© XXX Page 1 of 11 CurveFS Client 概要设计（已实现）© XXX Page 2 of 11 背景 概述 关键接口分析 init destroy lookup write read open create & mknod mkdir forget unlink rmdir opendir readdir getattr & setattr access rename 作者 内容 2021-04-27 许超杰 初稿 背景 CurveFS初步设计见 ， 目前需细化Client端设计 CurveFS方案设计（总体设计，只实现了部分） 概述 CurveFS client 向上提供两层接口，分别是© XXX Page 3 of 11 对接fuse，提供通用文件系统接口。对于fuse接口，先前进行了一些调研，见FUSE调研 erblock），块分配器（bitmap）和root inode所在的copyset、 metaserver ip等信息 去metaserver获取文件系统信息（super block），缓存到client端。 destroy void (*destroy) (void *userdata); 清理init缓存的文件系统信息。 lookup void (*lookup) (fuse_req_t

URVE基本架构 01 02 03 04 Client总体介绍 热升级NEBD总体介绍 新版本Client/NEBD性能优化CURVE基本架构 • 元数据节点 MDS • 管理和存储元数据信息 • 感知集群状态，合理调度 • 数据节点 Chunkserver • 数据存储 • 副本一致性，raft • 客户端 Client • 对元数据增删改查 • 对数据增删改查 • • 快照克隆服务器CURVE基本架构 01 02 03 04 Client总体介绍 热升级NEBD总体介绍 新版本Client/NEBD性能优化 QEMU、Curve-NBD：上层应用  通过链接curve-client使用curve提供的服务  FileManager：提供接口，记录已挂载卷  FileInstance：对应一个已挂载的卷  LeaseExecuto 行通信  前者负责IO请求  后者负责获取复制组(copyset)的leader  MDSClient：负责与MDS交互，挂卸载卷、获取元数据信息 CLIENT整体架构QEMU： 实现了QEMU block与Client的对接层 向cinder/glance提供了Python API https://github.com/opencurve/curve-qemu-block-driver

© XXX Page 1 of 15 curvefs client 删除文件和目录功能设计© XXX Page 2 of 15 背景 相关调研 moosefs chubaofs 方案设计思考 1.Trash机制是实现1个(类似chubaofs)，还是2个（类似moosefs）？ 2. Trash放在哪里？ 3. 是否需要做session机制（在metaserver打开），来维护inode的打开情况？ 的打开情况？ 方案设计 Trash机制： Session机制： 遗留问题 工作量评估 背景 目前curvefs client版本对删除unlink和rmdir的设计只有简单的删除inode和dentry结构，遗留了nlink和lookup count相关的内容还未实现，是不完备的。本文首先调研moosefs，chubaofs等分布式系统，参考并设计解决上述遗留问题。 当前删除接口代码如下：© count需要减nlookup（forget的参数） 当umount时，所有lookup count减至0 不应该完全依赖forget接口去实现inode的移除，因为forget接口可能不会被内核调用（例如client崩溃） 相关调研 moosefs moosefs 未对接forget moosefs 实现了在mds上open，因此删除时可以判断文件是否被打开 moosefs使用了两种机制，来实现上述功

13.客户端Client的编程实现 主 讲 人 ： 古 月 话题模型 创建功能包 创建客户端代码（C++） • • • • turtle_spawn.cpp 配置客户端代码编译规则 • • CMakeLists.txt 编译并运行客户端 创建客户端代码（Python） turtle_spawn.py • • • • 感谢观看 怕什么真理无穷，进一寸有一寸的欢喜

of Require group .... Access control In 2.2, access control based on client hostname, IP address, and other characteristics of client requests was done using the directives Order, Allow, Deny, and Satisfy Require 127.0.0.1 access.log - GET /server-status 403 127.0.0.1 error.log - AH01797: client denied by server configuration: /var/www/html/server-status Why httpd denies access to servers-status Provides dynamically configured mass reverse proxies for mod_proxy mod_remoteip Replaces the apparent client remote IP address and hostname for the request with the IP address list presented by a proxies or

of Require group .... Access control In 2.2, access control based on client hostname, IP address, and other characteristics of client requests was done using the directives Order, Allow, Deny, and Satisfy Require 127.0.0.1 access.log - GET /server-status 403 127.0.0.1 error.log - AH01797: client denied by server configuration: /var/www/html/server-status Why httpd denies access to servers-status Provides dynamically configured mass reverse proxies for mod_proxy mod_remoteip Replaces the apparent client remote IP address and hostname for the request with the IP address list presented by a proxies or

of Require group .... Access control In 2.2, access control based on client hostname, IP address, and other characteristics of client requests was done using the directives Order, Allow, Deny, and Satisfy Provides dynamically configured mass reverse proxies for mod_proxy mod_remoteip Replaces the apparent client remote IP address and hostname for the request with the IP address list presented by a proxies or check the validation status of a client certificate. The default responder is configurable, along with the decision on whether to prefer the responder designated in the client certificate itself. mod_ssl now

function, ap_log_cerror has been added to log errors that occur with the client's connection. When logged, the message includes the client IP address. Test Configuration Hook Added A new hook, test_config proxy_http. mod_negotiation A new ForceLanguagePriority directive can be used to assure that the client receives a single document in all cases, rather than NOT ACCEPTABLE or MULTIPLE CHOICES responses In contrast, the webspace is the view of your site as delivered by the web server and seen by the client. So the path /dir/ in the webspace corresponds to the path /usr/local/apache2/htdocs/dir/ in the

function, ap_log_cerror has been added to log errors that occur with the client's connection. When logged, the message includes the client IP address. Test Configuration Hook Added A new hook, test_config proxy_http. mod_negotiation A new ForceLanguagePriority directive can be used to assure that the client receives a single document in all cases, rather than NOT ACCEPTABLE or MULTIPLE CHOICES responses In contrast, the webspace is the view of your site as delivered by the web server and seen by the client. So the path /dir/ in the webspace corresponds to the path /usr/local/apache2/htdocs/dir/ in the

function, ap_log_cerror has been added to log errors that occur with the client's connection. When logged, the message includes the client IP address. Test Configuration Hook Added A new hook, test_config proxy_http. mod_negotiation A new ForceLanguagePriority directive can be used to assure that the client receives a single document in all cases, rather than NOT ACCEPTABLE or MULTIPLE CHOICES responses In contrast, the webspace is the view of your site as delivered by the web server and seen by the client. So the path /dir/ in the webspace corresponds to the path /usr/local/apache2/htdocs/dir/ in the