githaven-fork/templates/admin
wxiaoguang 6f9c278559
Rewrite queue (#24505)
# ⚠️ Breaking

Many deprecated queue config options are removed (actually, they should
have been removed in 1.18/1.19).

If you see the fatal message when starting Gitea: "Please update your
app.ini to remove deprecated config options", please follow the error
messages to remove these options from your app.ini.

Example:

```
2023/05/06 19:39:22 [E] Removed queue option: `[indexer].ISSUE_INDEXER_QUEUE_TYPE`. Use new options in `[queue.issue_indexer]`
2023/05/06 19:39:22 [E] Removed queue option: `[indexer].UPDATE_BUFFER_LEN`. Use new options in `[queue.issue_indexer]`
2023/05/06 19:39:22 [F] Please update your app.ini to remove deprecated config options
```

Many options in `[queue]` are are dropped, including:
`WRAP_IF_NECESSARY`, `MAX_ATTEMPTS`, `TIMEOUT`, `WORKERS`,
`BLOCK_TIMEOUT`, `BOOST_TIMEOUT`, `BOOST_WORKERS`, they can be removed
from app.ini.

# The problem

The old queue package has some legacy problems:

* complexity: I doubt few people could tell how it works.
* maintainability: Too many channels and mutex/cond are mixed together,
too many different structs/interfaces depends each other.
* stability: due to the complexity & maintainability, sometimes there
are strange bugs and difficult to debug, and some code doesn't have test
(indeed some code is difficult to test because a lot of things are mixed
together).
* general applicability: although it is called "queue", its behavior is
not a well-known queue.
* scalability: it doesn't seem easy to make it work with a cluster
without breaking its behaviors.

It came from some very old code to "avoid breaking", however, its
technical debt is too heavy now. It's a good time to introduce a better
"queue" package.

# The new queue package

It keeps using old config and concept as much as possible.

* It only contains two major kinds of concepts:
    * The "base queue": channel, levelqueue, redis
* They have the same abstraction, the same interface, and they are
tested by the same testing code.
* The "WokerPoolQueue", it uses the "base queue" to provide "worker
pool" function, calls the "handler" to process the data in the base
queue.
* The new code doesn't do "PushBack"
* Think about a queue with many workers, the "PushBack" can't guarantee
the order for re-queued unhandled items, so in new code it just does
"normal push"
* The new code doesn't do "pause/resume"
* The "pause/resume" was designed to handle some handler's failure: eg:
document indexer (elasticsearch) is down
* If a queue is paused for long time, either the producers blocks or the
new items are dropped.
* The new code doesn't do such "pause/resume" trick, it's not a common
queue's behavior and it doesn't help much.
* If there are unhandled items, the "push" function just blocks for a
few seconds and then re-queue them and retry.
* The new code doesn't do "worker booster"
* Gitea's queue's handlers are light functions, the cost is only the
go-routine, so it doesn't make sense to "boost" them.
* The new code only use "max worker number" to limit the concurrent
workers.
* The new "Push" never blocks forever
* Instead of creating more and more blocking goroutines, return an error
is more friendly to the server and to the end user.

There are more details in code comments: eg: the "Flush" problem, the
strange "code.index" hanging problem, the "immediate" queue problem.

Almost ready for review.

TODO:

* [x] add some necessary comments during review
* [x] add some more tests if necessary
* [x] update documents and config options
* [x] test max worker / active worker
* [x] re-run the CI tasks to see whether any test is flaky
* [x] improve the `handleOldLengthConfiguration` to provide more
friendly messages
* [x] fine tune default config values (eg: length?)

## Code coverage:

![image](https://user-images.githubusercontent.com/2114189/236620635-55576955-f95d-4810-b12f-879026a3afdf.png)
2023-05-08 19:49:59 +08:00
..
applications Change to vertical navbar layout for secondary navbar for repo/user/admin settings (#24246) 2023-04-23 18:21:21 +08:00
auth Update LDAP filters to include both username and email address (#24547) 2023-05-05 14:18:53 -04:00
base Optimize html templates (#22080) 2022-12-09 21:34:51 +08:00
emails Improve some modal action buttons (#24289) 2023-04-24 07:08:59 -04:00
org Fix template function DateTime (#24317) 2023-04-25 15:48:30 -04:00
packages Fix template function DateTime (#24317) 2023-04-25 15:48:30 -04:00
repo Add "Updated" column for admin repositories list (#24429) 2023-04-29 20:40:10 +02:00
runners Move secrets and runners settings to actions settings (#24200) 2023-04-27 20:08:47 -04:00
user Fix template function DateTime (#24317) 2023-04-25 15:48:30 -04:00
actions.tmpl Move secrets and runners settings to actions settings (#24200) 2023-04-27 20:08:47 -04:00
config.tmpl Improve template helper (#24417) 2023-04-29 08:02:29 -04:00
cron.tmpl Replace N/A with - everywhere (#24474) 2023-05-02 05:54:29 -04:00
dashboard.tmpl Start cleaning the messy ".ui.left / .ui.right", improve label list page, fix stackable menu (#24393) 2023-04-29 07:35:59 -04:00
hook_new.tmpl Change to vertical navbar layout for secondary navbar for repo/user/admin settings (#24246) 2023-04-23 18:21:21 +08:00
hooks.tmpl Change to vertical navbar layout for secondary navbar for repo/user/admin settings (#24246) 2023-04-23 18:21:21 +08:00
layout_footer.tmpl Change to vertical navbar layout for secondary navbar for repo/user/admin settings (#24246) 2023-04-23 18:21:21 +08:00
layout_head.tmpl Change to vertical navbar layout for secondary navbar for repo/user/admin settings (#24246) 2023-04-23 18:21:21 +08:00
monitor.tmpl Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
navbar.tmpl Move secrets and runners settings to actions settings (#24200) 2023-04-27 20:08:47 -04:00
notice.tmpl Modify width of ui container, fine tune css for settings pages and org header (#24315) 2023-04-26 11:59:08 -04:00
process-row.tmpl Use auto-updating, natively hoverable, localized time elements (#23988) 2023-04-11 01:01:20 +02:00
process.tmpl Refactor i18n to locale (#20153) 2022-06-27 15:58:46 -05:00
queue_manage.tmpl Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
queue.tmpl Rewrite queue (#24505) 2023-05-08 19:49:59 +08:00
stacktrace-row.tmpl Use auto-updating, natively hoverable, localized time elements (#23988) 2023-04-11 01:01:20 +02:00
stacktrace.tmpl Improve some modal action buttons (#24289) 2023-04-24 07:08:59 -04:00