Great. +1 from my side. Thanks. Best Regards, - He Xiaoqiao
On Thu, Feb 13, 2025 at 10:15 AM jian zhang <keeprom...@apache.org> wrote: > Hi, He Xiaoqiao > > I have rebased HDFS-17531 again and resolved the conflicts. The current > pipeline failure is unrelated to the ARR feature and was introduced by > slfan1989's PR: HADOOP-19415. [JDK17] Upgrade JUnit from 4 to 5 in > hadoop-common Part 1. (#7339). slfan1989 will fix it later. > > Best Regards, > - Jian Zhang > > Xiaoqiao He <hexiaoq...@apache.org> 于2025年2月11日周二 11:15写道： > > > Hi Jian Zhang, Thanks for your great work. Please fix the conflict first, > > others make sense to me. > > I will give my +1 once it is ready. > > Another thing, before check in we need to launch another official vote > > thread. Good luck. > > > > BTW, Happy lunar new year! > > > > Best Regards, > > - He Xiaoqiao > > > > On Thu, Feb 6, 2025 at 5:30 PM jian zhang <keeprom...@apache.org> wrote: > > > >> Hi, all, > >> Currently this feature has been developed and passed the pipeline. > Please > >> continue to help review this feature. > >> > >> Best Regards, > >> Jian Zhang > >> > >> Zhanghaobo <hfutzhan...@163.com> 于2025年1月22日周三 18:22写道： > >> > >>> @Hui Fei Hi, Sir: > >>> For the first opinion, I have create an umbrella JIRA > >>> https://issues.apache.org/jira/browse/HDFS-17716 > >>> and move non-core JIRA under it. > >>> > >>> Best Wishes > >>> Haobo Zhang > >>> > >>> ---- Replied Message ---- > >>> From Hui Fei<feihui.u...@gmail.com> <feihui.u...@gmail.com> > >>> Date 01/22/2025 17:37 > >>> To jian zhang<keeprom...@apache.org> <keeprom...@apache.org> > >>> Cc Hdfs-dev<hdfs-dev@hadoop.apache.org> , > >>> <hdfs-dev@hadoop.apache.org> <priv...@hadoop.apache.org> , > >>> <priv...@hadoop.apache.org> Xiaoqiao He<hexiaoq...@apache.org> , > >>> <hexiaoq...@apache.org> <common-...@hadoop.apache.org> > >>> <common-...@hadoop.apache.org> > >>> Subject Re: [DISCUSS] Request to merge branch HDFS-17531 into trunk. > >>> Got your idea. Thank you! > >>> - How about removing unfinished tasks and placing them under a new task > >>> as > >>> subtasks, like ARR improvements? If this feature is completed but there > >>> are > >>> still some open tasks, it looks strange. > >>> - Will it take a long time to add documentation? Discussion may last > for > >>> several days. If it takes a long time, I think it may block the trunk > >>> release and All community members need to remember that there is > >>> documentation required. It doesn't look good. That's my thought, and we > >>> can > >>> wait for others' opinions > >>> > >>> jian zhang <keeprom...@apache.org> 于2025年1月22日周三 16:53写道： > >>> > >>> Hi, Hui Fei, > >>> - The remaining 3 sub tasks are not related to the core functions of > >>> the asynchronous router, and these sub tasks have little impact on the > >>> trunk branch, we can wait until HDFS-17531 is merged into the trunk, > and > >>> then submit the remaining PRs directly to the trunk. > >>> - It is indeed necessary to add a documentation to > >>> "HDFSRouterFederation.md", how about submitting a PR to do this after > >>> merging HDFS-17531 into the trunk branch? > >>> > >>> Best Regards, > >>> Jian Zhang > >>> > >>> Hui Fei <feihui.u...@gmail.com> 于2025年1月22日周三 16:24写道： > >>> > >>> Thanks for your great work, looking forward to this feature. > >>> > >>> Some comments from me. > >>> - I checked and found that there are still 3 sub tasks under this > >>> feature jira ticket, are they necessary to be solved? > >>> - I didn't find the documentation for this feature. It's a key feature, > >>> Is it necessary to add documentation to HDFSRouterFederation.md? > >>> > >>> jian zhang <zjkeeprom...@gmail.com> 于2025年1月22日周三 10:29写道： > >>> > >>> Hi, all, the development of the asynchronous router functionality has > >>> been completed. The development branch is HDFS-17531, and it is ready > to > >>> be > >>> merged into the trunk branch. > >>> > >>> JIRA: HDFS-17531 https://issues.apache.org/jira/browse/HDFS-17531 > >>> PR: https://github.com/apache/hadoop/pull/7308 > >>> > >>> Here is the functionality introduction of the asynchronous router for > >>> everyone to review: > >>> I. Overview > >>> > >>> The asynchronous router aims to address the performance bottleneck > >>> issues of the synchronous router in high - concurrency and multi - > >>> nameservices scenarios. By introducing an asynchronous processing > >>> mechanism, it optimizes the request handling process, improves the > >>> system's > >>> concurrency ability and resource utilization, and is particularly > >>> suitable > >>> for the federated scenarios where multiple downstream services (NS) > need > >>> to > >>> be processed. > >>> > >>> II. Problems of the Synchronous Router > >>> > >>> - Performance Bottleneck: The performance of the synchronous router > >>> is limited by the number of handler threads. Even if the connection > >>> thread > >>> can still forward requests to the downstream namenode, the handler must > >>> wait for each request to complete before processing the next one, > >>> resulting > >>> in limited processing capacity. > >>> - Thread Resource Waste: To improve performance, increasing the > >>> number of handler threads will lead to more thread switches, which > >>> instead > >>> reduces the system