Modified: helix/site-content/1.0.1-docs/tutorial_agent.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_agent.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_agent.html (original) +++ helix/site-content/1.0.1-docs/tutorial_agent.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Helix Agent</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header>
Modified: helix/site-content/1.0.1-docs/tutorial_cloud_support.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_cloud_support.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_cloud_support.html (original) +++ helix/site-content/1.0.1-docs/tutorial_cloud_support.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Cloud Support</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_controller.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_controller.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_controller.html (original) +++ helix/site-content/1.0.1-docs/tutorial_controller.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Controller</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_customized_view.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_customized_view.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_customized_view.html (original) +++ helix/site-content/1.0.1-docs/tutorial_customized_view.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Customized View</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Added: helix/site-content/1.0.1-docs/tutorial_distributed_lock.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_distributed_lock.html?rev=1890233&view=auto ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_distributed_lock.html (added) +++ helix/site-content/1.0.1-docs/tutorial_distributed_lock.html Wed May 26 21:09:44 2021 @@ -0,0 +1,408 @@ + +<!DOCTYPE html> +<!-- + Generated by Apache Maven Doxia at 2021-05-26 + Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) +--> +<html xml:lang="en" lang="en"> + + <head> + <meta charset="UTF-8" /> + <title>Apache Helix - Tutorial - Distributed Lock</title> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /> + <meta name="description" content="" /> + <meta http-equiv="content-language" content="en" /> + + <link href="./css/bootstrap.min.css" rel="stylesheet" /> + <link href="./css/bootstrap-responsive.min.css" rel="stylesheet" /> + <link href="./css/docs.css" rel="stylesheet" /> + <link href="./css/reflow-skin.css" rel="stylesheet" /> + + + <link href="./css/lightbox.css" rel="stylesheet" /> + + <link href="./css/site.css" rel="stylesheet" /> + <link href="./css/print.css" rel="stylesheet" media="print" /> + + <!-- Le HTML5 shim, for IE6-8 support of HTML5 elements --> + <!--[if lt IE 9]> + <script src="http://html5shim.googlecode.com/svn/trunk/html5.js";></script> + <![endif]--> + +<script type="text/javascript">var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-3211522-12']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; + var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); + })();</script> + </head> + + <body class="page-tutorial_distributed_lock project-101-docs" data-spy="scroll" data-offset="60" data-target="#toc-scroll-target"> + + <div class="navbar navbar-fixed-top"> + <div class="navbar-inner"> + <div class="container"> + <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse"> + <span class="icon-bar"></span> + <span class="icon-bar"></span> + <span class="icon-bar"></span> + </a> + <a class="brand" href="..">Apache Helix</a> + <div class="nav-collapse"> + <ul class="nav pull-right"> + <li><a href="index.html" title="Helix 1.0.1">Helix 1.0.1 </a></li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Get Helix <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="download.html" title="Download">Download </a></li> + <li><a href="Building.html" title="Building">Building </a></li> + <li><a href="releasenotes/release-1.0.1.html" title="Release Notes">Release Notes </a></li> + </ul> + </li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Hands-On <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="Quickstart.html" title="Quick Start">Quick Start </a></li> + <li><a href="Tutorial.html" title="Tutorial">Tutorial </a></li> + <li><a href="../javadocs/1.0.1" title="Javadocs">Javadocs </a></li> + </ul> + </li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Recipes <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="recipes/lock_manager.html" title="Distributed lock manager">Distributed lock manager </a></li> + <li><a href="recipes/rabbitmq_consumer_group.html" title="Rabbit MQ consumer group">Rabbit MQ consumer group </a></li> + <li><a href="recipes/rsync_replicated_file_store.html" title="Rsync replicated file store">Rsync replicated file store </a></li> + <li><a href="recipes/service_discovery.html" title="Service discovery">Service discovery </a></li> + <li><a href="recipes/task_dag_execution.html" title="Distributed task DAG execution">Distributed task DAG execution </a></li> + </ul> + </li> + </ul> + </div><!--/.nav-collapse --> + </div> + </div> + </div> + + <div class="container"> + + <!-- Masthead + ================================================== --> + <header class="jumbotron subhead"> + <div class="row" id="banner"> + <div class="span12"> + <div class="pull-left"> + <a href="../" id="bannerLeft"><img src="../images/helix-logo.jpg" alt='"''"' /></a> + <p class="lead">A cluster management framework for partitioned and replicated distributed resources</p> + </div> + <div class="pull-right"> + <a href="http://www.apache.org/"; id="bannerRight"><img src="../images/feather_small.gif" alt='"''"' /></a> + </div> + </div> + </div> + <div> + <ul class="breadcrumb"> + <li><a href="../" title="Apache Helix">Apache Helix </a></li> + <li class="divider">/</li> + <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> + <li class="divider">/</li> + <li> Tutorial - Distributed Lock</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> + </ul> + </div> + </header> + + <div class="main-body"> + <div class="row"> + <div class="span12"> + <div class="body-content"> +<!-- - +Licensed to the Apache Software Foundation (ASF) under one +or more contributor license agreements. See the NOTICE file +distributed with this work for additional information +regarding copyright ownership. The ASF licenses this file +to you under the Apache License, Version 2.0 (the +"License"); you may not use this file except in compliance +with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an +"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +KIND, either express or implied. See the License for the +specific language governing permissions and limitations +under the License. --> +<p></p> +<div class="section"> + <div class="page-header"> + <h2 id="Helix_Tutorial:_Distributed_Lock"><a href="./Tutorial.html">Helix Tutorial</a>: Distributed Lock</h2> + </div> + <p>In a distributed system, there are many cases that we need a mechanism to make sure different processes can cooperate correctly. For example, if two processes that run on different machines, or different networks, or even different data centers would like to work on the same resource, we must have a mutually exclusive lock to ensure that their operations do not step on each other. Only when a process acquires the lock, it can perform the operation. </p> + <p>Since Helix is built on top of ZooKeeper, which is a widely used framework to manage coordination across a cluster of machines, a natural solution for implementing a distributed lock is to leverage ZooKeeper. Specifically, we can represent the lock itself as a znode. Currently, many distributed systems use Apache Helix as a generic cluster management framework to automatically manage resources hosted on a cluster of nodes. Implementing a distributed lock in Helix would allow Helixâs existing customers to use a reliable lock with little overhead.</p> + <div class="section"> + <h3 id="Helix_Lock_Interface">Helix Lock Interface</h3> + <p>Helix provides a generic lock interface that can be implemented with different kinds of locks. Several key functions are defined in the interface.