Re: Loading dylibs
I don’t know Dylibs in detail, but can you call a static method where it checks
if it has been already executed and if not then it loads the library (Singleton
pattern)?
> Am 27.08.2019 um 06:39 schrieb Vishwas Siravara :
>
> Hi guys,
> I have a flink application that loads a dylib like this
> System.loadLibrary("vibesimplejava");
>
> The application runs fine , when I restart the job I get this exception :
>
> com.visa.aip.cryptolib.aipcyptoclient.EncryptionException: Unexpected
> errorjava.lang.UnsatisfiedLinkError: Native Library
> /usr/mware/SimpleAPI/voltage-simple-api-java-05.12.-Linux-x86_64-64b-r234867/lib/libvibesimplejava.so
> already loaded in another classloader
> This happens because the dylib has already been loaded once by the
> taskmanger, how can I mitigate this? It seems problematic if two applications
> are loading the same dylib.
>
> Thanks,
> Vishwas
>
Re: Loading dylibs
Hi Jörn,
I tried that. Here is my snippet :
String[] loadedlibs =
getLoadedLibraries(Thread.currentThread().getContextClassLoader());
if(!containsVibeSimpleLib(loadedlibs)) {
System.loadLibrary("vibesimplejava");
}
Now I get the exception Unexpected errorjava.lang.UnsatisfiedLinkError:
com.voltage.securedata.enterprise.ConstantsNative.DIGEST_MD5()I which means
that it could not find vibesimplejava in the loaded libs but I know that
the if was not executed because vibesimplejava was present in loadedlibs(
the control never went inside the if block. Any other suggestions?
Thanks,
Vishwas
On Tue, Aug 27, 2019 at 12:25 AM Jörn Franke wrote:
> I don’t know Dylibs in detail, but can you call a static method where it
> checks if it has been already executed and if not then it loads the library
> (Singleton pattern)?
>
> Am 27.08.2019 um 06:39 schrieb Vishwas Siravara :
>
> Hi guys,
> I have a flink application that loads a dylib like this
>
> System.loadLibrary("vibesimplejava");
>
>
> The application runs fine , when I restart the job I get this exception :
>
> com.visa.aip.cryptolib.aipcyptoclient.EncryptionException: Unexpected
> errorjava.lang.UnsatisfiedLinkError: Native Library
> /usr/mware/SimpleAPI/voltage-simple-api-java-05.12.-Linux-x86_64-64b-r234867/lib/libvibesimplejava.so
> already loaded in another classloader
>
> This happens because the dylib has already been loaded once by the
> taskmanger, how can I mitigate this? It seems problematic if two
> applications are loading the same dylib.
>
> Thanks,
> Vishwas
>
>
Re: Loading dylibs
Yes this is exactly what happens , as a work around I created a small jar
file which has code to load the dylib and I placed it under the lib folder
, this library is in provided scope in my actual job, so the dylib gets
loaded only once when the tm/jm jvm starts .
What I found interesting in my old approach was even when I check whether
the dylib has already been loaded in the current thread , and if it is I
still get the unsatisfied link error even though that dylib is loaded in
the task manager .
On Wed, Aug 28, 2019 at 7:04 AM Aleksey Pak wrote:
> Hi Vishwas,
>
> There is a known issue in the Flink Jira project [1].
> Is it possible that you have encountered the same problem?
>
> [1]: https://issues.apache.org/jira/browse/FLINK-11402
>
> Regards,
> Aleksey
>
>
> On Tue, Aug 27, 2019 at 8:03 AM Vishwas Siravara
> wrote:
>
>> Hi Jörn,
>> I tried that. Here is my snippet :
>>
>> String[] loadedlibs =
>> getLoadedLibraries(Thread.currentThread().getContextClassLoader());
>> if(!containsVibeSimpleLib(loadedlibs)) {
>> System.loadLibrary("vibesimplejava");
>> }
>>
>> Now I get the exception Unexpected errorjava.lang.UnsatisfiedLinkError:
>> com.voltage.securedata.enterprise.ConstantsNative.DIGEST_MD5()I which means
>> that it could not find vibesimplejava in the loaded libs but I know that
>> the if was not executed because vibesimplejava was present in loadedlibs(
>> the control never went inside the if block. Any other suggestions?
