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kafkaex-lag-exporter/lib/kafkaex_lag_exporter/consumer_offset_fetcher.ex

41 lines
1.2 KiB
Elixir

defmodule KafkaexLagExporter.ConsumerOffsetFetcher do
@moduledoc "Calculate summarized lag for each consumer group"
require Logger
# TODO: change return type
@spec get(KafkaexLagExporter.KafkaWrapper.endpoint()) :: {any(), any()}
def get(endpoint) do
consumer_group_names = KafkaexLagExporter.KafkaUtils.get_consumer_group_names(endpoint)
consumer_lags =
KafkaexLagExporter.KafkaUtils.topic_names_for_consumer_groups(
endpoint,
[],
consumer_group_names
)
|> Enum.map(fn [consumer_group, topics] ->
[consumer_group, get_lag_for_consumer(consumer_group, topics)]
end)
consumer_lag_sum = get_lag_for_consumer_sum(consumer_lags)
%{lags: consumer_lags, sum: consumer_lag_sum}
end
defp get_lag_for_consumer(consumer_group, topics) do
topics
|> Enum.flat_map(fn topic ->
KafkaexLagExporter.KafkaUtils.lag(topic, consumer_group, :client1)
end)
end
defp get_lag_for_consumer_sum(lags_per_consumer_group) do
lags_per_consumer_group
|> Enum.map(fn [topic, lag_per_partition] -> [topic, sum_topic_lag(lag_per_partition, 0)] end)
end
defp sum_topic_lag([], acc), do: acc
defp sum_topic_lag([h | t], acc), do: sum_topic_lag(t, acc + elem(h, 1))
end