</p> + <div class="source"> + <pre>/** + * Generic interface for Helix distributed lock + */ +public interface DistributedLock { + /** + * Blocking call to acquire a lock if it is free at the time of request + * @return true if the lock was successfully acquired, + * false if the lock could not be acquired + */ + boolean tryLock(); + + /** + * Blocking call to unlock a lock + * @return true if the lock was successfully released or if the locked is not currently locked, + * false if the lock is not locked by the user or the unlock operation failed + */ + boolean unlock(); + + /** + * Retrieve the information of the current lock on the resource this lock object specifies, e.g. lock timeout, lock message, etc. + * @return lock metadata information + */ + LockInfo getCurrentLockInfo(); + + /** + * If the user is current lock owner of the resource + * @return true if the user is the lock owner, + * false if the user is not the lock owner or the lock doesn't have a owner + */ + boolean isCurrentOwner(); + + /** + * Call this method to close the lock's zookeeper connection + * The lock has to be unlocked or expired before this method can be called + */ + void close(); +} +</pre> + </div> + <p>Currently, Helix supports two kinds of locks. One is basic lock, and the other is priority lock. We will describe their definition and usage as follows.</p> + </div> + <div class="section"> + <h3 id="Helix_Basic_Lock">Helix Basic Lock</h3> + <div class="section"> + <h4 id="Features">Features</h4> + <ul> + <li> <p>Non-blocking lock. It means every request to acquire the lock will immediately get a result (success or failure) instead of waiting until the lock is successfully acquired.</p></li> + <li> <p>Timeout support. A client needs to input the timeout when it tries to acquire the lock. We use lazy timeout for the lock. It means even after the timeout, if no other client tries to get the lock, the client can still keep the lock, if other client tries to acquire the lock, and finds the previous client already timed out, the previous client will automatically lose the lock.</p></li> + <li> <p>Lock message support. A client can input the reason for the lock (as a string) when it tries to acquire the lock. This enables future lock operation, when fails, can know the reason from the lock message of the current lock. </p></li> + <li> <p>Java API support for clients to use the lock.</p></li> + <li> <p>No notification support. When a client loses its lock after the timeout or due to some urgent maintenance work who does not check the lock, there is no notification sent out to the previous lock owner.</p></li> + </ul> + </div> + <div class="section"> + <h4 id="How_to_Use_Helix_Basic_Lock">How to Use Helix Basic Lock</h4> + <p>The implementation of Helix lock is called âZkHelixNonblockingLockâ. It has two different constructors as shown below. One constructor takes clusterName, and HelixConfigScope as inputs. HelixConfigScope can be âclusterâ, âparticipantâ, or âresourceâ. The other constructor takes a lockPath string as input. ``` /** * Initialize the lock with Helix scope. */ public ZKHelixNonblockingLock(String clusterName, HelixConfigScope scope, String zkAddress, Long timeout, String lockMsg) </p> + <p>/** * Initialize the lock with lock path under zookeeper. */ public ZKHelixNonblockingLock(String lockPath, String zkAddress, Long timeout, String lockMsg) ```</p> + <p>The client can use the lock in two different ways. If the client would like to use the lock for some specific Helix resource, it can use the first constructor which requires clusterName and HelixConfigScope. We show an example below on how to use Helix scope. Or the client may choose to use the lock for generic purpose, basically on any resource they have. In this case, the client needs to provide the lock path, which is a string, and it represents where the lock should exist under zookeeper. <tt> List<String> pathKeys = new ArrayList<>(); pathKeys.add(clusterName); HelixLockScope participantScope = new HelixLockScope(HelixLockScope.LockScopeProperty.CLUSTER, pathKeys); </tt></p> + <p>Note that if users have onboarded to ZooScalability that has multiple realms, they should instead use the builder instead of the above constructors.</p> + </div> + </div> + <div class="section"> + <h3 id="Helix_Priority_Lock">Helix Priority Lock</h3> + <div class="section"> + <h4 id="Features">Features</h4> + <ul> + <li>Priority support. A client with higher priority can override lock owned by a client with lower priority.</li> + <li>Notification support. After the higher priority client overrides the lock owned by lower priority client, the low priority client will get notified.</li> + <li>Cleanup support. The low priority client will be given some time to do the cleanup and roll back the system to normal state when its lock is preempted.</li> + </ul> + </div> + <div class="section"> + <h4 id="Priority_Lock_Definitions">Priority Lock Definitions</h4> + <p>There are a few concepts defined for priority lock. </p> + <div class="section"> + <h5 id="Definition_1:_Priority_of_the_lock.">Definition 1: Priority of the lock.</h5> + <p>Any client that wants to acquire a lock needs to have a priority so that Helix knows what to do when there are multiple clients that want the same lock. We accept non-negative integers as meaningful priority representation. The lowest priority is 0. The larger the number, the higher the priority is. Same number denotes the same priority. We do not have an upper limit for the priority definition. However, we reserve the value of INT_MAX for emergency use by SREs, i.e., they may override all other priorities in case of urgent operations. If a client does not have a priority defined when it tries to acquire the lock, the default value 0 will be assigned to the client and thus the client is with lowest priority. </p> + </div> + <div class="section"> + <h5 id="Definition_2:_Timeout_of_the_lock.">Definition 2: Timeout of the lock.</h5> + <p>When a request for a lock is issued, there can be three types of timeout associated with the lock. We explain them respectively as follows.</p> + <ul> + <li> <p>lease timeout: it is the userâs requirement of how long the lease it needs. It denotes how long it takes to finish the work by the client that requires the locked resource. This is the same concept as the timeout in basic lock. This field must be set to a positive value. Otherwise the lock is meaningless.</p></li> + <li> <p>cleanup timeout: it defines how long it takes for a client to clean up the work done with the locked resource and bring back the resource to a clean state if the client is preempted by a higher priority client. If a user does not define this field, the clean up timeout will be set to the default value 0, meaning no cleanup work is needed. Once there is a higher priority client requested the lock, the lock will be immediately given to the high priority one after the notification is sent to the low priority client. </p></li> + <li> <p>waiting timeout: it defines how long the client that requests the lock can wait for the lower priority client to finish the cleanup work. Specifically, if the work is urgent to get executed, a client should set a shorter waiting timeout. To the extreme, if users set the waiting timeout to be 0, the lock will be acquired immediately. If the waiting timeout is not set, it will be default as infinite, meaning that the high priority client will not get the lock until the low priority client finishes all the cleanup work. </p></li> + </ul> + <p>The three timeout are specific to the particular client that requests the lock and should be independent of each other. In short, the lease timeout includes all the time needed in normal operation (perform the work, clean up when work is completed, etc.); cleanup timeout is userâs best estimate of time needed for reverting the system to previous stable state in case of preemption; waiting timeout shows how urgent the client needs to acquire the lock. Please note that it is possible that a clientâs waiting timeout is shorter than the other clientâs cleanup timeout. In this case, the