>>
>> Thanks,
>> Vishwas
>>
>>
>>
>>
>>
>>
>> On Tue, Aug 27, 2019 at 12:25 AM Jörn Franke
>> wrote:
>>
>>> I don’t know Dylibs in detail, but can you call a static method where it
>>> checks if it has been already executed and if not then it loads the library
>>> (Singleton pattern)?
>>>
>>> Am 27.08.2019 um 06:39 schrieb Vishwas Siravara :
>>>
>>> Hi guys,
>>> I have a flink application that loads a dylib like this
>>>
>>> System.loadLibrary("vibesimplejava");
>>>
>>>
>>> The application runs fine , when I restart the job I get this exception
>>> :
>>>
>>> com.visa.aip.cryptolib.aipcyptoclient.EncryptionException: Unexpected
>>> errorjava.lang.UnsatisfiedLinkError: Native Library
>>> /usr/mware/SimpleAPI/voltage-simple-api-java-05.12.-Linux-x86_64-64b-r234867/lib/libvibesimplejava.so
>>> already loaded in another classloader
>>>
>>> This happens because the dylib has already been loaded once by the
>>> taskmanger, how can I mitigate this? It seems problematic if two
>>> applications are loading the same dylib.
>>>
>>> Thanks,
>>> Vishwas
>>>
>>>
Re: Loading dylibs
Hi Vishwas,
I think it just because dylib is loaded more than once in a jvm
process(TaskManager).
Multiple tasks are deployed in one TaskManager and running in different
threads.
So if you want to make the dylib only loaded once, maybe you use the parent
classloader.
You could use the the following config option to set the packages to be
loaded by parent classloader.
*classloader.parent-first-patterns.additional: xxx.yyy.**
Have a try :)
Best,
Yang
Vishwas Siravara 于2019年8月28日周三 下午9:40写道：
> Yes this is exactly what happens , as a work around I created a small jar
> file which has code to load the dylib and I placed it under the lib folder
> , this library is in provided scope in my actual job, so the dylib gets
> loaded only once when the tm/jm jvm starts .
> What I found interesting in my old approach was even when I check whether
> the dylib has already been loaded in the current thread , and if it is I
> still get the unsatisfied link error even though that dylib is loaded in
> the task manager .
>
> On Wed, Aug 28, 2019 at 7:04 AM Aleksey Pak wrote:
>
>> Hi Vishwas,
>>
>> There is a known issue in the Flink Jira project [1].
>> Is it possible that you have encountered the same problem?
>>
>> [1]: https://issues.apache.org/jira/browse/FLINK-11402
>>
>> Regards,
>> Aleksey
>>
>>
>> On Tue, Aug 27, 2019 at 8:03 AM Vishwas Siravara
>> wrote:
>>
>>> Hi Jörn,
>>> I tried that. Here is my snippet :
>>>
>>> String[] loadedlibs =
>>> getLoadedLibraries(Thread.currentThread().getContextClassLoader());
>>> if(!containsVibeSimpleLib(loadedlibs)) {
>>> System.loadLibrary("vibesimplejava");
>>> }
>>>
>>> Now I get the exception Unexpected errorjava.lang.UnsatisfiedLinkError:
>>> com.voltage.securedata.enterprise.ConstantsNative.DIGEST_MD5()I which means
>>> that it could not find vibesimplejava in the loaded libs but I know that
>>> the if was not executed because vibesimplejava was present in loadedlibs(
>>> the control never went inside the if block. Any other suggestions?
>>>
>>> Thanks,
>>> Vishwas
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Tue, Aug 27, 2019 at 12:25 AM Jörn Franke
>>> wrote:
>>>
I don’t know Dylibs in detail, but can you call a static method where
it checks if it has been already executed and if not then it loads the
library (Singleton pattern)?
Am 27.08.2019 um 06:39 schrieb Vishwas Siravara :
Hi guys,
I have a flink application that loads a dylib like this
System.loadLibrary("vibesimplejava");
The application runs fine , when I restart the job I get this exception
:
com.visa.aip.cryptolib.aipcyptoclient.EncryptionException: Unexpected
errorjava.lang.UnsatisfiedLinkError: Native Library
/usr/mware/SimpleAPI/voltage-simple-api-java-05.12.-Linux-x86_64-64b-r234867/lib/libvibesimplejava.so
already loaded in another classloader
This happens because the dylib has already been loaded once by the
taskmanger, how can I mitigate this? It seems problematic if two
applications are loading the same dylib.
Thanks,
Vishwas
