gitlab-org--gitlab-foss/app/models/push_event.rb

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Migrate events into a new format This commit migrates events data in such a way that push events are stored much more efficiently. This is done by creating a shadow table called "events_for_migration", and a table called "push_event_payloads" which is used for storing push data of push events. The background migration in this commit will copy events from the "events" table into the "events_for_migration" table, push events in will also have a row created in "push_event_payloads". This approach allows us to reclaim space in the next release by simply swapping the "events" and "events_for_migration" tables, then dropping the old events (now "events_for_migration") table. The new table structure is also optimised for storage space, and does not include the unused "title" column nor the "data" column (since this data is moved to "push_event_payloads"). == Newly Created Events Newly created events are inserted into both "events" and "events_for_migration", both using the exact same primary key value. The table "push_event_payloads" in turn has a foreign key to the _shadow_ table. This removes the need for recreating and validating the foreign key after swapping the tables. Since the shadow table also has a foreign key to "projects.id" we also don't have to worry about orphaned rows. This approach however does require some additional storage as we're duplicating a portion of the events data for at least 1 release. The exact amount is hard to estimate, but for GitLab.com this is expected to be between 10 and 20 GB at most. The background migration in this commit deliberately does _not_ update the "events" table as doing so would put a lot of pressure on PostgreSQL's auto vacuuming system. == Supporting Both Old And New Events Application code has also been adjusted to support push events using both the old and new data formats. This is done by creating a PushEvent class which extends the regular Event class. Using Rails' Single Table Inheritance system we can ensure the right class is used for the right data, which in this case is based on the value of `events.action`. To support displaying old and new data at the same time the PushEvent class re-defines a few methods of the Event class, falling back to their original implementations for push events in the old format. Once all existing events have been migrated the various push event related methods can be removed from the Event model, and the calls to `super` can be removed from the methods in the PushEvent model. The UI and event atom feed have also been slightly changed to better handle this new setup, fortunately only a few changes were necessary to make this work. == API Changes The API only displays push data of events in the new format. Supporting both formats in the API is a bit more difficult compared to the UI. Since the old push data was not really well documented (apart from one example that used an incorrect "action" nmae) I decided that supporting both was not worth the effort, especially since events will be migrated in a few days _and_ new events are created in the correct format.
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class PushEvent < Event
# This validation exists so we can't accidentally use PushEvent with a
# different "action" value.
validate :validate_push_action
# Authors are required as they're used to display who pushed data.
#
# We're just validating the presence of the ID here as foreign key constraints
# should ensure the ID points to a valid user.
validates :author_id, presence: true
# The project is required to build links to commits, commit ranges, etc.
#
# We're just validating the presence of the ID here as foreign key constraints
# should ensure the ID points to a valid project.
validates :project_id, presence: true
# These fields are also not used for push events, thus storing them would be a
# waste.
validates :target_id, absence: true
validates :target_type, absence: true
delegate :branch?, to: :push_event_payload
delegate :tag?, to: :push_event_payload
delegate :commit_from, to: :push_event_payload
delegate :commit_to, to: :push_event_payload
delegate :ref_type, to: :push_event_payload
delegate :commit_title, to: :push_event_payload
delegate :commit_count, to: :push_event_payload
alias_method :commits_count, :commit_count
Rework how recent push events are retrieved Whenever you push to a branch GitLab will show a button to create a merge request (should one not exist already). The underlying code to display this data was quite inefficient. For example, it involved multiple slow queries just to figure out what the most recent push event was. This commit changes the way this data is retrieved so it's much faster. This is achieved by caching the ID of the last push event on every push, which is then retrieved when loading certain pages. Database queries are only executed if necessary and the cached data is removed automatically once a merge request has been created, or 2 hours after being stored. A trade-off of this approach is that we _only_ track the last event. Previously if you were to push to branch A and B then create a merge request for branch B we'd still show the widget for branch A. As of this commit this is no longer the case, instead we will only show the widget for the branch you pushed to most recently. Once a merge request exists the widget is no longer displayed. Alternative solutions are either too complex and/or too slow, hence the decision was made to settle for this trade-off. Performance Impact ------------------ In the best case scenario (= a user didn't push anything for more than 2 hours) we perform a single Redis GET per page. Should there be cached data we will run a single (and lightweight) SQL query to get the event data from the database. If a merge request already exists we will run an additional DEL to remove the cache key. The difference in response timings can vary a bit per project. On GitLab.com the 99th percentile of time spent in User#recent_push hovers between 100 milliseconds and 1 second, while the mean hovers around 50 milliseconds. With the changes in this MR the expected time spent in User#recent_push is expected to be reduced down to just a few milliseconds. Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/35990
2017-09-01 06:50:14 -04:00
# Returns events of pushes that either pushed to an existing ref or created a
# new one.
def self.created_or_pushed
actions = [
PushEventPayload.actions[:pushed],
PushEventPayload.actions[:created]
]
joins(:push_event_payload)
.where(push_event_payloads: { action: actions })
