When I synchronize using ZSyncer, very frequently the indicator text beside the folder still shows as "out of date" even though it is not (the date and content are correct). Is this typical? And what can I do? Because this happens, I am syncing a lot of folders that probably don't need it. Thanks. __________________________________ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com
On Thu, Sep 18, 2003 at 08:23:28AM -0700, Sophia Grimm wrote:
When I synchronize using ZSyncer, very frequently the indicator text beside the folder still shows as "out of date" even though it is not (the date and content are correct). Is this typical? And what can I do? Because this happens, I am syncing a lot of folders that probably don't need it.
This is a known limitation. It happens when the source system's clock is a bit (or a lot) ahead of the destination. So you modify something and immediately sync it and the destination modification time is returned as older than you think. To prevent it in the future, ensure that the source and destination servers have their clocks set as close as possible. However, this won't help with existing objects. Current CVS of zsyncer tries uses DublinCore timestamps instead of bobobase_modification_time, when possible. This gives better results for CMF content. Unfortunately, it's hard to do better for most other zope types, because they only provide bobobase_modification_time, which is under control of the underlying ZODB and cannot be overridden by zope. There are plans to investigate checksumming and other strategies for more reliably determining sync status, but currently I don't have much time for this. -- Paul Winkler http://www.slinkp.com Look! Up in the sky! It's RASPUTINIC SCHIZOID MEGABOT! (random hero from isometric.spaceninja.com)
One way to help keep everything in sync is to reset the system clock on a regular basis. On Linux, add the following line to your root cron file: 47 23 * * * rdate -s time.nist.gov; /usr/sbin/hwclock --systohc You may want to change the firing time... the first entries in the table correspond to (min, hour, day, mon, dayofweek, ...) '*' is interpreted as 'all in range' otherwise they are interpreted as a comma separated list of values. The commands are fired off whenever the pattern defined by the first entries matches the current clock. The entry above, for example, goes off at thirteen minutes before midnight every day. Updating once a day does a reasonable job of keeping everything in sync. If you need to really syncronize the clocks, this won't do it. You need some really heavy-duty mechanism. (See Leslie Lamport's papers on the topic for an explanation....) But for Sync's purposes, it's probably OK.B I presume there is an equivalent mechanism for Windows, but I don't know what it is. On Thu, 18 Sep 2003, Paul Winkler wrote:
On Thu, Sep 18, 2003 at 08:23:28AM -0700, Sophia Grimm wrote:
When I synchronize using ZSyncer, very frequently the indicator text beside the folder still shows as "out of date" even though it is not (the date and content are correct). Is this typical? And what can I do? Because this happens, I am syncing a lot of folders that probably don't need it.
This is a known limitation. It happens when the source system's clock is a bit (or a lot) ahead of the destination. So you modify something and immediately sync it and the destination modification time is returned as older than you think.
To prevent it in the future, ensure that the source and destination servers have their clocks set as close as possible. However, this won't help with existing objects.
Current CVS of zsyncer tries uses DublinCore timestamps instead of bobobase_modification_time, when possible. This gives better results for CMF content.
Unfortunately, it's hard to do better for most other zope types, because they only provide bobobase_modification_time, which is under control of the underlying ZODB and cannot be overridden by zope.
There are plans to investigate checksumming and other strategies for more reliably determining sync status, but currently I don't have much time for this.
--
Paul Winkler http://www.slinkp.com Look! Up in the sky! It's RASPUTINIC SCHIZOID MEGABOT! (random hero from isometric.spaceninja.com)
_______________________________________________ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
One way to help keep everything in sync is to reset the system clock on a regular basis. On Linux, add the following line to your root cron file:
47 23 * * * rdate -s time.nist.gov; /usr/sbin/hwclock --systohc
...
If you need to really syncronize the clocks, this won't do it. You need some really heavy-duty mechanism. (See Leslie Lamport's papers on the topic for an explanation....) But for Sync's purposes, it's probably OK.B
I presume there is an equivalent mechanism for Windows, but I don't know what it is.
ntpdate on Linux (and presumably any Unixish system) is a more accurate choice. It'll get you as close as you can reasonably get. There are Windows programs that will do this too. Back when I used Windows I had one, but don't remember what it was called anymore. Check Tucows or some such place. I think MS even stuck an NTP service (or whatever) in one of its recent Windows. (The corresponding story is that they also pointed it to a third party and didn't bother to tell them. A good story if true.) Not that I'm not veering off-topic or anything... --jcc -- "Code generators follow the 80/20 rule. They solve most of the problems, but not all of the problems. There are always features and edge cases that will need hand-coding. Even if code generation could build 100 percent of the application, there will still be an endless supply of boring meetings about feature design." (http://www.devx.com/java/editorial/15511)
Thanks to all who responded (Dennis, Dieter, Paul). I'm going to work on getting my system clocks in sync, as this sounds like a reasonable explanation. --- Paul Winkler <pw_lists@slinkp.com> wrote:
On Thu, Sep 18, 2003 at 08:23:28AM -0700, Sophia Grimm wrote:
When I synchronize using ZSyncer, very frequently the indicator text beside the folder still shows as "out of date" even though it is not (the date and content are correct). Is this typical? And what can I do? Because this happens, I am syncing a lot of folders that probably don't need it.
This is a known limitation. It happens when the source system's clock is a bit (or a lot) ahead of the destination. So you modify something and immediately sync it and the destination modification time is returned as older than you think.
To prevent it in the future, ensure that the source and destination servers have their clocks set as close as possible. However, this won't help with existing objects.
Current CVS of zsyncer tries uses DublinCore timestamps instead of bobobase_modification_time, when possible. This gives better results for CMF content.
Unfortunately, it's hard to do better for most other zope types, because they only provide bobobase_modification_time, which is under control of the underlying ZODB and cannot be overridden by zope.
There are plans to investigate checksumming and other strategies for more reliably determining sync status, but currently I don't have much time for this.
--
Paul Winkler http://www.slinkp.com Look! Up in the sky! It's RASPUTINIC SCHIZOID MEGABOT! (random hero from isometric.spaceninja.com)
_______________________________________________ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
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Sophia Grimm wrote at 2003-9-18 08:23 -0700:
When I synchronize using ZSyncer, very frequently the indicator text beside the folder still shows as "out of date" even though it is not (the date and content are correct). Is this typical? And what can I do? Because this happens, I am syncing a lot of folders that probably don't need it.
I have seen it, too, occationally, but did not investigate. Somehow, the times on the servers seem not to match. Dieter
participants (5)
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Dennis Allison -
Dieter Maurer -
J Cameron Cooper -
Paul Winkler -
Sophia Grimm