Commit 0395c471 authored by Yorick Peterse's avatar Yorick Peterse

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.
parent afd6e517
......@@ -48,6 +48,7 @@ class Event < ActiveRecord::Base
belongs_to :author, class_name: "User"
belongs_to :project
belongs_to :target, polymorphic: true # rubocop:disable Cop/PolymorphicAssociations
has_one :push_event_payload, foreign_key: :event_id
# For Hash only
serialize :data # rubocop:disable Cop/ActiveRecordSerialize
......@@ -55,6 +56,7 @@ class Event < ActiveRecord::Base
# Callbacks
after_create :reset_project_activity
after_create :set_last_repository_updated_at, if: :push?
after_create :replicate_event_for_push_events_migration
# Scopes
scope :recent, -> { reorder(id: :desc) }
......@@ -64,10 +66,36 @@ class Event < ActiveRecord::Base
where(project_id: projects.pluck(:id)).recent
end
scope :with_associations, -> { includes(:author, :project, project: :namespace).preload(:target) }
scope :with_associations, -> do
# We're using preload for "push_event_payload" as otherwise the association
# is not always available (depending on the query being built).
includes(:author, :project, project: :namespace)
.preload(:target, :push_event_payload)
end
scope :for_milestone_id, ->(milestone_id) { where(target_type: "Milestone", target_id: milestone_id) }
self.inheritance_column = 'action'
class << self
def find_sti_class(action)
if action.to_i == PUSHED
PushEvent
else
Event
end
end
def subclass_from_attributes(attrs)
# Without this Rails will keep calling this method on the returned class,
# resulting in an infinite loop.
return unless self == Event
action = attrs.with_indifferent_access[inheritance_column].to_i
PushEvent if action == PUSHED
end
# Update Gitlab::ContributionsCalendar#activity_dates if this changes
def contributions
where("action = ? OR (target_type IN (?) AND action IN (?)) OR (target_type = ? AND action = ?)",
......@@ -290,6 +318,16 @@ class Event < ActiveRecord::Base
@commits ||= (data[:commits] || []).reverse
end
def commit_title
commit = commits.last
commit[:message] if commit
end
def commit_id
commit_to || commit_from
end
def commits_count
data[:total_commits_count] || commits.count || 0
end
......@@ -385,6 +423,16 @@ class Event < ActiveRecord::Base
user ? author_id == user.id : false
end
# We're manually replicating data into the new table since database triggers
# are not dumped to db/schema.rb. This could mean that a new installation
# would not have the triggers in place, thus losing events data in GitLab
# 10.0.
def replicate_event_for_push_events_migration
new_attributes = attributes.with_indifferent_access.except(:title, :data)
EventForMigration.create!(new_attributes)
end
private
def recent_update?
......
# This model is used to replicate events between the old "events" table and the
# new "events_for_migration" table that will replace "events" in GitLab 10.0.
class EventForMigration < ActiveRecord::Base
self.table_name = 'events_for_migration'
end
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
# The "data" field must not be set for push events since it's not used and a
# waste of space.
validates :data, absence: 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
def self.sti_name
PUSHED
end
def push?
true
end
def push_with_commits?
!!(commit_from && commit_to)
end
def tag?
return super unless push_event_payload
push_event_payload.tag?
end
def branch?
return super unless push_event_payload
push_event_payload.branch?
end
def valid_push?
return super unless push_event_payload
push_event_payload.ref.present?
end
def new_ref?
return super unless push_event_payload
push_event_payload.created?
end
def rm_ref?
return super unless push_event_payload
push_event_payload.removed?