clientâs waiting timeout will override the other clientâs cleanup timeout. We always honor the waiting timeout of the high priority client before cleanup timeout of the low priority client when there is a contention for the lock. Lock users should be responsible for setting up different timeout of their locks. However, it is possible that at the beginning they can only prov ide an estimation for the timeout which is not accurate enough. Either Helix or user code could implement some statistic logic to analyze the real execution or clean up times used. For example, Helix may be able to calculate how many times the workflow finishes the cleanup job in the designated cleanup timeout, and if not, what is the real cleanup time (in case that the waiting timeout is larger). Based on the results, users could tune their timeout to better handle lock preemption. </p> + </div> + <div class="section"> + <h5 id="Definition_3:_Forcefulness_of_the_lock">Definition 3: Forcefulness of the lock</h5> + <p>Forcefulness means whether a lock requested by a client is forceful or not in case of a preemption. If it is a forceful lock, when time is out, no matter whether the cleanup work of low priority client is finished or not, the high priority client will grab the lock from low priority client. However, if it is not a forceful lock, the high priority client will receive an exception, knowing that the low priority client has not finished its work yet. Then it is up to human beings to decide what is the next step. We could trigger an alert based on this kind of exception. Users can set up an approval workflow to act based on the alert. They may manually check the exception and the previous lock owner to make the decision on whether they will respect the previous ownerâs work or forcefully grab the lock. Or later with some experience on handling these exceptions, they can also make the process fully automatic. For example, with low priority client A and high priority client B, if in the case of exception thrown during preemption, user always chooses to forcefully grab the lock and assign the lock owner to B, we may have a rule set up for this condition which will automatically transfer the lock owner.</p> + </div> + </div> + <div class="section"> + <h4 id="Priority_Lock_Workflow">Priority Lock Workflow</h4> + <p>To better visualize the above analysis, we draw the following diagram shows how a client may go through the possible scenarios. <img src="./images/HelixPriorityLockWorkflow.jpeg" alt="HelixPriorityLockWorkflow" /></p> + </div> + <div class="section"> + <h4 id="Priority_Lock_Usage">Priority Lock Usage</h4> + <div class="section"> + <h5 id="Lock_information_Definition">Lock information Definition</h5> + <div class="source"> + <pre> public enum LockInfoAttribute { + OWNER, + MESSAGE, + TIMEOUT, + PRIORITY, + WAITING_TIMEOUT, + CLEANUP_TIMEOUT, + REQUESTOR_ID, + REQUESTOR_PRIORITY, + REQUESTOR_WAITING_TIMEOUT, + REQUESTING_TIMESTAMP + } +</pre> + </div> + </div> + <div class="section"> + <h5 id="Priority_Lock_Constructor">Priority Lock Constructor</h5> + <div class="source"> + <pre> /** + * Internal construction of the lock with user provided information, e.g., lock path under + * zookeeper, etc. + * @param lockPath the path of the lock under Zookeeper + * @param leaseTimeout the leasing timeout period of the lock + * @param lockMsg the reason for having this lock + * @param userId a universal unique userId for lock owner identity + * @param priority the priority of the lock + * @param waitingTimeout the waiting timeout period of the lock when the tryLock request is issued + * @param cleanupTimeout the time period needed to finish the cleanup work by the lock when it + * is preempted + * @param isForceful whether the lock is a forceful one. This determines the behavior when the + * lock encountered an exception during preempting lower priority lock + * @param lockListener the listener associated to the lock + * @param baseDataAccessor baseDataAccessor instance to do I/O against ZK with + */ + private ZKDistributedNonblockingLock(String lockPath, Long leaseTimeout, String lockMsg, + String userId, int priority, long waitingTimeout, long cleanupTimeout, boolean isForceful, + LockListener lockListener, BaseDataAccessor<ZNRecord> baseDataAccessor) +</pre> + </div> + </div> + <div class="section"> + <h5 id="Priority_Lock_Usage_Example:">Priority Lock Usage Example:</h5> + <div class="source"> + <pre> ZKDistributedNonblockingLock.Builder lockBuilder = new ZKDistributedNonblockingLock.Builder(); + lockBuilder.setLockScope(new HelixLockScope(HelixLockScope.LockScopeProperty.CLUSTER, pathKeys)).setZkAddress(ZK_ADDR).setTimeout(3600000L) + .setLockMsg("test lock").setUserId("test Id").setPriority(0).setWaitingTimeout(1000) + .setCleanupTimeout(2000).setIsForceful(false) + .setLockListener(new LockListener() {@Override public void onCleanupNotification() {}); + ZKDistributedNonblockingLock testLock = lockBuilder.build(); +</pre> + </div> + </div> + </div> + </div> +</div> + </div> + </div> + </div> + </div> + + </div><!-- /container --> + + <!-- Footer + ================================================== --> + <footer class="well"> + <div class="container"> + <div class="row"> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Get Helix</li> + <li> + <a href="download.html" title="Download">Download </a> + </li> + <li> + <a href="Building.html" title="Building">Building </a> + </li> + <li> + <a href="releasenotes/release-1.0.1.html" title="Release Notes">Release Notes </a> + </li> + </ul> + </div> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Hands-On</li> + <li> + <a href="Quickstart.html" title="Quick Start">Quick Start </a> + </li> + <li> + <a href="Tutorial.html" title="Tutorial">Tutorial </a> + </li> + <li> + <a href="../javadocs/1.0.1" title="Javadocs">Javadocs </a> + </li> + </ul> + </div> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Recipes</li> + <li> + <a href="recipes/lock_manager.html" title="Distributed lock manager">Distributed lock manager </a> + </li> + <li> + <a href="recipes/rabbitmq_consumer_group.html" title="Rabbit MQ consumer group">Rabbit MQ consumer group </a> + </li> + <li> + <a href="recipes/rsync_replicated_file_store.html" title="Rsync replicated file store">Rsync replicated file store </a> + </li> + <li> + <a href="recipes/service_discovery.html" title="Service discovery">Service discovery </a> + </li> + <li> + <a href="recipes/task_dag_execution.html" title="Distributed task DAG execution">Distributed task DAG execution </a> + </li> + </ul> + </div> + </div> + </div> + </footer> + + <div class="container subfooter"> + <div class="row"> + <div class="span12"> + <p class="pull-right"><a href="#">Back to top</a></p> + <p class="copyright">Copyright ©2021 <a href="http://www.apache.org/";>The Apache Software Foundation</a>. All Rights Reserved.</p> + <p><a href="http://github.com/andriusvelykis/reflow-maven-skin"; title="Reflow Maven skin">Reflow Maven skin</a> by <a href="http://andrius.velykis.lt"; target="_blank" title="Andrius Velykis">Andrius Velykis</a>.</p> + +<div class="row span16"> + <div>Apache Helix, Apache, the Apache feather logo, and the Apache Helix project logos are trademarks of The Apache Software Foundation. + All other marks mentioned may be trademarks or registered trademarks of their respective owners.</div> + <a href="http://helix.apache.org/1.0.1-docs/privacy-policy.html";>Privacy Policy</a> +</div> </div> + </div> + </div> + + <!-- Le javascript + ================================================== --> + <!-- Placed at the end of the document so the pages load faster --> + + <!-- Fallback jQuery loading from Google CDN: + http://stackoverflow.com/questions/1014203/best-way-to-use-googles-hosted-jquery-but-fall-back-to-my-hosted-library-on-go --> + <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js";></script> + <script type="text/javascript"> + if (typeof jQuery == 'undefined') + { + document.write(unescape("%3Cscript src='./js/jquery-1.8.3.min.js' type='text/javascript'%3E%3C/script%3E")); + } + </script> + + <script src="./js/bootstrap.min.js"></script> + <script src="./js/lightbox.js"></script> + <script src="./js/jquery.smooth-scroll.min.js"></script> + <!