1. 01 Nov, 2015 2 commits
  2. 31 Oct, 2015 3 commits
  3. 30 Oct, 2015 10 commits
    • Dmitriy Zaporozhets's avatar
      Merge branch 'gitlab-workhorse' into 'master' · 73353959
      Dmitriy Zaporozhets authored
      Switch to gitlab-workhorse
      
      This is a little annoying but it is better to change this name then
      to be stuck with a bad name for a long time. Reasons for the name
      change: https://gitlab.com/gitlab-org/gitlab-git-http-server/issues/13
      
      See merge request !1707
      73353959
    • Yorick Peterse's avatar
      Merge branch 'optimize-user-find-by-any-email' into 'master' · a0ba6c6c
      Yorick Peterse authored
      Improve performance of User.find_by_any_email
      
      
      
      See merge request !1698
      a0ba6c6c
    • Takuya Noguchi's avatar
      Fix deadlink in docs for ci/examples · 31ea88cf
      Takuya Noguchi authored
      31ea88cf
    • Dmitriy Zaporozhets's avatar
      Merge branch 'minor-ui-fixes' into 'master' · 49a73b6e
      Dmitriy Zaporozhets authored
      Minor ui fixes
      
      
      
      See merge request !1704
      49a73b6e
    • Yorick Peterse's avatar
      Adjusted ips/sec for find_by_any_email benchmarks · 6d3068be
      Yorick Peterse authored
      While these benchmarks run at roughly 1500 i/sec setting the threshold
      to 1000 leaves some room for deviations (e.g. due to different DB
      setups).
      6d3068be
    • Yorick Peterse's avatar
      Use a subquery with IDs only for find_by_any_email · a9df7147
      Yorick Peterse authored
      This further improves performance of User.find_by_any_email and is
      roughly twice as fast as the previous UNION setup.
      
      Thanks again to @dlemstra for suggesting this.
      a9df7147
    • Yorick Peterse's avatar
      Fixed UNION syntax for MySQL · bba46623
      Yorick Peterse authored
      MySQL doesn't support the previous syntax.
      bba46623
    • Yorick Peterse's avatar
      Use a UNION for User.find_by_any_email · 24c8f422
      Yorick Peterse authored
      This is significantly faster than using a sub-query, at least when run
      on the GitLab.com production database. The benchmarks are a lot slower
      now with these changes, most likely due to PostgreSQL choosing a
      different (and less efficient) plan based on the amount of data present
      in the test database.
      
      Thanks to @dlemstra for suggesting the use of a UNION.
      24c8f422
    • Yorick Peterse's avatar
      0a6aaf25
    • Yorick Peterse's avatar
      Improve performance of User.find_by_any_email · 49c081b9
      Yorick Peterse authored
      This query used to rely on a JOIN, effectively producing the following
      SQL:
      
          SELECT users.*
          FROM users
          LEFT OUTER JOIN emails ON emails.user_id = users.id
          WHERE (users.email = X OR emails.email = X)
          LIMIT 1;
      
      The use of a JOIN means having to scan over all Emails and users, join
      them together and then filter out the rows that don't match the criteria
      (though this step may be taken into account already when joining).
      
      In the new setup this query instead uses a sub-query, producing the
      following SQL:
      
          SELECT *
          FROM users
          WHERE id IN (select user_id FROM emails WHERE email = X)
          OR email = X
          LIMIT 1;
      
      This query has the benefit that it:
      
      1. Doesn't have to JOIN any rows
      2. Only has to operate on a relatively small set of rows from the
         "emails" table.
      
      Since most users will only have a handful of Emails associated
      (certainly not hundreds or even thousands) the size of the set returned
      by the sub-query is small enough that it should not become problematic.
      
      Performance of the old versus new version can be measured using the
      following benchmark:
      
          # Save this in ./bench.rb
          require 'benchmark/ips'
      
          email = 'yorick@gitlab.com'
      
          def User.find_by_any_email_old(email)
            user_table = arel_table
            email_table = Email.arel_table
      
            query = user_table.
              project(user_table[Arel.star]).
              join(email_table, Arel::Nodes::OuterJoin).
              on(user_table[:id].eq(email_table[:user_id])).
              where(user_table[:email].eq(email).or(email_table[:email].eq(email)))
      
            find_by_sql(query.to_sql).first
          end
      
          Benchmark.ips do |bench|
            bench.report 'original' do
              User.find_by_any_email_old(email)
            end
      
            bench.report 'optimized' do
              User.find_by_any_email(email)
            end
      
            bench.compare!
          end
      
      Running this locally using "bundle exec rails r bench.rb" produces the
      following output:
      
          Calculating -------------------------------------
                      original     1.000  i/100ms
                     optimized    93.000  i/100ms
          -------------------------------------------------
                      original     11.103  (± 0.0%) i/s -     56.000
                     optimized    948.713  (± 5.3%) i/s -      4.743k
      
          Comparison:
                     optimized:      948.7 i/s
                      original:       11.1 i/s - 85.45x slower
      
      In other words, the new setup is 85x faster compared to the old setup,
      at least when running this benchmark locally.
      
      For GitLab.com these improvements result in User.find_by_any_email
      taking only ~170 ms to run, instead of around 800 ms. While this is
      "only" an improvement of about 4.5 times (instead of 85x) it's still
      significantly better than before.
      
      Fixes #3242
      49c081b9
  4. 29 Oct, 2015 14 commits
  5. 28 Oct, 2015 11 commits