end
def commit_from
return super unless push_event_payload
push_event_payload.commit_from
end
def commit_to
return super unless push_event_payload
push_event_payload.commit_to
end
def ref_name
return super unless push_event_payload
push_event_payload.ref
end
def ref_type
return super unless push_event_payload
push_event_payload.ref_type
end
def branch_name
return super unless push_event_payload
ref_name
end
def tag_name
return super unless push_event_payload
ref_name
end
def commit_title
return super unless push_event_payload
push_event_payload.commit_title
end
def commit_id
commit_to || commit_from
end
def commits_count
return super unless push_event_payload
push_event_payload.commit_count
end
def validate_push_action
return if action == PUSHED
errors.add(:action, "the action #{action.inspect} is not valid")
end
end
class PushEventPayload < ActiveRecord::Base
include ShaAttribute
belongs_to :event, inverse_of: :push_event_payload
validates :event_id, :commit_count, :action, :ref_type, presence: true
validates :commit_title, length: { maximum: 70 }
sha_attribute :commit_from
sha_attribute :commit_to
enum action: {
created: 0,
removed: 1,
pushed: 2
}
enum ref_type: {
branch: 0,
tag: 1
}
end
......@@ -71,7 +71,14 @@ class EventCreateService
end
def push(project, current_user, push_data)
create_event(project, current_user, Event::PUSHED, data: push_data)
# We're using an explicit transaction here so that any errors that may occur
# when creating push payload data will result in the event creation being
# rolled back as well.
Event.transaction do
event = create_event(project, current_user, Event::PUSHED)
PushEventPayloadService.new(event, push_data).execute
end
Users::ActivityService.new(current_user, 'push').execute
end
......
# Service class for creating push event payloads as stored in the
# "push_event_payloads" table.
#
# Example:
#
# data = Gitlab::DataBuilder::Push.build(...)
# event = Event.create(...)
#
# PushEventPayloadService.new(event, data).execute
class PushEventPayloadService
# event - The event this push payload belongs to.
# push_data - A Hash produced by `Gitlab::DataBuilder::Push.build` to use for
# building the push payload.
def initialize(event, push_data)
@event = event
@push_data = push_data
end
# Creates and returns a new PushEventPayload row.
#
# This method will raise upon encountering validation errors.
#
# Returns an instance of PushEventPayload.
def execute
@event.build_push_event_payload(
commit_count: commit_count,
action: action,
ref_type: ref_type,
commit_from: commit_from_id,
commit_to: commit_to_id,
ref: trimmed_ref,
commit_title: commit_title,
event_id: @event.id
)
@event.push_event_payload.save!
@event.push_event_payload
end
# Returns the commit title to use.
#
# The commit title is limited to the first line and a maximum of 70
# characters.
def commit_title
commit = @push_data.fetch(:commits).last
return nil unless commit && commit[:message]
raw_msg = commit[:message]
# Find where the first line ends, without turning the entire message into an
# Array of lines (this is a waste of memory for large commit messages).
index = raw_msg.index("\n")
message = index ? raw_msg[0..index] : raw_msg
message.strip.truncate(70)
end
def commit_from_id
if create?
nil
else
revision_before
end
end
def commit_to_id
if remove?
nil
else
revision_after
end
end
def commit_count
@push_data.fetch(:total_commits_count)
end
def ref
@push_data.fetch(:ref)
end
def revision_before
@push_data.fetch(:before)
end
def revision_after
@push_data.fetch(:after)
end
def trimmed_ref
Gitlab::Git.ref_name(ref)
end
def create?
Gitlab::Git.blank_ref?(revision_before)
end
def remove?
Gitlab::Git.blank_ref?(revision_after)
end
def action
if create?
:created
elsif remove?