-- back button support for smooth scroll --> + <script src="./js/jquery.ba-bbq.min.js"></script> + + <script src="./js/reflow-skin.js"></script> + + </body> +</html> \ No newline at end of file Modified: helix/site-content/1.0.1-docs/tutorial_health.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_health.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_health.html (original) +++ helix/site-content/1.0.1-docs/tutorial_health.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Customizing Heath Checks</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_messaging.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_messaging.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_messaging.html (original) +++ helix/site-content/1.0.1-docs/tutorial_messaging.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Messaging</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_participant.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_participant.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_participant.html (original) +++ helix/site-content/1.0.1-docs/tutorial_participant.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Participant</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_propstore.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_propstore.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_propstore.html (original) +++ helix/site-content/1.0.1-docs/tutorial_propstore.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Application Property Store</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_rebalance.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_rebalance.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_rebalance.html (original) +++ helix/site-content/1.0.1-docs/tutorial_rebalance.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Rebalancing Algorithms</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_rest_service.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_rest_service.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_rest_service.html (original) +++ helix/site-content/1.0.1-docs/tutorial_rest_service.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - REST Service 2.0</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_spectator.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_spectator.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_spectator.html (original) +++ helix/site-content/1.0.1-docs/tutorial_spectator.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Spectator</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_state.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_state.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_state.html (original) +++ helix/site-content/1.0.1-docs/tutorial_state.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - State Machine Configuration</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_task_framework.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_task_framework.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_task_framework.html (original) +++ helix/site-content/1.0.1-docs/tutorial_task_framework.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Task Framework</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_task_throttling.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_task_throttling.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_task_throttling.html (original) +++ helix/site-content/1.0.1-docs/tutorial_task_throttling.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Task Throttling</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_throttling.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_throttling.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_throttling.html (original) +++ helix/site-content/1.0.1-docs/tutorial_throttling.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Throttling</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_ui.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_ui.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_ui.html (original) +++ helix/site-content/1.0.1-docs/tutorial_ui.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - Helix UI Setup</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_user_content_store.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_user_content_store.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_user_content_store.html (original) +++ helix/site-content/1.0.1-docs/tutorial_user_content_store.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - User Defined Content Store for Tasks</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_user_def_rebalancer.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_user_def_rebalancer.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_user_def_rebalancer.html (original) +++ helix/site-content/1.0.1-docs/tutorial_user_def_rebalancer.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - User-Defined Rebalancing</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Modified: helix/site-content/1.0.1-docs/tutorial_yaml.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.1-docs/tutorial_yaml.html?rev=1890233&r1=1890232&r2=1890233&view=diff ============================================================================== --- helix/site-content/1.0.1-docs/tutorial_yaml.html (original) +++ helix/site-content/1.0.1-docs/tutorial_yaml.html Wed May 26 21:09:44 2021 @@ -1,7 +1,7 @@ <!DOCTYPE html> <!-- - Generated by Apache Maven Doxia at 2021-02-01 + Generated by Apache Maven Doxia at 2021-05-26 Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) --> <html xml:lang="en" lang="en"> @@ -109,7 +109,7 @@ <li><a href="./" title="Release 1.0.1">Release 1.0.1 </a></li> <li class="divider">/</li> <li> Tutorial - YAML Cluster Setup</li> - <li class="publishDate version-date pull-right">Last Published: 2021-02-01</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> </ul> </div> </header> Added: helix/site-content/1.0.2-docs/.htaccess URL: http://svn.apache.org/viewvc/helix/site-content/1.0.2-docs/.htaccess?rev=1890233&view=auto ============================================================================== --- helix/site-content/1.0.2-docs/.htaccess (added) +++ helix/site-content/1.0.2-docs/.htaccess Wed May 26 21:09:44 2021 @@ -0,0 +1,20 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +# + +Redirect /download.html /download.cgi Added: helix/site-content/1.0.2-docs/Building.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.2-docs/Building.html?rev=1890233&view=auto ============================================================================== --- helix/site-content/1.0.2-docs/Building.html (added) +++ helix/site-content/1.0.2-docs/Building.html Wed May 26 21:09:44 2021 @@ -0,0 +1,267 @@ + +<!DOCTYPE html> +<!-- + Generated by Apache Maven Doxia at 2021-05-26 + Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) +--> +<html xml:lang="en" lang="en"> + + <head> + <meta charset="UTF-8" /> + <title>Apache Helix - Build Instructions</title> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /> + <meta name="description" content="" /> + <meta http-equiv="content-language" content="en" /> + + <link href="./css/bootstrap.min.css" rel="stylesheet" /> + <link href="./css/bootstrap-responsive.min.css" rel="stylesheet" /> + <link href="./css/docs.css" rel="stylesheet" /> + <link href="./css/reflow-skin.css" rel="stylesheet" /> + + + <link href="./css/lightbox.css" rel="stylesheet" /> + + <link href="./css/site.css" rel="stylesheet" /> + <link href="./css/print.css" rel="stylesheet" media="print" /> + + <!-- Le HTML5 shim, for IE6-8 support of HTML5 elements --> + <!