44 lines
1.4 KiB
Ruby
44 lines
1.4 KiB
Ruby
# frozen_string_literal: true
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class RemoveOrphanedLabelLinks < ActiveRecord::Migration
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include Gitlab::Database::MigrationHelpers
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DOWNTIME = false
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disable_ddl_transaction!
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class LabelLinks < ActiveRecord::Base
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self.table_name = 'label_links'
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include EachBatch
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def self.orphaned
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where('NOT EXISTS ( SELECT 1 FROM labels WHERE labels.id = label_links.label_id )')
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end
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end
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def up
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# Some of these queries can take up to 10 seconds to run on GitLab.com,
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# which is pretty close to our 15 second statement timeout. To ensure a
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# smooth deployment procedure we disable the statement timeouts for this
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# migration, just in case.
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disable_statement_timeout do
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# On GitLab.com there are over 2,000,000 orphaned label links. On
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# staging, removing 100,000 rows generated a max replication lag of 6.7
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# MB. In total, removing all these rows will only generate about 136 MB
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# of data, so it should be safe to do this.
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LabelLinks.orphaned.each_batch(of: 100_000) do |batch|
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batch.delete_all
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end
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end
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add_concurrent_foreign_key(:label_links, :labels, column: :label_id, on_delete: :cascade)
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end
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def down
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# There is no way to restore orphaned label links.
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if foreign_key_exists?(:label_links, column: :label_id)
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remove_foreign_key(:label_links, column: :label_id)
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end
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end
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end
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