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Using Compute Sanitizer with the RAPIDS Accelerator for Apache Spark

Compute Sanitizer is a functional correctness checking suite included in the CUDA toolkit. This suite contains multiple tools that can perform different type of checks. Of main interest to the RAPIDS Accelerator is the memcheck tool that is capable of precisely detecting and attributing out of bounds and misaligned memory access errors in CUDA applications.

To use Compute Sanitizer with a single worker, you can start the worker with compute-sanitizer in front of the worker start command.

Here is an example that starts up a worker in standalone mode, sanitizes it and the shell until the shell exits (using Ctrl+D) while stopping the worker process at the end.

compute-sanitizer --target-processes all bash -c " \
${SPARK_HOME}/sbin/start-worker.sh $master_url & \
$SPARK_HOME/bin/spark-shell; \
${SPARK_HOME}/sbin/stop-worker.sh"

To use Compute Sanitizer in a distributed Spark standalone cluster, follow these steps:

  • Create a “fake” Java home, for example, in /opt/compute-sanitizer-java:
    mkdir -p /opt/compute-sanitizer-java/bin
    
  • Create a “fake” java binary:
    echo 'compute-sanitizer java "$@"' > /opt/compute-sanitizer-java/bin/java
    chmod +x /opt/compute-sanitizer-java/bin/java
    
  • When launching jobs, set the following Spark configuration:
    --conf spark.executorEnv.JAVA_HOME="/opt/compute-sanitizer-java"
    

Now each executor will use the “fake” java binary instead of the real one, and run under compute-sanizer. The executor stdout may produce errors like these:

========= COMPUTE-SANITIZER
========= Program hit invalid device context (error 201) on CUDA API call to cuCtxGetDevice.
=========     Saved host backtrace up to driver entry point at error
=========     Host Frame: [0x24331b]
=========                in /lib/x86_64-linux-gnu/libcuda.so.1
=========     Host Frame:uct_cuda_base_query_devices_common [0x6209]
=========                in /usr/lib/ucx/libuct_cuda.so.0.0.0
=========     Host Frame:uct_md_query_tl_resources [0x12976]
=========                in /usr/lib/libuct.so.0.0.0
=========     Host Frame: [0x17b17]
=========                in /usr/lib/libucp.so.0.0.0
=========     Host Frame: [0x191c0]
=========                in /usr/lib/libucp.so.0.0.0
=========     Host Frame: [0x19674]
=========                in /usr/lib/libucp.so.0.0.0
=========     Host Frame:ucp_init_version [0x1a4e3]
=========                in /usr/lib/libucp.so.0.0.0
=========     Host Frame:Java_org_openucx_jucx_ucp_UcpContext_createContextNative [0x38ff]
=========                in /tmp/jucx4889414997471006264/libjucx.so
=========     Host Frame: [0x7fdbc9017da7]
=========                in

Enable Line Numbers

To help with debugging, you can build libcudf with line numbers enabled:

cmake .. <other options> -DCUDA_ENABLE_LINEINFO=ON