Could you explain how you profile the time? The ledger device isn't the dominated factor, The journal device is.
- Sijie On Tue, Aug 26, 2014 at 9:13 AM, Jaln <[email protected]> wrote: > Hi Sijie, > Thanks, > One of my result is > entrysize: 1k > Throttle: 10k > Latency is 1324.1137182178 ms > I also profile the time and find that the ledger device can contribute > 232 ms. > > I don't think the ledger device should cause any cost. > > Jialin > > > On Tue, Aug 26, 2014 at 10:59 AM, Sijie Guo <[email protected]> wrote: > > > The latency I think is between the client added the message and received > > acknowledge from quorum of bookies. Journal device will significantly > > affect the latency, Ledger device might slightly affect but not too much > > (it depends). If you are using only one disk for both ledger & journal > > devices, you will definitely get really bad disk behavior. > > > > At the mean time, your configuration on bookie journal (e.g. group commit > > interval, commit buffer) will also affect the latency. > > > > So for your case, please specify your environment and configuration, we > > will figure out why it takes to 2s. > > > > - Sijie > > > > > > On Tue, Aug 26, 2014 at 8:27 AM, Jaln <[email protected]> wrote: > > > > > Hi, > > > I'm running the bookkeeper benchmark on a single node, > > > The latency is about 2s using one disk. > > > I would like to know how this latency is calculated, > > > is the `latency' the time between "client sent the write msg" and the > > > "write is committed on the journal devices and the ack code is > returned"? > > > > > > Does the ledger device affect the latency? Assuming ledger and journal > is > > > on > > > different disk. > > > > > > Best, > > > Jialin > > > > > >
