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From 姜 为 <ydswcy...@gmail.com>
Subject Re: OptimizedClassDescriptor verifyChecksum object set as optional
Date Wed, 11 Nov 2015 02:54:55 GMT
Hi Denis:

	I tried compute.call(new ExampleServiceImplA());

	But if my service is by ModuleA.ExampleServiceImpl call ModuleB.ExampleServiceImpl,
	and ModuleB.ExampleServiceImpl call other complicated service.
	
	The ModuleA only has ExampleServiceImpl there is none ModuleB.other service.
	It does not work.


> 在 2015年11月10日,下午9:55,Denis Magda <dmagda@gridgain.com <mailto:dmagda@gridgain.com>>
写道:
> 
> It should fail because you send your service impl inside of Callable
> compute.call(new Callable(new ExampleServiceImplA()));
> 
> Callable is loaded by application class loader and presents on both the sender and receiver.
This leads to the situation when the receiver tries to loads ExampleServiceImplA using the
app class loader as well.
> 
> To avoid this try to implement IgniteCallable by ExampleServiceImplA and send the task
this way:
> 
> compute.call(new ExampleServiceImplA());
> 
> 
> > I think. If I have lots of type servers. It will be ExampleServiceImpl1 2 3 4 5….,will
look very bloated.
> 
> You can use java 8 closures sending a particular one depending on a server type. Will
it work for you?
> https://apacheignite.readme.io/docs/distributed-closures <https://apacheignite.readme.io/docs/distributed-closures>
> 
> 
> Regards,
> Denis
> On 11/10/2015 4:31 PM, 姜 为 wrote:
>> Hi Denis,
>> 
>> 	I tried your suggested,  here is the code : <https://github.com/wmz7year/ignite-test/commit/4eaa4231e165eaa4de00dab94cd394f629e68497>https://github.com/wmz7year/ignite-test/commit/4eaa4231e165eaa4de00dab94cd394f629e68497
<https://github.com/wmz7year/ignite-test/commit/4eaa4231e165eaa4de00dab94cd394f629e68497>
>> 	
>> 	But I still got ClassNotFoundException.
>> 
>> 	<邮件附件.png>
>> 
>> 
>> 	I think. If I have lots of type servers. It will be ExampleServiceImpl1 2 3 4 5….,will
look very bloated.
>> 	
>> 
>>> 在 2015年11月10日,下午8:02,Denis Magda < <mailto:dmagda@gridgain.com>dmagda@gridgain.com
<mailto:dmagda@gridgain.com>> 写道:
>>> 
>>> Jiang,
>>> 
>>> This exception happens exactly because you have two implementations with the
same name. If the names were different you wouldn't get to the point of checksum validation.
>>> Here I fully share Val's opinion that checksum's verification shouldn't be optional
and it's a responsibility of an application to take care of such situations.
>>> 
>>> I see the following approaches you can use in your code to get required behavior:
>>> 
>>> 1) As suggested below use the approach with Serializable + serialVersionUID.
It will work;
>>> 
>>> 2) More preferable is to have different implementations with different names
(ExampleServiceImpl1, ExampleServiceImpl2, etc...). Is there any reasons you can't use this
straightforward approach?
>>> When the implementations are ready you can put their classes onto every machine
in order to have them in the classpath or you can leverage IgniteConfiguration.peerClassLoadingEnabled
feature.
>>> The feature allows to load missing classes from a machine that sends compute
based tasks onto a machine that will execute a task and you don't need to copy implementations'
classes manually at all. 
>>> You can read more on this here: https://apacheignite.readme.io/docs/zero-deployment
<https://apacheignite.readme.io/docs/zero-deployment>
>>> 
>>> Regards,
>>> Denis
>>> 
>>> On 11/10/2015 10:39 AM, 姜 为 wrote:
>>>> Hi:
>>>> 
>>>> 	Here is example: https://github.com/wmz7year/ignite-test <https://github.com/wmz7year/ignite-test>
>>>> 
>>>> 	First start ModuleB, then start ModuleA.
>>>> 
>>>> 	ModuleB ExampleServiceImpl has three field.
>>>> 
>>>>     ModuleA ExampleServiceImpl has only one field.
>>>> 
>>>> 	Then throw Exception :
>>>> 
>>>> 	<邮件 附件.png>
>>>>> 在 2015年11月10日,下午2:48,Denis Magda <dmagda@gridgain.com
<mailto:dmagda@gridgain.com>> 写道:
>>>>> 
>>>>> Hi,
>>>>> 
>>>>> +1 to Val.
>>>>> 
