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-...@hadoop.apache.org> , >>> <hdfs-...@hadoop.apache.org> <priv...@hadoop.apache.org> , >>> <priv...@hadoop.apache.org> Xiaoqiao He<hexiaoq...@apache.org> , >>> <hexiaoq...@apache.org> <common-dev@hadoop.apache.org> >>> <common-dev@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 >>> >>> >>>
