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hoey168:
请问楼主,ICE 客户端连接多个服务端,tcp -h 172. ...
ZeroC ICE之旅------负载均衡及容错 -
iOracleSun:
makeC++SharedLib 增加 -G参数即可链接成功 ...
AIX apache module问题 -
fanyonglu:
不错,讲的很细,学习中
ZeroC ICE之旅------java -
click_guobin:
...
我在深圳,每月收入850元,怎么也花不完,晒一晒我是怎么开销和投资的(zz) -
hanyu332:
引用修改%apache%/conf/httpd.conf修改为 ...
awstats日志分析小结(1)
New Features
Binary Protocol
A new feature that brings new features. We now have goodness like CAS-everywhere (e.g. delete), silent, but verifiable mutation commands, and many other wonders.
Note that the original protocol is not deprecated. It will be supported indefinitely, although some new features may only be available in the binary protocol.
Client Availability
Many clients for the binary protocol are available.
C
libmemcached supports just about anything you can do with a memcached protocol and is the foundation for many clients in many different languages (which you can find linked from the project page).
Project page: http://tangent.org/552/libmemcached.html
Java
spymemcached has very good text and binary protocol support over IPv4 and IPv6 with a quite comprehensive test suite.
Project page: http://code.google.com/p/spymemcached/
Protocol Spec
NIH problem? Go write your own client. :)
http://cloud.github.com/downloads/memcached/memcached/protocol-binary.txt
Performance
Lots of effort has gone into increasing performance.
There is no longer a build-time distinction between a single-threaded and multi-threaded memcached. If you want a single-threaded memcached, ask for one thread (though there'll still be utility threads and other such things in the background). This change lets us focus on a future where multiple cores can be saturated for servicing requests.
Facebook-inspired contention reduction with per-thread stat collection and the Facebook connection dispatch and thread starvation prevention contributions helped our scalability.
Lock analysis also showed us that we had quite a bit of contention on hash table expansion which has been moved into its own thread, greatly improving the scalability on multicore hardware.
A variety of smaller things also shook out of performance testing and analysis.
There's also a memory optimization for users who don't actually make use of CAS. Running memcached with -C disables the use of CAS resulting in a savings of about eight bytes per item. If you have big caches, and don't use CAS, this can lead to a considerable savings.
Stats
There are several new stats and some new ways to look at older stats.
New Stats
stats settings
Show all current server settings (useful for troubleshooting as well as internal verification).
Delete
The global stats now contain statistics on deletion.
delete_hits refers to the number of times a deletion command was issued which resulted in a modification of the cache while delete_misses refers to the number of times a deletion command was issued which had no effect due to a key mismatch.
Incr/Decr
Incr and decr each have a pair of stats showing when a successful/unsuccessful incr occurred. incr_hits, incr_misses, decr_hits, and decr_misses show where such mutations worked and where they failed to find an existing object to mutate.
CAS
CAS stats are tracked in three different ways:
* cas_hits
Number of attempts to CAS in a new value that worked.
* cas_misses
Number of attempts to CAS in a value where the key was not found.
* cas_badval
Number of attempts to CAS in a value where the CAS failed due to the object changing between the gets and the update.
slab class evicted time
Per slab class, you can now see how recently accessed the most recent evicted data was. This is a useful gauge to determine eviction velocity on a slab so you can know whether evictions are healthy or if you've got a problem.
Connection yield counts
The -R option allows you to limit how many requests are handled in a single trip through the network state machine. The conn_yields stat reports how many times this has occurred.
This is most useful when you have very high rates of operations from a single client which seems to be hogging server resources unfairly, such as extremely large multi-get operations. We do not expect this to be a common situation, but this stat can help diagnose such issues if they should occur.
More Granular Stats
Where possible, stats are now tracked individually by slab class. The following stats are available on a per-slab-class basis (via "stats slabs"):
* get_hits
* cmd_set
* delete_hits
* incr_hits
* decr_hits
* cas_hits
* cas_badval
(misses are obviously not available as they refer to a non-existent item)
Removed stats
"stats malloc" and "stats maps" have been removed.