--[if lt IE 9]> + <script src="http://html5shim.googlecode.com/svn/trunk/html5.js";></script> + <![endif]--> + +<script type="text/javascript">var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-3211522-12']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; + var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); + })();</script> + </head> + + <body class="page-building project-102-docs" data-spy="scroll" data-offset="60" data-target="#toc-scroll-target"> + + <div class="navbar navbar-fixed-top"> + <div class="navbar-inner"> + <div class="container"> + <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse"> + <span class="icon-bar"></span> + <span class="icon-bar"></span> + <span class="icon-bar"></span> + </a> + <a class="brand" href="..">Apache Helix</a> + <div class="nav-collapse"> + <ul class="nav pull-right"> + <li><a href="index.html" title="Helix 1.0.2">Helix 1.0.2 </a></li> + <li class="dropdown active"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Get Helix <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="download.html" title="Download">Download </a></li> + <li class="active"><a href="" title="Building">Building </a></li> + <li><a href="releasenotes/release-1.0.2.html" title="Release Notes">Release Notes </a></li> + </ul> + </li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Hands-On <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="Quickstart.html" title="Quick Start">Quick Start </a></li> + <li><a href="Tutorial.html" title="Tutorial">Tutorial </a></li> + <li><a href="../javadocs/1.0.2" title="Javadocs">Javadocs </a></li> + </ul> + </li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Recipes <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="recipes/lock_manager.html" title="Distributed lock manager">Distributed lock manager </a></li> + <li><a href="recipes/rabbitmq_consumer_group.html" title="Rabbit MQ consumer group">Rabbit MQ consumer group </a></li> + <li><a href="recipes/rsync_replicated_file_store.html" title="Rsync replicated file store">Rsync replicated file store </a></li> + <li><a href="recipes/service_discovery.html" title="Service discovery">Service discovery </a></li> + <li><a href="recipes/task_dag_execution.html" title="Distributed task DAG execution">Distributed task DAG execution </a></li> + </ul> + </li> + </ul> + </div><!--/.nav-collapse --> + </div> + </div> + </div> + + <div class="container"> + + <!-- Masthead + ================================================== --> + <header class="jumbotron subhead"> + <div class="row" id="banner"> + <div class="span12"> + <div class="pull-left"> + <a href="../" id="bannerLeft"><img src="../images/helix-logo.jpg" alt='"''"' /></a> + <p class="lead">A cluster management framework for partitioned and replicated distributed resources</p> + </div> + <div class="pull-right"> + <a href="http://www.apache.org/"; id="bannerRight"><img src="../images/feather_small.gif" alt='"''"' /></a> + </div> + </div> + </div> + <div> + <ul class="breadcrumb"> + <li><a href="../" title="Apache Helix">Apache Helix </a></li> + <li class="divider">/</li> + <li><a href="./" title="Release 1.0.2">Release 1.0.2 </a></li> + <li class="divider">/</li> + <li>Build Instructions</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> + </ul> + </div> + </header> + + <div class="main-body"> + <div class="row"> + <div class="span12"> + <div class="body-content"> +<!-- - +Licensed to the Apache Software Foundation (ASF) under one +or more contributor license agreements. See the NOTICE file +distributed with this work for additional information +regarding copyright ownership. The ASF licenses this file +to you under the Apache License, Version 2.0 (the +"License"); you may not use this file except in compliance +with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an +"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +KIND, either express or implied. See the License for the +specific language governing permissions and limitations +under the License. --> +<div class="section"> + <div class="page-header"> + <h2 id="Build_Instructions">Build Instructions</h2> + </div> + <div class="section"> + <h3 id="From_Source">From Source</h3> + <p>Requirements: JDK 1.8+, Maven 3.5.0+</p> + <div class="source"> + <pre>git clone https://git-wip-us.apache.org/repos/asf/helix.git +cd helix +git checkout tags/helix-1.0.2 +mvn install package -DskipTests +</pre> + </div> + </div> + <div class="section"> + <h3 id="Maven_Dependency">Maven Dependency</h3> + <div class="source"> + <pre><dependency> + <groupId>org.apache.helix</groupId> + <artifactId>helix-core</artifactId> + <version>1.0.2</version> +</dependency> +</pre> + </div> + </div> +</div> + </div> + </div> + </div> + </div> + + </div><!-- /container --> + + <!-- Footer + ================================================== --> + <footer class="well"> + <div class="container"> + <div class="row"> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Get Helix</li> + <li> + <a href="download.html" title="Download">Download </a> + </li> + <li class="active"> + <a href="#" title="Building">Building </a> + </li> + <li> + <a href="releasenotes/release-1.0.2.html" title="Release Notes">Release Notes </a> + </li> + </ul> + </div> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Hands-On</li> + <li> + <a href="Quickstart.html" title="Quick Start">Quick Start </a> + </li> + <li> + <a href="Tutorial.html" title="Tutorial">Tutorial </a> + </li> + <li> + <a href="../javadocs/1.0.2" title="Javadocs">Javadocs </a> + </li> + </ul> + </div> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Recipes</li> + <li> + <a href="recipes/lock_manager.html" title="Distributed lock manager">Distributed lock manager </a> + </li> + <li> + <a href="recipes/rabbitmq_consumer_group.html" title="Rabbit MQ consumer group">Rabbit MQ consumer group </a> + </li> + <li> + <a href="recipes/rsync_replicated_file_store.html" title="Rsync replicated file store">Rsync replicated file store </a> + </li> + <li> + <a href="recipes/service_discovery.html" title="Service discovery">Service discovery </a> + </li> + <li> + <a href="recipes/task_dag_execution.html" title="Distributed task DAG execution">Distributed task DAG execution </a> + </li> + </ul> + </div> + </div> + </div> + </footer> + + <div class="container subfooter"> + <div class="row"> + <div class="span12"> + <p class="pull-right"><a href="#">Back to top</a></p> + <p class="copyright">Copyright ©2021 <a href="http://www.apache.org/";>The Apache Software Foundation</a>. All Rights Reserved.</p> + <p><a href="http://github.com/andriusvelykis/reflow-maven-skin"; title="Reflow Maven skin">Reflow Maven skin</a> by <a href="http://andrius.velykis.lt"; target="_blank" title="Andrius Velykis">Andrius Velykis</a>.</p> + +<div class="row span16"> + <div>Apache Helix, Apache, the Apache feather logo, and the Apache Helix project logos are trademarks of The Apache Software Foundation. + All other marks mentioned may be trademarks or registered trademarks of their respective owners.</div> + <a href="http://helix.apache.org/1.0.2-docs/privacy-policy.html";>Privacy Policy</a> +</div> </div> + </div> + </div> + + <!-- Le javascript + ================================================== --> + <!-- Placed at the end of the document so the pages load faster --> + + <!-- Fallback jQuery loading from Google CDN: + http://stackoverflow.com/questions/1014203/best-way-to-use-googles-hosted-jquery-but-fall-back-to-my-hosted-library-on-go --> + <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js";></script> + <script type="text/javascript"> + if (typeof jQuery == 'undefined') + { + document.write(unescape("%3Cscript src='./js/jquery-1.8.3.min.js' type='text/javascript'%3E%3C/script%3E")); + } + </script> + + <script src="./js/bootstrap.min.js"></script> + <script src="./js/lightbox.js"></script> + <script src="./js/jquery.smooth-scroll.min.js"></script> + <!-- back button support for smooth scroll --> + <script src="./js/jquery.ba-bbq.min.js"></script> + + <script src="./js/reflow-skin.js"></script> + + </body> +</html> \ No newline at end of file Added: helix/site-content/1.0.2-docs/Features.html URL: http://svn.apache.org/viewvc/helix/site-content/1.0.2-docs/Features.html?rev=1890233&view=auto ============================================================================== --- helix/site-content/1.0.2-docs/Features.html (added) +++ helix/site-content/1.0.2-docs/Features.html Wed May 26 21:09:44 2021 @@ -0,0 +1,475 @@ + +<!DOCTYPE html> +<!