Random, unpredictable failure to connect

[NSILMike]

Originally Posted by chaley

Clearly something made a difference. Hard to know what exactly, but given what you changed and what happened, your theory makes sense.

If it breaks again then post again. We might be able to figure out what is causing the problems. Until then, enjoy reading.

It is randomly happening again, and I have figured out something that might help debug it...
Recall that sometimes I thought it took a laptop reboot to cure the issue. While that might have been true, I am not so sure now. When I can't connect, my first try was to shut down Calibre and restart that. I got curious and opened the windows task manager. I noticed that it takes the two Calibre processes (calibre.exe and calibre-parallel.exe) up to around 15 seconds to fully shut down when I have the issue. Otherwise they both shut down in maybe a second or two... If I restart Calibre before the two are fully shut down, the problem persists. If I wait, it is cured. (Thus my suspicion that the reboot was only helping by killing the two calibre processes.)

[chaley]

Originally Posted by NSILMike

It is randomly happening again, and I have figured out something that might help debug it...
Recall that sometimes I thought it took a laptop reboot to cure the issue. While that might have been true, I am not so sure now. When I can't connect, my first try was to shut down Calibre and restart that. I got curious and opened the windows task manager. I noticed that it takes the two Calibre processes (calibre.exe and calibre-parallel.exe) up to around 15 seconds to fully shut down when I have the issue. Otherwise they both shut down in maybe a second or two... If I restart Calibre before the two are fully shut down, the problem persists. If I wait, it is cured. (Thus my suspicion that the reboot was only helping by killing the two calibre processes.)

Thanks for the feedback. I can see only one reason why having a worker process would block connections, and that way is supposed to be almost impossible to trigger, requiring an event that happens in a millisecond window.

Questions:

1. Are you running conversions or other jobs when you connect?
2. Are you running calibre 2.27? There were a few changes in that release that improved connection reliability.

[NSILMike]

Originally Posted by chaley

Thanks for the feedback. I can see only one reason why having a worker process would block connections, and that way is supposed to be almost impossible to trigger, requiring an event that happens in a millisecond window.

Questions:

1. Are you running conversions or other jobs when you connect?
2. Are you running calibre 2.27? There were a few changes in that release that improved connection reliability.

I would typically be running skype, and a browser (chrome and/or Firefox depending on what I am doing at the moment for work.) Calibre could be downloading or converting to mobi, but probably not as I download many news sources at specific times, and typically sync to Calibre Companion when all are done.)
And I am always running the current version of Calibre, as I would download and install the same day it notifies me of the upgrade. So, now and since last Friday (when the updates seem to arrive) I am on 2.27
By the way, as mentioned it seemed better for a while, and has come back. Initially it was happening maybe 40-50% of the time. Now it is maybe 1 out of 4 or 5 days.

[NSILMike]

By the way, your support is excellent. But, since this glitch seems limited to me, pls do not spend too much time on it. I seem to have a reasonable work-around, so I certainly do not want to distract you from more valuable efforts!

[chaley]

Originally Posted by NSILMike

By the way, your support is excellent. But, since this glitch seems limited to me, pls do not spend too much time on it. I seem to have a reasonable work-around, so I certainly do not want to distract you from more valuable efforts!

Not to worry. First, we don't know that it is limited to you. All we know is that you are the only person willing to take the time to talk about it. Second, as I can't repeat it I can't do much besides keep the info in mind, hoping that an "ah ha moment" will arrive one day.

for the help.

[NSILMike]

Originally Posted by chaley

Clearly something made a difference. Hard to know what exactly, but given what you changed and what happened, your theory makes sense.

If it breaks again then post again. We might be able to figure out what is causing the problems. Until then, enjoy reading.

It has started again... sigh...
I think I have some additional info that may help, that I had reported before as well.
1) When it happens, I open windows task manager, close calibre, and can see that two processes take quite a few seconds to shut down (these are calibre.exe and caliber-parallel.exe)
2) If I wait long enough for both processes to terminate (normally... I do not force them) and restart Calibre, CC can find Calibre about 50% of the time and sync nomally. If it fails, I have to reboot windows 7 and it works 100% of the time after that (it's the first thing I do after reboot.)

