The other possibility is the sender doesn't think the prior RPC completed
and didn't update the sequence number (although I haven't looked at the
code to see if this is possible).  With a mismatch of one out of 59643
seems like the server is reaching exactly the wrong conclusion (this is a
new host) rather than the right one (there was a communications problem on
the prior contact).  If it were a new host, shouldn't the sequence number
be near 0?


On Fri, Aug 8, 2014 at 10:19 AM, Richard Haselgrove <
[email protected]> wrote:

> In probably the fullest message board description on the last circuit
> round this merry-go-round,
>
> http://setiathome.berkeley.edu/forum_thread.php?id=70946
>
> we observed a number of occasions where client message logs contained
> lines like
>
> 22.05.2013 13:45:56 | SETI@home | Not sending work - last request too
> recent: 76 sec
>
> at times not unadjacent to the times when abandonments were recorded for
> user tasks. That led us into 'clutching at straws' mode: was another
> computer sending out-of-sequence RPC requests with duplicate credentials?
> (the users swore not). Were entire RPC requests being delayed in a transit
> queue and arriving out of sequence? Unlikely. Was the server receiving the
> RPCs in a timely fashion, but processing them out of order - perhaps
> delaying one because of incomplete packets?
>
> And so on. Most of this was happening before the server move to CoLo, when
> the SETI data line was heavily congested - we thought the problem might
> diminish with the higher-quality internet service at the bottom of the
> hill, and so it seems to have transpired. But doesn't help our friends
> outwith the continental USA.
>
> Incidentally, I reported seeing one 'last request too recent' in my own
> logs, and traced it back to an internet time update changing the computer
> clock. But I didn't suffer any abandoned tasks in that event.
>
>   ------------------------------
>  *From:* Eric J Korpela <[email protected]>
> *To:* Richard Haselgrove <[email protected]>
> *Cc:* "[email protected]" <[email protected]>
> *Sent:* Friday, 8 August 2014, 17:47
>
> *Subject:* Re: [boinc_dev] astropulse robustness / abandonned tasks
>
> His host seems to be losing track of RPC sequence numbers.  Loss of cached
> writes on restart?
>
> 2014-08-08 07:13:53.1883 [PID=28339]  [HOST#6960982] [USER#8522684] RPC
> seqno 59642 less than expected 59643; creating new host
> 2014-08-08 07:13:53.1896 [PID=28339]  [HOST#6960982] [USER#8522684] Found
> similar existing host for this user - assigned.
> 2014-08-08 07:13:53.1932 [PID=28339] [CRITICAL]  [HOST#6960982]
> [RESULT#3670788988] [WU#1562416658] changed CPID: marking in-progress
> result 03se08ad.16169.8252.438086664200.12.220_0 as client error!
> 2014-08-08 07:13:53.1932 [PID=28339]  Request: [USER#8522684]
> [HOST#6960982] [IP 41.79.224.134] client 7.2.42
>
>
>
> On Fri, Aug 8, 2014 at 9:17 AM, Richard Haselgrove <
> [email protected]> wrote:
>
> > The same user appears to have suffered another 'abandon' event today:
> >
> > http://setiathome.berkeley.edu/results.php?hostid=6960982&state=6
> >
> > The reasons mentioned by Eric are all valid, but there appears to be an
> > irreducible core of sporadic events which cannot be ascribed to user
> > malfeasance. In earlier reports like this, many (but not all) of the
> cases
> > appeared to be associated with long-distance and/or poor quality internet
> > connections - again, like this one.
> >
> >  ------------------------------
> >  *From:* Eric J Korpela <[email protected]>
> > *To:* "McLeod, John" <[email protected]>
> > *Cc:* "[email protected]" <[email protected]>; Richard
> > Haselgrove <[email protected]>
> > *Sent:* Friday, 8 August 2014, 16:56
> >
> > *Subject:* Re: [boinc_dev] astropulse robustness / abandonned tasks
>
> >
> > Astropulse does checkpoint quite frequently, and restarts without problem
> > most of the time.  "Abandoned" is definitely a server side decision that
> > indicates a client detach or a reset or some sort of confusion as to the
> > identity of a host and whether it was working on those results.  (Other
> > possibilities include multiple hosts using a copied or shared BOINC
> > directory, multiple copies of BOINC on one host using the same BOINC
> client
> > directory, deletion or corruption or bad permissions on files in the
> BOINC
> > client directory, any of which could confuse client or server).
