Data Discovery and Tokenization

11. Data Discovery and Tokenization#

The Research and Engineering team at the Kempner Institute is actively developing a testbed to support AI/ML research and development. The testbed is a collection of hardware and software resources that are used to test and validate new AI/ML models, algorithms, and tools. Currently the primary focus of the testbed is easing access and exploration of data, through the tatm python library. Specific details on using tatm can be found in the tatm documentation, but key points regarding Kempner specific usage are detailed below.

11.1. Using tatm on the Kempner AI Cluster#

You should follow the instructions in the tatm documentation to install the tatm library. Once you have installed tatm, you can use it to access data on the Kempner AI cluster. The tatm library provides a simple interface to access data on the cluster, and it is designed to be easy to use. In order to take advantage of the semantic name resolution provided by tatm, you need to be using at least version 0.2.0 of the library and have the the TATM_BASE_DIR environment variable set to /n/holylfs06/LABS/kempner_shared/Everyone/testbed (the path to the root of the data directory on the cluster). Path based data access will still work if you do not have the TATM_BASE_DIR environment variable set.

For a brief overview of loading data using tatm, you can refer to the guide in the documentation here which covers basic use of the get_dataset function.

11.2. Online Data Exploration#

In order to support exploration of data available, we have deployed an online data exploration tool. This tool allows you to search for data available on the cluster, and provides the command to load the data using tatm. You can access the online data exploration tool at https://data.eng.kempnerinstitute.harvard.edu. The username for logging in is kempneruser@kempner.edu. Click the section below to reveal the password.

Click to reveal password

K3mpnerData!

11.3. Using tatm with OLMo#

We have built support for custom PyTorch datasets (including those output by the tatm get_dataset function) into the Kempner fork of OLMo. We’ve also had a PR accepted into the main Ai2 branch of OLMo bringing that support into the mainline codebase which should be available in future releases. In order to use data made available by tatm with OLMo, you will need to utilize that custom dataset support. The following data section of the OLMo config file is an example of how to do this:

data:
  pad_direction: right
  num_workers: 2
  drop_last: true
  pin_memory: true
  prefetch_factor: 1
  persistent_workers: true
  timeout: 0
  custom_dataset:
    name: "tatm.data.get_dataset"
    args:
      metadata: "Red Pajama v1-tokenized_t5-base_arxiv"
      context_length: 2048
    collate_config:
      input_id_field: "token_ids"

The custom_dataset provides OLMo the necessary information to load the dataset. The name section provides the name of the python object or function that will return a Pytorch dataset object (in this case the tatm.data.get_dataset function). The args section specifies the keyword arguments to the function or class constructor in name. For these specfic arguments, the metadata field specifies the semantic name of the dataset to load and can also be used to point to a metadata file on disk or a directory containing a metadata file, and the context_length field specifies the length of the input sequences. The collate_config section specifies how to collate the data into batches. In this case, we are using the custom collator in OLMo which maps output fields in a custom class to expected fields in the OLMo model. The input_id_field specifies the name of the field in the dataset that contains the input IDs. This maps the token_ids field in the dataset to the input_ids field in the OLMo dataset.

Using this config in an environment with OLMo and tatm installed and running OLMo as normal should allow you to load the dataset and train a model using the data.

11.3.1. Known Issues#

  • In tatm version 0.2.1 and prior, we have observed memory issues when using tatm datasets in contexts where multiple copies of the dataset object are created in multiple processes with the torch DistributedSampler and when new processes are created with the spawn method. This issue is now fixed in the current development version of tatm and will be included in all future releases. If you run into this issue, please follow instructions in the tatm documentation to install the latest development branch of tatm.

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