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在 DLAMI 上使用 EFA
以下部分描述如何在 Amazon Deep Learning AMI上使用 EFA 来运行多节点应用程序。
使用 EFA 来运行多节点应用程序
要在节点群集中运行应用程序，需要进行以下配置
启用无密码 SSH
选择集群中的一个节点作为领导节点。其余节点称为成员节点。
在领导节点上，生成 RSA 密钥对。
ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa更改领导节点上私有密钥的权限。
chmod 600 ~/.ssh/id_rsa将公钥复制
~/.ssh/id_rsa.pub到集群中的成员节点，并将其附加到~/.ssh/authorized_keys集群中的成员节点。现在，您应该能够使用私有 ip 从领导节点直接登录到成员节点。
ssh <member private ip>通过将以下内容添加到领导节点上的 ~/.ssh/config 文件中，禁用 strictHostKey检查并在领导节点上启用代理转发：
Host * ForwardAgent yes Host * StrictHostKeyChecking no在 Amazon Linux 2 实例上，在领导节点上运行以下命令，为配置文件提供正确的权限：
chmod 600 ~/.ssh/config
创建主机文件
在领导节点上，创建主机文件以标识集群中的节点。主机文件必须针对集群中的每个节点都有一个条目。创建文件 ~/hosts 并使用私有 IP 添加每个节点，如下所示：
localhost slots=8 <private ip of node 1> slots=8 <private ip of node 2> slots=8
NCCL 测试
注意
这些测试是使用 EFA 版本 1.30.0 和 OFI NCCL Plugin 1.7.4 运行的。
下面列出了由 Nvidia 提供的 NCCL 测试子集，用于测试多个计算节点的功能和性能
支持的实例：p3dn、P4、P5
NCCL 消息传输多节点测试
nccl_message_transfer 是一项简单的测试，可确保 NCCL OFI 插件按预期工作。该测试验证 NCCL 的连接建立和数据传输 API 的功能。当使用 EFA 来运行 NCCL 应用程序时，请确保按照示例所示使用到 mpirun 的完整路径。根据集群中实例和 GPU 的数量更改参数 np 和 N。有关更多信息，请参阅 Amazon OFI NCCL 文档
以下 nccl_message_transfer 测试适用于通用 CUDA xx.x 版本。通过替换脚本中的 CUDA 版本，您可以在您的 Amazon EC2 实例中运行适用于任何可用 CUDA 版本的命令。
$/opt/amazon/openmpi/bin/mpirun -n 2 -N 1 --hostfile hosts \ -x LD_LIBRARY_PATH=/usr/local/cuda-xx.x/efa/lib:/usr/local/cuda-xx.x/lib:/usr/local/cuda-xx.x/lib64:/usr/local/cuda-xx.x:$LD_LIBRARY_PATH \ --mca btl tcp,self --mca btl_tcp_if_exclude lo,docker0 --bind-to none \ opt/aws-ofi-nccl/tests/nccl_message_transfer
您的输出应与以下内容类似。您可以检查输出，以查看 EFA 是否正在用作 OFI 提供程序。
INFO: Function: nccl_net_ofi_init Line: 1069: NET/OFI Selected Provider is efa (found 4 nics) INFO: Function: nccl_net_ofi_init Line: 1160: NET/OFI Using transport protocol SENDRECV INFO: Function: configure_ep_inorder Line: 261: NET/OFI Setting FI_OPT_EFA_SENDRECV_IN_ORDER_ALIGNED_128_BYTES not supported. INFO: Function: configure_nccl_proto Line: 227: NET/OFI Setting NCCL_PROTO to "simple" INFO: Function: main Line: 86: NET/OFI Process rank 1 started. NCCLNet device used on ip-172-31-13-179 is AWS Libfabric. INFO: Function: main Line: 91: NET/OFI Received 4 network devices INFO: Function: main Line: 111: NET/OFI Network supports communication using CUDA buffers. Dev: 3 INFO: Function: main Line: 118: NET/OFI Server: Listening on dev 3 INFO: Function: main Line: 131: NET/OFI Send connection request to rank 1 INFO: Function: main Line: 173: NET/OFI Send connection request to rank 0 INFO: Function: main Line: 137: NET/OFI Server: Start accepting requests INFO: Function: main Line: 141: NET/OFI Successfully accepted connection from rank 1 INFO: Function: main Line: 145: NET/OFI Send 8 requests to rank 1 INFO: Function: main Line: 