+1. Thanks for the great work on the KIP! I have only one minor question, in the wiki (and the doc) the new message set format has a "FirstSequence" field, should it just be "Sequence" if the sequence is always associated with a message set?
On Fri, Feb 17, 2017 at 3:28 AM, Michael Pearce <michael.pea...@ig.com> wrote: > +0 > > I think need some unified agreement on the VarInts. > > Would this also change in all other area’s of the protocol, e.g. value and > key length in message protocol, to keep this uniform across all protocols > going forwards? > > > > On 17/02/2017, 00:23, "Apurva Mehta" <apu...@confluent.io> wrote: > > Hi Jun, > > Thanks for the reply. Comments inline. > > On Thu, Feb 16, 2017 at 2:29 PM, Jun Rao <j...@confluent.io> wrote: > > > Hi, Apurva, > > > > Thanks for the reply. A couple of comment below. > > > > On Wed, Feb 15, 2017 at 9:45 PM, Apurva Mehta <apu...@confluent.io> > wrote: > > > > > Hi Jun, > > > > > > Answers inline: > > > > > > 210. Pid snapshots: Is the number of pid snapshot configurable or > > hardcoded > > > > with 2? When do we decide to roll a new snapshot? Based on time, > byte, > > or > > > > offset? Is that configurable too? > > > > > > > > > > When a replica becomes a follower, we do a bit log truncation. > Having an > > older snapshot allows us to recover the PID->sequence mapping much > quicker > > than rescanning the whole log. > > > This is a good point. I have updated the doc with a more detailed > proposal. > Essentially, snapshots will be created on a periodic basis. A > reasonable > period would be every 30 or 60 seconds. We will keep at most 2 copies > of > the snapshot file. With this setup, we would have to replay at most 60 > or > 120 seconds of the log in the event of log truncation during leader > failover. > > If we need to make any of this configurable, we can expose a config in > the > future. It would be easier to add a config we need than remove one with > marginal utility. > > > > > > > > > > > > 211. I am wondering if we should store ExpirationTime in the > producer > > > > transactionalId mapping message as we do in the producer > transaction > > > status > > > > message. If a producer only calls initTransactions(), but never > > publishes > > > > any data, we still want to be able to expire and remove the > producer > > > > transactionalId mapping message. > > > > > > > > > > > Actually, the document was inaccurate. The transactionalId will be > > expired > > > only if there is no active transaction, and the age of the last > > transaction > > > with that transactionalId is older than the transactioanlId > expiration > > > time. With these semantics, storing the expiration time in the > > > transactionalId mapping message won't be useful, since the > expiration > > time > > > is a moving target based on transaction activity. > > > > > > I have updated the doc with a clarification. > > > > > > > > > > > Currently, the producer transactionalId mapping message doesn't carry > > ExpirationTime, but the producer transaction status message does. > It would > > be useful if they are consistent. > > > > > You are right. The document has been updated to remove the > ExpirationTime > from the transaction status messages as well. Any utility for this > field > can be achieved by using the timestamp of the message itself along with > another expiration time (like transactionalId expiration time, > transaction > expiration time, etc.). > > Thanks, > Apurva > > > The information contained in this email is strictly confidential and for > the use of the addressee only, unless otherwise indicated. If you are not > the intended recipient, please do not read, copy, use or disclose to others > this message or any attachment. Please also notify the sender by replying > to this email or by telephone (+44(020 7896 0011) and then delete the email > and any copies of it. Opinions, conclusion (etc) that do not relate to the > official business of this company shall be understood as neither given nor > endorsed by it. IG is a trading name of IG Markets Limited (a company > registered in England and Wales, company number 04008957) and IG Index > Limited (a company registered in England and Wales, company number > 01190902). Registered address at Cannon Bridge House, 25 Dowgate Hill, > London EC4R 2YA. Both IG Markets Limited (register number 195355) and IG > Index Limited (register number 114059) are authorised and regulated by the > Financial Conduct Authority. >
