“最大化公平”未必”最公平”
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FreeBSD 6.4-RELEASE Release Notes
提供了 amd64/i386 平台 DVD安装盘ISO
November 30, 2008
November 29, 2008
November 28, 2008
淘宝用户规模的一些数据(2008)
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November 25, 2008
[ZT] Ubuntu vs. OpenSolaris vs. FreeBSD Benchmarks
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November 20, 2008
[ZT] Why Google Chrome Needs Add-Ons
Why Google Chrome Needs Add-Ons: Firefox Users Download 1 Billion (GOOG)
http://www.alleyinsider.com/2008/11/google-chrome-needs-add-ons
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October 16, 2008
September 24, 2008
[ZT] 7 Reasons Why BSD Is Better than Linux
7 Reasons Why BSD Is Better than Linux
http://www.intranetjournal.com/articles/200809/pij_09_22_08a.html
September 17, 2008
[ZT] Why isn’t PostgreSQL using my index?
...PostgreSQL's query optimizer is smart, really smart and unless you have evidence otherwise you should trust what it is doing. In this particular case, the optimizer realizes that if a table has only a few rows that using the index is actually slower than just spinning through the entire table. Just because PostgreSQL isn't using your index today with a small number of rows, does not mean it won't choose to use it later when you have more data or the query changes...September 16, 2008
September 15, 2008
[ZT] Best practices for using gjournal with gmirror
FROM: http://unix.derkeiler.com/Mailing-Lists/FreeBSD/hackers/2007-01/msg00220.html
—
[Q:] When using gjournal and for a gmirror volume, does the journal need to be mirrored as well to maintain redundancy? If so, when storing the journal on the same physical disks as the mirror, is it better to mirror at the slice level (journal and fs on different partitions in the same mirror) or at the partition level (journal and fs each have their own mirror) or does it matter?
[A:] The problem with mirroring each partition/slice separately is that when you have a crash, on boot, gmirror will start to rebuild all partitions at once, which may be problematic. On the other hand, when you mirror each partition/slice separately, and some partitions weren’t modified in last few seconds before the crash, gmirror will not resync them on boot, so not entire disk will be synchronized.
注：Gmirror如果对整个硬盘作镜像，系统崩溃重启后，gmirror将有较大可能需要自动重建所有分区(如果是1T HD，会是个大问题)。
如果对每个分区单独做镜像，如果某些个镜像分区在崩溃前几秒钟没有发生修改/写操作的话，镜像状态不会降级损坏，gmirror 就不需要在重启后重建这个分区，（如果将需要频繁写入的分区划为小于20G的独立分区做镜像，就可以一定程度上绕开以上的问题）。
When you run gjournal on top of gmirror/graid3 there is no need for resync after a crash, so bascially all cons against mirroring the whole disks and against mirroring partitions are no longer true. Both configurations will work the same. In that case I’d suggest mirroring the whole disks, because when one of your disks dies, you may just replace it and be down with it. If you mirror partitions separately, you first have to create partitions and insert each of them into their mirrors, which is more complex than simple ‘gmirror insert foo newdisk’.
注： 如果在Gmirror上启用gjournal, 就可以很大程度上避免在崩溃重启后重新同步(?) 这种情况下，推荐对整个硬盘做mirror。
—
[Q:] does a gjournal volume need to be fsck’ed after a crash? If not, will it just work (e.g. fsck -p sees that the filesystem is clean) or does it need to be disabled somehow?
[A:] Gjournaled file system has to be fscked, but only to handle orphaned files. Such fsck on multiterabyte provider takes seconds, not hours.
注：gjournal 系统同样需要fsck, 但是非常迅速。
—
September 14, 2008
September 3, 2008
August 30, 2008
[08-08-30] @Links
[08-08-30] @Links:
August 28, 2008
OpenSQL Camp 2008: a community-organized database conference
From announcing-opensql-camp-2008:
Key facts:
- It is of, by and for the community (you).
- At this event, all open-source databases are created equal. We’ll learn together and grow together.
It’s a combination conference and hackathon. - It’s free.
- It is Friday night Nov 14, 18:00 through Sun the 16th at 18:00 in Charlottesville, Virginia USA in a very cool location.