:removed
else
:pushed
end
end
def ref_type
if Gitlab::Git.tag_ref?(ref)
:tag
else
:branch
end
end
end
%li.commit
.commit-row-title
= link_to truncate_sha(commit[:id]), project_commit_path(project, commit[:id]), class: "commit-sha", alt: '', title: truncate_sha(commit[:id])
= link_to truncate_sha(event.commit_id), project_commit_path(project, event.commit_id), class: "commit-sha", alt: '', title: truncate_sha(event.commit_id)
&middot;
= markdown event_commit_title(commit[:message]), project: project, pipeline: :single_line, author: event.author
= markdown event_commit_title(event.commit_title), project: project, pipeline: :single_line, author: event.author
%div{ xmlns: "http://www.w3.org/1999/xhtml" }
- event.commits.first(15).each do |commit|
%p
%strong= commit[:author][:name]
= link_to "(##{truncate_sha(commit[:id])})", project_commit_path(event.project, id: commit[:id])
%i
at
= commit[:timestamp].to_time.to_s(:short)
%blockquote= markdown(escape_once(commit[:message]), pipeline: :atom, project: event.project, author: event.author)
- if event.commits_count > 15
%p
%strong= event.author_name
= link_to "(#{truncate_sha(event.commit_id)})", project_commit_path(event.project, event.commit_id)
%i
at
= event.created_at.to_s(:short)
%blockquote= markdown(escape_once(event.commit_title), pipeline: :atom, project: event.project, author: event.author)
- if event.commits_count > 1
%p
%i
\... and
= pluralize(event.commits_count - 15, "more commit")
= pluralize(event.commits_count - 1, "more commit")
......@@ -14,9 +14,7 @@
- if event.push_with_commits?
.event-body
%ul.well-list.event_commits
- few_commits = event.commits[0...2]
- few_commits.each do |commit|
= render "events/commit", commit: commit, project: project, event: event
= render "events/commit", project: project, event: event
- create_mr = event.new_ref? && create_mr_button?(project.default_branch, event.ref_name, project) && event.authored_by?(current_user)
- if event.commits_count > 1
......@@ -44,9 +42,6 @@
= link_to create_mr_path(project.default_branch, event.ref_name, project) do
Create Merge Request
- elsif event.rm_ref?
- repository = project.repository
- last_commit = repository.commit(event.commit_from)
- if last_commit
.event-body
%ul.well-list.event_commits
= render "events/commit", commit: last_commit, project: project, event: event
.event-body
%ul.well-list.event_commits
= render "events/commit", project: project, event: event
---
title: Migrate events into a new format to reduce the storage necessary and improve performance
merge_request:
author:
# See http://doc.gitlab.com/ce/development/migration_style_guide.html
# for more information on how to write migrations for GitLab.
class PrepareEventsTableForPushEventsMigration < ActiveRecord::Migration
include Gitlab::Database::MigrationHelpers
# Set this constant to true if this migration requires downtime.
DOWNTIME = false
disable_ddl_transaction!
def up
# The order of these columns is deliberate and results in the following
# columns and sizes:
#
# * id (4 bytes)
# * project_id (4 bytes)
# * author_id (4 bytes)
# * target_id (4 bytes)
# * created_at (8 bytes)
# * updated_at (8 bytes)
# * action (2 bytes)
# * target_type (variable)
#
# Unfortunately we can't make the "id" column a bigint/bigserial as Rails 4
# does not support this properly.
create_table :events_for_migration do |t|
t.references :project,
index: true,
foreign_key: { on_delete: :cascade }
t.integer :author_id, index: true, null: false
t.integer :target_id
t.timestamps_with_timezone null: false
t.integer :action, null: false, limit: 2, index: true
t.string :target_type
t.index %i[target_type target_id]
end
# t.references doesn't like it when the column name doesn't make the table
# name so we have to add the foreign key separately.
add_concurrent_foreign_key(:events_for_migration, :users, column: :author_id)
end
def down
drop_table :events_for_migration
end
end
# See http://doc.gitlab.com/ce/development/migration_style_guide.html
# for more information on how to write migrations for GitLab.
class CreatePushEventPayloadsTables < ActiveRecord::Migration
include Gitlab::Database::MigrationHelpers
# Set this constant to true if this migration requires downtime.
DOWNTIME = false
disable_ddl_transaction!
