Using EFA on the DLAMI
The following section describes how to use EFA to run multi-node applications on the Amazon Deep Learning AMI.
Running Multi-Node Applications with EFA
To run an application across a cluster of nodes the following configuration is required
Enable Passwordless SSH
Select one node in your cluster as the leader node. The remaining nodes are referred to as the member nodes.
On the leader node, generate the RSA keypair.
ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsaChange the permissions of the private key on the leader node.
chmod 600 ~/.ssh/id_rsaCopy the public key
~/.ssh/id_rsa.pubto and append it to~/.ssh/authorized_keysof the member nodes in the cluster.You should now be able to directly login to the member nodes from the leader node using the private ip.
ssh <member private ip>Disable strictHostKeyChecking and enable agent forwarding on the leader node by adding the following to the ~/.ssh/config file on the leader node:
Host * ForwardAgent yes Host * StrictHostKeyChecking noOn Amazon Linux 2 instances, run the following command on the leader node to provide correct permissions to the config file:
chmod 600 ~/.ssh/config
Create Hosts File
On the leader node, create a hosts file to identify the nodes in the cluster. The hosts file must have an entry for each node in the cluster. Create a file ~/hosts and add each node using the private ip as follows:
localhost slots=8 <private ip of node 1> slots=8 <private ip of node 2> slots=8
NCCL Tests
Note
These tests have been run using EFA version 1.30.0 and OFI NCCL Plugin 1.7.4.
Listed below are a subset of NCCL Tests provided by Nvidia to test both functionality and performance over multiple compute nodes
Supported Instances: P3dn, P4, P5
NCCL Message Transfer Multi Node Test
The nccl_message_transfer is a simple test to ensure that the NCCL OFI Plugin is working
as expected. The test validates functionality of NCCL's connection establishment and data
transfer APIs. Make sure you use the complete path to mpirun as shown in the example while
running NCCL applications with EFA. Change the params np and N
based on the number of instances and GPUs in your cluster. For more information, see the Amazon OFI NCCL documentation
The following nccl_message_transfer test is for a generic CUDA xx.x version. You can run the commands for any available CUDA version in your Amazon EC2 instance by replacing the CUDA version in the script.
$/opt/amazon/openmpi/bin/mpirun -n 2 -N 1 --hostfile hosts \ -x LD_LIBRARY_PATH=/usr/local/cuda-xx.x/efa/lib:/usr/local/cuda-xx.x/lib:/usr/local/cuda-xx.x/lib64:/usr/local/cuda-xx.x:$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
Your output should look like the following. You can check the output to see that EFA is being used as the OFI provider.
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
Multi-node NCCL Performance Test on P4d.24xlarge
To check NCCL Performance with EFA, run the standard NCCL Performance test that is
available on the official NCCL-Tests Repo
When constructing your own script, refer to the following guidance:
-
Use the complete path to mpirun as shown in the example while running NCCL applications with EFA.
-
Change the params np and N based on the number of instances and GPUs in your cluster.
-
Add the NCCL_DEBUG=INFO flag and make sure that the logs indicate EFA usage as "Selected Provider is EFA".
-
Set the Training Log Location to parse for validation
TRAINING_LOG="testEFA_$(date +"%N").log"
Use the command watch nvidia-smi on any of the member nodes to monitor
GPU usage. The following watch nvidia-smi commands are for a generic CUDA xx.x version and
depend on the Operating System of your instance.
You can run the commands for any available CUDA version in your Amazon EC2 instance by replacing the CUDA version in the script.
-
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}
Your output should look like the following:
# 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
To Validate that the EFA tests returned a valid result, please use the following tests to confirm:
-
Get the instance type using EC2 Instance Metadata:
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) -
Run the Performance Tests
-
Set the Following Parameters
CUDA_VERSION CUDA_RUNTIME_VERSION NCCL_VERSION -
Validate the Results as shown:
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 ${CUDA_VERSION} *****************************" fi -
To access the benchmark data, we can parse the final row of table output from the Multi Node all_reduce test:
benchmark=$(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}"