179: NET/OFI Server: Start accepting requests INFO: Function: main Line: 183: NET/OFI Successfully accepted connection from rank 0 INFO: Function: main Line: 187: NET/OFI Rank 1 posting 8 receive buffers INFO: Function: main Line: 161: NET/OFI Successfully sent 8 requests to rank 1 INFO: Function: main Line: 251: NET/OFI Got completions for 8 requests for rank 0 INFO: Function: main Line: 251: NET/OFI Got completions for 8 requests for rank 1
P4d.24xlarge 上的多节点 NCCL 性能测试
要使用 EFA 来检查 NCCL 性能，请运行官方 NCCL-Tests 存储库
构建您自己的脚本时，请参阅以下指南：
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当使用 EFA 来运行 NCCL 应用程序时，按照示例所示使用到 mpirun 的完整路径。
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根据集群中实例和 GPU 的数量更改参数 np 和 N。
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添加 NCCL_DEBUG=INFO 标志，并确保日志将 EFA 用法指示为“所选提供程序是 EFA”。
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设置要解析的训练日志位置以进行验证
TRAINING_LOG="testEFA_$(date +"%N").log"
在任何成员节点上使用 watch nvidia-smi 命令来监视 GPU 使用情况。以下 watch nvidia-smi 命令适用于通用 CUDA xx.x 版本，并且依赖于您的实例的操作系统。通过替换脚本中的 CUDA 版本，您可以在您的 Amazon EC2 实例中运行适用于任何可用 CUDA 版本的命令。
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Amazon Linux 2：
$ /opt/amazon/openmpi/bin/mpirun -n 16 -N 8 \ -x NCCL_DEBUG=INFO -x --mca pml ^cm \ -x LD_LIBRARY_PATH=/usr/local/cuda-xx.x/efa/lib:/usr/local/cuda-xx.x/lib:/usr/local/cuda-xx.x/lib64:/usr/local/cuda-xx.x:/opt/amazon/efa/lib64:/opt/amazon/openmpi/lib64:$LD_LIBRARY_PATH \ --hostfile hosts --mca btl tcp,self --mca btl_tcp_if_exclude lo,docker0 --bind-to none \ /usr/local/cuda-xx.x/efa/test-cuda-xx.x/all_reduce_perf -x NCCL_PROTO=simple -b 8 -e 1G -f 2 -g 1 -c 1 -n 100 | tee ${TRAINING_LOG} -
Ubuntu 20.04：
$ /opt/amazon/openmpi/bin/mpirun -n 16 -N 8 \ -x NCCL_DEBUG=INFO -x --mca pml ^cm \ -x LD_LIBRARY_PATH=/usr/local/cuda-xx.x/efa/lib:/usr/local/cuda-xx.x/lib:/usr/local/cuda-xx.x/lib64:/usr/local/cuda-xx.x:/opt/amazon/efa/lib:/opt/amazon/openmpi/lib:$LD_LIBRARY_PATH \ --hostfile hosts --mca btl tcp,self --mca btl_tcp_if_exclude lo,docker0 --bind-to none \ /usr/local/cuda-xx.x/efa/test-cuda-xx.x/all_reduce_perf -x NCCL_PROTO=simple-b 8 -e 1G -f 2 -g 1 -c 1 -n 100 | tee ${TRAINING_LOG}
您的输出应与以下内容类似：
# nThread 1 nGpus 1 minBytes 8 maxBytes 1073741824 step: 2(factor) warmup iters: 5 iters: 100 agg iters: 1 validation: 1 graph: 0 # # Using devices # Rank 0 Group 0 Pid 9591 on ip-172-31-4-37 device 0 [0x10] NVIDIA A100-SXM4-40GB # Rank 1 Group 0 Pid 9592 on ip-172-31-4-37 device 1 [0x10] NVIDIA A100-SXM4-40GB # Rank 2 Group 0 Pid 9593 on ip-172-31-4-37 device 2 [0x20] NVIDIA A100-SXM4-40GB # Rank 3 Group 0 Pid 9594 on ip-172-31-4-37 device 3 [0x20] NVIDIA A100-SXM4-40GB # Rank 4 Group 0 Pid 9595 on ip-172-31-4-37 device 4 [0x90] NVIDIA A100-SXM4-40GB # Rank 5 Group 