end
# Returns events of pushes to a branch.
def self.branch_events
ref_type = PushEventPayload.ref_types[:branch]
joins(:push_event_payload)
.where(push_event_payloads: { ref_type: ref_type })
end
# Returns PushEvent instances for which no merge requests have been created.
def self.without_existing_merge_requests
existing_mrs = MergeRequest.except(:order)
.select(1)
.where('merge_requests.source_project_id = events.project_id')
.where('merge_requests.source_branch = push_event_payloads.ref')
# For reasons unknown the use of #eager_load will result in the
# "push_event_payload" association not being set. Because of this we're
# using "joins" here, which does mean an additional query needs to be
# executed in order to retrieve the "push_event_association" when the
# returned PushEvent is used.
joins(:push_event_payload)
.where('NOT EXISTS (?)', existing_mrs)
.created_or_pushed
.branch_events
end
Migrate events into a new format This commit migrates events data in such a way that push events are stored much more efficiently. This is done by creating a shadow table called "events_for_migration", and a table called "push_event_payloads" which is used for storing push data of push events. The background migration in this commit will copy events from the "events" table into the "events_for_migration" table, push events in will also have a row created in "push_event_payloads". This approach allows us to reclaim space in the next release by simply swapping the "events" and "events_for_migration" tables, then dropping the old events (now "events_for_migration") table. The new table structure is also optimised for storage space, and does not include the unused "title" column nor the "data" column (since this data is moved to "push_event_payloads"). == Newly Created Events Newly created events are inserted into both "events" and "events_for_migration", both using the exact same primary key value. The table "push_event_payloads" in turn has a foreign key to the _shadow_ table. This removes the need for recreating and validating the foreign key after swapping the tables. Since the shadow table also has a foreign key to "projects.id" we also don't have to worry about orphaned rows. This approach however does require some additional storage as we're duplicating a portion of the events data for at least 1 release. The exact amount is hard to estimate, but for GitLab.com this is expected to be between 10 and 20 GB at most. The background migration in this commit deliberately does _not_ update the "events" table as doing so would put a lot of pressure on PostgreSQL's auto vacuuming system. == Supporting Both Old And New Events Application code has also been adjusted to support push events using both the old and new data formats. This is done by creating a PushEvent class which extends the regular Event class. Using Rails' Single Table Inheritance system we can ensure the right class is used for the right data, which in this case is based on the value of `events.action`. To support displaying old and new data at the same time the PushEvent class re-defines a few methods of the Event class, falling back to their original implementations for push events in the old format. Once all existing events have been migrated the various push event related methods can be removed from the Event model, and the calls to `super` can be removed from the methods in the PushEvent model. The UI and event atom feed have also been slightly changed to better handle this new setup, fortunately only a few changes were necessary to make this work. == API Changes The API only displays push data of events in the new format. Supporting both formats in the API is a bit more difficult compared to the UI. Since the old push data was not really well documented (apart from one example that used an incorrect "action" nmae) I decided that supporting both was not worth the effort, especially since events will be migrated in a few days _and_ new events are created in the correct format.
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def self.sti_name
PUSHED
end
def push?
true
end
def push_with_commits?
!!(commit_from && commit_to)
end
def valid_push?
push_event_payload.ref.present?
end
def new_ref?
push_event_payload.created?
end
def rm_ref?
push_event_payload.removed?
end
def md_ref?
!(rm_ref? || new_ref?)
Migrate events into a new format This commit migrates events data in such a way that push events are stored much more efficiently. This is done by creating a shadow table called "events_for_migration", and a table called "push_event_payloads" which is used for storing push data of push events. The background migration in this commit will copy events from the "events" table into the "events_for_migration" table, push events in will also have a row created in "push_event_payloads". This approach allows us to reclaim space in the next release by simply swapping the "events" and "events_for_migration" tables, then dropping the old events (now "events_for_migration") table. The new table structure is also optimised for storage space, and does not include the unused "title" column nor the "data" column (since this data is moved to "push_event_payloads"). == Newly Created Events Newly created events are inserted into both "events" and "events_for_migration", both using the exact same primary key value. The table "push_event_payloads" in turn has a foreign key to the _shadow_ table. This removes the need for recreating and validating the foreign key after swapping the tables. Since the shadow table also has a foreign key to "projects.id" we also don't have to worry about orphaned rows. This approach however does require some additional storage as we're duplicating a portion of the events data for at least 1 release. The exact amount is hard to estimate, but for GitLab.com this is expected to be between 10 and 20 GB at most. The background migration in this commit deliberately does _not_ update the "events" table as doing so would put a lot of pressure on PostgreSQL's auto vacuuming system. == Supporting Both Old And New Events Application code has also been adjusted to support push events using both the old and new data formats. This is done by creating a PushEvent class which extends the regular Event class. Using Rails' Single Table Inheritance system we can ensure the right class is used for the right data, which in this case is based on the value of `events.action`. To support displaying old and new data at the same time the PushEvent class re-defines a few methods of the Event class, falling back to their original implementations for push events in the old format. Once all existing events have been migrated the various push event related methods can be removed from the Event model, and the calls to `super` can be removed from the methods in the PushEvent model. The UI and event atom feed have also been slightly changed to better handle this new setup, fortunately only a few changes were necessary to make this work. == API Changes The API only displays push data of events in the new format. Supporting both formats in the API is a bit more difficult compared to the UI. Since the old push data was not really well documented (apart from one example that used an incorrect "action" nmae) I decided that supporting both was not worth the effort, especially since events will be migrated in a few days _and_ new events are created in the correct format.
