Sorry I should have used more proper terminology in my original email, the
standard accepted term for this would be a "cycle". An object that has
references to its own type is one scenario where you _could_ have a cycle,
but it does not necessarily mean that you would have one. Here's a simpler
example:
public class Node implements Serializable {
public Node next;
}
// no cycle
Node a = new Node();
Node b = new Node();
a.next = b;
b.next = null;
collector.emit(a); // this is ok
// cycle
Node c = new Node();
Node d = new Node();
c.next = d;
d.next = c;
collector.emit(c); // this is bad
On Wed, May 20, 2015 at 10:54 PM, [email protected] <[email protected]>
wrote:
> Yeah, I did some guarantee to keep the data structure imutable just now.
> But I still cannot emit my data structure.
> There must be some problem in my structure, but I don't know what kind of
> lapse would cause such error.
> I got a data structure like this:
> public class Counter implements Serializable{
> private Counter left = null;
> private Counter right = null;
> /*
> the rest
> */
> }
> Is this you what referred to recursive reference?
> Thank you very much.
>
> ------------------------------
> [email protected]
>
> *From:* Nathan Leung <[email protected]>
> *Date:* 2015-05-21 10:25
> *To:* [email protected]
> *CC:* user <[email protected]>
> *Subject:* Re: Re: StackOverFlow
> If the data structure is not immutable then you cannot guarantee that
> it's the same as when your partner emitted it. :) It's hard to say
> without code, and even then, if it's a race condition between bolts I'm
> guessing it won't be easy to diagnose. If you have a fanout (bolt b and
> bolt c both subscribe to bolt a), then you could be in trouble (if tuple
> stays in the same worker for both b and c). If bolt a emits a tuple, then
> modifies the object, you could be in trouble. And whether you get into
> trouble or not, and how much trouble, depends on what you are doing with
> the object.
>
> On Wed, May 20, 2015 at 9:21 PM, [email protected] <[email protected]>
> wrote:
>
>> Nathan,
>> You are right ! I'm trying to emitting some data structure.
>> and I'm pretty sure the problem is caused by this.
>> but I can't figure out what is wrong with my data structure...
>> You said that the data structure may be cyclic, but my partner emitted
>> it perfectly,using the same data structure.
>> Do I have to do some serialization myself?
>> Or is some rules I overlooked?
>> If the data structure is not kept imutable, will this error happen too?
>> thank you~
>>
>> ------------------------------
>> [email protected]
>>
>> *From:* Nathan Leung <[email protected]>
>> *Date:* 2015-05-20 21:12
>> *To:* user <[email protected]>
>> *Subject:* Re: StackOverFlow
>> It looks like he's in a recursive loop in a java serialization routine
>> (ObjectOutputStream). This leads me to believe that he is serializing some
>> data structure (perhaps by emitting it in the framework) and since the data
>> structure is cyclic, the stack ends up blown.
>>
>> On Wed, May 20, 2015 at 9:03 AM, Jeffery Maass <[email protected]> wrote:
>>
>>> Nathan, could you expand on what you mean by "your data structure".
>>>
>>> [email protected], could you try turning off
>>> *Config.TOPOLOGY_FALL_BACK_ON_JAVA_SERIALIZATION
>>> ?* *Config conf = new backtype.storm.Config();*
>>> conf.setFallBackOnJavaSerialization(false);
>>> StormSubmitter.submitTopology(topo_name,
>>> conf, builder.createTopology());
>>> If what I think is happening is true, you will receive a different error
>>> in your worker.
>>>
>>>
>>>
>>>
>>> Thank you for your time!
>>>
>>> +++++++++++++++++++++
>>> Jeff Maass <[email protected]>
>>> linkedin.com/in/jeffmaass
>>> stackoverflow.com/users/373418/maassql
>>> +++++++++++++++++++++
>>>
>>>
>>> On Tue, May 19, 2015 at 10:23 PM, Nathan Leung <[email protected]>
>>> wrote:
>>>
>>>> Looks like you have a reference loop in your data structure
>>>> On May 19, 2015 11:07 PM, "[email protected]" <[email protected]>
>>>> wrote:
>>>>
>>>>> hi,
>>>>>
>>>>> I encountered the following error exception:
>>>>>
>>>>> java.lang.StackOverflowError at
>>>>> java.io.ObjectStreamClass$FieldReflector.getPrimFieldValues(ObjectStreamClass.java:1930)
>>>>> at
>>>>> java.io.ObjectStreamClass.getPrimFieldValues(ObjectStreamClass.java:1233)
>>>>> at
>>>>> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1532)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1508)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
>>>>> at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1177)
>>>>> at
>>>>> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1547)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1508)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
>>>>> at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1177)
>>>>> at
>>>>> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1547)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1508)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
>>>>> at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1177)
>>>>> at
>>>>> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1547)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1508)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
>>>>> at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1177)
>>>>> at
>>>>> java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1547)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1508)
>>>>> at
>>>>> java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1431)
>>>>> at
>>>>>
>>>>> …………
>>>>>
>>>>> I tried to locate the error, but I could hardly figure it out.
>>>>>
>>>>> I checked all my for loop and while loop, and there is no infinite
>>>>> loop.
>>>>>
>>>>> all tuples are 'newed' and kept imutable.
>>>>>
>>>>> how can I figure this out?
>>>>>
>>>>> thanks ...
>>>>>
>>>>> ps. this happened both in clusters and local mode.
>>>>>
>>>>> ------------------------------
>>>>> [email protected]
>>>>>
>>>>
>>>
>>
>