- The website, where all details will be posted: http://opensqlcamp.pbwiki.com/
- The mailing group, where details will be discussed, decided and arranged: http://groups.google.com/group/opensqlcamp
- Date, time and place are confirmed and will not change. You can make your travel plans now. There’s travel information on the wiki.
- We already have some great speakers who have offered to give great talks. These and other details will show up on the wiki as they’re finalized.
- Sponsors are needed. See the wiki.
August 1, 2008
BSD Hammer streaming 的一些信息
看样子有点像 Linux 下的 DRBD
two disks can be synchronized over a network link of any speed or reliability - it can be restarted and immediately begin where it left off, and the amount of bandwidth used can be controlled…
参考链接:
Hammer streaming
HAMMER Update 31-Jul-2008 - Streaming Mirroring on HEAD
July 31, 2008
[08-07-31] @Links
[08-07-31] @Links:
SSD / SATA 阵列性能对比
SSD vs. SATA RAID: A performance benchmark
Microsoft Backs Apache and Open Source
Microsoft announced their sponsorship of “The Apache Software Foundation”,
joining Google and Yahoo! at Platinum level.
KDE 4.1 Release
2008年7月29日 - KDE 4.1 发布
WinSCP: 4.1.6 released
2008-07-30: WinSCP: 4.1.6 released
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June 28, 2008
[2008-6-27] Bill Gates retires today
June 26, 2008
June 24, 2008
Symbian 要开源了
可能由 Symbian 基金会 管理
采用的许可证: Eclipse Public License
Symbian Foundation:
Industry leaders to unify the Symbian mobile platform and set it free
Foundation to be established to provide royalty-free open platform and accelerate innovation
相关的链接：
http://symbianfoundation.org
http://www.symbian.com
Nokia buys Symbian, will open Symbian OS
NetBSD 许可协议删除了#3 #4 条款
NetBSD 转向使用两条款 BSD 协议，#3 #4 关于广告支持的条款已从协议文本中删除。
http://mail-index.netbsd.org/…../msg000030.html
另，看一个有趣的对比：
June 21, 2008
说说 Firefox 3.0 的外观，到底咋样？
功能上的增强，不多说了。(地址栏 bookmarks 实时检索，很出彩! )
至于外观，还期待能进一步 “改进” 。。
http://tech.sina.com.cn/s/…/13172130234.shtml
http://www.firefox.net.cn/…?t=22099
June 19, 2008
June 14, 2008
June 10, 2008
Google Trends 三则
June 5, 2008
[PostgreSQL] pgAdmin III v1.8.4 released
2008-06-05 - pgAdmin III v1.8.4 released.
June 4, 2008
微软”跟随战略”之：MS版 memcached - “Velocity”
http://blogs.msdn.com/velocity/
Velocity is intended to provide distributed caching (in memory) for all .NET applications – from enterprise scale to web-scale. We believe that there are many applications that need a distributed caching mechanism, and that there is, therefore, a need for distributed caching as a core part of the .NET platform. We expect to have more integrated support for this functionality with other parts of the .NET platform in our upcoming releases.
[CVS] FreeBSD begins switch to Subversion
FreeBSD 源代码管理系统 开始从 CVS 转向 Subversion 。
3 June，2008:
The FreeBSD Project has begun the switch of its source code management system from CVS to Subversion. At this point in time, FreeBSD’s developers are making changes to the base system in the Subversion repository. We have a replication system in place that exports our work to the legacy CVS tree on a continuous basis.
People who are using our extensive CVS based distribution network (including anoncvs, CVSup, cvsweb, ftp) will not be interrupted by our work-in-progress. We are committed to maintaining the existing CVS based distribution system for at least the support lifetime of all existing “stable” branches. Security and errata patches will continue to be made available in their usual CVS locations.
We expect to make our Subversion based source tree and other supporting infrastructure public soon. There will be new mailing lists to subscribe to if you wish to receive Subversion commit notifications.
Our ports, doc and www trees are not affected at this time. A separate decision will be made regarding those CVS repositories soon.
Many people have contributed to the effort, but we wish to thank Michael Haggerty and the cvs2svn project developers for their assistance with cvs2svn. Peter Wemm spent several weeks of Yahoo!’s time repairing the CVS tree, preparing for and performing the conversion, and the configuration of the Subversion infrastructure. Yahoo! donated the server hardware.
