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 > > >
