Hi Jiang,
I'm a bit confused why you can't give different names to the services
located in different modules. If each service has a different name then
my approach will work for you, doesn't it?
But if my service is by ModuleA.ExampleServiceImpl call
ModuleB.ExampleServiceImpl,
and ModuleB.ExampleServiceImpl call other complicated service.
Could you provide me with the code showing what you're trying to achieve.
BTW, you use service notion in the thread. Probably you can implement
everything using Ignite Services module:
https://apacheignite.readme.io/docs/service-grid
What do you think?
Regards,
Denis
On 11/11/2015 5:54 AM, 姜 为 wrote:
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 <dma...@gridgain.com
<mailto:dma...@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:dma...@gridgain.com>dma...@gridgain.com
<mailto:dma...@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 <dma...@gridgain.com
<mailto:dma...@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:ydswcy...@gmail.com>ydswcy...@gmail.com
<mailto:ydswcy...@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:dma...@gridgain.com>dma...@gridgain.com
<mailto:dma...@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/>>