If you depended on these commands for anything, please let us know so we may suggest alternatives for you.
Misc
* More tests
* More/better documentation
* Code cleanup
Bug Fixes
* Build fixes on ubuntu (gcc and icc) and FreeBSD
* bad interaction with cas + incr ( bug 15 )
* setuid failures are reported properly at daemonization time
* decr overflow causing unnecessary truncation to 0 ( bug 21 )
* failure to bind on Linux with no network (i.e. laptop dev)
* some memcached-tool cleanup
* Alignment bug in binary stats ( bug26 )
* Occasional buffer overflow in stats ( bug27 )
* Try to recycle memory more aggressively. ( bug14 )
* incr validation ( bug31 )
* 64-bit incr/decr delta fixes ( bug21 )
* ascii UDP set ( bug36 )
* stats slabs' used chunks ( bug29 )
* stats reset should reset item stats, eviction counters, etc... ( bug22 )
* Fix all stat buffer management
* Fixes for -R handling ( bug61 )
* GCC 4.4 fixes ( bug60 )
Development Info
We've added a bunch of tests and new code coverage reports.
All included code in this release has been tested against the following platforms (using the in-tree test suite):
* ubuntu 8.10 (64-bit, both gcc and icc)
* ubuntu 8.04 (32-bit)
* ubuntu 9.10 (64-bit, gcc 4.4)
* OS X 10.5 (ppc and intel)
* OpenSolaris 5.11 x86 (with and without dtrace)
* Solaris 10 sparc (with and without dtrace)
* FreeBSD 7 x86
http://memcached.googlecode.com/files/memcached-1.4.0.tar.gz
发表评论
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Redis 2.2.0 RC1 is out
2010-12-17 10:15 1178Redis 2.2.0 RC1 新特性:很多都是我所期待的; ... -
iBATIS 3 for Java Released (BETA 1)
2009-08-09 13:52 1349A month ago iBATIS turned 7 yea ... -
nginx-0.7.60
2009-06-16 09:01 1438Changes with nginx 0.7.60 ... -
nginx-0.7.55
2009-05-06 18:47 1095Changes with nginx 0.7.55 ... -
Open Source SSL Acceleration
2009-04-17 11:15 1685SSL acceleration is a techniq ... -
March 2009 Web Server Survey
2009-04-02 12:49 984In the March 2009 survey, we re ... -
nginx 缓存功能
2009-03-26 16:02 4382随着 nginx-0.7.44的发布,nginx的c ... -
Memcached Beta 1.3.2 Released
2009-03-12 16:21 1176We've just released memcached ... -
nginx 0.7.40
2009-03-09 17:09 984Changes with nginx 0.7.40 ... -
February 2009 Web Server Survey
2009-03-02 09:19 1031In the February 2009 survey we ... -
Handle 1 Billion Events Per Day Using a Memory Gri
2009-02-17 10:41 1003Moshe Kaplan of RockeTier shows ... -
Scaling Digg and Other Web Applications
2009-02-16 11:36 1053Joe Stump, Lead Architect at D ... -
MySpace Architecture
2009-02-13 10:39 1186Information Sources Presenta ... -
Cloud Relationship Model
2009-01-20 09:53 1109Hiya All, welcome to my first g ... -
January 2009 Web Server Survey
2009-01-19 15:33 1054In the January 2009 survey we ... -
December 2008 Web Server Survey
2008-12-25 17:47 972In the December 2008 survey, ... -
Apache 2.2.11
2008-12-15 13:24 1378Changes with Apache 2.2.11 * ... -
nginx 0.7.26
2008-12-09 12:05 1030Changes with nginx 0.7.26 ... -
Python 3.0 final released
2008-12-04 10:47 1329We are pleased to announce the ... -
nginx-0.7.23
2008-11-28 08:38 869Changes with nginx 0.7.23 ...
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