[chaley]

Originally Posted by NSILMike

It has started again... sigh...
I think I have some additional info that may help, that I had reported before as well.
1) When it happens, I open windows task manager, close calibre, and can see that two processes take quite a few seconds to shut down (these are calibre.exe and caliber-parallel.exe)
2) If I wait long enough for both processes to terminate (normally... I do not force them) and restart Calibre, CC can find Calibre about 50% of the time and sync nomally. If it fails, I have to reboot windows 7 and it works 100% of the time after that (it's the first thing I do after reboot.)

If you exit a program with network sockets open then it usually takes a minute for the program to quit. This is caused by the timeout on the sockets.

If calibre thinks a device is connected via WiFi then the socket will be open. No other device can connect, and calibre cannot quit. If in fact no device is really connected then the problem should resolve itself in 60 to 90 seconds. If a device is in fact connected then it will remain in this state for a long time.

What happens if instead of rebooting the computer you restart the device?

[NSILMike]

Originally Posted by chaley

If you exit a program with network sockets open then it usually takes a minute for the program to quit. This is caused by the timeout on the sockets.

If calibre thinks a device is connected via WiFi then the socket will be open. No other device can connect, and calibre cannot quit. If in fact no device is really connected then the problem should resolve itself in 60 to 90 seconds. If a device is in fact connected then it will remain in this state for a long time.

What happens if instead of rebooting the computer you restart the device?

The device is a Nexus 7 (2012.) I tried that a few times when this was happening initially. It made no difference so I gave up on it. Haven't tried it this time...

[NSILMike]

I don't think this is related but...? I just tried manually to connect as wireless device/don't sync books and it sync'd!
I am on CC version 4.1.1(175)

[DoctorOhh]

Originally Posted by NSILMike

I don't think this is related but...? I just tried manually to connect as wireless device/don't sync books and it sync'd!
I am on CC version 4.1.1(175)

You probably already know this but CC always syncs metadata, covers, tags etc every time you connect.

If you connect via wireless device/sync books then not only metadata is sync'd but all books are compared and any book that has been altered is then sync'd (the entire book, not just metadata) to the device. Physically re-uploading any changed book may take a while.

[NSILMike]

Originally Posted by DoctorOhh

You probably already know this but CC always syncs metadata, covers, tags etc every time you connect.

If you connect via wireless device/sync books then not only metadata is sync'd but all books are compared and any book that has been altered is then sync'd (the entire book, not just metadata) to the device. Physically re-uploading any changed book may take a while.

Yes, thanks, I do know that. It sync'd the entire books, which in this case are news sources only. They have not changed because they have not (yet) sync'd down to the device.

[DoctorOhh]

Originally Posted by NSILMike

Yes, thanks, I do know that. It sync'd the entire books, which in this case are news sources only. They have not changed because they have not (yet) sync'd down to the device.

I haven't used the news feature in quite a while, but what you experienced is a feature of calibre when connecting to any device when there are new "News" items.

[NSILMike]

Originally Posted by DoctorOhh

I haven't used the news feature in quite a while, but what you experienced is a feature of calibre when connecting to any device when there are new "News" items.

Thanks, but no, that is not it. This was Calibre Companion, not Calibre. And there is no sync'ing to CC until the user initiates it via CC. (And think about it, there is no reason for those 2 CC sync options otherwise.)

[DoctorOhh]

Originally Posted by NSILMike

Thanks, but no, that is not it. This was Calibre Companion, not Calibre. And there is no sync'ing to CC until the user initiates it via CC. (And think about it, there is no reason for those 2 CC sync options otherwise.)

Like I said it has been a while, but any item tagged "News" will be auto sync'd to any device upon connection to calibre. The Reading list plugin has the same ability.

Calibre News sync is different from the sync option in CC. CC sync will auto sync any changed book, not just downloaded News.

Update: I just tested this and any downloaded "News" will be automatically sync'd to any device connected including CC.

[NSILMike]

Originally Posted by DoctorOhh

Like I said it has been a while, but any item tagged "News" will be auto sync'd to any device upon connection to calibre. The Reading list plugin has the same ability.

Calibre News sync is different from the sync option in CC. CC sync will auto sync any changed book, not just downloaded News.

Update: I just tested this and any downloaded "News" will be automatically sync'd to any device connected including CC.

Sorry but no, again. I've been doing this for quite awhile. These are not changed books, they are new books. They have never auto sync'd. Go ahead and reply if you like, but I'm done.