large system time change freezes hobbit client
list Daniel Bourque
Hi,
I noticed that a large clock change tends to stop the hobbit client from sending status messages to the server. For example, if a system boots with the wrong time, I get cpu alerts, I go restart ntpd on it, then I won't get anymore status until I restart hobbit-client on that system...
Is clientlaunch trying to keep track of the current time to determine when to launch hobbit-client.sh, instead of just sleeping 5 minutes ( default ) in between each invocations ?
Thanks
-Dan
list Greg L Hubbard
Wonder how "sleep" works? It may take current time, add 300 seconds, and then make a system call for an interrupt when that time arrives. So if you go BACK in time, the wait is a lot longer. If you go forward in time, the interrupt may not be delivered because it occurs in the past, unless sleep is smart enough to return immediately when it detects time travel. GLH
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-----Original Message-----
From: Daniel Bourque [mailto:user-a141068964db@xymon.invalid]
Sent: Wednesday, June 13, 2007 2:32 PM
To: user-ae9b8668bcde@xymon.invalid
Subject: [hobbit] large system time change freezes hobbit client
Hi,
I noticed that a large clock change tends to stop the hobbit client
from sending status messages to the server. For example, if a system
boots with the wrong time, I get cpu alerts, I go restart ntpd on it,
then I won't get anymore status until I restart hobbit-client on that
system...
Is clientlaunch trying to keep track of the current time to
determine when to launch hobbit-client.sh, instead of just sleeping 5
minutes ( default ) in between each invocations ?
Thanks
-Dan
list Henrik Størner
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On Wed, Jun 13, 2007 at 02:31:42PM -0500, Daniel Bourque wrote:
I noticed that a large clock change tends to stop the hobbit client from sending status messages to the server. For example, if a system boots with the wrong time, I get cpu alerts, I go restart ntpd on it, then I won't get anymore status until I restart hobbit-client on that system...
This was reported a few days ago for hobbitlaunch on the Hobbit server, but yes - the same issue occurs on clients. What happens is basically that hobbitlaunch remembers when it last ran one of the tasks, and then it will run it again when the time becomes (last_time_it_ran + interval). So if you set the current time back, it will stop running for some time. Clocks just aren't supposed to jump backwards ... There are a couple of ways to fix this. One is in the current snapshot, but I might do it differently. Regards, Henrik
list Jason Chambers
Time jumps backwards and forwards in some places for daylight savings. Is this going to cause issues? Jason Chambers I.T. Helpdesk Associate Geosoft Inc. XX Richmond St W - Toronto, ON, CA - M5H 2C9 - Tel: XXX.XXX.XXXX ext XXX - Fax: XXX.XXX.XXXX
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-----Original Message-----
From: Henrik Stoerner [mailto:user-ce4a2c883f75@xymon.invalid]
Sent: June-14-07 1:44 AM
To: user-ae9b8668bcde@xymon.invalid
Subject: Re: [hobbit] large system time change freezes hobbit client
On Wed, Jun 13, 2007 at 02:31:42PM -0500, Daniel Bourque wrote:I noticed that a large clock change tends to stop the hobbit client
from sending status messages to the server. For example, if a system boots with the wrong time, I get cpu alerts, I go restart ntpd on it, then I won't get anymore status until I restart hobbit-client on that system...
This was reported a few days ago for hobbitlaunch on the Hobbit server, but yes - the same issue occurs on clients. What happens is basically that hobbitlaunch remembers when it last ran one of the tasks, and then it will run it again when the time becomes (last_time_it_ran + interval). So if you set the current time back, it will stop running for some time. Clocks just aren't supposed to jump backwards ... There are a couple of ways to fix this. One is in the current snapshot, but I might do it differently. Regards, Henrik
list Daniel Bourque
On unix systems, that shouldn't cause a problem because the time is kept in seconds since epoch. Timezones are just masks that changes according to DST rules. On windows, it's probably going to be a problem, but I don't know enough about the bbwin to confirm that. -Dan
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Jason Chambers wrote:
Time jumps backwards and forwards in some places for daylight savings. Is this going to cause issues? Jason Chambers I.T. Helpdesk Associate Geosoft Inc. XX Richmond St W - Toronto, ON, CA - M5H 2C9 - Tel: XXX.XXX.XXXX ext XXX - Fax: XXX.XXX.XXXX -----Original Message----- From: Henrik Stoerner [mailto:user-ce4a2c883f75@xymon.invalid] Sent: June-14-07 1:44 AM To: user-ae9b8668bcde@xymon.invalid Subject: Re: [hobbit] large system time change freezes hobbit client On Wed, Jun 13, 2007 at 02:31:42PM -0500, Daniel Bourque wrote:I noticed that a large clock change tends to stop the hobbit clientfrom sending status messages to the server. For example, if a system boots with the wrong time, I get cpu alerts, I go restart ntpd on it, then I won't get anymore status until I restart hobbit-client on that system...This was reported a few days ago for hobbitlaunch on the Hobbit server, but yes - the same issue occurs on clients. What happens is basically that hobbitlaunch remembers when it last ran one of the tasks, and then it will run it again when the time becomes (last_time_it_ran + interval). So if you set the current time back, it will stop running for some time. Clocks just aren't supposed to jump backwards ... There are a couple of ways to fix this. One is in the current snapshot, but I might do it differently. Regards, Henrik