Jacques Le Roux wrote:
From: "Adrian Crum" <[email protected]>
Jacques Le Roux wrote:
Hi Deyan,
Thanks for your clear explanation and suggestion. As I'm busy with
another stuff, I have quickly put your comment as a quote in
OFBIZ-3333 .
There is however a major issue that CAN NOT be fixed in the current
implementation: the list and sequence of entities to be
synchronized gets created by entities' timestamp - date_created_tx
and last_update_tx. It works as long as the clocks of all the
syncing parties are in sync. You can easily achieve this by using NTP
for example - reliable enough. But if the clock of one of
the parties gets un-synced for just few minutes, and during those few
minutes records get inserted or updated than you are in
trouble. Syncing the clock back won't help you because you won't be
able to sync the broken records due to foreign key constraint
issues. Examples I could give but I guess you could think of such by
yourselves :)
So IMHO the best approach for synchronization is not the timestamp
but the TRANSACTION LOG. This approach is used in all major
databases - m$ $ql, oracle.
The problem with that approach is that it is database-specific. As an
alternative, you could query the other servers for their
current time and generate a set of offsets to adjust the timing.
Why asking from one to the others? Using NTP on all of them should be
enough, or do I miss something
Yes, you missed the part where one of the servers loses its NTP
connection and its time drifts.
PS: why mean Re: JUNK-> ?
Sorry about that. Our security appliance prepends JUNK-> to the subject
line of suspected spam emails. Most likely your mail server is on a
blacklist somewhere. I try to remove it before replying, but sometimes I
forget.
-Adrian
