Showing Posts For headcrash.6354:
Keep the faith.
If AN wrote the transaction code correctly (which I’m assuming they
did), they’ll be able to “catch the database up” with a log of the
transactions.
Since I’m waiting for the login server to come back up, I’ll add a bit
more info..
There’s the naive (read: dangerous) way of doing transactions on their
end: remove item from player A, add item to player B,. The problem? If
there’s an interruption (like a disconnect), player A loses the item.
The semi-naive way (read: a bit safer, but still problematic): Add item
to player B, remove item from player A The problem? If there’s an
interruption (like a disconnect), the item is duplicated (although
player A doesn’t “lose” the item, there’s still a big problem with
duplicate items).
The “best practices” (read: safer) way: log the removal from player A,
log the addition to player B, and now remove the item from player A,
then add the item to player B. If there’s an interruption (like a
disconnect), the database still has the item in player A’s inventory,
and we just go through the log’s sequence of events again (remove from
A, add to
. This is akin to “Write-ahead logging” (or “journaling”).
It’s a kind of consistency check that you’ve probably heard in (MMO
jargon-y) terms of a “roll back.” If you keep the log around, you can
rebuild the database up to any previously saved entries. Pretty cool, eh?