forgejo/modules/indexer/code/indexer.go
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

352 lines
10 KiB
Go

// Copyright 2016 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package code
import (
"context"
"os"
"runtime/pprof"
"strconv"
"strings"
"time"
"code.gitea.io/gitea/models/db"
repo_model "code.gitea.io/gitea/models/repo"
"code.gitea.io/gitea/modules/graceful"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
"code.gitea.io/gitea/modules/queue"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/timeutil"
)
// SearchResult result of performing a search in a repo
type SearchResult struct {
RepoID int64
StartIndex int
EndIndex int
Filename string
Content string
CommitID string
UpdatedUnix timeutil.TimeStamp
Language string
Color string
}
// SearchResultLanguages result of top languages count in search results
type SearchResultLanguages struct {
Language string
Color string
Count int
}
// Indexer defines an interface to index and search code contents
type Indexer interface {
Ping() bool
Index(ctx context.Context, repo *repo_model.Repository, sha string, changes *repoChanges) error
Delete(repoID int64) error
Search(ctx context.Context, repoIDs []int64, language, keyword string, page, pageSize int, isMatch bool) (int64, []*SearchResult, []*SearchResultLanguages, error)
Close()
}
func filenameIndexerID(repoID int64, filename string) string {
return indexerID(repoID) + "_" + filename
}
func indexerID(id int64) string {
return strconv.FormatInt(id, 36)
}
func parseIndexerID(indexerID string) (int64, string) {
index := strings.IndexByte(indexerID, '_')
if index == -1 {
log.Error("Unexpected ID in repo indexer: %s", indexerID)
}
repoID, _ := strconv.ParseInt(indexerID[:index], 36, 64)
return repoID, indexerID[index+1:]
}
func filenameOfIndexerID(indexerID string) string {
index := strings.IndexByte(indexerID, '_')
if index == -1 {
log.Error("Unexpected ID in repo indexer: %s", indexerID)
}
return indexerID[index+1:]
}
// IndexerData represents data stored in the code indexer
type IndexerData struct {
RepoID int64
}
var indexerQueue *queue.WorkerPoolQueue[*IndexerData]
func index(ctx context.Context, indexer Indexer, repoID int64) error {
repo, err := repo_model.GetRepositoryByID(ctx, repoID)
if repo_model.IsErrRepoNotExist(err) {
return indexer.Delete(repoID)
}
if err != nil {
return err
}
sha, err := getDefaultBranchSha(ctx, repo)
if err != nil {
return err
}
changes, err := getRepoChanges(ctx, repo, sha)
if err != nil {
return err
} else if changes == nil {
return nil
}
if err := indexer.Index(ctx, repo, sha, changes); err != nil {
return err
}
return repo_model.UpdateIndexerStatus(ctx, repo, repo_model.RepoIndexerTypeCode, sha)
}
// Init initialize the repo indexer
func Init() {
if !setting.Indexer.RepoIndexerEnabled {
indexer.Close()
return
}
ctx, cancel, finished := process.GetManager().AddTypedContext(context.Background(), "Service: CodeIndexer", process.SystemProcessType, false)
graceful.GetManager().RunAtTerminate(func() {
select {
case <-ctx.Done():
return
default:
}
cancel()
log.Debug("Closing repository indexer")
indexer.Close()
log.Info("PID: %d Repository Indexer closed", os.Getpid())
finished()
})
waitChannel := make(chan time.Duration, 1)
// Create the Queue
switch setting.Indexer.RepoType {
case "bleve", "elasticsearch":
handler := func(items ...*IndexerData) (unhandled []*IndexerData) {
idx, err := indexer.get()
if idx == nil || err != nil {
log.Error("Codes indexer handler: unable to get indexer!")
return items
}
for _, indexerData := range items {
log.Trace("IndexerData Process Repo: %d", indexerData.RepoID)
// FIXME: it seems there is a bug in `CatFileBatch` or `nio.Pipe`, which will cause the process to hang forever in rare cases
/*
sync.(*Cond).Wait(cond.go:70)
github.com/djherbis/nio/v3.(*PipeReader).Read(sync.go:106)
bufio.(*Reader).fill(bufio.go:106)
bufio.(*Reader).ReadSlice(bufio.go:372)
bufio.(*Reader).collectFragments(bufio.go:447)
bufio.(*Reader).ReadString(bufio.go:494)
code.gitea.io/gitea/modules/git.ReadBatchLine(batch_reader.go:149)
code.gitea.io/gitea/modules/indexer/code.(*BleveIndexer).addUpdate(bleve.go:214)
code.gitea.io/gitea/modules/indexer/code.(*BleveIndexer).Index(bleve.go:296)
code.gitea.io/gitea/modules/indexer/code.(*wrappedIndexer).Index(wrapped.go:74)
code.gitea.io/gitea/modules/indexer/code.index(indexer.go:105)
*/
if err := index(ctx, indexer, indexerData.RepoID); err != nil {
if !idx.Ping() {
log.Error("Code indexer handler: indexer is unavailable.")