-- + Generated by Apache Maven Doxia at 2021-05-26 + Rendered using Maven Reflow Skin 1.0.0 (http://andriusvelykis.github.com/reflow-maven-skin) +--> +<html xml:lang="en" lang="en"> + + <head> + <meta charset="UTF-8" /> + <title>Apache Helix - Features</title> + <meta name="viewport" content="width=device-width, initial-scale=1.0" /> + <meta name="description" content="" /> + <meta http-equiv="content-language" content="en" /> + + <link href="./css/bootstrap.min.css" rel="stylesheet" /> + <link href="./css/bootstrap-responsive.min.css" rel="stylesheet" /> + <link href="./css/docs.css" rel="stylesheet" /> + <link href="./css/reflow-skin.css" rel="stylesheet" /> + + + <link href="./css/lightbox.css" rel="stylesheet" /> + + <link href="./css/site.css" rel="stylesheet" /> + <link href="./css/print.css" rel="stylesheet" media="print" /> + + <!-- Le HTML5 shim, for IE6-8 support of HTML5 elements --> + <!--[if lt IE 9]> + <script src="http://html5shim.googlecode.com/svn/trunk/html5.js";></script> + <![endif]--> + +<script type="text/javascript">var _gaq = _gaq || []; + _gaq.push(['_setAccount', 'UA-3211522-12']); + _gaq.push(['_trackPageview']); + + (function() { + var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; + ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; + var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); + })();</script> + </head> + + <body class="page-features project-102-docs" data-spy="scroll" data-offset="60" data-target="#toc-scroll-target"> + + <div class="navbar navbar-fixed-top"> + <div class="navbar-inner"> + <div class="container"> + <a class="btn btn-navbar" data-toggle="collapse" data-target=".nav-collapse"> + <span class="icon-bar"></span> + <span class="icon-bar"></span> + <span class="icon-bar"></span> + </a> + <a class="brand" href="..">Apache Helix</a> + <div class="nav-collapse"> + <ul class="nav pull-right"> + <li><a href="index.html" title="Helix 1.0.2">Helix 1.0.2 </a></li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Get Helix <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="download.html" title="Download">Download </a></li> + <li><a href="Building.html" title="Building">Building </a></li> + <li><a href="releasenotes/release-1.0.2.html" title="Release Notes">Release Notes </a></li> + </ul> + </li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Hands-On <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="Quickstart.html" title="Quick Start">Quick Start </a></li> + <li><a href="Tutorial.html" title="Tutorial">Tutorial </a></li> + <li><a href="../javadocs/1.0.2" title="Javadocs">Javadocs </a></li> + </ul> + </li> + <li class="dropdown"> + <a href="#" class="dropdown-toggle" data-toggle="dropdown">Recipes <b class="caret"></b></a> + <ul class="dropdown-menu"> + <li><a href="recipes/lock_manager.html" title="Distributed lock manager">Distributed lock manager </a></li> + <li><a href="recipes/rabbitmq_consumer_group.html" title="Rabbit MQ consumer group">Rabbit MQ consumer group </a></li> + <li><a href="recipes/rsync_replicated_file_store.html" title="Rsync replicated file store">Rsync replicated file store </a></li> + <li><a href="recipes/service_discovery.html" title="Service discovery">Service discovery </a></li> + <li><a href="recipes/task_dag_execution.html" title="Distributed task DAG execution">Distributed task DAG execution </a></li> + </ul> + </li> + </ul> + </div><!--/.nav-collapse --> + </div> + </div> + </div> + + <div class="container"> + + <!-- Masthead + ================================================== --> + <header class="jumbotron subhead"> + <div class="row" id="banner"> + <div class="span12"> + <div class="pull-left"> + <a href="../" id="bannerLeft"><img src="../images/helix-logo.jpg" alt='"''"' /></a> + <p class="lead">A cluster management framework for partitioned and replicated distributed resources</p> + </div> + <div class="pull-right"> + <a href="http://www.apache.org/"; id="bannerRight"><img src="../images/feather_small.gif" alt='"''"' /></a> + </div> + </div> + </div> + <div> + <ul class="breadcrumb"> + <li><a href="../" title="Apache Helix">Apache Helix </a></li> + <li class="divider">/</li> + <li><a href="./" title="Release 1.0.2">Release 1.0.2 </a></li> + <li class="divider">/</li> + <li> Features</li> + <li class="publishDate version-date pull-right">Last Published: 2021-05-26</li> + </ul> + </div> + </header> + + <div class="main-body"> + <div class="row"> + <div class="span12"> + <div class="body-content"> +<!-- - +Licensed to the Apache Software Foundation (ASF) under one +or more contributor license agreements. See the NOTICE file +distributed with this work for additional information +regarding copyright ownership. The ASF licenses this file +to you under the Apache License, Version 2.0 (the +"License"); you may not use this file except in compliance +with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, +software distributed under the License is distributed on an +"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +KIND, either express or implied. See the License for the +specific language governing permissions and limitations +under the License. --> +<p></p> +<div class="section"> + <div class="page-header"> + <h2 id="Features">Features</h2> + </div> + <div class="section"> + <h3 id="CONFIGURING_IDEALSTATE">CONFIGURING IDEALSTATE</h3> + <p>Read concepts page for definition of Idealstate.</p> + <p>The placement of partitions in a DDS is very critical for reliability and scalability of the system. For example, when a node fails, it is important that the partitions hosted on that node are reallocated evenly among the remaining nodes. Consistent hashing is one such algorithm that can guarantee this. Helix by default comes with a variant of consistent hashing based of the RUSH algorithm. </p> + <p>This means given a number of partitions, replicas and number of nodes Helix does the automatic assignment of partition to nodes such that</p> + <ul> + <li>Each node has the same number of partitions and replicas of the same partition do not stay on the same node.</li> + <li>When a node fails, the partitions will be equally distributed among the remaining nodes</li> + <li>When new nodes are added, the number of partitions moved will be minimized along with satisfying the above two criteria.</li> + </ul> + <p>Helix provides multiple ways to control the placement and state of a replica. </p> + <div class="source"> + <pre> |AUTO REBALANCE| AUTO | CUSTOM | + ----------------------------------------- + LOCATION | HELIX | APP | APP | + ----------------------------------------- + STATE | HELIX | HELIX | APP | + ----------------------------------------- +</pre> + </div> + <div class="section"> + <h4 id="HELIX_EXECUTION_MODE">HELIX EXECUTION MODE</h4> + <p>Idealstate is defined as the state of the DDS when all nodes are up and running and healthy. Helix uses this as the target state of the system and computes the appropriate transitions needed in the system to bring it to a stable state. </p> + <p>Helix supports 3 different execution modes which allows application to explicitly control the placement and state of the replica.</p> + <div class="section"> + <h5 id="AUTO_REBALANCE">AUTO_REBALANCE</h5> + <p>When the idealstate mode is set to AUTO_REBALANCE, Helix controls both the location of the replica along with the state. This option is useful for applications where creation of a replica is not expensive. Example</p> + <div class="source"> + <pre>{ + "id" : "MyResource", + "simpleFields" : { + "IDEAL_STATE_MODE" : "AUTO_REBALANCE", + "NUM_PARTITIONS" : "3", + "REPLICAS" : "2", + "STATE_MODEL_DEF_REF" : "MasterSlave", + } + "listFields" : { + "MyResource_0" : [], + "MyResource_1" : [], + "MyResource_2" : [] + }, + "mapFields" : { + } +} +</pre> + </div> + <p>If there are 3 nodes in the cluster, then Helix will internally compute the ideal state as </p> + <div class="source"> + <pre>{ + "id" : "MyResource", + "simpleFields" : { + "NUM_PARTITIONS" : "3", + "REPLICAS" : "2", + "STATE_MODEL_DEF_REF" : "MasterSlave", + }, + "mapFields" : { + "MyResource_0" : { + "N1" : "MASTER", + "N2" : "SLAVE", + }, + "MyResource_1" : { + "N2" : "MASTER", + "N3" : "SLAVE", + }, + "MyResource_2" : { + "N3" : "MASTER", + "N1" : "SLAVE", + } + } +} +</pre> + </div> + <p>Another typical example is evenly distributing a group of tasks among the currently alive processes. For example, if there are 60 tasks and 4 nodes, Helix assigns 15 tasks to each node. When one node fails Helix redistributes its 15 tasks to the remaining 3 nodes. Similarly, if a node is added, Helix re-allocates 3 tasks from each of the 4 nodes to the 5th node. </p> + </div> + </div> + <div class="section"> + <h4 id="AUTO">AUTO</h4> + <p>When the idealstate mode is set to AUTO, Helix only controls STATE of the replicas where as the location of the partition is controlled by application. Example: The below idealstate indicates thats âMyResource_0â must be only on node1 and node2. But gives the control of assigning the STATE to Helix.