Make VimPerformanceTagValue no longer backed by a DB table

Follow up to ManageIQ#16692
This change removes all the code involved with reading vim_performance_tag_values
data from the table. It no longer necessary because it all generated on demand.

app/models/metric/common.rb

@@ -3,7 +3,6 @@ module Metric::Common
   included do
     belongs_to  :resource, :polymorphic => true
     belongs_to  :time_profile
-    has_many    :vim_performance_tag_values, :as => :metric, :dependent => :destroy
 
     belongs_to  :parent_host,        :class_name => "Host"
     belongs_to  :parent_ems_cluster, :class_name => "EmsCluster"

app/models/metric/purging.rb

@@ -61,29 +61,6 @@ def self.purge_count(older_than, interval)
     purge_scope(older_than, interval).count
   end
 
-  # Used for MetricRollup (not Metric)
-  # A list of ids (not a scope) is brought in and associated vimPerformanceTagValue records are deleted
-  #
-  # TODO: Would be more efficient to just use the full scope here (not id list)
-  #   - we would then just use the standard purge_in_batches
-  #   - remove the to_a from purge_in_batches
-  #   - possibly use the standard purge_in_batches
-  #   - change the metrics rollups to use truncate instead
-  def self.purge_associated_records(metric_type, ids)
-    # Since VimPerformanceTagValues are 6 * number of tags per performance
-    # record, we need to batch in smaller trips.
-    count_tag_values = 0
-    _log.info("Purging associated tag values.")
-    ids.each_slice(50) do |vp_ids|
-      tv_count, = Benchmark.realtime_block(:purge_vim_performance_tag_values) do
-        VimPerformanceTagValue.where(:metric_id => vp_ids, :metric_type => metric_type).delete_all
-      end
-      count_tag_values += tv_count
-    end
-    _log.info("Purged #{count_tag_values} associated tag values.")
-    count_tag_values
-  end
-
   def self.purge_daily(older_than, window = nil, total_limit = nil, &block)
     purge_by_date(older_than, "daily", window, total_limit, &block)
   end
@@ -128,15 +105,14 @@ def self.purge_by_date(older_than, interval, window = nil, total_limit = nil, &b
     scope = purge_scope(older_than, interval)
     window ||= purge_window_size
     _log.info("Purging #{total_limit || "all"} #{interval} metrics older than [#{older_than}]...")
-    total, total_tag_values, timings = purge_in_batches(scope, window, 0, total_limit, &block)
+    total, timings = purge_in_batches(scope, window, 0, total_limit, &block)
     _log.info("Purging #{total_limit || "all"} #{interval} metrics older than [#{older_than}]...Complete - " +
-              "Deleted #{total} records and #{total_tag_values} associated tag values - Timings: #{timings.inspect}")
+              "Deleted #{total} records - Timings: #{timings.inspect}")
 
     total
   end
 
   def self.purge_in_batches(scope, window, total = 0, total_limit = nil)
-    total_tag_values = 0
     query = scope.select(:id).limit(window)
 
     _, timings = Benchmark.realtime_block(:total_time) do
@@ -164,16 +140,11 @@ def self.purge_in_batches(scope, window, total = 0, total_limit = nil)
         break if count == 0
         total += count
 
-        if scope.klass == MetricRollup
-          count_tag_values = purge_associated_records(scope.name, batch_ids)
-          total_tag_values += count_tag_values
-        end
-
         yield(count, total) if block_given?
         break if count < window || (total_limit && (total_limit <= total))
       end
     end
 
-    [total, total_tag_values, timings]
+    [total, timings]
   end
 end

app/models/vim_performance_tag.rb

@@ -57,7 +57,6 @@ def self.group_by_tags(recs, options)
   def self.build_tag_value_recs(rec, options)
     tvrecs = VimPerformanceTagValue.build_for_association(rec,
                                                           options[:cat_model].pluralize.underscore,
-                                                          :save     => false,
                                                           :category => options[:category])
     tvrecs = tvrecs.select { |r| r.category == options[:category] }
 

app/models/vim_performance_tag_value.rb

@@ -1,7 +1,5 @@
-class VimPerformanceTagValue < ApplicationRecord
-  belongs_to :metric, :polymorphic => true
-
-  serialize :assoc_ids
+class VimPerformanceTagValue
+  attr_accessor :tag_name, :association_type, :category, :column_name, :value, :assoc_ids
 
   TAG_SEP = "|"
   TAG_COLS = {
@@ -42,13 +40,17 @@ class VimPerformanceTagValue < ApplicationRecord
     "Service"             => [:vms]
   }
 
-  def self.build_from_performance_record(parent_perf, options = {:save => true})
+  def initialize(options = {})
+    options.each { |k, v| public_send("#{k}=", v) }
+  end
+
+  def self.build_from_performance_record(parent_perf, options = {})
     RESOURCE_TYPE_TO_ASSOCIATIONS[parent_perf.resource_type].collect { |assoc| build_for_association(parent_perf, assoc, options) }.flatten
   end
 
   cache_with_timeout(:eligible_categories, 5.minutes) { Classification.category_names_for_perf_by_tag }
 
-  def self.build_for_association(parent_perf, assoc, options = {:save => true})
+  def self.build_for_association(parent_perf, assoc, options = {})
     eligible_cats = eligible_categories
     return [] if eligible_cats.empty?
 
@@ -116,19 +118,8 @@ def self.build_for_association(parent_perf, assoc, options = {:save => true})
       }
       attr = col == 'assoc_ids' ? :assoc_ids : :value
       new_rec[attr] = result[key]
-      if options[:save]
-        parent_perf_tag_value_recs = parent_perf.vim_performance_tag_values.inject({}) do |h, tv|
-          h.store_path(tv.association_type, tv.category, tv.tag_name, tv.column_name, tv)
-          h
-        end
 
-        tag_value_rec   = parent_perf_tag_value_recs.fetch_path(association_type, category, tag_name, col)
-        tag_value_rec ||= parent_perf_tag_value_recs.store_path(association_type, category, tag_name, col, parent_perf.vim_performance_tag_values.build)
-        tag_value_rec.update_attributes(new_rec)
-      else
-        tag_value_rec = new(new_rec)
-      end
-      a << tag_value_rec
+      a << new(new_rec)
     end
   end
 

lib/active_metrics/connection_adapters/miq_postgres_adapter.rb

@@ -52,7 +52,6 @@ def write_rows(resources, interval_name, start_time, end_time, data)
         samples_inventory_collection = nil
 
         if interval_name == 'hourly'
-          # TODO(lsmola) pff, it needs AR objects, quite ineffective to batch here
           _log.info("#{log_header} Adding missing timestamp intervals...")
           resources.each do |resource|
             Benchmark.realtime_block(:add_missing_intervals) { Metric::Processing.add_missing_intervals(resource, "hourly", start_time, end_time) }