Great. I would be appreciated it if you guide me how can I contribute it. Then I'll try in my spare time.
2017-04-11 7:46 GMT+09:00 Todd Lipcon <t...@cloudera.com>: > On Sun, Apr 9, 2017 at 6:38 PM, Jason Heo <jason.heo....@gmail.com> wrote: > >> Hi Todd. >> >> I hope you had a good weekend. >> >> Exactly, I'm testing the latency of cold-cache reads from SATA disks and >> performance of difference schema designs as well. >> >> We currently using Elasticsearch for a analytic service. ES has a "clear >> cache API" feature, it makes me easy to test. >> >> > Makes sense. I don't think it would be particularly difficult to add such > an API. Any interest in contributing a patch? I'm happy to point you in the > right direction, if so. > > -Todd > > >> 2017-04-08 5:05 GMT+09:00 Todd Lipcon <t...@cloudera.com>: >> >>> Hey Jason, >>> >>> Can I ask what the purposes of the testing is? >>> >>> One thing to note is that we're currently leaving a fair bit of >>> performance on the table for cold-cache reads from spinning disks. So, if >>> you find that the performance is not satisfactory, it's worth being aware >>> that we will likely make some significant improvements in this area in the >>> future. >>> >>> https://issues.apache.org/jira/browse/KUDU-1289 has some details. >>> >>> -Todd >>> >>> On Fri, Apr 7, 2017 at 8:44 AM, Dan Burkert <danburk...@apache.org> >>> wrote: >>> >>>> Hi Jason, >>>> >>>> There is no command to have Kudu evict its block cache, but restarting >>>> the tablet server process will have that effect. Ideally all written data >>>> will be flushed before the restart, otherwise startup/bootstrap will take a >>>> bit longer. Flushing typically happens within 60s of the last write. >>>> Waiting for flush and compaction is also a best-practice for read-only >>>> benchmarks. I'm not sure if someone else on the list has an easier way of >>>> determining when a flush happens, but I typically look at the 'MemRowSet' >>>> memory usage for the tablet on the /mem-trackers HTTP endpoint; it should >>>> show something minimal like 256B if it's fully flushed and empty. You can >>>> also see details about how much memory is in the block cache on that page, >>>> if that interests you. >>>> >>>> - Dan >>>> >>>> On Thu, Apr 6, 2017 at 11:23 PM, Jason Heo <jason.heo....@gmail.com> >>>> wrote: >>>> >>>>> Hi. >>>>> >>>>> I'm using Apache Kudu 1.2 on CDH 5.10. >>>>> >>>>> Currently, I'm doing a performance test of Kudu. >>>>> >>>>> Flushing OS Page Cache is easy, but I don't know how to flush >>>>> `block_cache_capacity_mb` easily. >>>>> >>>>> I currently execute SELECT statement over a unnecessarily table to >>>>> evict cached block of testing table. >>>>> >>>>> It is cumbersome, so I'd like to know is there a command for flushing >>>>> block caches (or another kudu's caches which I don't know yet) >>>>> >>>>> Thanks. >>>>> >>>>> Regards, >>>>> Jason >>>>> >>>> >>>> >>> >>> >>> -- >>> Todd Lipcon >>> Software Engineer, Cloudera >>> >> >> > > > -- > Todd Lipcon > Software Engineer, Cloudera >
