No work units and clock skew errors

[craiginsd]

In the past week or so, my FAHControl log (Running a Mac Pro 4,1 with 6 cores), I'm getting regular messages of; "Could not get an assignment" from server IPs 65.254.110.245:8080 and 18.218.241.186:80, but I'm also seeing occasional errors saying; "Detected clock skew (2 hours 18 mins) [or other timeframes], I/O delay, laptop hibernation or other slowdown noted, adjusting time estimates", for a machine that has been constantly on and has its time set by the Apple time server. Are these related issues, or suggested in another thread, are there really no available WUs at this time?

[bruce]

1) The processing resources that the Donors are offering to help with this analysis exceeds the amount of work that the servers are able to deliver, so "could not get an assignment" is sort of the same thing as saying please wait since we can't use your system right now. The folks at the data centers are frantically trying to generate more work and optimized their resources to be able to use everything that's being offered, but FAH will not give you an assignment that has already been completed by someone else. Some other *@home sites will distribute "busy work" so that their donors don't realize their efforts aren't really going to be used ... but not FAH.

2) When your computer has nothing to do, the Operating System will put it into a low-power state (commonly known a "hibernation" or "sleep") from which it can be awakened when something happens. While it's hibernating, the clock doesn't even run continuously but when it wakes up, the clock is reset to the then-current-time. FAH notices that the clock has been adjusted and reports that fact. It's nothing to worry about. It's sort of like a screen-saver that turns of your monitor when there's nothing new to look at.

Yes, there really are times when the servers have no WUs to distribute (see #1) but the clock resetting process is your computer's reaction to not having anything to do (see #2). I

[craiginsd]

Excellent explanation, and thanks very much! I noticed a few days ago a WU started up at 10% already completed, but terminated at only 28% just 26 minutes later. Nothing since then.

[bruce]

When a WU is being processed, the software periodically writes a checkpoint to disk ... maybe every 5% or 10% ... so restarting from 10% is possible.

Every WU has a deadline ... plus it earns more points if you complete it quickly than if your efforts are less productive. Assuming your computer was not folding part of the time, the WU might have expired at 28% or maybe an error was detected. FAH will return the incomplete WU and it will be assigned to someone else to be competed.

Starting a WU that you can't finish is expensive to FAH's progress, so please don't allow your computer to do that.

[Lasky]

Hello

Let me get this straight. When my computer goes to sleep, F @ H automatically wakes it up when new work is available ? That would be perfect and environmentally friendly, for my wallet

[Jesse_V]

Hello

Let me get this straight. When my computer goes to sleep, F @ H automatically wakes it up when new work is available ? That would be perfect and environmentally friendly, for my wallet

When your computer is asleep, processes are not running. F@h won't wake the computer. F@h can only tell if work is available by connecting to the server and asking for it. If it gets a new workunit, it will then engage the processing and return it back to the server when its complete. I think your best strategy might be to leave the computer up and idle with the monitor off. F@h will periodically connect to the servers and look for work and will then use the CPU or GPU when it can.