Module: Datadog::Contrib::Elasticsearch::Quantize

Defined in:
lib/ddtrace/contrib/elasticsearch/quantize.rb

Overview

Quantize contains ES-specific resource quantization tools.

Constant Summary collapse

PLACEHOLDER = 
'?'.freeze
ID_PLACEHOLDER = 
'\1?'.freeze
EXCLUDE_KEYS = 
[].freeze
SHOW_KEYS = 
[:_index, :_type, :_id].freeze
DEFAULT_OPTIONS = 
{
  exclude: EXCLUDE_KEYS,
  show: SHOW_KEYS,
  placeholder: PLACEHOLDER
}.freeze

Class Method Summary collapse

Class Method Details

.format_body(body, options = {}) ⇒ Object 



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# File 'lib/ddtrace/contrib/elasticsearch/quantize.rb', line 23

def format_body(body, options = {})
  format_body!(body, options)
rescue StandardError
  options[:placeholder] || PLACEHOLDER
end

.format_body!(body, options = {}) ⇒ Object 



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# File 'lib/ddtrace/contrib/elasticsearch/quantize.rb', line 29

def format_body!(body, options = {})
  options = merge_options(DEFAULT_OPTIONS, options)

  # Determine if bulk query or not, based on content
  statements = body.end_with?("\n") ? body.split("\n") : [body]

  # Parse each statement and quantize them.
  statements.collect do |string|
    reserialize_json(string, options[:placeholder]) do |obj|
      Datadog::Quantization::Hash.format(obj, options)
    end
  end.join("\n")
end

.format_url(url) ⇒ Object 



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# File 'lib/ddtrace/contrib/elasticsearch/quantize.rb', line 18

def format_url(url)
  sanitize_fragment_with_id(url)
    .gsub(/(?:[\d]+)/, PLACEHOLDER)
end

.merge_options(original, additional) ⇒ Object 



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# File 'lib/ddtrace/contrib/elasticsearch/quantize.rb', line 43

def merge_options(original, additional)
  {}.tap do |options|
    # Show
    # If either is :all, value becomes :all
    options[:show] = if original[:show] == :all || additional[:show] == :all
                       :all
                     else
                       (original[:show] || []).dup.concat(additional[:show] || []).uniq
                     end

    # Exclude
    options[:exclude] = (original[:exclude] || []).dup.concat(additional[:exclude] || []).uniq
  end
end

.reserialize_json(string, fail_value = PLACEHOLDER) ⇒ Object

Parses a JSON object from a string, passes its value to the block provided, and dumps its result back to JSON. If JSON parsing fails, it prints fail_value.



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# File 'lib/ddtrace/contrib/elasticsearch/quantize.rb', line 61

def reserialize_json(string, fail_value = PLACEHOLDER)
  return string unless block_given?
  begin
    JSON.dump(yield(JSON.parse(string)))
  rescue JSON::ParserError
    # If it can't parse/dump, don't raise an error.
    fail_value
  end
end

.sanitize_fragment_with_id(url) ⇒ Object

Sanitizes URL fragment by changing it to ? whenever a number is detected This is meant as simple heuristic that attempts to detect if particular fragment represents document Id. This is meant to reduce the cardinality in most frequent cases.



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# File 'lib/ddtrace/contrib/elasticsearch/quantize.rb', line 74

def sanitize_fragment_with_id(url)
  url.gsub(%r{^(/?[^/]*/[^/]*/)(?:[^\?/\d]*[\d]+[^\?/]*)}, ID_PLACEHOLDER)
end