ZOOKEEPER-3022: MAVEN MIGRATION - Iteration 1 - docs, it First iteration of the directory changes in maven migration. This time, the empty zookeeper-it for future integration tests were created, and the docs source were moved to zookeeper-docs. Tested with forest v0.9, documents generations were successful with ant.
Author: Norbert Kalmar <[email protected]> Reviewers: Andor Molnar <[email protected]> Closes #550 from nkalmar/ZOOKEEPER-3022-1 (cherry picked from commit 4607a3e156f36c52349bfb370e879dbd9e4d0691) Signed-off-by: Andor Molnar <[email protected]> Project: http://git-wip-us.apache.org/repos/asf/zookeeper/repo Commit: http://git-wip-us.apache.org/repos/asf/zookeeper/commit/b024a3e2 Tree: http://git-wip-us.apache.org/repos/asf/zookeeper/tree/b024a3e2 Diff: http://git-wip-us.apache.org/repos/asf/zookeeper/diff/b024a3e2 Branch: refs/heads/branch-3.5 Commit: b024a3e2959749b46850a700a0ed694b3ee1aaef Parents: 4694b8a Author: Norbert Kalmar <[email protected]> Authored: Wed Jul 4 13:02:19 2018 +0200 Committer: Andor Molnar <[email protected]> Committed: Wed Jul 4 13:02:43 2018 +0200 ---------------------------------------------------------------------- build.xml | 2 +- src/docs/forrest.properties | 109 - src/docs/src/documentation/README.txt | 7 - src/docs/src/documentation/TODO.txt | 227 -- .../classes/CatalogManager.properties | 37 - src/docs/src/documentation/conf/cli.xconf | 328 --- .../src/documentation/content/xdocs/index.xml | 87 - .../documentation/content/xdocs/javaExample.xml | 664 ----- .../src/documentation/content/xdocs/recipes.xml | 688 ------ .../src/documentation/content/xdocs/site.xml | 97 - .../src/documentation/content/xdocs/tabs.xml | 36 - .../content/xdocs/zookeeperAdmin.xml | 2312 ------------------ .../xdocs/zookeeperHierarchicalQuorums.xml | 75 - .../content/xdocs/zookeeperInternals.xml | 487 ---- .../content/xdocs/zookeeperJMX.xml | 236 -- .../content/xdocs/zookeeperObservers.xml | 145 -- .../content/xdocs/zookeeperOtherInfo.xml | 46 - .../content/xdocs/zookeeperOver.xml | 464 ---- .../content/xdocs/zookeeperProgrammers.xml | 1852 -------------- .../content/xdocs/zookeeperQuotas.xml | 71 - .../content/xdocs/zookeeperReconfig.xml | 883 ------- .../content/xdocs/zookeeperStarted.xml | 419 ---- .../content/xdocs/zookeeperTutorial.xml | 712 ------ .../src/documentation/resources/images/2pc.jpg | Bin 15174 -> 0 bytes .../resources/images/bk-overview.jpg | Bin 124211 -> 0 bytes .../documentation/resources/images/favicon.ico | Bin 766 -> 0 bytes .../resources/images/hadoop-logo.jpg | Bin 9443 -> 0 bytes .../resources/images/state_dia.dia | Bin 2597 -> 0 bytes .../resources/images/state_dia.jpg | Bin 51364 -> 0 bytes .../documentation/resources/images/zkarch.jpg | Bin 24535 -> 0 bytes .../resources/images/zkcomponents.jpg | Bin 30831 -> 0 bytes .../resources/images/zknamespace.jpg | Bin 35414 -> 0 bytes .../resources/images/zkperfRW-3.2.jpg | Bin 41948 -> 0 bytes .../documentation/resources/images/zkperfRW.jpg | Bin 161542 -> 0 bytes .../resources/images/zkperfreliability.jpg | Bin 69825 -> 0 bytes .../resources/images/zkservice.jpg | Bin 86790 -> 0 bytes .../resources/images/zookeeper_small.gif | Bin 4847 -> 0 bytes src/docs/src/documentation/skinconf.xml | 360 --- src/docs/status.xml | 74 - zookeeper-docs/forrest.properties | 109 + zookeeper-docs/src/documentation/README.txt | 7 + zookeeper-docs/src/documentation/TODO.txt | 227 ++ .../classes/CatalogManager.properties | 37 + zookeeper-docs/src/documentation/conf/cli.xconf | 328 +++ .../src/documentation/content/xdocs/index.xml | 87 + .../documentation/content/xdocs/javaExample.xml | 664 +++++ .../src/documentation/content/xdocs/recipes.xml | 688 ++++++ .../src/documentation/content/xdocs/site.xml | 97 + .../src/documentation/content/xdocs/tabs.xml | 36 + .../content/xdocs/zookeeperAdmin.xml | 2312 ++++++++++++++++++ .../xdocs/zookeeperHierarchicalQuorums.xml | 75 + .../content/xdocs/zookeeperInternals.xml | 487 ++++ .../content/xdocs/zookeeperJMX.xml | 236 ++ .../content/xdocs/zookeeperObservers.xml | 145 ++ .../content/xdocs/zookeeperOtherInfo.xml | 46 + .../content/xdocs/zookeeperOver.xml | 464 ++++ .../content/xdocs/zookeeperProgrammers.xml | 1852 ++++++++++++++ .../content/xdocs/zookeeperQuotas.xml | 71 + .../content/xdocs/zookeeperReconfig.xml | 883 +++++++ .../content/xdocs/zookeeperStarted.xml | 419 ++++ .../content/xdocs/zookeeperTutorial.xml | 712 ++++++ .../src/documentation/resources/images/2pc.jpg | Bin 0 -> 15174 bytes .../resources/images/bk-overview.jpg | Bin 0 -> 124211 bytes .../documentation/resources/images/favicon.ico | Bin 0 -> 766 bytes .../resources/images/hadoop-logo.jpg | Bin 0 -> 9443 bytes .../resources/images/state_dia.dia | Bin 0 -> 2597 bytes .../resources/images/state_dia.jpg | Bin 0 -> 51364 bytes .../documentation/resources/images/zkarch.jpg | Bin 0 -> 24535 bytes .../resources/images/zkcomponents.jpg | Bin 0 -> 30831 bytes .../resources/images/zknamespace.jpg | Bin 0 -> 35414 bytes .../resources/images/zkperfRW-3.2.jpg | Bin 0 -> 41948 bytes .../documentation/resources/images/zkperfRW.jpg | Bin 0 -> 161542 bytes .../resources/images/zkperfreliability.jpg | Bin 0 -> 69825 bytes .../resources/images/zkservice.jpg | Bin 0 -> 86790 bytes .../resources/images/zookeeper_small.gif | Bin 0 -> 4847 bytes zookeeper-docs/src/documentation/skinconf.xml | 360 +++ zookeeper-docs/status.xml | 74 + zookeeper-it/.empty | 0 78 files changed, 10417 insertions(+), 10417 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/build.xml ---------------------------------------------------------------------- diff --git a/build.xml b/build.xml index 39c1265..8470dc6 100644 --- a/build.xml +++ b/build.xml @@ -140,7 +140,7 @@ xmlns:cs="antlib:com.puppycrawl.tools.checkstyle.ant"> <property name="test.quick" value="no" /> <property name="conf.dir" value="${basedir}/conf"/> <property name="docs.dir" value="${basedir}/docs"/> - <property name="docs.src" value="${basedir}/src/docs"/> + <property name="docs.src" value="${basedir}/zookeeper-docs"/> <property name="javadoc.link.java" value="http://docs.oracle.com/javase/6/docs/api/"; /> <property name="javadoc.packages" value="org.apache.*" /> http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/forrest.properties ---------------------------------------------------------------------- diff --git a/src/docs/forrest.properties b/src/docs/forrest.properties deleted file mode 100644 index 70cf81d..0000000 --- a/src/docs/forrest.properties +++ /dev/null @@ -1,109 +0,0 @@ -# Copyright 2002-2004 The Apache Software Foundation -# -# Licensed 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. - -############## -# Properties used by forrest.build.xml for building the website -# These are the defaults, un-comment them if you need to change them. -############## - -# Prints out a summary of Forrest settings for this project -#forrest.echo=true - -# Project name (used to name .war file) -#project.name=my-project - -# Specifies name of Forrest skin to use -#project.skin=tigris -#project.skin=pelt - -# comma separated list, file:// is supported -#forrest.skins.descriptors=http://forrest.apache.org/skins/skins.xml,file:///c:/myskins/skins.xml - -############## -# behavioural properties -#project.menu-scheme=tab_attributes -#project.menu-scheme=directories - -############## -# layout properties - -# Properties