(转载)libeatmydata
原文:https://www.flamingspork.com/projects/libeatmydata/
libeatmydata is a small LD_PRELOAD library designed to (transparently) disable fsync (and friends, like open(O_SYNC)). This has two side-effects: making software that writes data safely to disk a lot quicker and making this software no longer crash safe.
DO NOT use libeatmydata on software where you care about what it stores. It's called libEAT-MY-DATA for a reason.
Source
I've recently been migrating things over to git from the old BZR repository.
Git repositories are on launchpad and github
Grab the latest by just doing git clone https://github.com/stewartsmith/libeatmydata.git
- although most Linux distros package libeatmydata as eatmydata
Download: The launchpad download page has all the latest libeatmydata downloads.
You can also download the source tarball from here: libeatmydata-105.tar.gz and GPG signature: libeatmydata-105.tar.gz.asc.
Install
If installing from source, do the following:
git clone https://github.com/stewartsmith/libeatmydata.git
(or extract from source tarball)cd libeatmydata
autoreconf -i
(if building from git only)./configure
make
make check
sudo make install
Using
Once libeatmydata is installed (either from a package or from source like above, simply run the eatmydata wrapper script:
eatmydata foo
Platform Support
I use it primarily on Linux. Others have reported success on MacOS X, OpenSolaris, Solaris, Debian GNU/kFreeBSD. Patches welcome!
Contributing
You can email me directly with patches. Development is hosted on launchpad and has been transitioning to github.
Performance Improvements
Running mysql-test-run --do-test=innodb without/with libeatmydata:
TEST RESULT TIME (ms) TIME (with libeatmydata)
-------------------------------------------------------------------------------+++
main.innodb-lock [ pass ] 4523 4323
main.innodb-replace [ pass ] 102 56
main.innodb-ucs2 [ pass ] 5786 1084
main.innodb [ pass ] 78306 24900
main.innodb_gis [ pass ] 2647 1544
main.innodb_mysql [ pass ] 86810 68579
main.innodb_notembedded [ pass ] 198 150
main.innodb_timeout_rollback [ pass ] 2990 2750
main.innodb_trx_weight [ pass ] 1608 841
------------------------------------------------------------+++
Stopping All Servers
All 9 tests were successful.
The servers were restarted 7 times
WITHOUT: Spent 182.97 seconds actually executing testcases
WITH : Spent 104.227 seconds actually executing testcases
WITHOUT: WITH:
real 3m36.053s real 2m10.610s
user 0m42.323s user 0m41.939s
sys 0m2.844s sys 0m2.356s
This saves us about a third of the total runtime!