cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Eric Plowe <eric.pl...@gmail.com>
Subject Re: Question about consistency
Date Wed, 09 Sep 2015 12:19:33 GMT
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
> <javascript:_e(%7B%7D,'cvml','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
>> <javascript:_e(%7B%7D,'cvml','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
>>>>>>
>>>>>>
>>>
>

Mime
View raw message