rgw源码走读-桶创建流程
rgw创建桶的流程 也是和其他请求一样，都是三部曲，主要流程在 RGWCreateBucket::execute() 里面，本次也是直接从这里出发（前面处理请求的大差不差，会有专门用一篇文章来介绍），这里组要介绍下bucket的概念，s3对桶的约束，以及解答以下几个问题？
- 创建桶的时候，桶的实例时持久化哪里？
- 那个池？是那个对象？有什么内容？桶id 的命名规则是？
创建桶后生成那些文件 ？
[root@node86 build]# s3cmd mb s3://hrp
[root@node86 build]# rados -p expondata.rgw.meta ls -N root
hrp
.bucket.meta.hrp:7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.1
[root@node86 build]# s3cmd mb s3://hrp1
[root@node86 build]# rados -p expondata.rgw.meta ls -N root|sort
.bucket.meta.hrp1:7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.2
.bucket.meta.hrp:7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.1
hrp
hrp1
# index 池
[root@node86 build]# rados -p expondata.rgw.buckets.index ls
ceph_context.cc:385:handle_conf_change:WARNING: all dangerous and experimental features are enabled.
.dir.7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.2
.dir.7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.1
[root@node86 build]#
分别创建两个桶可以观察到，每次创建桶都会新增 meta 池中都会新增两个obj，在index新增一个obj，总结下 obj 命名规则
.bucket.meta.hrp:7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.1- .bucket.meta.\[bucket\_name\]:\[桶id\]
- 桶id 构成：\[全局唯一的实例id\].\[num\]
其中num在当前RGW实例中单调递增
hrp- 桶名字
.dir.7fdb0063-3957-4eed-8d4e-c02b208c0d68.4192.1- .dir.\[bucket\_name\]:\[桶id\]
- 桶id 构成：\[全局唯一的实例id\].\[num\]
其中num在当前RGW实例中单调递增
这些obj作用是？
进入这函数分析下 RGWCreateBucket::execute
对于dir开头的obj，是对应每个bucket shard，在桶初始化时会在index吃 创建shard 数量的obj， bucket shard 的概念会在别的篇幅中介绍 RGW Bucket，
->RGWRados::create_bucket
->RGWRados::init_bucket_index
对应.bucket.meta 开头的obj ，存储了bucket instance， 看代码流程是 一些桶的关键信息 RGWBucketEntryPoint 结构体中， 然后在 meta池中写入这个oid中
RGWCreateBucket::execute()
->RGWRados::create\_bucket
->put\_linked\_bucket\_info
->RGWRados::put\_bucket\_instance\_info
->rgw\_bucket\_instance\_store\_info // RGWBucketInfo 写入 obj
->store->meta\_mgr->put\_entry
->handler->get\_pool\_and\_oid //构造 oid 名字 oid = RGW\_BUCKET\_INSTANCE\_MD\_PREFIX + key;
对应桶名字的obj
RGWCreateBucket::execute()
->RGWRados::create\_bucket
->put\_linked\_bucket\_info
->RGWRados::put\_bucket\_instance\_info
->put\_bucket\_entrypoint\_info // RGWBucketEntryPoint 写入 obj
->store->meta\_mgr->put\_entry
->handler->get\_pool\_and\_oid //构造 oid 名字 oid = bukcet那么
这个两个 oid 都在同一个函数实现
int RGWRados::put_linked_bucket_info(RGWBucketInfo& info, bool exclusive, real_time mtime, obj_version *pep_objv,
map<string, bufferlist> *pattrs, bool create_entry_point)
{
bool create_head = !info.has_instance_obj || create_entry_point;
// bucket_instance_info
int ret = put_bucket_instance_info(info, exclusive, mtime, pattrs);
if (ret < 0) {
return ret;
}
if (!create_head)
return 0; /* done! */
RGWBucketEntryPoint entry_point;
entry_point.bucket = info.bucket;
entry_point.owner = info.owner;
entry_point.creation_time = info.creation_time;
entry_point.linked = true;
