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17 commits

Author SHA1 Message Date
Yorick Peterse
83355336dd
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
2017-09-08 00:46:16 +02:00
Yorick Peterse
0395c47193
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.
2017-08-10 17:45:44 +02:00
Robert Speicher
72a7b30c9f Change all :empty_project to :project 2017-08-02 17:47:31 -04:00
Rémy Coutable
cddc5cacfb Use described_class when possible
Signed-off-by: Rémy Coutable <remy@rymai.me>
2017-07-27 14:31:53 +02:00
Rémy Coutable
ddccd24c13 Remove superfluous lib: true, type: redis, service: true, models: true, services: true, no_db: true, api: true
Signed-off-by: Rémy Coutable <remy@rymai.me>
2017-07-27 14:31:53 +02:00
Paul Charlton
cb3b4a15e6 Support multiple Redis instances based on queue type 2017-07-11 03:35:47 +00:00
Rémy Coutable
cfe19b795e Add a new Gitlab::UserActivities class to track user activities
This new class uses a Redis Hash instead of a Sorted Set.

Signed-off-by: Rémy Coutable <remy@rymai.me>
2017-04-14 15:20:55 +02:00
James Lopez
3cb84e06b7 Remove user activities table and use redis instead of PG for recording activities
Refactored specs and added a post deployment migration to remove the activity users table.
2017-04-14 15:20:55 +02:00
James Lopez
2951a8543e Add user activity service and spec. Also added relevant - NOT offline - migration
It uses a user activity table instead of a column in users.
Tested with mySQL and postgreSQL
2017-04-14 15:20:55 +02:00
Valery Sizov
ceb1ebd959 Active tense test coverage
Ports changes from https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/642 back into CE
2017-02-01 22:45:41 +00:00
Callum Dryden
9124310f28
Differentiate the expire from leave event
At the moment we cannot see weather a user left a project due to their
membership expiring of if they themselves opted to leave the project.
This adds a new event type that allows us to make this differentiation.
Note that is not really feasable to go back and reliably fix up the
previous events. As a result the events for previous expire removals
will remain the same however events of this nature going forward will be
correctly represented.
2016-10-20 00:26:45 +00:00
tiagonbotelho
1d268a89de adds second batch of tests changed to active tense 2016-08-09 15:11:39 +01:00
Robert Speicher
adc6ec4a9c Avoid describe-ing symbols in specs 2016-07-12 10:27:58 -05:00
Douwe Maan
a2cfb44157 Tag service specs 2015-12-09 11:55:49 +01:00
Stan Hu
d3d03d1362 Create a "destroyed Milestone" event and keep Milestone events around in the DB
for posterity.

Also fix issue where destroying a Milestone would cause odd, transient messages like
"created milestone" or "imported milestone".

Add "in" preposition when creating and destroying milestones

Closes #2382
2015-09-15 05:51:11 -07:00
Jeroen van Baarsen
0c4a70a306 Updated rspec to rspec 3.x syntax
Signed-off-by: Jeroen van Baarsen <jeroenvanbaarsen@gmail.com>
2015-02-12 19:17:35 +01:00
Dmitriy Zaporozhets
d89130b097
Collect all event creation logic in one place called EventCreateService
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
2014-03-25 14:48:02 +02:00