that can be set to override the default locations -# -# Parent properties must be set. This usually means uncommenting -# project.content-dir if any other property using it is uncommented - -#project.status=status.xml -#project.content-dir=src/documentation -project.configfile=${project.home}/src/documentation/conf/cli.xconf -#project.raw-content-dir=${project.content-dir}/content -#project.conf-dir=${project.content-dir}/conf -#project.sitemap-dir=${project.content-dir} -#project.xdocs-dir=${project.content-dir}/content/xdocs -#project.resources-dir=${project.content-dir}/resources -#project.stylesheets-dir=${project.resources-dir}/stylesheets -#project.images-dir=${project.resources-dir}/images -#project.schema-dir=${project.resources-dir}/schema -#project.skins-dir=${project.content-dir}/skins -#project.skinconf=${project.content-dir}/skinconf.xml -#project.lib-dir=${project.content-dir}/lib -#project.classes-dir=${project.content-dir}/classes -#project.translations-dir=${project.content-dir}/translations - -############## -# validation properties - -# This set of properties determine if validation is performed -# Values are inherited unless overridden. -# e.g. if forrest.validate=false then all others are false unless set to true. -forrest.validate=true -forrest.validate.xdocs=${forrest.validate} -forrest.validate.skinconf=${forrest.validate} -forrest.validate.stylesheets=${forrest.validate} -forrest.validate.skins=${forrest.validate} -forrest.validate.skins.stylesheets=${forrest.validate.skins} - -# Make Forrest work with JDK6 -forrest.validate.sitemap=false - -# *.failonerror=(true|false) - stop when an XML file is invalid -forrest.validate.failonerror=true - -# *.excludes=(pattern) - comma-separated list of path patterns to not validate -# e.g. -#forrest.validate.xdocs.excludes=samples/subdir/**, samples/faq.xml -#forrest.validate.xdocs.excludes= - - -############## -# General Forrest properties - -# The URL to start crawling from -#project.start-uri=linkmap.html -# Set logging level for messages printed to the console -# (DEBUG, INFO, WARN, ERROR, FATAL_ERROR) -#project.debuglevel=ERROR -# Max memory to allocate to Java -#forrest.maxmemory=64m -# Any other arguments to pass to the JVM. For example, to run on an X-less -# server, set to -Djava.awt.headless=true -#forrest.jvmargs= -# The bugtracking URL - the issue number will be appended -#project.bugtracking-url=http://issues.apache.org/bugzilla/show_bug.cgi?id= -#project.bugtracking-url=http://issues.apache.org/jira/browse/ -# The issues list as rss -#project.issues-rss-url= -#I18n Property only works for the "forrest run" target. -#project.i18n=true - -project.required.plugins=org.apache.forrest.plugin.output.pdf,org.apache.forrest.plugin.input.simplifiedDocbook http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/src/documentation/README.txt ---------------------------------------------------------------------- diff --git a/src/docs/src/documentation/README.txt b/src/docs/src/documentation/README.txt deleted file mode 100644 index 9bc261b..0000000 --- a/src/docs/src/documentation/README.txt +++ /dev/null @@ -1,7 +0,0 @@ -This is the base documentation directory. - -skinconf.xml # This file customizes Forrest for your project. In it, you - # tell forrest the project name, logo, copyright info, etc - -sitemap.xmap # Optional. This sitemap is consulted before all core sitemaps. - # See http://forrest.apache.org/docs/project-sitemap.html http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/src/documentation/TODO.txt ---------------------------------------------------------------------- diff --git a/src/docs/src/documentation/TODO.txt b/src/docs/src/documentation/TODO.txt deleted file mode 100644 index 84e7dfa..0000000 --- a/src/docs/src/documentation/TODO.txt +++ /dev/null @@ -1,227 +0,0 @@ -This is a running list of todo documentation items. Feel free -to add to the list or take on an item as you wish (in the form -of a JIRA patch of course). -------------------------------------------------------------- - -recipes.xml:110: -[maybe an illustration would be nice for each recipe?] - -recipes.xml:167: -"wait for each watch event". [how do you wait?] - -recipes.xml:457: -<remark>[tbd: myabe helpful to indicate which step this refers to?]</remark> - -zookeeperAdmin.xml:77: -because requires a majority <remark>[tbd: why?]</remark>, it is best to use... - -zookeeperAdmin.xml:112: - <screen>$yinst -i jdk-1.6.0.00_3 -br test <remark>[y! prop - replace with open equiv]</remark></screen> - -zookeeperAdmin.xml:99: -- use a maximum heap size of 3GB for a 4GB machine. <remark>[tbd: where would they do this? Environment variable, etc?]</remark> - -zookeeperAdmin.xml:120 -<screen>$ yinst install -nostart zookeeper_server <remark>[Y! prop - replace with open eq]</remark></screen> - -zookeeperAdmin.xml:171: -In Java, you can run the following command to execute simple operations:<remark> [tbd: also, maybe give some of those simple operations?] - -zookeeperAdmin.xml:194: -Running either program gives you a shell in which to execute simple file-system-like operations. <remark>[tbd: again, sample - operations?] - -zookeeperAdmin.xml:252: -If servers use different configuration files, -care must be taken to ensure that the list of servers in all of the -standard form, with legal values, etc]</remark> - -zookeeperAdmin.xml:408: -(Note: The system property has no zookeeper -prefix, and the configuration variable name is different from -the system property. Yes - it's not consistent, and it's -annoying.<remark> [tbd: is there any explanation for -this?]</remark>) - -zookeeperAdmin.xml:445: When the election algorithm is - "0" a UDP port with the same port number as the port listed in - the <emphasis role="bold">server.num</emphasis> option will be - used. <remark>[tbd: should that be <emphasis - role="bold">server.id</emphasis>? Also, why isn't server.id - documented anywhere?]</remark> - -zookeeperAdmin.xml:481: The default to this option is yes, which - means that a leader will accept client connections. - <remark>[tbd: how do you specifiy which server is the - leader?]</remark> - -zookeeperAdmin.xml:495 When the server - starts up, it determines which server it is by looking for the - file <filename>myid</filename> in the data directory.<remark> - [tdb: should we mention somewhere about creating this file, - myid, in the setup procedure?]</remark> - -zookeeperAdmin.xml:508: [tbd: is the next sentence explanation an of what the - election port or is it a description of a special case?] - </remark>If you want to test multiple servers on a single - machine, the individual choices of electionPort for each - server can be defined in each server's config files using the - line electionPort=xxxx to avoid clashes. - -zookeeperAdmin.xml:524: If followers fall too far behind a - leader, they will be dropped. <remark>[tbd: is this a correct - rewording: if followers fall beyond this limit, they are - dropped?]</remark> - -zookeeperAdmin.xml:551: ZooKeeper will not require updates - to be synced to the media. <remark>[tbd: useful because..., - dangerous because...]</remark> - -zookeeperAdmin.xml:580: Skips ACL checks. <remark>[tbd: when? where?]