RGWObjVersionTracker ot;
if (pep_objv && !pep_objv->tag.empty()) {
ot.write_version = *pep_objv;
} else {
ot.generate_new_write_ver(cct);
if (pep_objv) {
*pep_objv = ot.write_version;
}
}
//obj: bucekt id
ret = put_bucket_entrypoint_info(info.bucket.tenant, info.bucket.name, entry_point, exclusive, ot, mtime, NULL);
if (ret < 0)
return ret;
return 0;
}
- 这两个obj 有何不同？
.bucket.meta 开头对象记录很多 bucket 信息（写入了 结构体 RGWBucketInfo），而 bucket name 的对象只存放了简单bucket信息，保存桶名和桶实例id之间的映射， 两者是映射关系
可以用 radosgw-admin metadata 看到这obj的内容
[root@node86 build]# radosgw-admin metadata get bucket.instance:hrp901113311:ea296261-93d8-405c-a8a0-eee34d37c6bc.4192.3
{
"key": "bucket.instance:hrp901113311:ea296261-93d8-405c-a8a0-eee34d37c6bc.4192.3",
"ver": {
"tag": "_3cPYVcIE4NnQ5KNue_smzoy",
"ver": 1
},
"mtime": "2024-02-06 04:06:18.101843Z",
"data": {
"bucket_info": {
"bucket": {
"name": "hrp901113311",
"marker": "ea296261-93d8-405c-a8a0-eee34d37c6bc.4192.3",
"bucket_id": "ea296261-93d8-405c-a8a0-eee34d37c6bc.4192.3",
"tenant": "",
"explicit_placement": {
"data_pool": "",
"data_extra_pool": "",
"index_pool": ""
}
},
"creation_time": "2024-02-06 04:06:17.695464Z",
"owner": "testid",
"flags": 0,
"zonegroup": "49fb5987-dccb-4aaf-ad9e-3c3437b1f87f",
"placement_rule": "default-placement/STANDARD",
"has_instance_obj": "true",
"quota": {
"enabled": false,
"check_on_raw": false,
"max_size": -1,
"max_size_kb": 0,
"max_objects": -1
},
"redirection_rules": [],
"num_shards": 0,
"bi_shard_hash_type": 0,
"requester_pays": "false",
"has_website": "false",
"swift_versioning": "false",
"swift_ver_location": "",
"index_type": 0,
"mdsearch_config": [],
"reshard_status": 0,
"new_bucket_instance_id": "",
"merge_flag": 1,
"policy_rule": {
"policy_id": "",
"policy_info": [],
"ctime": "0.000000"
},
"obj_lock": {
"enabled": "true",
"rule_exist": "false",
"rule": {
"defaultRetention": {
"mode": "",
"days": 0,
"years": 0
}
}
},
"version": 7,
"redirect_mon": "false",
"tagsearch_config": []
},
"attrs": [
{
"key": "user.rgw.acl",
"val": "AgKNAAAAAwIXAAAABgAAAHRlc3RpZAkAAABNLiBUZXN0ZXIEA2oAAAABAQAAAAYAAAB0ZXN0aWQPAAAAAQAAAAYAAAB0ZXN0aWQFAzsAAAACAgQAAAAAAAAABgAAAHRlc3RpZAAAAAAAAAAAAgIEAAAADwAAAAkAAABNLiBUZXN0ZXIAAAAAAAAAAAAAAAAAAAAA"
}
]
}
}
[root@node86 build]# radosgw-admin metadata get bucket:hrp901113311
{
"key": "bucket:hrp901113311",
"ver": {
"tag": "_JZbsjMf61290xDFw3HGcofI",
"ver": 1
},
"mtime": "2024-02-06 04:06:18.115677Z",
"data": {
"bucket": {
"name": "hrp901113311",
"marker": "ea296261-93d8-405c-a8a0-eee34d37c6bc.4192.3",
"bucket_id": "ea296261-93d8-405c-a8a0-eee34d37c6bc.4192.3",
"tenant": "",
"explicit_placement": {
"data_pool": "",
"data_extra_pool": "",
"index_pool": ""
}
},
"owner": "testid",
"creation_time": "2024-02-06 04:06:17.695464Z",
"linked": "true",
"has_bucket_info": "false"
}
}
TODO： 两个obj能否合并在一起？ D版本之后是分开的，分开原因呢？