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From Eric Plowe <eric.pl...@gmail.com>
Subject Re: Question about consistency
Date Wed, 09 Sep 2015 14:11:56 GMT
Would this work:

ALTER TABLE session_state WITH speculative_retry = '0ms';
ALTER TABLE session_state WITH speculative_retry = '0PERCENTILE';

I can't set it to 0, but was wondering if these would have the same effect?

~Eric

On Wed, Sep 9, 2015 at 8:19 AM, Eric Plowe <eric.plowe@gmail.com> wrote:

> Interesting. I'll give it a try and report back my findings.
>
> Thank you, Michael.
>
>
> On Wednesday, September 9, 2015, Laing, Michael <michael.laing@nytimes.com>
> wrote:
>
>> Perhaps a variation on
>> https://issues.apache.org/jira/browse/CASSANDRA-9753?
>>
>> You could try setting speculative retry to 0 to avoid cross-dc reads.
>>
>> On Wed, Sep 9, 2015 at 7:55 AM, Eric Plowe <eric.plowe@gmail.com> wrote:
>>
>>> read_repair_chance: 0
>>> dclocal_read_repair_chance: 0.1
>>>
>>>
>>> On Wednesday, September 9, 2015, Laing, Michael <
>>> michael.laing@nytimes.com> wrote:
>>>
>>>> What are your read repair settings?
>>>>
>>>> On Tue, Sep 8, 2015 at 9:28 PM, Eric Plowe <eric.plowe@gmail.com>
>>>> wrote:
>>>>
>>>>> To further expand. We have two data centers, Miami and Dallas. Dallas
>>>>> is our disaster recovery data center. The cluster has 12 nodes, 6 in
Miami
>>>>> and 6 in Dallas. The servers in Miami only read/write to Miami using
data
>>>>> center aware load balancing policy of the driver. We have the problem
when
>>>>> writing and reading to the Miami cluster with LOCAL_QUORUM.
>>>>>
>>>>> Regards,
>>>>>
>>>>> Eric
>>>>>
>>>>> On Tuesday, September 8, 2015, Eric Plowe <eric.plowe@gmail.com>
>>>>> wrote:
>>>>>
>>>>>> Rob,
>>>>>>
>>>>>> All writes/reads are happening from DC1. DC2 is a backup. The web
app
>>>>>> does not handle live requests from DC2.
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> Eric Plowe
>>>>>>
>>>>>> On Tuesday, September 8, 2015, Robert Coli <rcoli@eventbrite.com>
>>>>>> wrote:
>>>>>>
>>>>>>> On Tue, Sep 8, 2015 at 4:40 PM, Eric Plowe <eric.plowe@gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> I'm using Cassandra as a storage mechanism for session state
>>>>>>>> persistence for an ASP.NET web application. I am seeing issues
>>>>>>>> where the session state is persisted on one page (setting
a value:
>>>>>>>> Session["key"] = "value" and when it redirects to another
(from a post back
>>>>>>>> event) and check for the existence of the value that was
set, it doesn't
>>>>>>>> exist.
>>>>>>>>
>>>>>>>> It's a 12 node cluster with 2 data centers (6 and 6) running
2.1.9.
>>>>>>>> The key space that the column family lives has a RF of 3
for each
>>>>>>>> data center. The session state provider is using the the
datastax csharp
>>>>>>>> driver v2.1.6. Writes and reads are at LOCAL_QUORUM.
>>>>>>>>
>>>>>>>
>>>>>>> 1) Write to DC_A with LOCAL_QUORUM
>>>>>>> 2) Replication to DC_B takes longer than it takes to...
>>>>>>> 3) Read from DC_B with LOCAL_QUORUM, do not see the write from
1)
>>>>>>>
>>>>>>> If you want to be able to read your writes from DC_A in DC_B,
you're
>>>>>>> going to need to use EACH_QUORUM.
>>>>>>>
>>>>>>> =Rob
>>>>>>>
>>>>>>>
>>>>
>>

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