efficiency. At the same time, a large number of > >>> handler > >>> threads are in a blocked state, wasting thread resources. > >>> - Poor Isolation in Multi - ns: If the performance of a certain > >>> nameservice in the downstream nameservice is poor, it will cause the > >>> handler to wait for a long time, thus affecting the forwarding of > >>> requests > >>> to other normal - performance ns, resulting in a decrease in the > overall > >>> performance of the downstream ns services perceived by the client. > >>> - Ineffective Utilization of Federation Multi - ns Performance: In > >>> high - concurrency scenarios, a large number of requests may be > >>> backlogged > >>> in the router's request queue, while the queues of downstream services > >>> are > >>> not fully utilized, leading to unreasonable resource allocation. > >>> > >>> III. Design and Improvements of the Asynchronous Router > >>> > >>> The asynchronous router solves the above problems by redesigning the > >>> request handling process and introducing an asynchronous processing > >>> mechanism. Its core improvements include: > >>> > >>> - Handler: Retrieves requests from the request queue for preliminary > >>> processing. If there are exceptions in the request (such as the mount > >>> point > >>> does not exist, etc.), it directly puts the response into the response > >>> queue; otherwise, it sends the request to the asynchronous handler > thread > >>> pool. > >>> - Async Handler: Puts the request into the call queue > >>> (connection.calls) of the connection thread and returns immediately > >>> without > >>> blocking and waiting. > >>> - Async Responder: Is responsible for processing the responses > >>> received by the connection thread. If the request needs to be re - > >>> initiated (such as the downstream service returns a standby exception), > >>> it > >>> re - adds the request to the asynchronous handler thread pool; > otherwise, > >>> it puts the response into the response queue. > >>> - Responder: Retrieves the response from the response queue and > >>> returns it to the client. > >>> > >>> IV. Advantages of the Asynchronous Router > >>> > >>> - High - Concurrency Performance: Through the asynchronous > >>> processing mechanism, the asynchronous router can handle a large number > >>> of > >>> requests simultaneously, significantly improving the system's > concurrent > >>> processing ability. > >>> - High Resource Utilization: It avoids thread blocking and frequent > >>> switching, reduces thread resource waste, and improves the overall > >>> efficiency of the system. > >>> - Isolation: Different ns are processed by different async handler > >>> thread pools, achieving isolation of different downstream services. > Even > >>> if > >>> the performance of a certain service is poor, it will not affect the > >>> processing ability of other services. > >>> > >>> V. Summary > >>> > >>> The asynchronous router solves the performance bottleneck problem of > >>> the traditional synchronous router in high - concurrency scenarios by > >>> introducing an asynchronous processing mechanism. It not only improves > >>> the > >>> system's concurrency ability and resource utilization but also achieves > >>> isolation of downstream services through the queue mechanism, enhancing > >>> the > >>> system's stability and adaptability. In the federated scenarios where > >>> multiple downstream services need to be processed, the asynchronous > >>> router > >>> is a more efficient and reliable solution. > >>> VI. Performance Testing > >>> > >>> > >>> > >>> > https://docs.google.com/document/d/1meHOCvhm3XRHlIMwvKFidfUSjveTJrb8yAMasrM_HrY/edit?tab=t.0#heading=h.du0zlo2k5sb1 > >>> > >>> VII. JIRA & RPs > >>> > >>> For more information, please refer to JIRA: > >>> JIRA: RBF: Asynchronous router RPC: > >>> https://issues.apache.org/jira/browse/HDFS-17531 > >>> PRs: > >>> HDFS-17543. [ARR] AsyncUtil makes asynchronous code more concise and > >>> easier. > >>> HADOOP-19235. IPC client uses CompletableFuture to support > >>> asynchronous operations. > >>> HDFS-17544. [ARR] The router client rpc protocol PB supports > >>> asynchrony. > >>> HDFS-17545. [ARR] router async rpc client. > >>> HDFS-17594. [ARR] RouterCacheAdmin supports asynchronous rpc. > >>> HDFS-17597. [ARR] RouterSnapshot supports asynchronous rpc. > >>> HDFS-17595. [ARR] ErasureCoding supports asynchronous rpc. > >>> HDFS-17601. [ARR] RouterRpcServer supports asynchronous rpc. > >>> HDFS-17596. [ARR] RouterStoragePolicy supports asynchronous rpc. > >>> HDFS-17656. [ARR] RouterNamenodeProtocol and RouterUserProtocol > >>> supports asynchronous rpc. > >>> HDFS-17659. [ARR]Router Quota supports asynchronous rpc. > >>> HDFS-17672. [ARR] Move asynchronous related classes to the async > >>> package. > >>> HADOOP-19361. RPC DeferredMetrics bugfix. > >>> HDFS-17640.[ARR] RouterClientProtocol supports asynchronous rpc. > >>> HDFS-17650. [ARR] The router server-side rpc protocol PB supports > >>> asynchrony. > >>> HDFS-17651.[ARR] Async handler executor isolation. > >>> --------------------------------------------------------------------- > >>> To unsubscribe, e-mail: hdfs-dev-unsubscr...@hadoop.apache.org > >>> For additional commands, e-mail: hdfs-dev-h...@hadoop.apache.org > >>> > >>> > >>> >
