-Question about offsets
David Arthur 2013-01-30, 04:39
Fiddling with my Python client on 0.8, noticed something has changed
It seems that instead of a byte offset in the log file, the offset is
now a logical one. I had a few questions about this:
1) How is the byte offset determined by the broker? Since messages are
not fixed width, does it use an index or do a simple binary search?
2) Regarding compressed MessageSets, how are the offsets incremented?
Suppose I have the following MessageSet
- Message A1, normal message
- Message A2, normal message
- Message A3, compressed MessageSet B
- MessageSet B
- Message B1
- Message B2
Assuming we start from 0, message A1 gets offset of 0, A2 of 1. Now I am
unclear how the numbering goes. Would A3 get offset 3, and B1 -> 4 B2 ->
5? Or are the offsets inside a compressed MessageSet not used?
Is it possible to request a message inside a compressed message set?
Also what about nested compression sets, what if Message B3 is itself a
compressed MessageSet (not that it makes sense, just curious what would
Jay Kreps 2013-01-30, 05:01
David Arthur 2013-01-30, 13:54