Continuous HTTP POSTs to Riak

Qiang Cao caoqiang.cs at gmail.com
Thu Mar 3 22:19:33 EST 2016


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 <caoqiang.cs at gmail.com> 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 <sargun at sargun.me> 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 <cmancini at basho.com>
>> 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 <mschmidt at orcawave.net>
>> 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:riak-users-bounces at lists.basho.com] On
>> Behalf Of
>> >> Qiang Cao
>> >> Sent: Thursday, March 03, 2016 6:13 PM
>> >> To: Dave King <djking at gmail.com>
>> >> Cc: riak-users <riak-users at lists.basho.com>
>> >> 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 <djking at gmail.com> wrote:
>> >>
>> >> You need to google 'Eventual consistency'.
>> >>
>> >>
>> >>
>> >> - Peace
>> >>
>> >> Dave
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> On Thu, Mar 3, 2016 at 4:23 PM, Qiang Cao <caoqiang.cs at gmail.com>
>> 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
>> >>
>> >>
>> >>
>> >> _______________________________________________
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>> >> riak-users at lists.basho.com
>> >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> riak-users mailing list
>> >> riak-users at lists.basho.com
>> >> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
>> >
>> > --
>> > Sincerely,
>> >
>> > Christopher Mancini
>> > -----------------------------
>> >
>> > employee = {
>> >     purpose: solve problems with code,
>> >     phone:    7164625591,
>> >     email:     cmancini at basho.com,
>> >     github:    http://www.github.com/christophermancini
>> > }
>> >
>> > _______________________________________________
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>> >
>>
>
>
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