unhandled = append(unhandled, indexerData)
continue
}
if !setting.IsInTesting {
log.Error("Codes indexer handler: index error for repo %v: %v", indexerData.RepoID, err)
}
}
}
return unhandled
}
indexerQueue = queue.CreateUniqueQueue("code_indexer", handler)
if indexerQueue == nil {
log.Fatal("Unable to create codes indexer queue")
}
default:
log.Fatal("Unknown codes indexer type; %s", setting.Indexer.RepoType)
}
go func() {
pprof.SetGoroutineLabels(ctx)
start := time.Now()
var (
rIndexer Indexer
populate bool
err error
)
switch setting.Indexer.RepoType {
case "bleve":
log.Info("PID: %d Initializing Repository Indexer at: %s", os.Getpid(), setting.Indexer.RepoPath)
defer func() {
if err := recover(); err != nil {
log.Error("PANIC whilst initializing repository indexer: %v\nStacktrace: %s", err, log.Stack(2))
log.Error("The indexer files are likely corrupted and may need to be deleted")
log.Error("You can completely remove the \"%s\" directory to make Gitea recreate the indexes", setting.Indexer.RepoPath)
}
}()
rIndexer, populate, err = NewBleveIndexer(setting.Indexer.RepoPath)
if err != nil {
cancel()
indexer.Close()
close(waitChannel)
log.Fatal("PID: %d Unable to initialize the bleve Repository Indexer at path: %s Error: %v", os.Getpid(), setting.Indexer.RepoPath, err)
}
case "elasticsearch":
log.Info("PID: %d Initializing Repository Indexer at: %s", os.Getpid(), setting.Indexer.RepoConnStr)
defer func() {
if err := recover(); err != nil {
log.Error("PANIC whilst initializing repository indexer: %v\nStacktrace: %s", err, log.Stack(2))
log.Error("The indexer files are likely corrupted and may need to be deleted")
log.Error("You can completely remove the \"%s\" index to make Gitea recreate the indexes", setting.Indexer.RepoConnStr)
}
}()
rIndexer, populate, err = NewElasticSearchIndexer(setting.Indexer.RepoConnStr, setting.Indexer.RepoIndexerName)
if err != nil {
cancel()
indexer.Close()
close(waitChannel)
log.Fatal("PID: %d Unable to initialize the elasticsearch Repository Indexer connstr: %s Error: %v", os.Getpid(), setting.Indexer.RepoConnStr, err)
}
default:
log.Fatal("PID: %d Unknown Indexer type: %s", os.Getpid(), setting.Indexer.RepoType)
}
indexer.set(rIndexer)
// Start processing the queue
go graceful.GetManager().RunWithShutdownFns(indexerQueue.Run)
if populate {
go graceful.GetManager().RunWithShutdownContext(populateRepoIndexer)
}
select {
case waitChannel <- time.Since(start):
case <-graceful.GetManager().IsShutdown():
}
close(waitChannel)
}()
if setting.Indexer.StartupTimeout > 0 {
go func() {
pprof.SetGoroutineLabels(ctx)
timeout := setting.Indexer.StartupTimeout
if graceful.GetManager().IsChild() && setting.GracefulHammerTime > 0 {
timeout += setting.GracefulHammerTime
}
select {
case <-graceful.GetManager().IsShutdown():
log.Warn("Shutdown before Repository Indexer completed initialization")
cancel()
indexer.Close()
case duration, ok := <-waitChannel:
if !ok {
log.Warn("Repository Indexer Initialization failed")
cancel()
indexer.Close()
return
}
log.Info("Repository Indexer Initialization took %v", duration)
case <-time.After(timeout):
cancel()
indexer.Close()
log.Fatal("Repository Indexer Initialization Timed-Out after: %v", timeout)
}
}()
}
}
// UpdateRepoIndexer update a repository's entries in the indexer
func UpdateRepoIndexer(repo *repo_model.Repository) {
indexData := &IndexerData{RepoID: repo.ID}
if err := indexerQueue.Push(indexData); err != nil {
log.Error("Update repo index data %v failed: %v", indexData, err)
}
}
// IsAvailable checks if issue indexer is available
func IsAvailable() bool {
idx, err := indexer.get()
if err != nil {
log.Error("IsAvailable(): unable to get indexer: %v", err)
return false
}
return idx.Ping()
}
// populateRepoIndexer populate the repo indexer with pre-existing data. This
// should only be run when the indexer is created for the first time.
func populateRepoIndexer(ctx context.Context) {
log.Info("Populating the repo indexer with existing repositories")
exist, err := db.IsTableNotEmpty("repository")
if err != nil {
log.Fatal("System error: %v", err)
} else if !exist {
return
}
// if there is any existing repo indexer metadata in the DB, delete it
// since we are starting afresh. Also, xorm requires deletes to have a
// condition, and we want to delete everything, thus 1=1.
if err := db.DeleteAllRecords("repo_indexer_status"); err != nil {
log.Fatal("System error: %v", err)
}
var maxRepoID int64
if maxRepoID, err = db.GetMaxID("repository"); err != nil {
log.Fatal("System error: %v", err)
}
// start with the maximum existing repo ID and work backwards, so that we
// don't include repos that are created after gitea starts; such repos will
// already be added to the indexer, and we don't need to add them again.
for maxRepoID > 0 {
select {
case <-ctx.Done():
log.Info("Repository Indexer population shutdown before completion")
return
default:
}
ids, err := repo_model.GetUnindexedRepos(repo_model.RepoIndexerTypeCode, maxRepoID, 0, 50)
if err != nil {
log.Error("populateRepoIndexer: %v", err)
return
} else if len(ids) == 0 {
break
}
for _, id := range ids {
select {
case <-ctx.Done():
log.Info("Repository Indexer population shutdown before completion")
return
default:
}
if err := indexerQueue.Push(&IndexerData{RepoID: id}); err != nil {
log.Error("indexerQueue.Push: %v", err)
return
}
maxRepoID = id - 1
}
}
log.Info("Done (re)populating the repo indexer with existing repositories")
}