> >
> >
> > Which client version and OS are you using?
> >
> >
> > On Fri, Aug 8, 2014 at 5:55 AM, McLeod, John <[email protected]>
> wrote:
> >
> > > BOINC has a checkpointing mechanism built in, but it requires that the
> > > project developers write checkpoint code.  Some projects can checkpoint
> > > almost any time, and others can checkpoint only every few minutes, and
> > some
> > > cannot checkpoint at all.  SETI can checkpoint frequently (and
> instigated
> > > the mechanism to NOT do every possible checkpoint, but only once every
> X
> > > minutes).  CPDN always checkpoints every time it can (typically this is
> > > several minutes).  I cannot remember an example of one that cannot
> > > checkpoint at all, but they exist.
> > >
> > > -----Original Message-----
> > > From: boinc_dev [mailto:[email protected]] On Behalf
> Of
> > > Richard Haselgrove
> > > Sent: Friday, August 08, 2014 4:48 AM
> > > To: Luc A. Germain; [email protected]
> > > Subject: Re: [boinc_dev] astropulse robustness / abandonned tasks
> > >
> > > The abandoning of tasks happens when the BOINC server 'thinks' that it
> > has
> > > 'evidence' that the client has detached from the project and then
> > > re-attached again. This has affected a number of users in the past, but
> > has
> > > proved extremely tricky to diagnose and resolve: not least, because
> most
> > of
> > > the evidence resides in the server logs.
> > >
> > > We did investigate one suspected case at Albert during credit testing,
> > but
> > > that turned out to be a genuine 'detach' caused by hard disk failure -
> it
> > > is distinguished from reports like this one because no running tasks
> were
> > > left on the host computer (they were on the drive that failed...) to
> > waste
> > > time and electricity.
> > >
> > > I would certainly welcome it if we could pair up a developer and a
> > project
> > > administrator with access to server logs to investigate this problem
> and
> > > cure it at source.
> > >
> > > The checkpointing question is a matter for the project developers, and
> > > I'll leave it to them to respond via this list.
> > >
> > >
> > >
> > > >________________________________
> > > > From: Luc A. Germain <[email protected]>
> > > >To: [email protected]
> > > >Sent: Friday, 8 August 2014, 9:41
> > > >Subject: [boinc_dev] astropulse robustness / abandonned tasks
> > > >
> > > >
> > > >Hi,
> > > >Two things:
> > > >1) A suggestion here for you develloppers ;-) As atropulse tasks take
> > > "some" time to complete they are more prone to power failure as we have
> > in
> > > the third world. When it happens most of the time the task restarts
> > > computing from start (this is even more frustrating when the task
> reaches
> > > near completion). Could it be possible to introduce regular checkpoints
> > by
> > > saving intermediate data, or work files, where the task computing could
> > > restart from, saving so a lot of computing time ? Maybe this could be
> an
> > > option in the user profile as I guess not everyone needs this.
> > > >
> > > >2) Two days ago I sent a message about abandonned tasks. Since, all my
> > > computing goes to the garbage bin as they are not taken into account.
> > Which
> > > procedure should/could I try to solve this problem ? Could
> > > uninstalling/reinstalling the application from my computers be a
> > solution?
> > > Should I wait till the problem solves by itself (and would this not
> take
> > > ages) ?
> > > >
> > > >An answer would be highly appreciated.
> > > >
> > > >Best regards and thanks for your work,
> > > >Luc
> > > >_______________________________________________
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> > > >(near bottom of page) enter your email address.
> > > >
> > > >
> > > >
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