Backport #26592 by @wxiaoguang
Simplify the log config
* Remove unnecessary `ROUTER` config, it defaults to the `MODE`.
* `XORM` config was deprecated
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
(cherry picked from commit b643b2ca9c)
(cherry picked from commit 1d7ce2a39c841e77492ef08c0e86c3544ecca88d)
(cherry picked from commit 3af8757583ab9bf8fc5eb05ed1e6901a34682512)
(cherry picked from commit 0b818152096d58e402e3c8bbc2415695af0cdfb9)
(cherry picked from commit 7180a3222a00c33ec7dc9bcaa7e5a1e3ae924735)
(cherry picked from commit 069044f4a6dd7457662e5ca296c714275d16becf)
(cherry picked from commit dd1438f38995e397399d8957fca696f82b73707e)
(cherry picked from commit 4ae6b5d64d59902ce003199b5d652d6c4799ffcf)
(cherry picked from commit c572666d78d0f2cf2a33d5a50ea363430ac9a0a9)
(cherry picked from commit de0a4480bc3e40d61aa5342d93a2ef510abe3826)
(cherry picked from commit 60272ef4f73608407ffedd27892376b6c36a7069)
(cherry picked from commit a68fdde4becef625ce4e654ba6ea8ebee55251e5)
(cherry picked from commit ff448cf3a698dd45c713b734fce3e374c99940bf)
(cherry picked from commit 208498caaab339d4543abfb2b77de3c5793a73c8)
(cherry picked from commit 1abd3efad842f276f1c768ab40213200b62a0d3b)
(cherry picked from commit 818c7f4ca9)
(cherry picked from commit 1e552bbe44f79d9a2f5567a0180505b9a41d39d3)
(cherry picked from commit 88dbd6da1d7b4a7faf9dda2d25d68f3202c250a5)
(cherry picked from commit b1c86fb7775dd34511f4d5069db1bd3e5ef68e7a)
(cherry picked from commit 4741ea07033ca458c30b8ba9fe4b00a2e79f971a)
(cherry picked from commit 3c48dc408a7097abe309ca8c443efefca6085a6c)
(cherry picked from commit a5e5dd6567c27655cf7576109f48906e47ecf62f)
# ⚠️ 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:
