Running RamCloud client with java

[MheniMerz]

hi all,
i have a running RamCloud instance on one node,
im trying to start a java client that can read and write data, i've been following these instructions to build and run the java client.
but when running sudo ./gradlew run -Plocator=build/install/ramcloud/bin/ramcloud
i get the following error

Exception in thread "main" java.lang.UnsatisfiedLinkError: /tmp/libramcloud_java759421568980880719.so: libramcloud.so: cannot open shared object file: No such file or directory
        at java.lang.ClassLoader$NativeLibrary.load(Native Method)
        at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1941)
        at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1824)
        at java.lang.Runtime.load0(Runtime.java:809)
        at java.lang.System.load(System.java:1086)
        at cz.adamh.utils.NativeUtils.loadLibraryFromJar(NativeUtils.java:116)
        at edu.stanford.ramcloud.Util.loadLibrary(Util.java:47)
        at edu.stanford.ramcloud.TestClient.<clinit>(TestClient.java:32)
:run FAILED

FAILURE: Build failed with an exception.

i tried running with the debug option and running ./runclient.sh i basically get the same output.
seems like it's looking for a ramcloud library file, but maybe it's looking in the wrong place ?
any one had this before ?
thanks.
Mheni.

[MheniMerz]

add the path to libramcloud.so to the LD_LIBRARY_PATH environment variable

• add this line to your .bashrc file export LD_LIBRARY_PATH=/home/antd/RAMCloud/obj.master in my case that's where the file libramcloud.so is located
• then execute the same command to avoid rebooting the system export LD_LIBRARY_PATH=/home/antd/RAMCloud/obj.master
• you can now run sudo ./gradlew run -Plocator=basic+udp:host=localhost,port=11100
  • Plocator here is the service locator for the coordinator and not a path to a file

[synapsics-sergiu]

This is not working for me unfortunately.
The path to my libramcloud.so is /home/ramdb/RAMCloud/obj.master/libramcloud.so

Did all the steps described above by you. Here is the output of LD_LIBRARY_PATH:

ramdb@ramdb:~/RAMCloud/obj.master$ echo $LD_LIBRARY_PATH
/home/ramdb/RAMCloud/obj.master

Here is the output while trying to run the client.

ramdb@ramdb:~/RAMCloud/bindings/java$ sudo ./gradlew run -Plocator=basic+udp:host=ramdb,port=11100
:compileJava UP-TO-DATE
:processResources UP-TO-DATE
:classes UP-TO-DATE
:javah UP-TO-DATE
:compileMainSharedLibraryMainCpp UP-TO-DATE
:linkMainSharedLibrary UP-TO-DATE
:mainSharedLibrary UP-TO-DATE
:copyLibs UP-TO-DATE
:jar UP-TO-DATE
:startScripts UP-TO-DATE
:installDist UP-TO-DATE
:make UP-TO-DATE
:run
Exception in thread "main" java.lang.UnsatisfiedLinkError: /tmp/libramcloud_java6503341304544372223.so: libramcloud.so: cannot open shared object file: No such file or directory
	at java.lang.ClassLoader$NativeLibrary.load(Native Method)
	at java.lang.ClassLoader.loadLibrary1(ClassLoader.java:1965)
	at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1890)
	at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1851)
	at java.lang.Runtime.load0(Runtime.java:795)
	at java.lang.System.load(System.java:1062)
	at cz.adamh.utils.NativeUtils.loadLibraryFromJar(NativeUtils.java:116)
	at edu.stanford.ramcloud.Util.loadLibrary(Util.java:47)
	at edu.stanford.ramcloud.TestClient.<clinit>(TestClient.java:32)
:run FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':run'.
> Process 'command '/usr/lib/jvm/java-7-oracle/bin/java'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

BUILD FAILED

Any other suggestions would be much appreciated.

[jdellithorpe]

Hi @centrys-sergiu

sudo doesn't preserve your environment variables (in particular, LD_LIBRARY_PATH). Can you run this without using sudo? I don't think sudo should be necessary to run this.

Best,
Jonathan

[synapsics-sergiu]

You are right! However in order to run the client without sudo, I had to remove all the folders that were generated at build with sudo.

Thanks

[jdellithorpe]

Awesome. As far as I know, btw, building shouldn’t require sudo. You may want to consider building without it to avoid this problem.