spacy_ray_collective

This github is inherited from spacy-ray (dev branch).

It trains model using the new collective calls available in current ray-1.2-dev, replacing the original get(), set() usage in spacy-ray.

The runtime comparison for 1000 update using spacy pipeline = ["tok2vec", "ner"] is showed below:

| Comparison    | spacy-ray     | spacy-ray-nccl |  ratio  |  
| ------------- | ------------- | -------------- | ------- | 
| 1 worker      | 137.5 ± 2.1   | 116.7 ± 2.51   |  1.18x  |
| 2 workers     | 354.1 ± 16.8  | 171.1 ± 1.11   |  2.07x  |  
| 4 workers     | 523.9 ± 10.4  | 179.6 ± 2.91   |  2.92x  |  
| 8 workers     | 710.1 ± 3.0   | 205.8 ± 1.20   |  3.45x  | 
| 16 workers    | 1296.1 ± 42.1 | 248.3 ± 3.63   |  5.22x  | 

Mean and standard deviation are obtained by three trials (unit: second). Each worker is on a different node.

Runtime comparison:

The ideal plot should be a horizontal line.

Speedup comparison:

The trivial speedup is a horizontal line y = 1.

Scalability comparison:

The ideal scalability is the line y = x.

To install the necessary module:

1. conda create -n spacy-ray python=3.7.3
   
2. conda activate spacy-ray
   
3. pip install spacy-nightly[cuda]
     - This will take some time, if observe a build error in cupy, try: pip install cupy-cuda[version]
     e.g. for cudatoolkit 11.0: pip install cupy-cuda110
   
4. pip install spacy-ray
     - run python -m spacy ray --help to check whether install correctly
   
5. The collective calls are only available in current ray github. Instead we use the latest ray-1.1 in pip to test runtime.
     - get collective code: git clone https://github.com/ray-project/ray
     - access the installed code of ray 1.1: cd [path-to-packages]/ray
     If using conda, typically the path would be [path-to-conda]/anaconda3/envs/spacy-ray/lib/python3.7/site-packages/
     - copy the code over: cp -r [path-to-github-ray]ray/python/ray/util/collective ./ray/util
     - add to "init" file: vim ./ray/util/__init__.py -> from ray.util import ray, append "collective" to the "all" dict.
   
6. The last step is to replace the installed spacy-ray using this github.
     - git clone https://github.com/MccRee177/spacy_ray_nccl
     - mv [path-to-github-spacy-ray-nccl] [path-to-packages]
     - make a copy of the original spacy_ray in case you would like to recover the comparison: <br \ > &nbsp: mv [path-to-packages]/spacy_ray [path-to-packages]/spacy_ray_original
     - mv [path-to-packages]/spacy_ray_nccl [path-to-packages]/spacy_ray
   

To run examples:

1. git clone https://github.com/MccRee177/spacy_ray_example
   
2. cd spacy_ray_example/tmp/experiments/en-ent-wiki
   
3. Setup the ray cluster in different machine. The code will detect the available ray cluster and attach.
   
4. Modify the config (for training hyperparameter) and project.yml (for number of workers)
   
5. Download and process necessary files: (reference: https://github.com/explosion/spacy-ray/tree/develop/tmp/experiments/en-ent-wiki)
     - spacy project assets
     - spacy project run corpus
   
6. spacy project run ray-train
   

Evaluation note:

The github turns off the score evaluation for comparison. This is because evaluation takes a long time, and we only want to measure the speedup during training.

To turn on: comment the hard-coded socres in train() function at worker.py, change the if condition from if self.rank ==0 to if True, and uncomment socres = self.evaluate()

Implementation note:

The original spacy-ray uses sharded parameter server and update the model parameter in each worker asynchronizely. The current implementation uses all_reduce strategy, which performs similarly to a sharded parameter server. It has a whole copy of the model parameter in each worker. For update, it uses collective.allreduce() to synchronize gradients.

Ray cluster setup node:

A template for setting up a 16 machine ray cluster:

  1 #!/bin/bash 
  2 
  3 MY_IPADDR=$(hostname -i) 
  4 echo $MY_IPADDR 
  5 
  6 ray stop --force 
  7 sleep 3 
  8 ray start --head --port=6380 --object-manager-port=8076  --object-store-memory=32359738368 
  9 sleep 2 
 10 
 11 for i in {1..15} 
 12 do 
 13   echo "=> node $i" 
 14   ssh -o StrictHostKeyChecking=no h$i.ray-dev-16.BigLearning "cd spacy_ray_example/tmp/experiments/en-ent-wiki;  source ~/anaconda3/bin/activate; conda activate spacy-ray; ray stop --force; ray start --address='$MY_IPADDR:6380' --object-manager-port=8076 --object-store-memory=32359738368"; 
 15 done 
 16 wait