</remark> - -zookeeperAdmin.xml:649: <remark>[tbd: Patrick, Ben, et al: I believe the Message Broker - team does perform routine monitoring of Zookeeper. But I might be - wrong. To your knowledge, is there any monitoring of a Zookeeper - deployment that will a Zookeeper sys admin will want to do, outside of - Yahoo?]</remark> - -zookeeperAdmin.xml:755: Also, - the server lists in each Zookeeper server configuration file - should be consistent with one another. <remark>[tbd: I'm assuming - this last part is true. Is it?]</remark> - -zookeeperAdmin.xml:812: For best results, take note of the following list of good - Zookeeper practices. <remark>[tbd: I just threw this section in. Do we - have list that is is different from the "things to avoid"? If not, I can - easily remove this section.]</remark> - - -zookeeperOver.xml:162: Ephemeral nodes are useful when you - want to implement <remark>[tbd]</remark>. - -zookeeperOver.xml:174: And if the - connection between the client and one of the Zoo Keeper servers is - broken, the client will receive a local notification. These can be used - to <remark>[tbd]</remark> - -zookeeperOver.xml:215: <para>For more information on these (guarantees), and how they can be used, see - <remark>[tbd]</remark></para> - -zookeeperOver.xml:294: <para><xref linkend="fg_zkComponents" /> shows the high-level components - of the ZooKeeper service. With the exception of the request processor, - <remark>[tbd: where does the request processor live?]</remark> - -zookeeperOver.xml:298: <para><xref linkend="fg_zkComponents" /> shows the high-level components - of the ZooKeeper service. With the exception of the request processor, - each of - the servers that make up the ZooKeeper service replicates its own copy - of each of components. <remark>[tbd: I changed the wording in this - sentence from the white paper. Can someone please make sure it is still - correct?]</remark> - -zookeeperOver.xml:342: The programming interface to ZooKeeper is deliberately simple. - With it, however, you can implement higher order operations, such as - synchronizations primitives, group membership, ownership, etc. Some - distributed applications have used it to: <remark>[tbd: add uses from - white paper and video presentation.]</remark> - - -zookeeperProgrammers.xml:94: <listitem> - <para><xref linkend="ch_programStructureWithExample" /> - <remark>[tbd]</remark></para> - </listitem> - -zookeeperProgrammers.xml:115: Also, - the <ulink url="#ch_programStructureWithExample">Simple Programmming - Example</ulink> <remark>[tbd]</remark> is helpful for understand the basic - structure of a ZooKeeper client application. - -zookeeperProgrammers.xml:142: The following characters are not - allowed because <remark>[tbd: - do we need reasons?]</remark> - -zookeeperProgrammers.xml:172: If - the version it supplies doesn't match the actual version of the data, - the update will fail. (This behavior can be overridden. For more - information see... )<remark>[tbd... reference here to the section - describing the special version number -1]</remark> - -zookeeperProgrammers.xml:197: More information about watches can be - found in the section - <ulink url="recipes.html#sc_recipes_Locks"> - Zookeeper Watches</ulink>. - <remark>[tbd: fix this link] [tbd: Ben there is note from to emphasize - that "it is queued". What is "it" and is what we have here - sufficient?]</remark></para> - -zookeeperProgrammers.xml:335: it will send the session id as a part of the connection handshake. - As a security measure, the server creates a password for the session id - that any ZooKeeper server can validate. <remark>[tbd: note from Ben: - "perhaps capability is a better word." need clarification on that.] - </remark> - -zookeeperProgrammers.xml:601: <ulink - url="recipes.html#sc_recipes_Locks">Locks</ulink> - <remark>[tbd:...]</remark> in <ulink - url="recipes.html">Zookeeper Recipes</ulink>. - <remark>[tbd:..]</remark>).</para> - -zookeeperProgrammers.xml:766: <para>See INSTALL for general information about running - <emphasis role="bold">configure</emphasis>. <remark>[tbd: what - is INSTALL? a directory? a file?]</remark></para> - - - -zookeeperProgrammers.xml:813: <para>To verify that the node's been created:</para> - - <para>You should see a list of node who are children of the root node - "/".</para><remark>[tbd: document all the cli commands (I think this is ben's comment) - -zookeeperProgrammers.xml:838: <para>Refer to <xref linkend="ch_programStructureWithExample"/>for examples of usage in Java and C. - <remark>[tbd]</remark></para> - -zookeeperProgrammers.xml 847: <remark>[tbd: This is a new section. The below - is just placeholder. Eventually, a subsection on each of those operations, with a little - bit of illustrative code for each op.] </remark> - -zookeeperProgrammers.xml:915: Program Structure, with Simple Example</title> - -zookeeperProgrammers.xml:999: <term>ZooKeeper Whitepaper <remark>[tbd: find url]</remark></term> - -zookeeperProgrammers.xml:1008: <term>API Reference <remark>[tbd: find url]</remark></term> - -zookeeperProgrammers.xml:1062: [tbd]</remark></term><listitem> - <para>Any other good sources anyone can think of...</para> - </listitem> - -zookeeperStarted.xml:73: <para>[tbd: should we start w/ a word here about were to get the source, - exactly what to download, how to unpack it, and where to put it? Also, - does the user need to be in sudo, or can they be under their regular - login?]</para> - -zookeeperStarted.xml:84: <para>This should generate a JAR file called zookeeper.jar. To start - Zookeeper, compile and run zookeeper.jar. <emphasis>[tbd, some more - instruction here. Perhaps a command line? Are these two steps or - one?]</emphasis></para> - -zookeeperStarted.xml:139: <para>ZooKeeper logs messages using log4j -- more detail available in - the <ulink url="zookeeperProgrammers.html#Logging">Logging</ulink> - section of the Programmer's Guide.<remark revision="include_tbd">[tbd: - real reference needed]</remark> - -zookeeperStarted.xml:201: The C bindings exist in two variants: single - threaded and multi-threaded. These differ only in how the messaging loop - is done. <remark>[tbd: what is the messaging loop? Do we talk about it - anywyhere? is this too much info for a getting started guide?]</remark> - -zookeeperStarted.xml:217: The entry <emphasis - role="bold">syncLimit</emphasis> limits how far out of date a server can - be from a leader. [TBD: someone please verify that the previous is - true.] - -zookeeperStarted.xml:232: These are the "electionPort" numbers of the servers (as opposed to - clientPorts), that is ports for <remark>[tbd: feedback need: what are - these ports, exactly?] - -zookeeperStarted.xml:258: <remark>[tbd: what is the other config param? - (I believe two are mentioned above.)]