>>>>> Actually if you have different class names on different machines (DataEntity,
ServiceEntity) I don't realize how you can get to the checksum validation stage.
>>>>> In my understanding you should have caught ClassNotFoundException.
>>>>> 
>>>>> Provide me with a full runnable example, I'll run and see what you're
trying to implement and at which point you fail.
>>>>> 
>>>>> --
>>>>> Denis
>>>>> 
>>>>> On 11/10/2015 9:30 AM, Valentin Kulichenko wrote:
>>>>>> Hi,
>>>>>> 
>>>>>> I'm against optional checksum verification. It's not safe, adds one
more
>>>>>> configuration property and I don't see any use case that can require
this.
>>>>>> 
>>>>>> I also don't completely understand what you're trying to achieve.
Can you
>>>>>> please describe the sequence of serialization/deserialization events
that
>>>>>> you expect in your application?
>>>>>> 
>>>>>> -Val
>>>>>> 
>>>>>> On Mon, Nov 9, 2015 at 5:13 PM, 姜 为 < <mailto:ydswcy513@gmail.com>ydswcy513@gmail.com
<mailto:ydswcy513@gmail.com>> wrote:
>>>>>> 
>>>>>>> Hi:
>>>>>>> 
>>>>>>>         The implementations name maybe not same.
>>>>>>> 
>>>>>>>         Like my example:
>>>>>>> 
>>>>>>>         class DataEntity {
>>>>>>>                 Integer id;
>>>>>>>                 string name;
>>>>>>>                 Integer age;
>>>>>>> 
>>>>>>>                 ….. and other
>>>>>>> 
>>>>>>>                 Externalizable.read(in){
>>>>>>>                         if(in.readBoolean()) {
>>>>>>>                 id = in.readInt();
>>>>>>>             }
>>>>>>>                         same as name,age...
>>>>>>>                 }
>>>>>>> 
>>>>>>>         Externalizable.write(out){
>>>>>>>             out.writeBoolean(id != null);
>>>>>>>             if(id != null) {
>>>>>>>                 out.writeInt(id);
>>>>>>>             }
>>>>>>>             same as name,age...
>>>>>>>         }
>>>>>>>         }
>>>>>>> 
>>>>>>>         class ServiceEntity {
>>>>>>>                 Integer id;
>>>>>>>                 Integer age;
>>>>>>> 
>>>>>>>                 …. and other
>>>>>>> 
>>>>>>>                 Externalizable.read(in){
>>>>>>>                         if(in.readBoolean()) {
>>>>>>>                 id = in.readInt();
>>>>>>>             }
>>>>>>>             if(in.readBoolean()) {
>>>>>>>                 in.readString(); // ignore name
>>>>>>>             }
>>>>>>>             if(in.readBoolean()) {
>>>>>>>                 age = in.readInt();
>>>>>>>             }
>>>>>>>                         … and other
>>>>>>>                 }
>>>>>>> 
>>>>>>>         Externalizable.write(out){
>>>>>>>             out.writeBoolean(id != null);
>>>>>>>             if(id != null) {
>>>>>>>                 out.writeInt(id);
>>>>>>>             }
>>>>>>>             out.writeBoolean(false); // null for name
>>>>>>>                        out.writeBoolean(age != null);
>>>>>>>             if(age != null) {
>>>>>>>                 out.writeInt(age);
>>>>>>>             }
>>>>>>>                     … and other
>>>>>>>         }
>>>>>>>         }
>>>>>>> 
>>>>>>>         The other implementation class can be serialized and
deserialized
>>>>>>> custom rules by Externalizable.read and Externalizable.write.
>>>>>>>         Each of the different types of servers property needs
are
>>>>>>> different,it does not require a complete serialization.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>>> 在 2015年11月9日,下午10:22,Denis Magda < <mailto:dmagda@gridgain.com>dmagda@gridgain.com
<mailto:dmagda@gridgain.com>> 写道:
>>>>>>>> 
>>>>>>>> Hi,
>>>>>>>> 
>>>>>>>> As I understand both servers have different implementations
but the
>>>>>>> names of those implementations are the same, correct?
>>>>>>>> Because otherwise I don't see how your code could get to
the point of
>>>>>>> checksum validation if one implementation's name is ServiceEntity
while the
>>>>>>> other's is DataEntity.
>>>>>>>> If my assumptions above are correct then I would recommend
to do the
>>>>>>> following:
>>>>>>>> 1) Extend Serializable instead of Externalizable
