Instead of processing all 22k HTML files every time, you can implement an incremental data update process where you only process the newly added or modified files.
Implement a mechanism to track which files are new or modified. You could store a timestamp or a hash value for each file (in a metadata store or database) and check this before processing. For example, compare the timestamp of the last processed file with the timestamp of the newly added files.
If you're storing files in Azure Blob Storage, you can use the blob's last modified time to identify new or modified files.
And then you need to modify your processing pipeline in Azure Machine Learning to only include the new or modified files instead of reprocessing all 22k files. You could write a script to filter out already indexed files before sending them for processing.
For the other part, you're correct that occasionally cleaning the index will be necessary, especially if you want to remove obsolete or old data.
Instead of re-creating the entire index, you might be able to perform partial updates (e.g., deleting only obsolete entries). This depends on the specific indexing method you're using.
If your index platform supports it (e.g., Azure Cognitive Search), you could set up incremental updates to only add, update, or delete specific documents based on file changes.
Training time for serverless models can be long depending on the complexity and scale of the data. First thing to do is to review the model complexity. If you're using a custom GPT model or fine-tuning, you may need to try to simplify or optimize the model architecture if possible.
For training on large datasets, you should consider breaking the data into smaller chunks and processing them in parallel if possible. This can be done using a distributed processing setup in Azure.
While you've mentioned the serverless compute option, for large datasets, switching to a dedicated Azure machine learning compute instance can reduce training time by providing more resources.