</remark> http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/src/documentation/classes/CatalogManager.properties ---------------------------------------------------------------------- diff --git a/src/docs/src/documentation/classes/CatalogManager.properties b/src/docs/src/documentation/classes/CatalogManager.properties deleted file mode 100644 index ac060b9..0000000 --- a/src/docs/src/documentation/classes/CatalogManager.properties +++ /dev/null @@ -1,37 +0,0 @@ -# Copyright 2002-2004 The Apache Software Foundation -# -# Licensed 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. - -#======================================================================= -# CatalogManager.properties -# -# This is the default properties file for Apache Forrest. -# This facilitates local configuration of application-specific catalogs. -# -# See the Apache Forrest documentation: -# http://forrest.apache.org/docs/your-project.html -# http://forrest.apache.org/docs/validation.html - -# verbosity ... level of messages for status/debug -# See forrest/src/core/context/WEB-INF/cocoon.xconf - -# catalogs ... list of additional catalogs to load -# (Note that Apache Forrest will automatically load its own default catalog -# from src/core/context/resources/schema/catalog.xcat) -# use full pathnames -# pathname separator is always semi-colon (;) regardless of operating system -# directory separator is always slash (/) regardless of operating system -# -#catalogs=/home/me/forrest/my-site/src/documentation/resources/schema/catalog.xcat -catalogs= - http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/src/documentation/conf/cli.xconf ---------------------------------------------------------------------- diff --git a/src/docs/src/documentation/conf/cli.xconf b/src/docs/src/documentation/conf/cli.xconf deleted file mode 100644 index c671340..0000000 --- a/src/docs/src/documentation/conf/cli.xconf +++ /dev/null @@ -1,328 +0,0 @@ -<?xml version="1.0"?> -<!-- - 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. ---> -<!--+ - | This is the Apache Cocoon command line configuration file. - | Here you give the command line interface details of where - | to find various aspects of your Cocoon installation. - | - | If you wish, you can also use this file to specify the URIs - | that you wish to generate. - | - | The current configuration information in this file is for - | building the Cocoon documentation. Therefore, all links here - | are relative to the build context dir, which, in the build.xml - | file, is set to ${build.context} - | - | Options: - | verbose: increase amount of information presented - | to standard output (default: false) - | follow-links: whether linked pages should also be - | generated (default: true) - | precompile-only: precompile sitemaps and XSP pages, but - | do not generate any pages (default: false) - | confirm-extensions: check the mime type for the generated page - | and adjust filename and links extensions - | to match the mime type - | (e.g. text/html->.html) - | - | Note: Whilst using an xconf file to configure the Cocoon - | Command Line gives access to more features, the use of - | command line parameters is more stable, as there are - | currently plans to improve the xconf format to allow - | greater flexibility. If you require a stable and - | consistent method for accessing the CLI, it is recommended - | that you use the command line parameters to configure - | the CLI. See documentation at: - | http://cocoon.apache.org/2.1/userdocs/offline/ - | http://wiki.apache.org/cocoon/CommandLine - | - +--> - -<cocoon verbose="true" - follow-links="true" - precompile-only="false" - confirm-extensions="false"> - - <!--+ - | The context directory is usually the webapp directory - | containing the sitemap.xmap file. - | - | The config file is the cocoon.xconf file. - | - | The work directory is used by Cocoon to store temporary - | files and cache files. - | - | The destination directory is where generated pages will - | be written (assuming the 'simple' mapper is used, see - | below) - +--> - <context-dir>.</context-dir> - <config-file>WEB-INF/cocoon.xconf</config-file> - <work-dir>../tmp/cocoon-work</work-dir> - <dest-dir>../site</dest-dir> - - <!--+ - | A checksum file can be used to store checksums for pages - | as they are generated. When the site is next generated, - | files will not be written if their checksum has not changed. - | This means that it will be easier to detect which files - | need to be uploaded to a server, using the timestamp. - | - | The default path is relative to the core webapp directory. - | An asolute path can be used. - +--> - <!-- <checksums-uri>build/work/checksums</checksums-uri>--> - - <!--+ - | Broken link reporting options: - | Report into a text file, one link per line: - | <broken-links type="text" report="filename"/> - | Report into an XML file: - | <broken-links type="xml" report="filename"/> - | Ignore broken links (default): - | <broken-links type="none"/> - | - | Two attributes to this node specify whether a page should - | be generated when an error has occurred. 'generate' specifies - | whether a page should be generated (default: true) and - | extension specifies an extension that should be appended - | to the generated page's filename (default: none) - | - | Using this, a quick scan through the destination directory - | will show broken links, by their filename extension. - +--> - <broken-links type="xml" - file="../brokenlinks.xml" - generate="false" - extension=".error" - show-referrers="true"/> - - <!--+ - | Load classes at startup. This is necessary for generating - | from sites that use SQL databases and JDBC. - | The <load-class> element can be repeated if multiple classes - | are needed. - +--> - <!-- - <load-class>org.firebirdsql.jdbc.Driver</load-class> - --> - - <!--+ - | Configures logging. - | The 'log-kit' parameter specifies the location of the log kit - | configuration file (usually called logkit.xconf. - | - | Logger specifies the logging category (for all logging prior - | to other Cocoon logging categories taking over) - | - | Available log levels are: - | DEBUG: prints all level of log messages. - | INFO: prints all level of log messages except DEBUG - | ones. - | WARN: prints all level of log messages except DEBUG - | and INFO ones. - | ERROR: prints all level of log messages except DEBUG, - | INFO and WARN ones. - | FATAL_ERROR: prints only log messages of this level - +--> - <!-- <logging log-kit="WEB-INF/logkit.xconf" logger="cli" level="ERROR" /> --> - - <!--+ - | Specifies the filename to be appended to URIs that - | refer to a directory (i.e. end with a forward slash). - +--> - <default-filename>index.html</default-filename> - - <!--+ - | Specifies a user agent string to the sitemap when - | generating the site. - | - | A generic term for a web browser is "user agent". Any - | user agent, when connecting to a web server, will provide - | a string to identify itself (e.g. as Internet Explorer or - | Mozilla). It is possible to have Cocoon serve different - | content depending upon the user agent string provided by - | the browser. If your site does this, then you may want to - | use this <user-agent> entry to provide a 'fake' user agent - | to Cocoon, so that it generates the correct version of your - | site. - | - | For most sites, this can be ignored. - +--> - <!-- - <user-agent>Cocoon Command Line Environment 2.1</user-agent> - --> - - <!--+ - | Specifies an accept string to the sitemap when generating - | the site. - | User agents can specify to an HTTP server what types of content - | (by mime-type) they are able to receive. E.g. a browser may be - | able to handle jpegs, but not pngs. The HTTP accept header - | allows the server to take the browser's capabilities into account, - | and only send back content that it can handle. - | - | For most sites, this can be ignored. - +--> - - <accept>*/*</accept> - - <!