Il gio 12 apr 2018, 19:59 Sam Just <sj...@salesforce.com> ha scritto:
> IIRC, InterleavedLedgerStorage has for each ledger an index file > mapping the entries to entry logger offsets, you could probably scan > that directly (particularly if you included a lower bound -- probably > the client's current idea of the LAC). > -Sam > Thank you Sam, I think that the major point is about introducing a standard interface to be implemented by LedgerStorage, now we already have 3 implementations. Options are: 1) let the client drive the scan 2) add a scan() method to LedgerStorage 3) add a getMaxEntry() to LedgerStorage For bp14 I just need 1) or 3) but 1) is also a protocol issue and so it is more expensive for long term maintenance Enrico > > On Thu, Apr 12, 2018 at 12:31 AM, Enrico Olivelli <eolive...@gmail.com> > wrote: > > Hi BookKeepers, > > during implementation of BP-14 I am facing a problem so I am asking for > > suggestions. > > > > My need is to be able to know the list of all entries stored on a > > LedgerStorage given a ledgerId. > > > > Scanning from 0 to LedgerStorage#getLastAddConfirmed() does not seem to > > work because we have to deal with WriteAdvHandle, so there can be > temporary > > "gaps" in the sequence of entries. > > > > I can have a writer which writes entries 0,1,5,6,7. Its LAC will be at > most > > 1 as entries 2,3,4 are not written yet. > > I need on the bookie to able to know that entries 0, 1, 5, 6, 7 are > stored > > on LedgerStorage. > > > > I cannot issue a scan from 0 to Long.MAX_VALUE, my current 'solution' it > to > > make the client (writer) send the 'maximum entry id' and perform a scan > > from 0 to maxEntryId. > > In the example the writer will send a forceLedger RPC with maxEntryId = > 7. > > > > This is need only for recoveries are bookie restart because I have to > > reconstruct the knowledge about which entries have been persisted durably > > on the Bookie. > > > > I am not very expert about LedgerStorage implementations, and I don't > know > > if it would be feasible to have such 'scan all entries' method. > > > > This is the code I am talking about > > > https://github.com/apache/bookkeeper/pull/1317/files#diff-3b81b1c90d1f51017627b3c032676168R1210 > > > > Any help is really appreciated > > Enrico > -- -- Enrico Olivelli
