30 lines
1 KiB
Ruby
30 lines
1 KiB
Ruby
class ScheduleMergeRequestLatestMergeRequestDiffIdMigrations < ActiveRecord::Migration
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include Gitlab::Database::MigrationHelpers
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DOWNTIME = false
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BATCH_SIZE = 50_000
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MIGRATION = 'PopulateMergeRequestsLatestMergeRequestDiffId'
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disable_ddl_transaction!
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class MergeRequest < ActiveRecord::Base
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self.table_name = 'merge_requests'
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include ::EachBatch
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end
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# On GitLab.com, we saw that we generated about 500,000 dead tuples over 5 minutes.
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# To keep replication lag from ballooning, we'll aim for 50,000 updates over 5 minutes.
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#
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# Assuming that there are 5 million rows affected (which is more than on
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# GitLab.com), and that each batch of 50,000 rows takes up to 5 minutes, then
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# we can migrate all the rows in 8.5 hours.
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def up
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MergeRequest.where(latest_merge_request_diff_id: nil).each_batch(of: BATCH_SIZE) do |relation, index|
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range = relation.pluck('MIN(id)', 'MAX(id)').first
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BackgroundMigrationWorker.perform_in(index * 5.minutes, MIGRATION, range)
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end
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end
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end
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