--+ - | Specifies which URIs should be included or excluded, according - | to wildcard patterns. - | - | These includes/excludes are only relevant when you are following - | links. A link URI must match an include pattern (if one is given) - | and not match an exclude pattern, if it is to be followed by - | Cocoon. It can be useful, for example, where there are links in - | your site to pages that are not generated by Cocoon, such as - | references to api-documentation. - | - | By default, all URIs are included. If both include and exclude - | patterns are specified, a URI is first checked against the - | include patterns, and then against the exclude patterns. - | - | Multiple patterns can be given, using muliple include or exclude - | nodes. - | - | The order of the elements is not significant, as only the first - | successful match of each category is used. - | - | Currently, only the complete source URI can be matched (including - | any URI prefix). Future plans include destination URI matching - | and regexp matching. If you have requirements for these, contact - | [email protected]. - +--> - - <exclude pattern="**/"/> - <exclude pattern="**apidocs**"/> - <exclude pattern="api/**"/> - - <!-- ZOOKEEPER-2364 - we build our own release notes separately --> - <exclude pattern="releasenotes.**"/> - -<!-- - This is a workaround for FOR-284 "link rewriting broken when - linking to xml source views which contain site: links". - See the explanation there and in declare-broken-site-links.xsl ---> - <exclude pattern="site:**"/> - <exclude pattern="ext:**"/> - <exclude pattern="lm:**"/> - <exclude pattern="**/site:**"/> - <exclude pattern="**/ext:**"/> - <exclude pattern="**/lm:**"/> - - <!-- Exclude tokens used in URLs to ASF mirrors (interpreted by a CGI) --> - <exclude pattern="[preferred]/**"/> - <exclude pattern="[location]"/> - - <!-- <include-links extension=".html"/>--> - - <!--+ - | <uri> nodes specify the URIs that should be generated, and - | where required, what should be done with the generated pages. - | They describe the way the URI of the generated file is created - | from the source page's URI. There are three ways that a generated - | file URI can be created: append, replace and insert. - | - | The "type" attribute specifies one of (append|replace|insert): - | - | append: - | Append the generated page's URI to the end of the source URI: - | - | <uri type="append" src-prefix="documents/" src="index.html" - | dest="build/dest/"/> - | - | This means that - | (1) the "documents/index.html" page is generated - | (2) the file will be written to "build/dest/documents/index.html" - | - | replace: - | Completely ignore the generated page's URI - just - | use the destination URI: - | - | <uri type="replace" src-prefix="documents/" src="index.html" - | dest="build/dest/docs.html"/> - | - | This means that - | (1) the "documents/index.html" page is generated - | (2) the result is written to "build/dest/docs.html" - | (3) this works only for "single" pages - and not when links - | are followed - | - | insert: - | Insert generated page's URI into the destination - | URI at the point marked with a * (example uses fictional - | zip protocol) - | - | <uri type="insert" src-prefix="documents/" src="index.html" - | dest="zip://*.zip/page.html"/> - | - | This means that - | (1) - | - | In any of these scenarios, if the dest attribute is omitted, - | the value provided globally using the <dest-dir> node will - | be used instead. - +--> - <!-- - <uri type="replace" - src-prefix="samples/" - src="hello-world/hello.html" - dest="build/dest/hello-world.html"/> - --> - - <!--+ - | <uri> nodes can be grouped together in a <uris> node. This - | enables a group of URIs to share properties. The following - | properties can be set for a group of URIs: - | * follow-links: should pages be crawled for links - | * confirm-extensions: should file extensions be checked - | for the correct mime type - | * src-prefix: all source URIs should be - | pre-pended with this prefix before - | generation. The prefix is not - | included when calculating the - | destination URI - | * dest: the base destination URI to be - | shared by all pages in this group - | * type: the method to be used to calculate - | the destination URI. See above - | section on <uri> node for details. - | - | Each <uris> node can have a name attribute. When a name - | attribute has been specified, the -n switch on the command - | line can be used to tell Cocoon to only process the URIs - | within this URI group. When no -n switch is given, all - | <uris> nodes are processed. Thus, one xconf file can be - | used to manage multiple sites. - +--> - <!-- - <uris name="mirrors" follow-links="false"> - <uri type="append" src="mirrors.html"/> - </uris> - --> - - <!--+ - | File containing URIs (plain text, one per line). - +--> - <!-- - <uri-file>uris.txt</uri-file> - --> -</cocoon> http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/src/documentation/content/xdocs/index.xml ---------------------------------------------------------------------- diff --git a/src/docs/src/documentation/content/xdocs/index.xml b/src/docs/src/documentation/content/xdocs/index.xml deleted file mode 100644 index 969e482..0000000 --- a/src/docs/src/documentation/content/xdocs/index.xml +++ /dev/null @@ -1,87 +0,0 @@ -<?xml version="1.0"?> -<!-- - Copyright 2002-2004 The Apache Software Foundation - - Licensed 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. ---> - -<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd";> - -<document> - - <header> - <title>ZooKeeper: Because Coordinating Distributed Systems is a Zoo</title> - </header> - - <body> - <p>ZooKeeper is a high-performance coordination service for - distributed applications. It exposes common services - such as - naming, configuration management, synchronization, and group - services - in a simple interface so you don't have to write them - from scratch. You can use it off-the-shelf to implement - consensus, group management, leader election, and presence - protocols. And you can build on it for your own, specific needs. - </p> - - <p> - The following documents describe concepts and procedures to get - you started using ZooKeeper. If you have more questions, please - ask the <a href="ext:lists">mailing list</a> or browse the - archives. - </p> - <ul> - - <li><strong>ZooKeeper Overview</strong><p>Technical Overview Documents for Client Developers, Adminstrators, and Contributors</p> - <ul><li><a href="zookeeperOver.html">Overview</a> - a bird's eye view of ZooKeeper, including design concepts and architecture</li> - <li><a href="zookeeperStarted.html">Getting Started</a> - a tutorial-style guide for developers to install, run, and program to ZooKeeper</li> - <li><a href="ext:relnotes">Release Notes</a> - new developer and user facing features, improvements, and incompatibilities</li> - </ul> - </li> - - <li><strong>Developers</strong><p> Documents for Developers using the ZooKeeper Client API</p> - <ul> - <li><a href="ext:api/index">API Docs</a> - the technical reference to ZooKeeper Client APIs</li> - <li><a href="zookeeperProgrammers.html">Programmer's Guide</a> - a client application developer's guide to ZooKeeper</li> - <li><a href="javaExample.html">ZooKeeper Java Example</a> - a simple Zookeeper client appplication, written in Java</li> - <li><a href="zookeeperTutorial.html">Barrier and Queue Tutorial</a> - sample implementations of