Ming the Mechanic
The NewsLog of Flemming Funch

Friday, July 4, 2003day link 

 Server move
I moved most of the contents of my server yesterday. It went reasonably well. That is, however, always a time when thing can go horribly wrong very quickly. The configuration of a linux server usually consists of hundreds of little details that have been done at different times, and it is not easy to make sure the same environment will exist on a new server.

What went most wrong sofar was the mysql database for NCN. Since it is a community site with many facilities and there's always somebody there, I was trying to minimize the downtime, so I was planning on going for a replication scheme. See, because of the way DNS lookups work there will be a period of time where a visitor might be sent to either the old site or the new site, and there's not a good way of knowing which one. And no matter what they do on that site, there will be database records created. Now, mysql has some neat replication features which would allow the database in two locations to be closely in sync in real-time, and which in principle would allow that changes could be made in either place and nothing would be lost. But I failed to notice that the replication process had stopped sometime during the day. And I didn't get that fixed before some people had jumped from the old to the new site and become surprised that their newslog entries and comments and recent changes suddenly had disappeared, and after new stuff had been posted in the new location. So, when I then activated the replicatation process again, all the lost content for the day did indeed appear, but there were conflicts in id numbers for various records, so a few things ended up in the wrong place. Mostly comments that got applied in the wrong place it seems.

Could be worse. Most things work, including the many majordomo mailing lists. I just need to fix some things about webbased mail, upload of gif files, and java support.
[ | 2003-07-04 23:39 | 7 comments | PermaLink ]  More >

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