6f9c278559
# ⚠️ 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: 
110 lines
3 KiB
Go
110 lines
3 KiB
Go
// Copyright 2019 The Gitea Authors. All rights reserved.
|
|
// SPDX-License-Identifier: MIT
|
|
|
|
package queue
|
|
|
|
import (
|
|
"context"
|
|
"sync"
|
|
"time"
|
|
|
|
"code.gitea.io/gitea/modules/log"
|
|
"code.gitea.io/gitea/modules/setting"
|
|
)
|
|
|
|
// Manager is a manager for the queues created by "CreateXxxQueue" functions, these queues are called "managed queues".
|
|
type Manager struct {
|
|
mu sync.Mutex
|
|
|
|
qidCounter int64
|
|
Queues map[int64]ManagedWorkerPoolQueue
|
|
}
|
|
|
|
type ManagedWorkerPoolQueue interface {
|
|
GetName() string
|
|
GetType() string
|
|
GetItemTypeName() string
|
|
GetWorkerNumber() int
|
|
GetWorkerActiveNumber() int
|
|
GetWorkerMaxNumber() int
|
|
SetWorkerMaxNumber(num int)
|
|
GetQueueItemNumber() int
|
|
|
|
// FlushWithContext tries to make the handler process all items in the queue synchronously.
|
|
// It is for testing purpose only. It's not designed to be used in a cluster.
|
|
FlushWithContext(ctx context.Context, timeout time.Duration) error
|
|
}
|
|
|
|
var manager *Manager
|
|
|
|
func init() {
|
|
manager = &Manager{
|
|
Queues: make(map[int64]ManagedWorkerPoolQueue),
|
|
}
|
|
}
|
|
|
|
func GetManager() *Manager {
|
|
return manager
|
|
}
|
|
|
|
func (m *Manager) AddManagedQueue(managed ManagedWorkerPoolQueue) {
|
|
m.mu.Lock()
|
|
defer m.mu.Unlock()
|
|
m.qidCounter++
|
|
m.Queues[m.qidCounter] = managed
|
|
}
|
|
|
|
func (m *Manager) GetManagedQueue(qid int64) ManagedWorkerPoolQueue {
|
|
m.mu.Lock()
|
|
defer m.mu.Unlock()
|
|
return m.Queues[qid]
|
|
}
|
|
|
|
func (m *Manager) ManagedQueues() map[int64]ManagedWorkerPoolQueue {
|
|
m.mu.Lock()
|
|
defer m.mu.Unlock()
|
|
|
|
queues := make(map[int64]ManagedWorkerPoolQueue, len(m.Queues))
|
|
for k, v := range m.Queues {
|
|
queues[k] = v
|
|
}
|
|
return queues
|
|
}
|
|
|
|
// FlushAll tries to make all managed queues process all items synchronously, until timeout or the queue is empty.
|
|
// It is for testing purpose only. It's not designed to be used in a cluster.
|
|
func (m *Manager) FlushAll(ctx context.Context, timeout time.Duration) error {
|
|
var finalErr error
|
|
qs := m.ManagedQueues()
|
|
for _, q := range qs {
|
|
if err := q.FlushWithContext(ctx, timeout); err != nil {
|
|
finalErr = err // TODO: in Go 1.20: errors.Join
|
|
}
|
|
}
|
|
return finalErr
|
|
}
|
|
|
|
// CreateSimpleQueue creates a simple queue from global setting config provider by name
|
|
func CreateSimpleQueue[T any](name string, handler HandlerFuncT[T]) *WorkerPoolQueue[T] {
|
|
return createWorkerPoolQueue(name, setting.CfgProvider, handler, false)
|
|
}
|
|
|
|
// CreateUniqueQueue creates a unique queue from global setting config provider by name
|
|
func CreateUniqueQueue[T any](name string, handler HandlerFuncT[T]) *WorkerPoolQueue[T] {
|
|
return createWorkerPoolQueue(name, setting.CfgProvider, handler, true)
|
|
}
|
|
|
|
func createWorkerPoolQueue[T any](name string, cfgProvider setting.ConfigProvider, handler HandlerFuncT[T], unique bool) *WorkerPoolQueue[T] {
|
|
queueSetting, err := setting.GetQueueSettings(cfgProvider, name)
|
|
if err != nil {
|
|
log.Error("Failed to get queue settings for %q: %v", name, err)
|
|
return nil
|
|
}
|
|
w, err := NewWorkerPoolQueueBySetting(name, queueSetting, handler, unique)
|
|
if err != nil {
|
|
log.Error("Failed to create queue %q: %v", name, err)
|
|
return nil
|
|
}
|
|
GetManager().AddManagedQueue(w)
|
|
return w
|
|
}
|