From commits-return-25538-archive-asf-public=cust-asf.ponee.io@pulsar.apache.org Thu Mar 28 01:39:03 2019 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id 972E118076D for ; Thu, 28 Mar 2019 02:39:02 +0100 (CET) Received: (qmail 67520 invoked by uid 500); 28 Mar 2019 01:39:01 -0000 Mailing-List: contact commits-help@pulsar.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@pulsar.apache.org Delivered-To: mailing list commits@pulsar.apache.org Received: (qmail 67498 invoked by uid 99); 28 Mar 2019 01:39:01 -0000 Received: from ec2-52-202-80-70.compute-1.amazonaws.com (HELO gitbox.apache.org) (52.202.80.70) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 28 Mar 2019 01:39:01 +0000 From: GitBox To: commits@pulsar.apache.org Subject: [GitHub] [pulsar] Jennifer88huang commented on a change in pull request #3844: [Doc]Fix typo and language issues in the faq.md file Message-ID: <155373714088.19726.9378305888595852275.gitbox@gitbox.apache.org> Date: Thu, 28 Mar 2019 01:39:00 -0000 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Jennifer88huang commented on a change in pull request #3844: [Doc]Fix typo and language issues in the faq.md file URL: https://github.com/apache/pulsar/pull/3844#discussion_r269830854 ########## File path: faq.md ########## @@ -2,108 +2,107 @@ - Getting Started - Concepts and Design - Usage and Configuration +- Advanced Questions --- ## Getting Started ### What is the minimum requirements for Apache Pulsar ? -You need 3 kind of clusters: bookie, broker, zookeeper. But if not have enough resource, it's ok to run them on same machine. - +You need three kinds of clusters: bookie, broker, and zookeeper. If you do not have enough resources, you can also run the three clusters on the same machine. --- - ## Concepts and Design ### Is ack tied to subscription? Yes, ack is tied to a particular subscription. -### Where should I look into to tweak load balancing ? -There are few parameters to look at : -1. The topic assignments to brokers are done in terms of “bundles”, that is in group of topic -2. Topics are matched to bundles by hashing on the name -3. Effectively, a bundle is a hash-range where topics falls into -4. Initially the default is to have 4 “bundles” for a namespace -5. When the traffic increases on a given bundle, it will be split in 2 and reassigned to a different broker -6. There are some adjustable thresholds that can be used to control when the split happens, based on number of topics/partitions, messages in/out, bytes in/out, etc.. -7. It’s also possible to specify a higher number of bundles when creating a namepsac -8. There are the load-manager threshold that control when a broker should offload some of the bundles to other brokers +### Where do I look into to tweak load balancing ? +There are a few parameters to look at : +1. The topic assignments to brokers are done in terms of “bundles”, that is in group of topic. +2. Topics are matched to bundles by hashing on the name. +3. A bundle is a hash-range where topics fall into. +4. The default is to have four “bundles” for a namespace. +5. When the traffic increases on a given bundle, it is split in two and reassigned to a different broker. +6. There are some adjustable thresholds that can be used to control when the split happens, based on the number of topics/partitions, messages in/out, bytes in/out, and so on. +7. It’s also possible to specify a higher number of bundles when creating a namespace. +8. The load-manager threshold controls when a broker should offload some of the bundles to other brokers. -### What is the lifecycle of subscription? -Once it’s created, it retains all messages published after that (minus explicit TTL). Subscriptions can be dropped by explicitly unsubscribing (in `Consumer` API) or through the REST/CLI . +### What is the life-cycle of subscription? +When a subscription is created, it retains all messages published after that (minus explicit TTL). You can drop subscriptions by explicitly unsubscribing (in `Consumer` API) or through the REST/CLI . ### What is a bundle? -In Pulsar, "namespaces" are the administrative unit: you can configure most options on a namespace and they will be applied on the topics contained on the namespace. It gives the convenience of doing settings and operations on a group of topics rather than doing it once per topic. +In Pulsar, "namespace" is the administrative unit: you can configure most options on a namespace, and the configuration is applied on the topics contained on the namespace. It is convenient to configure settings and operations on a group of topics rather than doing it once per topic. -In general, the pattern is to use a namespace for each user application. So a single user/tenant, can create multiple namespaces to manage its own applications. +In general, the pattern is to use a namespace for each user application. So a single user/tenant can create multiple namespaces to manage its own applications. -When it comes to topics, we need a way to assign topics to brokers, control the load and move them if a broker becomes overloaded. Rather that doing this operations per each single topic (ownership, load-monitoring, assigning), we do it in bundles, or "groups of topics". +Concerning topics, topics are assigned to brokers, control the load and move them if a broker becomes overloaded. Rather than doing these operations per each single topic (ownership, load-monitoring, assigning), we do it in bundles, or "groups of topics". Review comment: so shall we remove it or refine it? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: users@infra.apache.org With regards, Apache Git Services