</p> + <div class="source"> + <pre>{ + "id" : "MyResource", + "simpleFields" : { + "IDEAL_STATE_MODE" : "AUTO", + "NUM_PARTITIONS" : "3", + "REPLICAS" : "2", + "STATE_MODEL_DEF_REF" : "MasterSlave", + } + "listFields" : { + "MyResource_0" : [node1, node2], + "MyResource_1" : [node2, node3], + "MyResource_2" : [node3, node1] + }, + "mapFields" : { + } +} +</pre> + </div> + <p>In this mode when node1 fails, unlike in AUTO-REBALANCE mode the partition is not moved from node1 to others nodes in the cluster. Instead, Helix will decide to change the state of MyResource_0 in N2 based on the system constraints. For example, if a system constraint specified that there should be 1 Master and if the Master failed, then node2 will be made the new master. </p> + </div> + <div class="section"> + <h4 id="CUSTOM">CUSTOM</h4> + <p>Helix offers a third mode called CUSTOM, in which application can completely control the placement and state of each replica. Applications will have to implement an interface that Helix will invoke when the cluster state changes. Within this callback, the application can recompute the idealstate. Helix will then issue appropriate transitions such that Idealstate and Currentstate converges.</p> + <div class="source"> + <pre>{ + "id" : "MyResource", + "simpleFields" : { + "IDEAL_STATE_MODE" : "CUSTOM", + "NUM_PARTITIONS" : "3", + "REPLICAS" : "2", + "STATE_MODEL_DEF_REF" : "MasterSlave", + }, + "mapFields" : { + "MyResource_0" : { + "N1" : "MASTER", + "N2" : "SLAVE", + }, + "MyResource_1" : { + "N2" : "MASTER", + "N3" : "SLAVE", + }, + "MyResource_2" : { + "N3" : "MASTER", + "N1" : "SLAVE", + } + } +} +</pre> + </div> + <p>For example, the current state of the system might be âMyResource_0â -> {N1:MASTER,N2:SLAVE} and the application changes the ideal state to âMyResource_0â -> {N1:SLAVE,N2:MASTER}. Helix will not blindly issue MASTERâ>SLAVE to N1 and SLAVEâ>MASTER to N2 in parallel since it might result in a transient state where both N1 and N2 are masters. Helix will first issue MASTERâ>SLAVE to N1 and after its completed it will issue SLAVEâ>MASTER to N2. </p> + </div> + </div> + <div class="section"> + <h3 id="State_Machine_Configuration">State Machine Configuration</h3> + <p>Helix comes with 3 default state models that are most commonly used. Its possible to have multiple state models in a cluster. Every resource that is added should have a reference to the state model. </p> + <ul> + <li>MASTER-SLAVE: Has 3 states OFFLINE,SLAVE,MASTER. Max masters is 1. Slaves will be based on the replication factor. Replication factor can be specified while adding the resource</li> + <li>ONLINE-OFFLINE: Has 2 states OFFLINE and ONLINE. Very simple state model and most applications start off with this state model.</li> + <li>LEADER-STANDBY:1 Leader and many stand bys. In general the standbyâs are idle.</li> + </ul> + <p>Apart from providing the state machine configuration, one can specify the constraints of states and transitions.</p> + <p>For example one can say Master:1. Max number of replicas in Master state at any time is 1. OFFLINE-SLAVE:5 Max number of Offline-Slave transitions that can happen concurrently in the system</p> + <p>STATE PRIORITY Helix uses greedy approach to satisfy the state constraints. For example if the state machine configuration says it needs 1 master and 2 slaves but only 1 node is active, Helix must promote it to master. This behavior is achieved by providing the state priority list as MASTER,SLAVE.</p> + <p>STATE TRANSITION PRIORITY Helix tries to fire as many transitions as possible in parallel to reach the stable state without violating constraints. By default Helix simply sorts the transitions alphabetically and fires as many as it can without violating the constraints. One can control this by overriding the priority order.</p> + </div> + <div class="section"> + <h3 id="Config_management">Config management</h3> + <p>Helix allows applications to store application specific properties. The configuration can have different scopes.</p> + <ul> + <li>Cluster</li> + <li>Node specific</li> + <li>Resource specific</li> + <li>Partition specific</li> + </ul> + <p>Helix also provides notifications when any configs are changed. This allows applications to support dynamic configuration changes.</p> + <p>See HelixManager.getConfigAccessor for more info</p> + </div> + <div class="section"> + <h3 id="Intra_cluster_messaging_api">Intra cluster messaging api</h3> + <p>This is an interesting feature which is quite useful in practice. Often times, nodes in DDS requires a mechanism to interact with each other. One such requirement is a process of bootstrapping a replica.</p> + <p>Consider a search system use case where the index replica starts up and it does not have an index. One of the commonly used solutions is to get the index from a common location or to copy the index from another replica. Helix provides a messaging api, that can be used to talk to other nodes in the system. The value added that Helix provides here is, message recipient can be specified in terms of resource, partition, state and Helix ensures that the message is delivered to all of the required recipients. In this particular use case, the instance can specify the recipient criteria as all replicas of P1. Since Helix is aware of the global state of the system, it can send the message to appropriate nodes. Once the nodes respond Helix provides the bootstrapping replica with all the responses.</p> + <p>This is a very generic api and can also be used to schedule various periodic tasks in the cluster like data backups etc. System Admins can also perform adhoc tasks like on demand backup or execute a system command(like rm -rf ;-)) across all nodes.</p> + <div class="source"> + <pre> ClusterMessagingService messagingService = manager.getMessagingService(); + //CONSTRUCT THE MESSAGE + Message requestBackupUriRequest = new Message( + MessageType.USER_DEFINE_MSG, UUID.randomUUID().toString()); + requestBackupUriRequest + .setMsgSubType(BootstrapProcess.REQUEST_BOOTSTRAP_URL); + requestBackupUriRequest.setMsgState(MessageState.NEW); + //SET THE RECIPIENT CRITERIA, All nodes that satisfy the criteria will receive the message + Criteria recipientCriteria = new Criteria(); + recipientCriteria.setInstanceName("%"); + recipientCriteria.setRecipientInstanceType(InstanceType.PARTICIPANT); + recipientCriteria.setResource("MyDB"); + recipientCriteria.setPartition(""); + //Should be processed only the process that is active at the time of sending the message. + //This means if the recipient is restarted after message is sent, it will not be processed. + recipientCriteria.setSessionSpecific(true); + // wait for 30 seconds + int timeout = 30000; + //The handler that will be invoked when any recipient responds to the message. + BootstrapReplyHandler responseHandler = new BootstrapReplyHandler(); + //This will return only after all recipients respond or after timeout. + int sentMessageCount = messagingService.sendAndWait(recipientCriteria, + requestBackupUriRequest, responseHandler, timeout); +</pre> + </div> + <p>See HelixManager.getMessagingService for more info.