Site breaks moving to new web server

[Chemosabe]

I'm moving the site from one server to another, but since DNS updates can take some time to propagate, I want to run the two in parallel for a while..

I've moved the entire site directory to the new server, and modified the config.php to point to the other server's mysql instance.

If I then update my hosts file to point at the new IP, the front index.php does the header/footer and nothing else (regardless of whether you're logged in or not). Seems lots of people have had this problem, but I haven't found a solution by searching the forums.

Anyway, here's where it gets strange. If I go the admin page for vBa and edit the modules (disable one and then re-enable it), it starts working from the new server, but stops working on the old one. If I go back to the old server and make the same edit, it reverts to the prior behavior.

I dumped the Mysql binlog to find out what was being updated, and all I see is two updates, one to adv_modules and the other to insert some serialized data into datastore. I don't see any part of this which would make it work with one web server, but not another.

Any suggestions? My next step in troubleshooting will be to compare the SQL statements from the two to find the specific differences, but I'm not confident that it will reveal anything useful, so I'm posting here in case anyone has a clue what's going on.

[Chemosabe]

Quick update.. It looks like, when I make the update from server2, the resulting entry in the datastore table is corrupt somehow. If I query it an attempt to unserialize(), it returns false.

So, at this point I'm suspecting a configuration difference somewhere to do with escaping quotes, which is probably where the serialized data is breaking. I'll update with my findings later.

[Brian]

It sounds more like you're still pulling data from the old server on the new on, or vice versa. There shouldn't be any way that you could make a change on one server and have it affect the other one otherwise.

[Chemosabe]

Well that's the point.. I'm just migrating the web piece at this stage, so I want them both to be hitting the same DB (which is located on the old server). Once the DNS updates have propagated, I'll take down the old web server, and then ultimately move the DB over.

Anyway, what I think it's coming down to is a difference in encoding. The old server is using latin1 and the new one is using utf8. Shouldn't be hard to fix now I've identified the issue, but it was hugely confusing to begin with..

[Brian]

Ahhh, gotcha. I'm not sure that the encoding would be the root of the issue though... Is there a difference in PHP versions between the two servers? Also, what version of the CMPS and vBulletin exactly are you running?