Migration headache
Göran Krampe
goran at krampe.se
Thu Feb 26 11:24:01 UTC 2009
Hi!
Ok, so Gjallar is improving day-by-day and the current Gjallar is built
on Squeak 3.10.2-7179 and MC packages "r42Alpha4" + "Magma sunit" from
MagmaTester on SS. I have been working on this latest incarnation of
Magma the latest few days and it seems to be working fine (although
marked as alpha).
I now need to migrate an existing Gjallar customer over to the above new
system/version.
The older Gjallar runs MagmaServerLoader-kph.35 in a 3.8.1-6747 image.
This is of course a rather old Magma but it has been running for over a
year, continuous use (although on the lighter side) with no serious
problems at all. Good work Chris! :)
Questions:
1. Would I be better off to use r41.2 than r42Alpha? Presuming that is
the latest official release, which I think it is?
2. Are there migration instructions?
I did the simplest thing first, just opened up the old db using the new
image. Of course it says that hey, this repo is version 9 so I need to
migrate it. Cool, go ahead. :)
Then after that phase I stumbled on 2 issues I "solved":
- Missing ivar in MaRootAnchor. Fine, seems to be "stats" so I just told
Magma to go forward with that.
- Then Magma blew up because it was sending "node" in
#sendToWarmBackups: and getting nil. After a bit of investigation I
realized this is related to the latest HA-code so this little trick
seemed to repair that:
MagmaRepositoryController allInstances anyOne session commit: [node :=
MagmaNode new]
Then it got harder. :) It looks very promising at this stage, most of
Gjallar seems to work fine. I can explore the db and it all looks fine
except for one important thing: SortedCollections with stored sortBlocks
In the old image it all works fine, in the new image I end up with a
garbled SortedCollection with these ivars:
array: 4081353
firstIndex: 281473902968834
lastIndex: 281473902968835
sortBlock: 4081234
...so obviously there is a problem here with SortedCollection instances
*that have sortBlocks* - because in other places I have
SortedCollections with a nil sortBlock, and those work fine.
Hmmm, I will try to work around this but of course it might be
interesting for you to be aware of the issue.
regards, Göran
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