</p> + </div> + <div class="section"> + <h3 id="Application_specific_property_storage">Application specific property storage</h3> + <p>There are several usecases where applications needs support for distributed data structures. Helix uses Zookeeper to store the application data and hence provides notifications when the data changes. One value add Helix provides is the ability to specify cache the data and also write through cache. This is more efficient than reading from ZK every time.</p> + <p>See HelixManager.getHelixPropertyStore</p> + </div> + <div class="section"> + <h3 id="Throttling">Throttling</h3> + <p>Since all state changes in the system are triggered through transitions, Helix can control the number of transitions that can happen in parallel. Some of the transitions may be light weight but some might involve moving data around which is quite expensive. Helix allows applications to set threshold on transitions. The threshold can be set at the multiple scopes.</p> + <ul> + <li>MessageType e.g STATE_TRANSITION</li> + <li>TransitionType e.g SLAVE-MASTER</li> + <li>Resource e.g database</li> + <li>Node i.e per node max transitions in parallel.</li> + </ul> + <p>See HelixManager.getHelixAdmin.addMessageConstraint() </p> + </div> + <div class="section"> + <h3 id="Health_monitoring_and_alerting">Health monitoring and alerting</h3> + <p>This in currently in development mode, not yet productionized.</p> + <p>Helix provides ability for each node in the system to report health metrics on a periodic basis. Helix supports multiple ways to aggregate these metrics like simple SUM, AVG, EXPONENTIAL DECAY, WINDOW. Helix will only persist the aggregated value. Applications can define threshold on the aggregate values according to the SLAâs and when the SLA is violated Helix will fire an alert. Currently Helix only fires an alert but eventually we plan to use this metrics to either mark the node dead or load balance the partitions. This feature will be valuable in for distributed systems that support multi-tenancy and have huge variation in work load patterns. Another place this can be used is to detect skewed partitions and rebalance the cluster.</p> + <p>This feature is not yet stable and do not recommend to be used in production.</p> + </div> + <div class="section"> + <h3 id="Controller_deployment_modes">Controller deployment modes</h3> + <p>Read Architecture wiki for more details on the Role of a controller. In simple words, it basically controls the participants in the cluster by issuing transitions.</p> + <p>Helix provides multiple options to deploy the controller.</p> + <div class="section"> + <h4 id="STANDALONE">STANDALONE</h4> + <p>Controller can be started as a separate process to manage a cluster. This is the recommended approach. How ever since one controller can be a single point of failure, multiple controller processes are required for reliability. Even if multiple controllers are running only one will be actively managing the cluster at any time and is decided by a leader election process. If the leader fails, another leader will resume managing the cluster.</p> + <p>Even though we recommend this method of deployment, it has the drawback of having to manage an additional service for each cluster. See Controller As a Service option.</p> + </div> + <div class="section"> + <h4 id="EMBEDDED">EMBEDDED</h4> + <p>If setting up a separate controller process is not viable, then it is possible to embed the controller as a library in each of the participant. </p> + </div> + <div class="section"> + <h4 id="CONTROLLER_AS_A_SERVICE">CONTROLLER AS A SERVICE</h4> + <p>One of the cool feature we added in helix was use a set of controllers to manage a large number of clusters. For example if you have X clusters to be managed, instead of deploying X*3(3 controllers for fault tolerance) controllers for each cluster, one can deploy only 3 controllers. Each controller can manage X/3 clusters. If any controller fails the remaining two will manage X/2 clusters. At LinkedIn, we always deploy controllers in this mode. </p> + </div> + </div> +</div> + </div> + </div> + </div> + </div> + + </div><!-- /container --> + + <!-- Footer + ================================================== --> + <footer class="well"> + <div class="container"> + <div class="row"> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Get Helix</li> + <li> + <a href="download.html" title="Download">Download </a> + </li> + <li> + <a href="Building.html" title="Building">Building </a> + </li> + <li> + <a href="releasenotes/release-1.0.2.html" title="Release Notes">Release Notes </a> + </li> + </ul> + </div> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Hands-On</li> + <li> + <a href="Quickstart.html" title="Quick Start">Quick Start </a> + </li> + <li> + <a href="Tutorial.html" title="Tutorial">Tutorial </a> + </li> + <li> + <a href="../javadocs/1.0.2" title="Javadocs">Javadocs </a> + </li> + </ul> + </div> + <div class="span3 bottom-nav"> + <ul class="nav nav-list"> + <li class="nav-header">Recipes</li> + <li> + <a href="recipes/lock_manager.html" title="Distributed lock manager">Distributed lock manager </a> + </li> + <li> + <a href="recipes/rabbitmq_consumer_group.html" title="Rabbit MQ consumer group">Rabbit MQ consumer group </a> + </li> + <li> + <a href="recipes/rsync_replicated_file_store.html" title="Rsync replicated file store">Rsync replicated file store </a> + </li> + <li> + <a href="recipes/service_discovery.html" title="Service discovery">Service discovery </a> + </li> + <li> + <a href="recipes/task_dag_execution.html" title="Distributed task DAG execution">Distributed task DAG execution </a> + </li> + </ul> + </div> + </div> + </div> + </footer> + + <div class="container subfooter"> + <div class="row"> + <div class="span12"> + <p class="pull-right"><a href="#">Back to top</a></p> + <p class="copyright">Copyright ©2021 <a href="http://www.apache.org/";>The Apache Software Foundation</a>. All Rights Reserved.</p> + <p><a href="http://github.com/andriusvelykis/reflow-maven-skin"; title="Reflow Maven skin">Reflow Maven skin</a> by <a href="http://andrius.velykis.lt"; target="_blank" title="Andrius Velykis">Andrius Velykis</a>.</p> + +<div class="row span16"> + <div>Apache Helix, Apache, the Apache feather logo, and the Apache Helix project logos are trademarks of The Apache Software Foundation. + All other marks mentioned may be trademarks or registered trademarks of their respective owners.</div> + <a href="http://helix.apache.org/1.0.2-docs/privacy-policy.html";>Privacy Policy</a> +</div> </div> + </div> + </div> + + <!-- Le javascript + ================================================== --> + <!-- Placed at the end of the document so the pages load faster --> + + <!-- Fallback jQuery loading from Google CDN: + http://stackoverflow.com/questions/1014203/best-way-to-use-googles-hosted-jquery-but-fall-back-to-my-hosted-library-on-go --> + <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js";></script> + <script type="text/javascript"> + if (typeof jQuery == 'undefined') + { + document.write(unescape("%3Cscript src='./js/jquery-1.8.3.min.js' type='text/javascript'%3E%3C/script%3E")); + } + </script> + + <script src="./js/bootstrap.min.js"></script> + <script src="./js/lightbox.js"></script> + <script src="./js/jquery.smooth-scroll.min.js"></script> + <!-- back button support for smooth scroll --> + <script src="./js/jquery.ba-bbq.min.js"></script> + + <script src="./js/reflow-skin.js"></script> + + </body> +</html> \ No newline at end of file Added: helix/site-content/1.0.2-docs/JobExample.json URL: http://svn.apache.org/viewvc/helix/site-content/1.0.2-docs/JobExample.json?rev=1890233&view=auto ============================================================================== --- helix/site-content/1.0.2-docs/JobExample.json (added) +++ helix/site-content/1.0.2-docs/JobExample.json Wed May 26 21:09:44 2021 @@ -0,0 +1,19 @@ +{ + "id" : "TestJob", + "simpleFields": { + "JobID":"Job2", + "WorkflowID":"Workflow1" + }, + "mapFields":{ + "Task1" : { + "TASK_ID":"Task1", + "TASK_COMMAND":"Backup", + "TASK_TARGET_PARTITION":"p1" + }, + "Task2" : { + "TASK_ID":"Task2", + "TASK_COMMAND":"ReIndex", + } + }, + "listFields":{} +}