0 Pid 9596 on ip-172-31-4-37 device 5 [0x90] NVIDIA A100-SXM4-40GB # Rank 6 Group 0 Pid 9597 on ip-172-31-4-37 device 6 [0xa0] NVIDIA A100-SXM4-40GB # Rank 7 Group 0 Pid 9598 on ip-172-31-4-37 device 7 [0xa0] NVIDIA A100-SXM4-40GB # Rank 8 Group 0 Pid 10216 on ip-172-31-13-179 device 0 [0x10] NVIDIA A100-SXM4-40GB # Rank 9 Group 0 Pid 10217 on ip-172-31-13-179 device 1 [0x10] NVIDIA A100-SXM4-40GB # Rank 10 Group 0 Pid 10218 on ip-172-31-13-179 device 2 [0x20] NVIDIA A100-SXM4-40GB # Rank 11 Group 0 Pid 10219 on ip-172-31-13-179 device 3 [0x20] NVIDIA A100-SXM4-40GB # Rank 12 Group 0 Pid 10220 on ip-172-31-13-179 device 4 [0x90] NVIDIA A100-SXM4-40GB # Rank 13 Group 0 Pid 10221 on ip-172-31-13-179 device 5 [0x90] NVIDIA A100-SXM4-40GB # Rank 14 Group 0 Pid 10222 on ip-172-31-13-179 device 6 [0xa0] NVIDIA A100-SXM4-40GB # Rank 15 Group 0 Pid 10223 on ip-172-31-13-179 device 7 [0xa0] NVIDIA A100-SXM4-40GB ip-172-31-4-37:9591:9591 [0] NCCL INFO Bootstrap : Using ens32:172.31.4.37 ip-172-31-4-37:9591:9591 [0] NCCL INFO NET/Plugin: Failed to find ncclCollNetPlugin_v6 symbol. ip-172-31-4-37:9591:9591 [0] NCCL INFO NET/Plugin: Failed to find ncclCollNetPlugin symbol (v4 or v5). ip-172-31-4-37:9591:9591 [0] NCCL INFO cudaDriverVersion 12020 NCCL version 2.18.5+cuda12.2 ... ip-172-31-4-37:9024:9062 [6] NCCL INFO NET/OFI Initializing aws-ofi-nccl 1.7.4-aws ip-172-31-4-37:9020:9063 [2] NCCL INFO NET/OFI Using CUDA runtime version 11070 ip-172-31-4-37:9020:9063 [2] NCCL INFO NET/OFI Configuring AWS-specific options ip-172-31-4-37:9024:9062 [6] NCCL INFO NET/OFI Using CUDA runtime version 11070 ip-172-31-4-37:9024:9062 [6] NCCL INFO NET/OFI Configuring AWS-specific options ip-172-31-4-37:9024:9062 [6] NCCL INFO NET/OFI Setting provider_filter to efa ip-172-31-4-37:9024:9062 [6] NCCL INFO NET/OFI Setting FI_EFA_FORK_SAFE environment variable to 1 ip-172-31-4-37:9024:9062 [6] NCCL INFO NET/OFI Disabling NVLS support due to NCCL version 21602 ip-172-31-4-37:9020:9063 [2] NCCL INFO NET/OFI Setting provider_filter to efa ip-172-31-4-37:9020:9063 [2] NCCL INFO NET/OFI Setting FI_EFA_FORK_SAFE environment variable to 1 ip-172-31-4-37:9020:9063 [2] NCCL INFO NET/OFI Disabling NVLS support due to NCCL version 21602 ip-172-31-4-37:9020:9063 [2] NCCL INFO NET/OFI Running on p4d.24xlarge platform, Setting NCCL_TOPO_FILE environment variable to /opt/aws-ofi-nccl/share/aws-ofi-nccl/xml/p4d-24xl-topo.xml ... -----------------------------some output truncated----------------------------------- # out-of-place in-place # size count type redop root time algbw busbw #wrong time algbw busbw #wrong # (B) (elements) (us) (GB/s) (GB/s) (us) (GB/s) (GB/s) 0 0 float sum -1 11.02 0.00 0.00 0 11.04 0.00 0.00 0 0 0 float sum -1 11.01 0.00 