2017-07-10 11:43:57 -04:00
end
def ref_name
push_event_payload.ref
end
alias_method :branch_name, :ref_name
alias_method :tag_name, :ref_name
Migrate events into a new format This commit migrates events data in such a way that push events are stored much more efficiently. This is done by creating a shadow table called "events_for_migration", and a table called "push_event_payloads" which is used for storing push data of push events. The background migration in this commit will copy events from the "events" table into the "events_for_migration" table, push events in will also have a row created in "push_event_payloads". This approach allows us to reclaim space in the next release by simply swapping the "events" and "events_for_migration" tables, then dropping the old events (now "events_for_migration") table. The new table structure is also optimised for storage space, and does not include the unused "title" column nor the "data" column (since this data is moved to "push_event_payloads"). == Newly Created Events Newly created events are inserted into both "events" and "events_for_migration", both using the exact same primary key value. The table "push_event_payloads" in turn has a foreign key to the _shadow_ table. This removes the need for recreating and validating the foreign key after swapping the tables. Since the shadow table also has a foreign key to "projects.id" we also don't have to worry about orphaned rows. This approach however does require some additional storage as we're duplicating a portion of the events data for at least 1 release. The exact amount is hard to estimate, but for GitLab.com this is expected to be between 10 and 20 GB at most. The background migration in this commit deliberately does _not_ update the "events" table as doing so would put a lot of pressure on PostgreSQL's auto vacuuming system. == Supporting Both Old And New Events Application code has also been adjusted to support push events using both the old and new data formats. This is done by creating a PushEvent class which extends the regular Event class. Using Rails' Single Table Inheritance system we can ensure the right class is used for the right data, which in this case is based on the value of `events.action`. To support displaying old and new data at the same time the PushEvent class re-defines a few methods of the Event class, falling back to their original implementations for push events in the old format. Once all existing events have been migrated the various push event related methods can be removed from the Event model, and the calls to `super` can be removed from the methods in the PushEvent model. The UI and event atom feed have also been slightly changed to better handle this new setup, fortunately only a few changes were necessary to make this work. == API Changes The API only displays push data of events in the new format. Supporting both formats in the API is a bit more difficult compared to the UI. Since the old push data was not really well documented (apart from one example that used an incorrect "action" nmae) I decided that supporting both was not worth the effort, especially since events will be migrated in a few days _and_ new events are created in the correct format.
2017-07-10 11:43:57 -04:00
def commit_id
commit_to || commit_from
end
def last_push_to_non_root?
branch? && project.default_branch != branch_name
Migrate events into a new format This commit migrates events data in such a way that push events are stored much more efficiently. This is done by creating a shadow table called "events_for_migration", and a table called "push_event_payloads" which is used for storing push data of push events. The background migration in this commit will copy events from the "events" table into the "events_for_migration" table, push events in will also have a row created in "push_event_payloads". This approach allows us to reclaim space in the next release by simply swapping the "events" and "events_for_migration" tables, then dropping the old events (now "events_for_migration") table. The new table structure is also optimised for storage space, and does not include the unused "title" column nor the "data" column (since this data is moved to "push_event_payloads"). == Newly Created Events Newly created events are inserted into both "events" and "events_for_migration", both using the exact same primary key value. The table "push_event_payloads" in turn has a foreign key to the _shadow_ table. This removes the need for recreating and validating the foreign key after swapping the tables. Since the shadow table also has a foreign key to "projects.id" we also don't have to worry about orphaned rows. This approach however does require some additional storage as we're duplicating a portion of the events data for at least 1 release. The exact amount is hard to estimate, but for GitLab.com this is expected to be between 10 and 20 GB at most. The background migration in this commit deliberately does _not_ update the "events" table as doing so would put a lot of pressure on PostgreSQL's auto vacuuming system. == Supporting Both Old And New Events Application code has also been adjusted to support push events using both the old and new data formats. This is done by creating a PushEvent class which extends the regular Event class. Using Rails' Single Table Inheritance system we can ensure the right class is used for the right data, which in this case is based on the value of `events.action`. To support displaying old and new data at the same time the PushEvent class re-defines a few methods of the Event class, falling back to their original implementations for push events in the old format. Once all existing events have been migrated the various push event related methods can be removed from the Event model, and the calls to `super` can be removed from the methods in the PushEvent model. The UI and event atom feed have also been slightly changed to better handle this new setup, fortunately only a few changes were necessary to make this work. == API Changes The API only displays push data of events in the new format. Supporting both formats in the API is a bit more difficult compared to the UI. Since the old push data was not really well documented (apart from one example that used an incorrect "action" nmae) I decided that supporting both was not worth the effort, especially since events will be migrated in a few days _and_ new events are created in the correct format.
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end
def validate_push_action
return if action == PUSHED
errors.add(:action, "the action #{action.inspect} is not valid")
end
end