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From Clint Kelly <clint.ke...@gmail.com>
Subject Re: Index creation sometimes fails
Date Tue, 15 Jul 2014 18:40:54 GMT
Hi DuyHai,

Thanks for the response.  Is the recommended best practice therefore
to do what I describe above?

Is there some way to get the driver to block until the schema code has
propagated everywhere?  My currently solution feels rather janky!

Thanks!

Best regards,
Clint


On Tue, Jul 15, 2014 at 11:32 AM, DuyHai Doan <doanduyhai@gmail.com> wrote:
> As far as I know, schema propagation always takes some times in the cluster.
> On this mailing list some people in the past faced similar behavior.
>
>
> On Tue, Jul 15, 2014 at 8:20 PM, Clint Kelly <clint.kelly@gmail.com> wrote:
>>
>> FWIW I was able to work around this problem by having my code run the
>> following loop:
>>
>> while (the index doesn't exit and we haven't hit our limit of number of
>> tries):
>>     try to create the index
>>     read from system.schema_columns to see if the index exists
>>     if so, then break
>>     if not, pause 5 seconds
>>
>> This loop took three iterations to create the index.
>>
>> Is this expected?  This seems really weird!
>>
>> Best regards,
>> Clint
>>
>> On Mon, Jul 14, 2014 at 5:54 PM, Clint Kelly <clint.kelly@gmail.com>
>> wrote:
>> > BTW I have seen this using versions 2.0.1 and 2.0.3 of the java driver
>> > on a three-node cluster with DSE 4.5.
>> >
>> > On Mon, Jul 14, 2014 at 5:51 PM, Clint Kelly <clint.kelly@gmail.com>
>> > wrote:
>> >> Hi everyone,
>> >>
>> >> I have some code that I've been fiddling with today that uses the
>> >> DataStax Java driver to create a table and then create a secondary
>> >> index on a column in that table.  I've testing this code fairly
>> >> thoroughly on a single-node Cassandra instance on my laptop and in
>> >> unit test (using the CassandraDaemon).
>> >>
>> >> When running on a three-node cluster, however, I see strange behavior.
>> >> Although my table always gets created, the secondary index often does
>> >> not!  If I delete the table and then create it again (through the same
>> >> code that I've written), I've never seen the index fail to appear the
>> >> second time.
>> >>
>> >> Does anyone have any idea what to look for here?  I have no experience
>> >> working on a Cassandra cluster and I wonder if maybe I am doing
>> >> something dumb (I basically just installed DSE and started up the
>> >> three nodes and that was it).  I don't see anything that looks unusual
>> >> in OpsCenter for DSE.
>> >>
>> >> The only thing I've noticed is that the presence of output like the
>> >> following from my program after executing the command to create the
>> >> index is perfectly correlated with successful creation of the index:
>> >>
>> >> 14/07/14 17:40:01 DEBUG com.datastax.driver.core.Cluster: Received
>> >> event EVENT CREATED kiji_retail2.t_model_repo, scheduling delivery
>> >> 14/07/14 17:40:01 DEBUG com.datastax.driver.core.ControlConnection:
>> >> [Control connection] Refreshing schema for kiji_retail2
>> >> 14/07/14 17:40:01 DEBUG com.datastax.driver.core.Cluster: Refreshing
>> >> schema for kiji_retail2
>> >> 14/07/14 17:40:01 DEBUG com.datastax.driver.core.ControlConnection:
>> >> Checking for schema agreement: versions are
>> >> [9a8d72f9-e384-3aa8-bc85-185e2c303ade,
>> >> b309518a-35d2-3790-bb66-ea39bb0d188c]
>> >> 14/07/14 17:40:02 DEBUG com.datastax.driver.core.ControlConnection:
>> >> Checking for schema agreement: versions are
>> >> [9a8d72f9-e384-3aa8-bc85-185e2c303ade,
>> >> b309518a-35d2-3790-bb66-ea39bb0d188c]
>> >> 14/07/14 17:40:02 DEBUG com.datastax.driver.core.ControlConnection:
>> >> Checking for schema agreement: versions are
>> >> [9a8d72f9-e384-3aa8-bc85-185e2c303ade,
>> >> b309518a-35d2-3790-bb66-ea39bb0d188c]
>> >> 14/07/14 17:40:02 DEBUG com.datastax.driver.core.ControlConnection:
>> >> Checking for schema agreement: versions are
>> >> [9a8d72f9-e384-3aa8-bc85-185e2c303ade,
>> >> b309518a-35d2-3790-bb66-ea39bb0d188c]
>> >> 14/07/14 17:40:02 DEBUG com.datastax.driver.core.ControlConnection:
>> >> Checking for schema agreement: versions are
>> >> [b309518a-35d2-3790-bb66-ea39bb0d188c]
>> >>
>> >> If anyone can give me a hand, I would really appreciate it.  I am out
>> >> of ideas!
>> >>
>> >> Best regards,
>> >> Clint
>
>

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