def up
create_table :push_event_payloads, id: false do |t|
t.bigint :commit_count, null: false
t.integer :event_id, null: false
t.integer :action, null: false, limit: 2
t.integer :ref_type, null: false, limit: 2
t.binary :commit_from
t.binary :commit_to
t.text :ref
t.string :commit_title, limit: 70
t.index :event_id, unique: true
end
# We're adding a foreign key to the _shadow_ table, and this is deliberate.
# By using the shadow table we don't have to recreate/revalidate this
# foreign key after swapping the "events_for_migration" and "events" tables.
#
# The "events_for_migration" table has a foreign key to "projects.id"
# ensuring that project removals also remove events from the shadow table
# (and thus also from this table).
add_concurrent_foreign_key(
:push_event_payloads,
:events_for_migration,
column: :event_id
)
end
def down
drop_table :push_event_payloads
end
end
# See http://doc.gitlab.com/ce/development/migration_style_guide.html
# for more information on how to write migrations for GitLab.
class ScheduleEventMigrations < ActiveRecord::Migration
include Gitlab::Database::MigrationHelpers
DOWNTIME = false
BUFFER_SIZE = 1000
disable_ddl_transaction!
class Event < ActiveRecord::Base
include EachBatch
self.table_name = 'events'
end
def up
jobs = []
Event.each_batch(of: 1000) do |relation|
min, max = relation.pluck('MIN(id), MAX(id)').first
if jobs.length == BUFFER_SIZE
# We push multiple jobs at a time to reduce the time spent in
# Sidekiq/Redis operations. We're using this buffer based approach so we
# don't need to run additional queries for every range.
BackgroundMigrationWorker.perform_bulk(jobs)
jobs.clear
end
jobs << ['MigrateEventsToPushEventPayloads', [min, max]]
end
BackgroundMigrationWorker.perform_bulk(jobs) unless jobs.empty?
end
def down
end
end
......@@ -534,6 +534,21 @@ ActiveRecord::Schema.define(version: 20170807160457) do
add_index "events", ["target_id"], name: "index_events_on_target_id", using: :btree
add_index "events", ["target_type"], name: "index_events_on_target_type", using: :btree
create_table "events_for_migration", force: :cascade do |t|
t.integer "project_id"
t.integer "author_id", null: false
t.integer "target_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "action", limit: 2, null: false
t.string "target_type"
end
add_index "events_for_migration", ["action"], name: "index_events_for_migration_on_action", using: :btree
add_index "events_for_migration", ["author_id"], name: "index_events_for_migration_on_author_id", using: :btree
add_index "events_for_migration", ["project_id"], name: "index_events_for_migration_on_project_id", using: :btree
add_index "events_for_migration", ["target_type", "target_id"], name: "index_events_for_migration_on_target_type_and_target_id", using: :btree
create_table "feature_gates", force: :cascade do |t|
t.string "feature_key", null: false
t.string "key", null: false
......@@ -1254,6 +1269,19 @@ ActiveRecord::Schema.define(version: 20170807160457) do
add_index "protected_tags", ["project_id"], name: "index_protected_tags_on_project_id", using: :btree
create_table "push_event_payloads", id: false, force: :cascade do |t|
t.integer "commit_count", limit: 8, null: false
t.integer "event_id", null: false
t.integer "action", limit: 2, null: false
t.integer "ref_type", limit: 2, null: false
t.binary "commit_from"
t.binary "commit_to"
t.text "ref"
t.string "commit_title", limit: 70
end
add_index "push_event_payloads", ["event_id"], name: "index_push_event_payloads_on_event_id", unique: true, using: :btree
create_table "redirect_routes", force: :cascade do |t|
