Great news! I'm so excited to see it at work :) Diego
Il giorno mar 4 mag 2021 alle ore 20:38 Venkateswara Rao Jujjuri < jujj...@gmail.com> ha scritto: > > how you justify removing the ledger as opposed to removing the ledger > storage and preserving the journal > > I will be waiting for the BP on this point too. :) But glad to see that we > are working to avoid double writes. :) > With the EntryLogPerLedger (ELPL) feature, it is a more-or-less journal per > ledger. > With the entrylogs, we need to maintain index files and journals, hence > two writes if we want to persist > data in-lieu of Journal. > > Another way to think about this is, having a ledger durability mode. Does > it need fragment level durability, or durability at close. > Based on that we can completely avoid journal writes with ELPL + flush on > close. > > Thanks, > JV > > On Mon, May 3, 2021 at 8:34 AM Anup Ghatage <ghat...@gmail.com> wrote: > > > HI! > > > > I know we are interested in this for sure. (cc @Venkateswara Rao Jujjuri > > <jujj...@gmail.com>) > > Is this similar to Matteo Merli's PR which I found was simple and still > > got the job done: https://github.com/apache/bookkeeper/pull/2401/files > > > > Regards, > > Anup > > > > On Mon, May 3, 2021 at 8:04 AM Flavio Junqueira <f...@apache.org> wrote: > > > >> +1, it makes sense to enable bookies to run without duplicating IOs for > >> entry data. I'm curious to see how you justify removing the ledger as > >> opposed to removing the ledger storage and preserving the journal. I > >> suspect that the random reads against the ledger storage matter more to > you > >> than the sequential writes, and you're possibly able to make it perform > >> well enough with SSD and even NVMe drives. > >> > >> I should wait for your write up rather than speculate. Looking forward > to > >> seeing the BP. > >> > >> -Flavio > >> > >> > On 3 May 2021, at 16:52, Enrico Olivelli <eolive...@gmail.com> wrote: > >> > > >> > Il giorno lun 3 mag 2021 alle ore 16:30 Jack Vanlightly > >> > <jvanligh...@splunk.com.invalid <mailto: > jvanligh...@splunk.com.invalid>> > >> ha scritto: > >> >> > >> >> Hi all, > >> >> > >> >> At Splunk we have defined and implemented changes to BookKeeper to > >> allow > >> >> bookies to run without the journal. The motivation for this work is > to > >> >> allow BookKeeper to be run with lower operating costs while still > >> offering > >> >> decent data safety guarantees. > >> >> > >> >> Before submitting the work as a PR we'd like to formalise the > proposed > >> >> changes in a BP where we state our motivation, explain the protocol > >> >> changes, the work on formally verifying the proposal and be open to > >> comment. > >> >> > >> >> We'll create a BP this week if that sounds good to you all. > >> > > >> > Great to hear that ! > >> > > >> > Thanks > >> > Enrico > >> > > >> >> > >> >> Thanks > >> >> Jack > >> >> > >> >> -- > >> >> *Jack Vanlightly* > >> >> Principal Software Engineer > >> >> Splunk Inc. > >> >> jvanligh...@splunk.com <mailto:jvanligh...@splunk.com> < > >> kramas...@splunk.com <mailto:kramas...@splunk.com>> > >> >> Barcelona > >> > >> > > > > -- > > Anup Ghatage > > www.ghatage.com > > > > > -- > Jvrao > --- > First they ignore you, then they laugh at you, then they fight you, then > you win. - Mahatma Gandhi >