来源：http://www.freebsd.org/news/newsflash.html#event20080603:01
相关：http://blogs.freebsdish.org/ivoras/2008/06/01/freebsd-on-subversion/
有趣的东东，Goosh.org
Goosh.org: a Unix-like Shell For Google
Neat idea:
goosh.org - the unofficial google shell. This google-interface behaves similar to a unix-shell.
You type commands and the results are shown on this page.— by Vivek
May 31, 2008
[HACKERS] Core team statement on replication in PostgreSQL (备查)
built-in replication in PostgreSQL 看来有戏了，留个记号在此备查！
* From: Tom Lane
* To: pgsql-hackers(at)postgreSQL(dot)org
* Subject: Core team statement on replication in PostgreSQL
* Date: Thu, 29 May 2008 10:12:55 -0400
* Message-id: <26529(dot)1212070375(at)sss(dot)pgh(dot)pa(dot)us>
http://archives.postgresql.org/pgsql-hackers/2008-05/msg00913.php
The Postgres core team met at PGCon to discuss a few issues, the largest
of which is the need for simple, built-in replication for PostgreSQL.
Historically the project policy has been to avoid putting replication
into core PostgreSQL, so as to leave room for development of competing
solutions, recognizing that there is no “one size fits all” replication
solution. However, it is becoming clear that this policy is hindering
acceptance of PostgreSQL to too great an extent, compared to the benefit
it offers to the add-on replication projects. Users who might consider
PostgreSQL are choosing other database systems because our existing
replication options are too complex to install and use for simple cases.
In practice, simple asynchronous single-master-multiple-slave
replication covers a respectable fraction of use cases, so we have
concluded that we should allow such a feature to be included in the core
project. We emphasize that this is not meant to prevent continued
development of add-on replication projects that cover more complex use
cases.We believe that the most appropriate base technology for this is
probably real-time WAL log shipping, as was demoed by NTT OSS at PGCon.
We hope that such a feature can be completed for 8.4. Ideally this
would be coupled with the ability to execute read-only queries on the
slave servers, but we see technical difficulties that might prevent that
from being completed before 8.5 or even further out. (The big problem
is that long-running slave-side queries might still need tuples that are
vacuumable on the master, and so replication of vacuuming actions would
cause the slave’s queries to deliver wrong answers.)Again, this will not replace Slony, pgPool, Continuent, Londiste, or
other systems for many users, as it will be not be highly scalable nor
support long-distance replication nor replicating less than an entire
installation. But it is time to include a simple, reliable basic
replication feature in the core system.—regards, tom lane
May 26, 2008
[Jignesh K. Shah] Problems with PG on Multi-Cores with Multi-TB Data
Problems with PostgreSQL on Multi-core Systems with Multi-Terabyte Data.
– by Jignesh K. Shah
PDF: http://www.blowfisher.net/pubs/pgcon_problems-JigneshK.Shah.pdf
Current Market Trends in Systems
• Quad-core sockets are current market standards
> Also 8-core sockets available now and could become a standard in next couple of year• Most common rack servers now have two sockets
> 8-core (or more ) systems are the norm with trend going to 12-16 core systems soon• Most Servers have internal drives > 146 GB
> Denser in capacity, smaller in size but essentially same or lower speed
> More denser in case of SATA-II drives
Current Market Trends in Software
• Software (including Operating Systems) have yet to fully catch up with multi-core systems
> “tar” still single process utility• Horizontal Scaling helps a lot but not a good clean solution for multi-core systems
• Virtualization is the new buzzword for Consolidations
> Hides the fact that the software is not able to fully capitalize the extra cores
• Research being done on new paradigms
> Complexity of parallelized software is huge
Current Market Trends in Data
• 12 years ago, a 20GB data warehouse was considered a big database
• Now everybody talks about 200GB-5TB databases
• Some 2005 Survey numbers:
> Top OLTP DB sizes = 5,973 GB to 23,101 GB
> Top DW DB Sizes = 17,685 GB to 100,386 GB
> Source http://www.wintercorp.com/VLDB/2005_TopTen_Survey/TopTenWinners_2005.asp• Some 2007 Survey numbers:
> Top DB sizes = 20+ TB to 220 TB ( 6+ PB on tape)
> Source http://www.businessintelligencelowdown.com/2007/02/top_10_largest.html