barriers and queues</li> - <li><a href="recipes.html">ZooKeeper Recipes</a> - higher level solutions to common problems in distributed applications</li> - </ul> - </li> - - <li><strong>Administrators & Operators</strong> <p> Documents for Administrators and Operations Engineers of ZooKeeper Deployments</p> - <ul> - <li><a href="zookeeperAdmin.html">Administrator's Guide</a> - a guide for system administrators and anyone else who might deploy ZooKeeper</li> - <li><a href="zookeeperQuotas.html">Quota Guide</a> - a guide for system administrators on Quotas in ZooKeeper. </li> - <li><a href="zookeeperJMX.html">JMX</a> - how to enable JMX in ZooKeeper</li> - <li><a href="zookeeperHierarchicalQuorums.html">Hierarchical quorums</a></li> - <li><a href="zookeeperObservers.html">Observers</a> - non-voting ensemble members that easily improve ZooKeeper's scalability</li> - <li><a href="zookeeperReconfig.html">Dynamic Reconfiguration</a> - a guide on how to use dynamic reconfiguration in ZooKeeper</li> - </ul> - </li> - - <li><strong>Contributors</strong><p> Documents for Developers Contributing to the ZooKeeper Open Source Project</p> - <ul> - <li><a href="zookeeperInternals.html">ZooKeeper Internals</a> - assorted topics on the inner workings of ZooKeeper</li> - </ul> - </li> - - <li><strong>Miscellaneous ZooKeeper Documentation</strong> - <ul> - <li><a href="ext:wiki">Wiki</a></li> - <li><a href="ext:faq">FAQ</a></li> - </ul> - </li> - </ul> - </body> - -</document> http://git-wip-us.apache.org/repos/asf/zookeeper/blob/b024a3e2/src/docs/src/documentation/content/xdocs/javaExample.xml ---------------------------------------------------------------------- diff --git a/src/docs/src/documentation/content/xdocs/javaExample.xml b/src/docs/src/documentation/content/xdocs/javaExample.xml deleted file mode 100644 index 16f7795..0000000 --- a/src/docs/src/documentation/content/xdocs/javaExample.xml +++ /dev/null @@ -1,664 +0,0 @@ -<?xml version="1.0" encoding="UTF-8"?> -<!-- - Copyright 2002-2004 The Apache Software Foundation - - Licensed 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. ---> - -<!DOCTYPE article PUBLIC "-//OASIS//DTD Simplified DocBook XML V1.0//EN" -"http://www.oasis-open.org/docbook/xml/simple/1.0/sdocbook.dtd";> -<article id="ar_JavaExample"> - <title>ZooKeeper Java Example</title> - - <articleinfo> - <legalnotice> - <para>Licensed 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 <ulink - url="http://www.apache.org/licenses/LICENSE-2.0";>http://www.apache.org/licenses/LICENSE-2.0</ulink>.</para> - - <para>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.</para> - </legalnotice> - - <abstract> - <para>This article contains sample Java code for a simple watch client.</para> - - </abstract> - </articleinfo> - - <section id="ch_Introduction"> - <title>A Simple Watch Client</title> - - <para>To introduce you to the ZooKeeper Java API, we develop here a very simple - watch client. This ZooKeeper client watches a ZooKeeper node for changes - and responds to by starting or stopping a program.</para> - - <section id="sc_requirements"><title>Requirements</title> - - <para>The client has four requirements:</para> - - <itemizedlist><listitem><para>It takes as parameters:</para> - <itemizedlist> - <listitem><para>the address of the ZooKeeper service</para></listitem> - <listitem><para>the name of a znode - the one to be watched</para></listitem> - <listitem><para>the name of a file to write the output to</para></listitem> - <listitem><para>an executable with arguments.</para></listitem></itemizedlist></listitem> - <listitem><para>It fetches the data associated with the znode and starts the executable.</para></listitem> - <listitem><para>If the znode changes, the client refetches the contents and restarts the executable.</para></listitem> - <listitem><para>If the znode disappears, the client kills the executable.</para></listitem></itemizedlist> - - </section> - - <section id="sc_design"> - <title>Program Design</title> - - <para>Conventionally, ZooKeeper applications are broken into two units, one which maintains the connection, - and the other which monitors data. In this application, the class called the <emphasis role="bold">Executor</emphasis> - maintains the ZooKeeper connection, and the class called the <emphasis role="bold">DataMonitor</emphasis> monitors the data - in the ZooKeeper tree. Also, Executor contains the main thread and contains the execution logic. - It is responsible for what little user interaction there is, as well as interaction with the exectuable program you - pass in as an argument and which the sample (per the requirements) shuts down and restarts, according to the - state of the znode.</para> - - </section> - - </section> - - <section id="sc_executor"><title>The Executor Class</title> - <para>The Executor object is the primary container of the sample application. It contains - both the <emphasis role="bold">ZooKeeper</emphasis> object, <emphasis role="bold">DataMonitor</emphasis>, as described above in - <xref linkend="sc_design"/>. </para> - - <programlisting> - // from the Executor class... - - public static void main(String[] args) { - if (args.length < 4) { - System.err - .println("USAGE: Executor hostPort znode filename program [args ...]"); - System.exit(2); - } - String hostPort = args[0]; - String znode = args[1]; - String filename = args[2]; - String exec[] = new String[args.length - 3]; - System.arraycopy(args, 3, exec, 0, exec.length); - try { - new Executor(hostPort, znode, filename, exec).run(); - } catch (Exception e) { - e.printStackTrace(); - } - } - - public Executor(String hostPort, String znode, String filename, - String exec[]) throws KeeperException, IOException { - this.filename = filename; - this.exec = exec; - zk = new ZooKeeper(hostPort, 3000, this); - dm = new DataMonitor(zk, znode, null, this); - } - - public void run() { - try { - synchronized (this) { - while (!dm.dead) { - wait(); - } - } - } catch (InterruptedException e) { - } - } -</programlisting> - - - <para> - Recall that the Executor's job is to start and stop the executable whose name you pass in on the command line. - It does this in response to events fired by the ZooKeeper object. As you can see in the code above, the Executor passes - a reference to itself as the Watcher argument in the ZooKeeper constructor. It also passes a reference to itself - as DataMonitorListener argument to the DataMonitor constructor. Per the Executor's definition, it implements both these - interfaces: - </para> - - <programlisting> -public class Executor implements Watcher, Runnable, DataMonitor.DataMonitorListener { -...</programlisting> - - <para>The <emphasis role="bold">Watcher</emphasis> interface is defined by the ZooKeeper Java API. - ZooKeeper uses it to communicate back to its container. It supports only one method, <command>process()</command>, and ZooKeeper uses - it to communciates generic events that the main thread would be intersted in, such as the state of the ZooKeeper connection or the ZooKeeper session.The Executor - in this example simply forwards those events down to the DataMonitor to decide what to do with them. It does this simply to illustrate - the point that, by convention, the Executor or some Executor-like object "owns" the ZooKeeper connection, but it is free to delegate the events to other - events to other objects. It also uses this as the default channel on which to fire watch events. (More on this later.)