Thanks Eric, Let me go back to the app team
On Tue, Feb 18, 2020 at 6:49 PM Erick Ramirez <erick.rami...@datastax.com>
wrote:
> We are on cassandra 3.11 , we are using G1GC and using 16GB of heap.
>>
>
> Which exact version of C* is it again?
>
>> WARN [MessagingService-Incoming-/10.X.X.X] 2020-02-18 14:21:47,115
>> IncomingTcpConnection.java:103 - UnknownColumnFamilyException reading from
>> socket; closing
>>
>
> This is expected because your app is trying to read the MV you just
> dropped.
>
> ERROR [MutationStage-9] 2020-02-18 14:21:47,267 Keyspace.java:593 -
> Attempting to mutate non-existant table 7bb4b2d2-8622-11e8-a44b-a92f2dd93ff1
>>
>>
> Any view update transactions which are already in-flight will fail. Again,
> this is expected since the MV updates are not synchronous with the base
> table updates.
>
> WARN [BatchlogTasks:1] 2020-02-18 14:21:53,786 BatchlogManager.java:252 -
> Skipped batch replay of a19c6480-5294-11ea-9e09-3948c59ad0f5 due to {}
>>
>>
> As above, this is expected since the MV updates which are already in the
> queue will fail to apply because the MV got dropped.
>
> WARN [HintsDispatcher:6737] 2020-02-18 14:22:24,932 HintsReader.java:237 -
> Failed to read a hint for /10.X.X.X: f75e58e8-c255-4318-a553-06487b6bbe8c -
> table with id 7bb4b2d2-8622-11e8-a44b-a92f2dd93ff1 is unknown in file
> f75e58e8-c255-4318-a553-06487b6bbe8c-1582060925656-1.hints
>>
>>
> This is also expected. It won't be able to read the hint for a
> non-existent MV.
>
> So where to from here? The symptoms you described indicate that you
> haven't updated your app *before* you dropped the MVs. That is key here
> -- your app shouldn't be issuing reads for the MV since your intention is
> to drop it. What I think happened is that the nodes were backed up with
> read requests for the MV which no longer exists.
>
> Can you confirm that you have changed your application so it is not
> supposed to issue reads to the MV? You shouldn't drop MVs if you're still
> going to issue read requests from them just like you shouldn't drop tables
> your app is still expected to access. I hope that makes sense. Cheers!
>