0.00 0 11.00 0.00 0.00 0 0 0 float sum -1 11.02 0.00 0.00 0 11.02 0.00 0.00 0 0 0 float sum -1 11.01 0.00 0.00 0 11.00 0.00 0.00 0 0 0 float sum -1 11.02 0.00 0.00 0 11.02 0.00 0.00 0 256 4 float sum -1 632.7 0.00 0.00 0 628.2 0.00 0.00 0 512 8 float sum -1 627.4 0.00 0.00 0 629.6 0.00 0.00 0 1024 16 float sum -1 632.2 0.00 0.00 0 631.7 0.00 0.00 0 2048 32 float sum -1 631.0 0.00 0.00 0 634.2 0.00 0.00 0 4096 64 float sum -1 623.3 0.01 0.01 0 633.6 0.01 0.01 0 8192 128 float sum -1 635.1 0.01 0.01 0 633.5 0.01 0.01 0 16384 256 float sum -1 634.8 0.03 0.02 0 637.0 0.03 0.02 0 32768 512 float sum -1 647.9 0.05 0.05 0 636.8 0.05 0.05 0 65536 1024 float sum -1 658.9 0.10 0.09 0 667.0 0.10 0.09 0 131072 2048 float sum -1 671.9 0.20 0.18 0 662.9 0.20 0.19 0 262144 4096 float sum -1 692.1 0.38 0.36 0 685.1 0.38 0.36 0 524288 8192 float sum -1 715.3 0.73 0.69 0 696.6 0.75 0.71 0 1048576 16384 float sum -1 734.6 1.43 1.34 0 729.2 1.44 1.35 0 2097152 32768 float sum -1 785.9 2.67 2.50 0 794.5 2.64 2.47 0 4194304 65536 float sum -1 837.2 5.01 4.70 0 837.6 5.01 4.69 0 8388608 131072 float sum -1 929.2 9.03 8.46 0 931.4 9.01 8.44 0 16777216 262144 float sum -1 1773.6 9.46 8.87 0 1772.8 9.46 8.87 0 33554432 524288 float sum -1 2110.2 15.90 14.91 0 2116.1 15.86 14.87 0 67108864 1048576 float sum -1 2650.9 25.32 23.73 0 2658.1 25.25 23.67 0 134217728 2097152 float sum -1 3943.1 34.04 31.91 0 3945.9 34.01 31.89 0 268435456 4194304 float sum -1 7216.5 37.20 34.87 0 7178.6 37.39 35.06 0 536870912 8388608 float sum -1 13680 39.24 36.79 0 13676 39.26 36.80 0 [ 1073741824 16777216 float sum -1 25645 41.87 39.25 0 25497 42.11 39.48 0 ] <- Used For Benchmark ... # Out of bounds values : 0 OK # Avg bus bandwidth : 7.46044
要验证 EFA 测试返回的结果是否有效，请使用以下测试进行确认：
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使用 EC2 实例元数据获取实例类型：
TOKEN=$(curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600") INSTANCE_TYPE=$(curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/meta-data/instance-type) -
运行性能测试
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设置以下参数
CUDA_VERSION CUDA_RUNTIME_VERSION NCCL_VERSION -
验证结果，如下所示：
RETURN_VAL=`echo $?` if [ ${RETURN_VAL} -eq 0 ]; then # Information on how the version come from logs # # ip-172-31-27-205:6427:6427 [0] NCCL INFO cudaDriverVersion 12020 # NCCL version 2.16.2+cuda11.8 # ip-172-31-27-205:6427:6820 [0] NCCL INFO NET/OFI Initializing aws-ofi-nccl 1.7.1-aws # ip-172-31-27-205:6427:6820 [0] NCCL INFO NET/OFI Using CUDA runtime version 11060 # cudaDriverVersion 12020 --> This is max supported cuda version by nvidia driver # NCCL version 2.16.2+cuda11.8 --> This is NCCL version compiled with cuda version # Using CUDA runtime version 11060 --> This is selected cuda version # Validation