = 16 We call this configuration B. The next… would be cached (i.e., no special treatment of sequential writes) and with a 50% dirty page threshold. Again, for comparison…
Comment: State of the art: Galera - synchronous replication for InnoDB
April 23, 2013 By 15 Comments
The link http://www.codership.com/en/content/benchmarking-write-scalability does not work anymore? I am running mysqlslap against … right now and don’t see the same kind of disk i/o on it that I have seen when running… master/slave. I wonder if it is writing as synchronous? I was able to write 100,000 queries in about 50-60…
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… note the transaction produces 4 INSERTs and workload is very write intensive. So what are results in this case: InnoDB gradually…_size=4096 #####plugin options innodb_read_io_threads = 16 innodb_write_io_threads = 4 innodb_io_capacity = 4000 innodb_use_native…
Comment: Open Source, the MySQL market (and TokuDB in particular)
May 11, 2013 By 13 Comments
For pure-disk servers the advantages of TokuDB versus InnoDB are limited to … to InnoDB compression on my data) and larger (more sequential) writes means that you will buy much less flash and either…
