<commit_before>[[breaking_60_cat_changes]]
=== Cat API changes

==== Unbounded queue size in cat thread pool

Previously if a queue size backing a thread pool was unbounded, the cat thread pool API would output an empty string in
the queue_size column. This has been changed to now output -1 so that the output is always present and always numeric.
Note that if you're running in a mixed version cluster with 5.0.x and 5.1.y nodes, you will see different responses
from the cat thread pool API depending on the version of the node that your request hits.<commit_msg>Remove 5.x references from cat API migration doc<commit_after>[[breaking_60_cat_changes]]
=== Cat API changes

==== Unbounded queue size in cat thread pool

Previously if a queue size backing a thread pool was unbounded, the cat thread pool API would output an empty string in
the queue_size column. This has been changed to now output -1 so that the output is always present and always numeric.
{'fraction_non_alphanumeric': 0.045785639958376693, 'fraction_numerical': 0.011446409989594173, 'mean_word_length': 4.625730994152047, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 3, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '247993', 'n_tokens_mistral': 245, 'n_tokens_neox': 228, 'n_words': 151}