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From "Laing, Michael" <michael.la...@nytimes.com>
Subject Re: Question about consistency
Date Wed, 09 Sep 2015 12:13:46 GMT
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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