Your explanation makes sense.
https://github.com/apache/helix/blob/helix-0.6.4/helix-core/src/main/java/org/apache/helix/manager/zk/ZKHelixDataAccessor.java.
For bucketized resource we see that path is deleted and set again. Jason,
any idea why we are removing the path?
case EXTERNALVIEW: if (value.getBucketSize() == 0) { records.add(value.
getRecord()); } else { _baseDataAccessor.remove(path, options);
On Sat, Mar 7, 2015 at 4:03 PM, Varun Sharma <[email protected]> wrote:
> How does the writing of externalview work for bucketized resources -is it
> possible that the top level znode for the resource is first deleted and
> then rewritten with the latest external view ?
>
> On Sat, Mar 7, 2015 at 3:56 PM, Varun Sharma <[email protected]> wrote:
>
>> Here is the stack trace - there is a zookeeper race and the detailed
>> stack trace appears for bucketized resources. I saw that the ideal state
>> for the resource was created on 26th Feb and was modified on 7th March.
>> However, the external view for the resource is showing up as created on 7th
>> march as well as modified on 7th march. The external view is created at
>> 10:36:04 on 7th march which is 20 seconds after this log message stack
>> trace is spit out. After this the routing table provider no longer receives
>> any more zk callbacks.
>>
>> 2015-03-07 10:35:43,735 [main-EventThread] (ZkAsyncCallbacks.java:127)
>> WARN
>> org.apache.helix.manager.zk.ZkAsyncCallbacks$SetDataCallbackHandler@3c8589f0,
>> rc:NONODE, path:
>> /main_a/EXTERNALVIEW/$terrapin$data$visual_seo_joins_staging$1422384697040
>>
>> 2015-03-07 10:35:43,736 [main-EventThread] (ZkAsyncCallbacks.java:127)
>> WARN
>> org.apache.helix.manager.zk.ZkAsyncCallbacks$SetDataCallbackHandler@63230a9a,
>> rc:NONODE, path:
>> /main_a/EXTERNALVIEW/$terrapin$data$recommendation_p2p_exp_candset_1$1425671237739
>>
>> 2015-03-07 10:35:43,736 [main-EventThread] (ZkAsyncCallbacks.java:127)
>> WARN
>> org.apache.helix.manager.zk.ZkAsyncCallbacks$SetDataCallbackHandler@118d374f,
>> rc:NONODE, path: /main_a/EXTERNALVIEW/$terrapin$data$None$1422308641250
>>
>> 2015-03-07 10:35:43,736 [ZkClient-EventThread-17-terrapinzk001a:2181]
>> (CallbackHandler.java:304) WARN fail to subscribe child/data change. path:
>> /main_a/EXTERNALVIEW, listener:
>> com.pinterest.terrapin.controller.TerrapinRoutingTableProvider@2c6691da
>>
>> *org.I0Itec.zkclient.exception.ZkNoNodeException:
>> org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode =
>> NoNode for /main_a/EXTERNALVIEW/$terrapin$data$None$1422308641250*
>>
>> at
>> org.I0Itec.zkclient.exception.ZkException.create(ZkException.java:47)
>>
>> at
>> org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:685)
>>
>> at
>> org.apache.helix.manager.zk.ZkClient.getChildren(ZkClient.java:210)
>>
>> at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:409)
>>
>> at
>> org.apache.helix.manager.zk.CallbackHandler.subscribeForChanges(CallbackHandler.java:279)
>>
>> at
>> org.apache.helix.manager.zk.CallbackHandler.invoke(CallbackHandler.java:202)
>>
>> at
>> org.apache.helix.manager.zk.CallbackHandler.handleChildChange(CallbackHandler.java:391)
>>
>> at org.I0Itec.zkclient.ZkClient$7.run(ZkClient.java:570)
>>
>> at org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:71)
>>
>> Caused by: org.apache.zookeeper.KeeperException$NoNodeException:
>> KeeperErrorCode = NoNode for
>> /main_a/EXTERNALVIEW/$terrapin$data$None$1422308641250
>>
>> at
>> org.apache.zookeeper.KeeperException.create(KeeperException.java:102)
>> at org.apache.zookeeper.KeeperException.create(KeeperException.java:42)
>>
>> at org.apache.zookeeper.ZooKeeper.getChildren(ZooKeeper.java:1249)
>>
>> 2015-03-07 10:35:43,848 [ZkClient-EventThread-17-terrapinzk001a:2181]
>> (RoutingTableProvider.java:99) INFO *Resetting* the routing table.
>>
>> On Thu, Mar 5, 2015 at 11:33 AM, Varun Sharma <[email protected]>
>> wrote:
>>
>>> I suspect the callbacks are not coming in, for a long time now.
>>>
>>> On Thu, Mar 5, 2015 at 11:30 AM, Varun Sharma <[email protected]>
>>> wrote:
>>>
>>>> I grepped this and found nothing:
>>>>
>>>> sudo grep START:INVOKE.*EXTERNALVIEW /var/log/terrapin/controller.log*
>>>>
>>>> I found a bunch of START:INVOKE for the IDEALSTATES znode though.
>>>>
>>>> On Thu, Mar 5, 2015 at 11:15 AM, Zhen Zhang <[email protected]>
>>>> wrote:
>>>>
>>>>> Yes. you should see a pair of "START:INVOKE..." and "END:INVOKE:..."
>>>>> for each callback in your log.
>>>>> ------------------------------
>>>>> *From:* Varun Sharma [[email protected]]
>>>>> *Sent:* Thursday, March 05, 2015 11:11 AM
>>>>> *To:* [email protected]
>>>>> *Subject:* Re: RoutingTableProvider dropping callbacks
>>>>>
>>>>> Ohk - is there a way to confirm that the callbacks are being
>>>>> processed (from the logs etc.) ?
>>>>>
>>>>> On Thu, Mar 5, 2015 at 10:50 AM, Zhen Zhang <[email protected]>
>>>>> wrote:
>>>>>
>>>>>> Hi Varun,
>>>>>>
>>>>>> This should not be a problem. When we register a callback, we are
>>>>>> expecting a call back type of INIT first, followed by a sequence of
>>>>>> CALLBACK types, and when you unregister the callback, you will received a
>>>>>> FINALIZED type. Since unregister is an async operation, when you receive
>>>>>> a
>>>>>> FINALIZED type, you might still see a couple of CALLBACK type callbacks,
>>>>>> which are simply ignored. The log is basically telling you that.
>>>>>>
>>>>>> Thanks,
>>>>>> Jason
>>>>>> ------------------------------
>>>>>> *From:* Varun Sharma [[email protected]]
>>>>>> *Sent:* Thursday, March 05, 2015 10:44 AM
>>>>>> *To:* [email protected]
>>>>>> *Subject:* RoutingTableProvider dropping callbacks
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> It seems that the RoutingTableProvider is dropping callbacks in our
>>>>>> case. Here is a log:
>>>>>>
>>>>>> [ZkClient-EventThread-17-terrapinzk001a:2181]
>>>>>> (CallbackHandler.java:130) WARN Skip processing callbacks for listener:
>>>>>> com.pinterest.terrapin.controller.TerrapinRoutingTableProvider@7e7f8062,
>>>>>> path: /main_a/EXTERNALVIEW, expected types: [INIT] but was CALLBACK
>>>>>>
>>>>>>
>>>>>> We have a custom RoutingTableProvider to catch callbacks and do
>>>>>> some processing - this is causing a lot of issues for us. What could be
>>>>>> causing this ?
>>>>>>
>>>>>> Thanks
>>>>>> Varun
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
>
