I think that mailing lists can be configured to allow attachments, but apparently this list is not configured that way.
Gerald's suggestion sounds good :) Cheers, Till On 21 Feb 2019, at 10:29, Gerald Sangudi wrote: > I believe the Apache mailer does not allow attachments, or at least images > as attachments. I could be wrong, but I think I saw that elsewhere. > > If necessary, you can post the image somewhere (e.g. Google drive) and > email out a link. > > -Gerald > > > On Thu, Feb 21, 2019 at 10:27 AM Chen Luo <[email protected]> wrote: > >> I re-attached the image as follows. In case it still doesn't show up, the >> average point lookup throughput of* SSD for LSM + Logging* is only around >> *3-4k/s*. When a separate hard disk is used for logging, the average >> point lookup throughput reaches *30k-40k/s*. >> >> [image: image.png] >> >> Best regards, >> Chen Luo >> >> On Thu, Feb 21, 2019 at 10:01 AM abdullah alamoudi <[email protected]> >> wrote: >> >>> Thanks for sharing Chen, very interesting. >>> >>> The image doesn't show up for me. Not sure if it shows up for others? >>> >>> Cheers, >>> Abdullah. >>> >>> On Wed, Feb 20, 2019 at 1:29 PM Chen Luo <[email protected]> wrote: >>> >>>> Hi Devs, >>>> >>>> Recently I've been running experiments with concurrent ingestions and >>>> queries on SSDs. I'd like to share an important lesson from my >>> experiments. >>>> In short,* it is very important (from the performance perspective) to >>> use >>>> a separate disk for logging, even SSDs are good at random I/Os*. >>>> >>>> The following experiment illustrates this point. I was using YCSB with >>>> 100GB base data (100M records, each has 1KB). During each experiment, >>> there >>>> was a constant data arrival process of 3600 records/s. I executed >>>> concurrent point lookups (uniformly distributed) as much as possible >>> using >>>> 16 query threads (to saturate the disk). The page size was set to 4KB. >>> The >>>> experiments were performed on SSDs. The only difference is that one >>>> experiment had a separate hard disk for logging, while the other used >>> the >>>> same SSD for both LSM and logging. The point lookup throughput over time >>>> was plotted below. The negative impact of logging is huge! >>>> >>>> [image: image.png] >>>> >>>> The reason is that logging needs to frequently force disk writes (in >>> this >>>> experiment, the log flusher forces 70-80 times per second). Even though >>> the >>>> disk bandwidth used by the log flusher is small (4-5MB/s), the frequent >>>> disk forces could seriously impact the overall disk throughput. If you >>> have >>>> a workload with concurrent data ingestion and queries, please DO >>> consider >>>> using a separate disk for logging to fully utilize the SSD bandwidth. >>>> >>>> Best regards, >>>> Chen Luo >>>> >>> >>
