HTraceConfiguration Class Not Found Exception

[Francis-Liu]

I want to run YCSB with Cassandra, "ycsb load" command failed immediately with the following error:

bin/ycsb.sh load cassandra-cql -p hosts="10.40.1.167" -P workloads/workloada
/usr/lib/jvm/jre-1.8.0-openjdk/bin/java  -classpath /home/cc/YCSB/conf:/home/cc/YCSB/core/target/core-0.12.0-SNAPSHOT.jar:/home/cc/YCSB/cassandra/target/cassandra-binding-0.12.0-SNAPSHOT.jar:/home/cc/YCSB/cassandra/target/dependency/cassandra-driver-core-3.0.0.jar:/home/cc/YCSB/cassandra/target/dependency/guava-16.0.1.jar:/home/cc/YCSB/cassandra/target/dependency/metrics-core-3.1.2.jar:/home/cc/YCSB/cassandra/target/dependency/netty-buffer-4.0.33.Final.jar:/home/cc/YCSB/cassandra/target/dependency/netty-codec-4.0.33.Final.jar:/home/cc/YCSB/cassandra/target/dependency/netty-common-4.0.33.Final.jar:/home/cc/YCSB/cassandra/target/dependency/netty-handler-4.0.33.Final.jar:/home/cc/YCSB/cassandra/target/dependency/netty-transport-4.0.33.Final.jar:/home/cc/YCSB/cassandra/target/dependency/slf4j-api-1.6.4.jar com.yahoo.ycsb.Client -load -db com.yahoo.ycsb.db.CassandraCQLClient -p hosts=10.40.1.167 -P workloads/workloada
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/htrace/core/HTraceConfiguration
        at com.yahoo.ycsb.Client.main(Client.java:947)
Caused by: java.lang.ClassNotFoundException: org.apache.htrace.core.HTraceConfiguration
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        ... 1 more

I did not install htrace on my computer. In the latest version of YCSB, is htrace turned on by default? If so, is there a way to turn it off?

Also, I am curious how 'deeply' is htrace integrated with YCSB, only at the 'global' YCSB client level? Or is the htrase code implemented in every individual database interfaces?

[busbey]

This looks like an error in the classpath generation for maven source runs. Can you try one of more of the following:

• run from the 0.11.0 release's binary artifact
• build a binary artifact from a git checkout and run from that artifact
• run from source checkout using the old 'ycsb' python script rather than the newer bash

I did not install htrace on my computer. In the latest version of YCSB, is htrace turned on by default? If so, is there a way to turn it off?

By default HTrace is set to no tracing. However, like log levels in e.g. slf4j this still requires a call into the htrace library (to check if tracing is on, for example).

Also, I am curious how 'deeply' is htrace integrated with YCSB, only at the 'global' YCSB client level? Or is the htrase code implemented in every individual database interfaces?

AFAIK it's currently implemented around the wrapper we layer on top of the storage interfaces. That means we trace each kind of operation we do in YCSB. However, tracing through the individual storage engines would depend on if the client libraries of a given storage system.

[Francis-Liu]

@busbey Your answer is very helpful. Now I can run YCSB successfully. I think this issue should be closed.

Thank you so much!

[busbey]

I'm glad things helped. I'm going to reopen this issue so we can figure out where the failure is on using the bash script with a source build.

Let me know if you can't unsubscribe from updates and I'll switch to a new issue instead.

[mkaurin]

0.13.0-SNAPSHOT works by just invoking the python script instead of the bash script

[risdenk]

Closing this since #877 has some details related to the 0.12.0 release.

[KhanhCon]

I'm having this issue. Using the old python script doesn't help me.
Do I need to install Htrace on my computer?

[busbey]

Please open a new issue @KhanhCon

[KhanhCon]

@busbey Oh. I'm using 'bin\ycsb' command on Windows and this seems to run the ycsb.bat file.
I'm new to Github so is it appropriate to ask how run the python script on Windows here?
Thank you

[busbey]

In a new issue, sure. Go to "issues" for the project and then click on "new issue".