t.integer "source_id", null: false
t.string "source_type", null: false
......@@ -1654,6 +1682,8 @@ ActiveRecord::Schema.define(version: 20170807160457) do
add_foreign_key "deployments", "projects", name: "fk_b9a3851b82", on_delete: :cascade
add_foreign_key "environments", "projects", name: "fk_d1c8c1da6a", on_delete: :cascade
add_foreign_key "events", "projects", name: "fk_0434b48643", on_delete: :cascade
add_foreign_key "events_for_migration", "projects", on_delete: :cascade
add_foreign_key "events_for_migration", "users", column: "author_id", name: "fk_edfd187b6f", on_delete: :cascade
add_foreign_key "forked_project_links", "projects", column: "forked_to_project_id", name: "fk_434510edb0", on_delete: :cascade
add_foreign_key "gpg_keys", "users", on_delete: :cascade
add_foreign_key "gpg_signatures", "gpg_keys", on_delete: :nullify
......@@ -1696,6 +1726,7 @@ ActiveRecord::Schema.define(version: 20170807160457) do
add_foreign_key "protected_tag_create_access_levels", "protected_tags"
add_foreign_key "protected_tag_create_access_levels", "users"
add_foreign_key "protected_tags", "projects", name: "fk_8e4af87648", on_delete: :cascade
add_foreign_key "push_event_payloads", "events_for_migration", column: "event_id", name: "fk_36c74129da", on_delete: :cascade
add_foreign_key "releases", "projects", name: "fk_47fe2a0596", on_delete: :cascade
add_foreign_key "services", "projects", name: "fk_71cce407f9", on_delete: :cascade
add_foreign_key "snippets", "projects", name: "fk_be41fd4bb7", on_delete: :cascade
......
......@@ -79,7 +79,6 @@ Example response:
"target_id":160,
"target_type":"Issue",
"author_id":25,
"data":null,
"target_title":"Qui natus eos odio tempore et quaerat consequuntur ducimus cupiditate quis.",
"created_at":"2017-02-09T10:43:19.667Z",
"author":{
......@@ -99,7 +98,6 @@ Example response:
"target_id":159,
"target_type":"Issue",
"author_id":21,
"data":null,
"target_title":"Nostrum enim non et sed optio illo deleniti non.",
"created_at":"2017-02-09T10:43:19.426Z",
"author":{
......@@ -151,7 +149,6 @@ Example response:
"target_id": 830,
"target_type": "Issue",
"author_id": 1,
"data": null,
"target_title": "Public project search field",
"author": {
"name": "Dmitriy Zaporozhets",
......@@ -166,7 +163,7 @@ Example response:
{
"title": null,
"project_id": 15,
"action_name": "opened",
"action_name": "pushed",
"target_id": null,
"target_type": null,
"author_id": 1,
......@@ -179,31 +176,14 @@ Example response:
"web_url": "http://localhost:3000/root"
},
"author_username": "john",
"data": {
"before": "50d4420237a9de7be1304607147aec22e4a14af7",
"after": "c5feabde2d8cd023215af4d2ceeb7a64839fc428",
"ref": "refs/heads/master",
"user_id": 1,
"user_name": "Dmitriy Zaporozhets",
"repository": {
"name": "gitlabhq",
"url": "git@dev.gitlab.org:gitlab/gitlabhq.git",
"description": "GitLab: self hosted Git management software. \r\nDistributed under the MIT License.",
"homepage": "https://dev.gitlab.org/gitlab/gitlabhq"
},
"commits": [
{
"id": "c5feabde2d8cd023215af4d2ceeb7a64839fc428",
"message": "Add simple search to projects in public area",
"timestamp": "2013-05-13T18:18:08+00:00",
"url": "https://dev.gitlab.org/gitlab/gitlabhq/commit/c5feabde2d8cd023215af4d2ceeb7a64839fc428",
"author": {
"name": "Dmitriy Zaporozhets",
"email": "dmitriy.zaporozhets@gmail.com"
}
}
],
"total_commits_count": 1
"push_data": {
"commit_count": 1,
"action": "pushed",
"ref_type": "branch",
"commit_from": "50d4420237a9de7be1304607147aec22e4a14af7",
"commit_to": "c5feabde2d8cd023215af4d2ceeb7a64839fc428",
"ref": "master",