Hi Qiang, Since you are running with allow_mult=false, make sure the clocks of your Riak nodes are synchronized. If they are out of sync, newer values may get overridden by older ones on read, depending on the node a request hits first. Of course this won't cover 100% of cases because a perfect clock synchronization is just impossible.
Also, setting notfound_ok to "false" may help if you encounter not founds for keys you are sure have been written. Good luck! Vitaly On Fri, Mar 4, 2016 at 5:19 AM, Qiang Cao <[email protected]> wrote: > Sargun, do you mean I should also pass back the vclock with the GET > request? > > > On Thu, Mar 3, 2016 at 10:05 PM, Qiang Cao <[email protected]> wrote: > >> Thanks, Sargun and Alexander! I tried setting pr, pw, and sloppy_quorum. >> It looks that these help. I got less stale values. But the issue wasn't >> completely resolved. I'm using Riak 2.1.2. >> >> -Qiang >> >> >> On Thu, Mar 3, 2016 at 9:46 PM, Sargun Dhillon <[email protected]> wrote: >> >>> So, if you pass back the vclock while pr=pw=quorum, and sloppy_quorum >>> = false you should get RYOW consistency. >>> >>> On Thu, Mar 3, 2016 at 6:25 PM, Christopher Mancini <[email protected]> >>> wrote: >>> > If you don't need strong consistency for all Riak requests, just >>> certain >>> > ones, then explore the use of R and N vals that can be passed along >>> with the >>> > request or on a bucket-type level. >>> > >>> > On Thu, Mar 3, 2016 at 9:23 PM Mark Schmidt <[email protected]> >>> wrote: >>> >> >>> >> Hi Qiang, >>> >> >>> >> >>> >> >>> >> Other more skilled folks can correct me if I am wrong, but I believe >>> you >>> >> can enforce strong consistency on your nodes: >>> >> http://docs.basho.com/riak/latest/theory/concepts/strong-consistency/ >>> >> >>> >> >>> >> >>> >> If I recall, you will take a performance hit as all nodes must >>> receive the >>> >> data. >>> >> >>> >> >>> >> >>> >> Thanks, >>> >> >>> >> >>> >> >>> >> - Mark Schmidt >>> >> >>> >> >>> >> >>> >> From: riak-users [mailto:[email protected]] On >>> Behalf Of >>> >> Qiang Cao >>> >> Sent: Thursday, March 03, 2016 6:13 PM >>> >> To: Dave King <[email protected]> >>> >> Cc: riak-users <[email protected]> >>> >> Subject: Re: Continuous HTTP POSTs to Riak >>> >> >>> >> >>> >> >>> >> Thanks, Dave! I'm aware of Riak's eventual consistency. I wonder how >>> I can >>> >> get Riak work in the way as I need. I'm in a situation where I expect >>> the >>> >> immediate GET reads the value I've just posted. And the GET request >>> isn't >>> >> sent out until the POST is done. >>> >> >>> >> >>> >> >>> >> Thanks, >>> >> >>> >> -Qiang >>> >> >>> >> >>> >> >>> >> On Thu, Mar 3, 2016 at 6:53 PM, Dave King <[email protected]> wrote: >>> >> >>> >> You need to google 'Eventual consistency'. >>> >> >>> >> >>> >> >>> >> - Peace >>> >> >>> >> Dave >>> >> >>> >> >>> >> >>> >> >>> >> >>> >> On Thu, Mar 3, 2016 at 4:23 PM, Qiang Cao <[email protected]> >>> wrote: >>> >> >>> >> Hi All, >>> >> >>> >> >>> >> >>> >> I use Riak as a KV store and send http requests to its REST API to >>> update >>> >> entries. Instead of using curl, I use Apache HttpClient to send >>> requests. >>> >> >>> >> >>> >> >>> >> One thing bothering me is that sometimes I find the entry isn't >>> properly >>> >> updated after an HTTP POST/PUT. For example, if I do an HTTP GET on >>> the same >>> >> key immediately after an HTTP POST, the chance is good that I get a >>> stale >>> >> value. This happens when I continuously POST to a multi-node Riak, >>> and some >>> >> of the posts target the same key. >>> >> >>> >> >>> >> >>> >> Also, I find I don't have this issue if I use a single-node Riak. So I >>> >> think something wasn't correct with my multi-node Riak cluster (I set >>> >> "allow_mult" to false). Any thoughts? >>> >> >>> >> >>> >> >>> >> Thanks in advance! >>> >> >>> >> >>> >> >>> >> Qiang >>> >> >>> >> >>> >> >>> >> _______________________________________________ >>> >> riak-users mailing list >>> >> [email protected] >>> >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >>> >> >>> >> >>> >> >>> >> >>> >> >>> >> _______________________________________________ >>> >> riak-users mailing list >>> >> [email protected] >>> >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >>> > >>> > -- >>> > Sincerely, >>> > >>> > Christopher Mancini >>> > ----------------------------- >>> > >>> > employee = { >>> > purpose: solve problems with code, >>> > phone: 7164625591, >>> > email: [email protected], >>> > github: http://www.github.com/christophermancini >>> > } >>> > >>> > _______________________________________________ >>> > riak-users mailing list >>> > [email protected] >>> > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com >>> > >>> >> >> > > _______________________________________________ > riak-users mailing list > [email protected] > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com > >
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