>>>>>>>> 
>>>>>>>> interface Entity extends Serializable {
>>>>>>>>     .....
>>>>>>>> }
>>>>>>>> 
>>>>>>>> 2) Add custom serialVersionUID to each implementation. This
will help
>>>>>>> you get rid off checksum related exception
>>>>>>>> class EntityImpl implements Entity {
>>>>>>>> private static final long serialVersionUID = 0L;
>>>>>>>> ......
>>>>>>>> }
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Regards,
>>>>>>>> Denis
>>>>>>>> 
>>>>>>>> On 11/8/2015 3:27 PM, 姜 为 wrote:
>>>>>>>>> Hi guys:
>>>>>>>>> 
>>>>>>>>>      I’m using ignite 1.4.
>>>>>>>>>      In IgniteCompute.call will transfer of an object
to the cluster.
>>>>>>>>>     The object should implement Serializable or Externalizable
>>>>>>> interface.
>>>>>>>>>     OptimizedClassDescriptor.read method will check whether
the object
>>>>>>> is in the same class.
>>>>>>>>>     In my use case,I have some type of servers in cluster.
>>>>>>>>>     The server type A will check the business,and the
server type B
>>>>>>> will persistent data.
>>>>>>>>>     There is a entity interface Entity extends Externalizable
have
>>>>>>> different implementations on different servers.
>>>>>>>>>     Such like this:
>>>>>>>>> 
>>>>>>>>>     interface Entity extends Externalizable {
>>>>>>>>>      method a();
>>>>>>>>>      method b();
>>>>>>>>>              method c();
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      class  ServiceEntity implements Entity {
>>>>>>>>>      method a(){
>>>>>>>>>              // do something...
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      method b(){
>>>>>>>>>              // do something...
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      method c(){
>>>>>>>>>              throw new UnsupportedException...
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      Externalizable.read...
>>>>>>>>>      Externalizable.write...
>>>>>>>>>     }
>>>>>>>>> 
>>>>>>>>>     class DataEntity implements Entity {
>>>>>>>>>      method a(){
>>>>>>>>>              // do something...
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      method b(){
>>>>>>>>>              throw new UnsupportedException...
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      method c(){
>>>>>>>>>              // do something...
>>>>>>>>>      }
>>>>>>>>> 
>>>>>>>>>      Externalizable.read...
>>>>>>>>>      Externalizable.write...
>>>>>>>>>     }
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>>     And IgniteCompute.call(new IgniteCallable(
>>>>>>>>>              public Object call(){
>>>>>>>>>                      Entity.a() or b and c;..
>>>>>>>>>              }
>>>>>>>>>      ));
>>>>>>>>> 
>>>>>>>>>    Different implementations of the same class are to
achieve read and
>>>>>>> write methods.
>>>>>>>>>    But OptimizedClassDescriptor.read will check the class
sum and throw
>>>>>>> ClassNotFoundException.
>>>>>>>>>    I recommend verifyChecksum object set as optional,and
I really need
>>>>>>> is change.
>>>>>>>>>    Here is my pr:
>>>>>>>>>    https://issues.apache.org/jira/browse/IGNITE-1854
<https://issues.apache.org/jira/browse/IGNITE-1854> <
>>>>>>> https://issues.apache.org/jira/browse/IGNITE-1854 <https://issues.apache.org/jira/browse/IGNITE-1854>>
<
>>>>>>> https://issues.apache.org/jira/browse/IGNITE-1854 <https://issues.apache.org/jira/browse/IGNITE-1854>>
<
>>>>>>> https://issues.apache.org/jira/browse/IGNITE-1854 <https://issues.apache.org/jira/browse/IGNITE-1854>>
>>>>>>>>>        <https://github.com/apache/ignite/pull/200/>https://github.com/apache/ignite/pull/200/
<https://github.com/apache/ignite/pull/200/> <
>>>>>>> https://github.com/apache/ignite/pull/200/ <https://github.com/apache/ignite/pull/200/>>
<
>>>>>>> https://github.com/apache/ignite/pull/200/ <https://github.com/apache/ignite/pull/200/>>
<
>>>>>>> https://github.com/apache/ignite/pull/200/ <https://github.com/apache/ignite/pull/200/>>
>>>>>>>>> 
>>>>>>> 
>>>>> 
>>>> 
>>> 
>> 
> 


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