forgejo/modules/indexer/stats/indexer.go
Jason Song 375fd15fbf
Refactor indexer (#25174)
Refactor `modules/indexer` to make it more maintainable. And it can be
easier to support more features. I'm trying to solve some of issue
searching, this is a precursor to making functional changes.

Current supported engines and the index versions:

| engines | issues | code |
| - | - | - |
| db | Just a wrapper for database queries, doesn't need version | - |
| bleve | The version of index is **2** | The version of index is **6**
|
| elasticsearch | The old index has no version, will be treated as
version **0** in this PR | The version of index is **1** |
| meilisearch | The old index has no version, will be treated as version
**0** in this PR | - |


## Changes

### Split

Splited it into mutiple packages

```text
indexer
├── internal
│   ├── bleve
│   ├── db
│   ├── elasticsearch
│   └── meilisearch
├── code
│   ├── bleve
│   ├── elasticsearch
│   └── internal
└── issues
    ├── bleve
    ├── db
    ├── elasticsearch
    ├── internal
    └── meilisearch
```

- `indexer/interanal`: Internal shared package for indexer.
- `indexer/interanal/[engine]`: Internal shared package for each engine
(bleve/db/elasticsearch/meilisearch).
- `indexer/code`: Implementations for code indexer.
- `indexer/code/internal`: Internal shared package for code indexer.
- `indexer/code/[engine]`: Implementation via each engine for code
indexer.
- `indexer/issues`: Implementations for issues indexer.

### Deduplication

- Combine `Init/Ping/Close` for code indexer and issues indexer.
- ~Combine `issues.indexerHolder` and `code.wrappedIndexer` to
`internal.IndexHolder`.~ Remove it, use dummy indexer instead when the
indexer is not ready.
- Duplicate two copies of creating ES clients.
- Duplicate two copies of `indexerID()`.


### Enhancement

- [x] Support index version for elasticsearch issues indexer, the old
index without version will be treated as version 0.
- [x] Fix spell of `elastic_search/ElasticSearch`, it should be
`Elasticsearch`.
- [x] Improve versioning of ES index. We don't need `Aliases`:
- Gitea does't need aliases for "Zero Downtime" because it never delete
old indexes.
- The old code of issues indexer uses the orignal name to create issue
index, so it's tricky to convert it to an alias.
- [x] Support index version for meilisearch issues indexer, the old
index without version will be treated as version 0.
- [x] Do "ping" only when `Ping` has been called, don't ping
periodically and cache the status.
- [x] Support the context parameter whenever possible.
- [x] Fix outdated example config.
- [x] Give up the requeue logic of issues indexer: When indexing fails,
call Ping to check if it was caused by the engine being unavailable, and
only requeue the task if the engine is unavailable.
- It is fragile and tricky, could cause data losing (It did happen when
I was doing some tests for this PR). And it works for ES only.
- Just always requeue the failed task, if it caused by bad data, it's a
bug of Gitea which should be fixed.

---------

Co-authored-by: Giteabot <teabot@gitea.io>
2023-06-23 12:37:56 +00:00

86 lines
2.2 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package stats
import (
"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"
)
// Indexer defines an interface to index repository stats
// TODO: this indexer is quite different from the others, maybe this package should be moved out from module/indexer
type Indexer interface {
Index(id int64) error
Close()
}
// indexer represents a indexer instance
var indexer Indexer
// Init initialize the repo indexer
func Init() error {
indexer = &DBIndexer{}
if err := initStatsQueue(); err != nil {
return err
}
go populateRepoIndexer()
return nil
}
// 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() {
log.Info("Populating the repo stats indexer with existing repositories")
isShutdown := graceful.GetManager().IsShutdown()
exist, err := db.IsTableNotEmpty("repository")
if err != nil {
log.Fatal("System error: %v", err)
} else if !exist {
return
}
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 <-isShutdown:
log.Info("Repository Stats Indexer population shutdown before completion")
return
default:
}
ids, err := repo_model.GetUnindexedRepos(repo_model.RepoIndexerTypeStats, maxRepoID, 0, 50)
if err != nil {
log.Error("populateRepoIndexer: %v", err)
return
} else if len(ids) == 0 {
break
}
for _, id := range ids {
select {
case <-isShutdown:
log.Info("Repository Stats Indexer population shutdown before completion")
return
default:
}
if err := statsQueue.Push(id); err != nil {
log.Error("statsQueue.Push: %v", err)
}
maxRepoID = id - 1
}
}
log.Info("Done (re)populating the repo stats indexer with existing repositories")
}