of logs grep "NET/OFI Using CUDA runtime version ${CUDA_RUNTIME_VERSION}" ${TRAINING_LOG} || { echo "Runtime cuda text not found"; exit 1; } grep "NET/OFI Initializing aws-ofi-nccl" ${TRAINING_LOG} || { echo "aws-ofi-nccl is not working, please check if it is installed correctly"; exit 1; } grep "NET/OFI Configuring AWS-specific options" ${TRAINING_LOG} || { echo "AWS-specific options text not found"; exit 1; } grep "Using network AWS Libfabric" ${TRAINING_LOG} || { echo "AWS Libfabric text not found"; exit 1; } grep "busbw" ${TRAINING_LOG} || { echo "busbw text not found"; exit 1; } grep "Avg bus bandwidth " ${TRAINING_LOG} || { echo "Avg bus bandwidth text not found"; exit 1; } grep "NCCL version $NCCL_VERSION" ${TRAINING_LOG} || { echo "Text not found: NCCL version $NCCL_VERSION"; exit 1; } if [[ ${INSTANCE_TYPE} == "p4d.24xlarge" ]]; then grep "NET/AWS Libfabric/0/GDRDMA" ${TRAINING_LOG} || { echo "Text not found: NET/AWS Libfabric/0/GDRDMA"; exit 1; } grep "NET/OFI Selected Provider is efa (found 4 nics)" ${TRAINING_LOG} || { echo "Selected Provider is efa text not found"; exit 1; } grep "aws-ofi-nccl/xml/p4d-24xl-topo.xml" ${TRAINING_LOG} || { echo "Topology file not found"; exit 1; } elif [[ ${INSTANCE_TYPE} == "p4de.24xlarge" ]]; then grep "NET/AWS Libfabric/0/GDRDMA" ${TRAINING_LOG} || { echo "Avg bus bandwidth text not found"; exit 1; } grep "NET/OFI Selected Provider is efa (found 4 nics)" ${TRAINING_LOG} || { echo "Avg bus bandwidth text not found"; exit 1; } grep "aws-ofi-nccl/xml/p4de-24xl-topo.xml" ${TRAINING_LOG} || { echo "Topology file not found"; exit 1; } elif [[ ${INSTANCE_TYPE} == "p5.48xlarge" ]]; then grep "NET/AWS Libfabric/0/GDRDMA" ${TRAINING_LOG} || { echo "Avg bus bandwidth text not found"; exit 1; } grep "NET/OFI Selected Provider is efa (found 32 nics)" ${TRAINING_LOG} || { echo "Avg bus bandwidth text not found"; exit 1; } grep "aws-ofi-nccl/xml/p5.48xl-topo.xml" ${TRAINING_LOG} || { echo "Topology file not found"; exit 1; } elif [[ ${INSTANCE_TYPE} == "p3dn.24xlarge" ]]; then grep "NET/OFI Selected Provider is efa (found 4 nics)" ${TRAINING_LOG} || { echo "Selected Provider is efa text not found"; exit 1; } fi echo "***************************** check_efa_nccl_all_reduce passed for cuda version ${CUDA_VERSION} *****************************" else echo "***************************** check_efa_nccl_all_reduce failed for cuda version ${CUDA_VERSION} *****************************" fi -
要访问基准数据，我们可以解析多节点 all_reduce 测试的最后一行表输出：
benchmark=$(sudo cat ${TRAINING_LOG} | grep '1073741824' | tail -n1 | awk -F " " '{{print $12}}' | sed 's/ //' | sed 's/ 5e-07//') if [[ -z "${benchmark}" ]]; then echo "benchmark variable is empty" exit 1 fi echo "Benchmark throughput: ${benchmark}"