|
|
发表于 2010-5-11 14:54:30
|
显示全部楼层
May 10, 2010
Update on WU shortage
We've been working on the WU shortage issue and have some positive items to report.
First, we have greatly improved the AS logic so it uses more information about the CPU. This information is only available in the v6 client or later, so it is important to upgrade to v6 if you're not getting WUs. The main jist is that we can now identify directly whether a machine has SSE or SSE2 support directly, so we can better assign to cores that only support SSE or SSE2 (such as the protomol core, which currently only supports SSE2). This should be a big help to Linux clients as well, which were not well handled by the AS before.
Second, there are a lot of available WUs for Protomol right now, but only for advanced methods clients. If you would like to try that out, set your client for the "Advanced Methods" setting. Note that the Protomol team looks to have fixed the checkpoint bug (which has kept this core in the Advanced Methods QA level) and we hope to roll out this core to all of FAH once again, with this issue fixed.
Finally, we have also identified a potential issue with the AS code which might make its logic fail in certain cases. Basically, in the old days of FAH, we could get away with 32-bit floating point numbers for internal AS calculations, but now with so many servers and all of FAH's complexities, floating point roundoff for certain AS logic could be causing problems. We will be working on a fix for this, but this is something we must do carefully (not just a global replace of float -> double) and so it will take some time to implement and test this.
大意：
缺粮进展
首先，我们调整了AS代码，现在能根据cpu按需分配了（需要v6版客户端支持，建议大家尽快升级）不会再把sse2任务分给不支持sse2的机器了。以前Linux不支持按需分配，现在支持了。
其次，现在Protomol任务很多，不过都是测试任务。如果你想算这些任务，就请打开"Advanced Methods"设置。注：Protomol开发组好像解决了Protomol存盘点异常的bug（之前就是因为这个原因，把Protomol从正式版降回测试版的），如果一切顺利，我们会尽快将Protomol转回正式版。
最后，我们发现了AS代码的一处潜在隐患。随着fah的发展，32位浮点型（float）貌似不够用了。我们会择机把代码升级至double，不过这个改动太大，我们需要小心行事。
low on jobs for Pentium 2/Pentium 3 CPUs -- and a discussion for why that happens and how you can help
We're low on jobs for machines w/o SSE capabilities. We are working to fix this.
By the way, I often get asked "how come FAH can get low on jobs?" This is a good question, considering that since FAH studies temporal phenomena, when one (Work Unit) WU comes in, the work servers automatically build the next one. So, it should be impossible (o rat least very difficult) to run out of jobs, IF everyone plays by the rules.
But that's not the case. Many people attempt to "cherry pick" WUs, i.e. they dump WUs until they get one which is most favorable for them points-wise. This means that they take away WUs from other people, since our server waits until the WU times out before sending it to someone else. This can take a long time on certain WUs.
We have several schemes implemented to fight cherry picking and keep WUs flowing to all the donors, but some times the cherry picking gets very aggressive and we run out of WUs, like today. We are looking into addressing this issue short term (getting more jobs going) as well as long term (better solutions to cherry picking problems). The FFF bonus scheme is such an example of a plan, which seems to be working reasonably well. We are looking into expanding it more broadly.
However, you can help us help other donors (and keep our research going). Please do not cherry pick WUs. This slows down FAHs progress, makes other donors unhappy, and (eg based on FFF schemes) will lead to lower points for those who do this in the future.
大意：
Pentium 2/Pentium 3 CPUs（sse任务）缺粮
有些人经常会问，为什么会缺粮。其实FAH服务器上基本上不缺任务，大部分是因为‘某些人’的行为造成的。他们‘挑食’，遇到‘不合算’的任务（PPD不高）就删除，直到接到合适任务为止。而这些所谓的‘不合算’任务，就会堆积在服务器上，直至过期才会发给其他人。最后就出现了，服务器上有任务，却发不出去的情况。
我们正在需求解决这个问题的办法。目前看来奖励积分是个不错的办法，我们准备大范围推广。
如果你真的想为科研做贡献，请不要‘挑食’了，这样会减慢FAH的研究进度，损害其他人的利益。将来对‘挑食’，我们准备采取积分扣减的惩罚性政策。 |
|
发表于 2010-5-11 12:33:03
发表于 2010-5-11 23:02:29