</para> - -<programlisting> - public void process(WatchedEvent event) { - dm.process(event); - } -</programlisting> - - <para>The <emphasis role="bold">DataMonitorListener</emphasis> - interface, on the other hand, is not part of the the ZooKeeper API. It is a completely custom interface, - designed for this sample application. The DataMonitor object uses it to communicate back to its container, which - is also the the Executor object.The DataMonitorListener interface looks like this:</para> - <programlisting> -public interface DataMonitorListener { - /** - * The existence status of the node has changed. - */ - void exists(byte data[]); - - /** - * The ZooKeeper session is no longer valid. - * - * @param rc - * the ZooKeeper reason code - */ - void closing(int rc); -} -</programlisting> - <para>This interface is defined in the DataMonitor class and implemented in the Executor class. - When <command>Executor.exists()</command> is invoked, - the Executor decides whether to start up or shut down per the requirements. Recall that the requires say to kill the executable when the - znode ceases to <emphasis>exist</emphasis>. </para> - - <para>When <command>Executor.closing()</command> - is invoked, the Executor decides whether or not to shut itself down in response to the ZooKeeper connection permanently disappearing.</para> - - <para>As you might have guessed, DataMonitor is the object that invokes - these methods, in response to changes in ZooKeeper's state.</para> - - <para>Here are Executor's implementation of - <command>DataMonitorListener.exists()</command> and <command>DataMonitorListener.closing</command>: - </para> - <programlisting> -public void exists( byte[] data ) { - if (data == null) { - if (child != null) { - System.out.println("Killing process"); - child.destroy(); - try { - child.waitFor(); - } catch (InterruptedException e) { - } - } - child = null; - } else { - if (child != null) { - System.out.println("Stopping child"); - child.destroy(); - try { - child.waitFor(); - } catch (InterruptedException e) { - e.printStackTrace(); - } - } - try { - FileOutputStream fos = new FileOutputStream(filename); - fos.write(data); - fos.close(); - } catch (IOException e) { - e.printStackTrace(); - } - try { - System.out.println("Starting child"); - child = Runtime.getRuntime().exec(exec); - new StreamWriter(child.getInputStream(), System.out); - new StreamWriter(child.getErrorStream(), System.err); - } catch (IOException e) { - e.printStackTrace(); - } - } -} - -public void closing(int rc) { - synchronized (this) { - notifyAll(); - } -} -</programlisting> - -</section> -<section id="sc_DataMonitor"><title>The DataMonitor Class</title> -<para> -The DataMonitor class has the meat of the ZooKeeper logic. It is mostly -asynchronous and event driven. DataMonitor kicks things off in the constructor with:</para> -<programlisting> -public DataMonitor(ZooKeeper zk, String znode, Watcher chainedWatcher, - DataMonitorListener listener) { - this.zk = zk; - this.znode = znode; - this.chainedWatcher = chainedWatcher; - this.listener = listener; - - // Get things started by checking if the node exists. We are going - // to be completely event driven - <emphasis role="bold">zk.exists(znode, true, this, null);</emphasis> -} -</programlisting> - -<para>The call to <command>ZooKeeper.exists()</command> checks for the existence of the znode, -sets a watch, and passes a reference to itself (<command>this</command>) -as the completion callback object. In this sense, it kicks things off, since the -real processing happens when the watch is triggered.</para> - -<note> -<para>Don't confuse the completion callback with the watch callback. The <command>ZooKeeper.exists()</command> -completion callback, which happens to be the method <command>StatCallback.processResult()</command> implemented -in the DataMonitor object, is invoked when the asynchronous <emphasis>setting of the watch</emphasis> operation -(by <command>ZooKeeper.exists()</command>) completes on the server. </para> -<para> -The triggering of the watch, on the other hand, sends an event to the <emphasis>Executor</emphasis> object, since -the Executor registered as the Watcher of the ZooKeeper object.</para> - -<para>As an aside, you might note that the DataMonitor could also register itself as the Watcher -for this particular watch event. This is new to ZooKeeper 3.0.0 (the support of multiple Watchers). In this -example, however, DataMonitor does not register as the Watcher.</para> -</note> - -<para>When the <command>ZooKeeper.exists()</command> operation completes on the server, the ZooKeeper API invokes this completion callback on -the client:</para> - -<programlisting> -public void processResult(int rc, String path, Object ctx, Stat stat) { - boolean exists; - switch (rc) { - case Code.Ok: - exists = true; - break; - case Code.NoNode: - exists = false; - break; - case Code.SessionExpired: - case Code.NoAuth: - dead = true; - listener.closing(rc); - return; - default: - // Retry errors - zk.exists(znode, true, this, null); - return; - } - - byte b[] = null; - if (exists) { - try { - <emphasis role="bold">b = zk.getData(znode, false, null);</emphasis> - } catch (KeeperException e) { - // We don't need to worry about recovering now. The watch - // callbacks will kick off any exception handling - e.printStackTrace(); - } catch (InterruptedException e) { - return; - } - } - if ((b == null && b != prevData) - || (b != null && !Arrays.equals(prevData, b))) { - <emphasis role="bold">listener.exists(b);</emphasis> - prevData = b; - } -} -</programlisting> - -<para> -The code first checks the error codes for znode existence, fatal errors, and -recoverable errors. If the file (or znode) exists, it gets the data from the znode, and -then invoke the exists() callback of Executor if the state has changed. Note, -it doesn't have to do any Exception processing for the getData call because it -has watches pending for anything that could cause an error: if the node is deleted -before it calls <command>ZooKeeper.getData()</command>, the watch event set by -the <command>ZooKeeper.exists()</command> triggers a callback; -if there is a communication error, a connection watch event fires when -the connection comes back up. -</para> - -<para>Finally, notice how DataMonitor processes watch events: </para> -<programlisting> - public void process(WatchedEvent event) { - String path = event.getPath(); - if (event.getType() == Event.EventType.None) { - // We are are being told that the state of the - // connection has changed - switch (event.getState()) { - case SyncConnected: - // In this particular example we don't need to do anything - // here - watches are automatically re-registered with - // server and any watches triggered while the client was - // disconnected will be delivered (in order of course) - break; - case Expired: - // It's all over - dead = true; - listener.closing(KeeperException.Code.SessionExpired); - break; - } - } else { - if (path != null && path.equals(znode)) { - // Something has changed on the node, let's find out - zk.exists(znode, true, this, null); - } - } - if (chainedWatcher != null) { - chainedWatcher.process(event); - } - } -</programlisting> -<para> -If the client-side ZooKeeper libraries can re-establish the -communication channel (SyncConnected event) to ZooKeeper before -session expiration (Expired event) all of the session's watches will -automatically be re-established with the server (auto-reset of watches -is new in ZooKeeper 3.0.0). See <ulink -url="zookeeperProgrammers.html#ch_zkWatches">ZooKeeper Watches</ulink> -in the programmer guide for more on this. A bit lower down in this -function, when DataMonitor gets an event for a znode, it calls -<command>ZooKeeper.exists()</command> to find out what has changed. -</para> -</section> - -<section id="sc_completeSourceCode"> - <title>Complete Source Listings</title> - <example id="eg_Executor_java"><title>Executor.java</title><programlisting> -/** - * A simple example program to use DataMonitor to start and - * stop executables based on a znode. The program watches the - * specified znode and saves the data that corresponds to the - * znode in the filesystem. It also starts the specified program - * with the specified arguments when the znode exists and kills - * the program if the znode goes away. - */ -import java.io.FileOutputStream; -import java.io.IOException; -import java.io.InputStream; -import java.io.OutputStream; - -import org.apache.zookeeper.KeeperException; -import org.apache.zookeeper.WatchedEvent; -import org.apache.zookeeper.Watcher; -import org.apache.zookeeper.ZooKeeper; - -public class Executor - implements Watcher, Runnable, DataMonitor.DataMonitorListener -{ - String znode; - - DataMonitor dm; - - ZooKeeper zk; - - String filename; - - String exec[]; - - Process child; - - public Executor(String hostPort, String znode, String filename, - String exec[]) throws KeeperException, IOException { - this.filename = filename; - this.exec = exec; - zk = new ZooKeeper(hostPort, 3000, this); - dm = new DataMonitor(zk, znode, null, this); - } - - /** - * @param args - */ - public static void main(String[] args) { - if (args.length < 4) { - System.err - .println("USAGE: Executor hostPort znode filename program [args ...]"); - System.exit(2); - } - String hostPort = args[0]; - String znode = args[1]; - String filename = args[2]; - String exec[] = new String[args.length - 3]; - System.arraycopy(args, 3, exec, 0, exec.length); - try { - new Executor(hostPort, znode, filename, exec).run(); - } catch (Exception e) { - e.printStackTrace(); - } - } - - /*************************************************************************** - * We do process any events ourselves, we just need to forward them on. - * - * @see org.apache.zookeeper.Watcher#process(org.apache.zookeeper.proto.WatcherEvent) - */ - public void process(WatchedEvent event) { - dm.process(event); - } - - public void run() { - try { - synchronized (this) { - while (!dm.dead) { - wait(); - } - } - } catch (InterruptedException e) { - } - } - - public void closing(int rc) { - synchronized (this) { - notifyAll(); - } - } - - static class StreamWriter extends Thread { - OutputStream os; - - InputStream is; - - StreamWriter(InputStream is, OutputStream os) { - this.is = is; - this.os = os; - start(); - } - - public void run() { - byte b[] = new byte[80]; - int rc; - try { - while ((rc = is.read(b)) > 0) { - os.write(b, 0, rc); - } - } catch (IOException e) { - } - - } - } - - public void exists(byte[] data) { - if (data == null) { - if (child != null) { - System.out.println("Killing process"); - child.destroy(); - try { - child.waitFor(); - } catch (InterruptedException e) { - } - } - child = null; - } else { - if (child != null) { - System.out.println("Stopping child"); - child.destroy(); - try { - child.waitFor(); - } catch (InterruptedException e) { - e.printStackTrace(); - } - } - try { - FileOutputStream fos = new FileOutputStream(filename); - fos.write(data); - fos.close(); - } catch (IOException e) { - e.printStackTrace(); - } - try { - System.out.println("Starting child"); - child = Runtime.getRuntime().exec(exec); - new StreamWriter(child.getInputStream(), System.out); - new StreamWriter(child.getErrorStream(), System.err); - } catch (IOException e) { - e.printStackTrace(); - } - } - } -} -</programlisting> - -</example> - -<example id="eg_DataMonitor_java"> - <title>DataMonitor.java</title> - <programlisting> -/** - * A simple class that monitors the data and existence of a ZooKeeper - * node. It uses asynchronous ZooKeeper APIs. - */ -import java.util.Arrays; - -import org.apache.zookeeper.KeeperException; -import org.apache.zookeeper.WatchedEvent; -import org.apache.zookeeper.Watcher; -import org.apache.zookeeper.ZooKeeper; -import org.apache.zookeeper.AsyncCallback.StatCallback; -import org.apache.zookeeper.KeeperException.Code; -import org.apache.zookeeper.data.Stat; - -public class DataMonitor implements Watcher, StatCallback { - - ZooKeeper zk; - - String znode; - - Watcher chainedWatcher; - - boolean dead; - - DataMonitorListener listener; - - byte prevData[]; - - public DataMonitor(ZooKeeper zk, String znode, Watcher chainedWatcher, - DataMonitorListener listener) { - this.zk = zk; - this.znode = znode; - this.chainedWatcher = chainedWatcher; - this.listener = listener; - // Get things started by checking if the node exists. We are going - // to be completely event driven - zk.exists(znode, true, this, null); - } - - /** - * Other classes use the DataMonitor by implementing this method - */ - public interface DataMonitorListener { - /** - * The existence status of the node has changed. - */ - void exists(byte data[]); - - /** - * The ZooKeeper session is no longer valid. - * - * @param rc - * the ZooKeeper reason code - */ - void closing(int rc); - } - - public void process(WatchedEvent event) { - String path = event.getPath(); - if (event.getType() == Event.EventType.None) { - // We are are being told that the state of the - // connection has changed - switch (event.getState()) { - case SyncConnected: - // In this particular example we don't need to do anything - // here - watches are automatically re-registered with - // server and any watches triggered while the client was - // disconnected will be delivered (in order of course) - break; - case Expired: - // It's all over - dead = true; - listener.closing(KeeperException.Code.SessionExpired); - break; - } - } else { - if (path != null && path.equals(znode)) { - // Something has changed on the node, let's find out - zk.exists(znode, true, this, null); - } - } - if (chainedWatcher != null) { - chainedWatcher.process(event); - } - } - - public void processResult(int rc, String path, Object ctx, Stat stat) { - boolean exists; - switch (rc) { - case Code.Ok: - exists = true; - break; - case Code.NoNode: - exists = false; - break; - case Code.SessionExpired: - case Code.NoAuth: - dead = true; - listener.closing(rc); - return; - default: - // Retry errors - zk.exists(znode, true, this, null); - return; - } - - byte b[] = null; - if (exists) { - try { - b = zk.getData(znode, false, null); - } catch (KeeperException e) { - // We don't need to worry about recovering now. The watch - // callbacks will kick off any exception handling - e.printStackTrace(); - } catch (InterruptedException e) { - return; - } - } - if ((b == null && b != prevData) - || (b != null && !Arrays.equals(prevData, b))) { - listener.exists(b); - prevData = b; - } - } -} -</programlisting> -</example> -</section> - - - -</article>
