README.rst 6.3 KB

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  1. Welcome to the repository for Hue
  2. =================================
  3. .. note::
  4. This is the development-oriented readme. If you want to write notes for
  5. end users, please put them in ``dist/README``.
  6. Hue is both a web UI for Hadoop and a framework to create interactive web
  7. applications. It features a FileBrowser for accessing HDFS, JobSub and
  8. JobBrowser applications for submitting and viewing MapReduce jobs, a Beeswax
  9. application for interacting with Hive. On top of that, the web frontend
  10. is mostly built from declarative widgets that require no JavaScript and are
  11. easy to learn.
  12. File Layout
  13. ===========
  14. The "core" stuff is in ``desktop/core/``, whereas installable apps live in
  15. ``apps/``. Please place third-party dependencies in the app's ext-py/
  16. directory.
  17. The typical directory structure for inside an application includes:
  18. src/
  19. for Python code
  20. conf/
  21. for configuration (``.ini``) files to be installed
  22. static/
  23. for static HTML and js resources
  24. templates/
  25. for data to be put through a template engine
  26. docs/
  27. for helpful notes
  28. The python code is structured simply as
  29. ``module/package.py``,
  30. where module may be "filebrowser" or "jobsub". Because it is unlikely that
  31. there are going to be huge conflicts, we're going without a deep nested
  32. hierarchy.
  33. URL Layout
  34. ==========
  35. ``core/src/desktop/urls.py`` contains the current layout for top-level URLs.
  36. For the URLs within your application, you should make your own ``urls.py``
  37. which will be automatically rooted at ``/yourappname/`` in the global
  38. namespace. See ``apps/hello/src/hello/urls.py`` for an example.
  39. Development Prerequisites
  40. ===========================
  41. 1. Also, you'll need these library development packages and tools installed on
  42. your system:
  43. Debian:
  44. * asciidoc
  45. * gcc
  46. * g++
  47. * libmysqlclient-dev
  48. * libsasl2-dev
  49. * libsqlite3-dev
  50. * libxml2-dev
  51. * libxslt-dev
  52. * maven2
  53. * python-dev
  54. * python-simplejson
  55. CentOS:
  56. * asciidoc
  57. * cyrus-sasl-devel
  58. * gcc
  59. * libxml2-devel
  60. * libxslt-devel
  61. * maven2
  62. * mysql
  63. * mysql-devel
  64. * python-devel
  65. * python-simplejson (for the crepo tool)
  66. * sqlite-devel
  67. MacOS (mac port):
  68. * liblxml
  69. * libxml2
  70. * libxslt
  71. * mysql5-devel
  72. * simplejson (easy_install)
  73. * sqlite3
  74. 2. You need to have crepo installed, and preferably on your path. If it is not
  75. on your path, set the environment variable ``CREPO`` to point to ``crepo.py``
  76. from that distribution. You can clone crepo from
  77. http://github.com/cloudera/crepo.git somewhere else on your system.
  78. Getting Started
  79. ===============
  80. To build and get the core server running::
  81. $ export HADOOP_HOME=<path-to-hadoop-home>
  82. $ git clone http://github.com/cloudera/hue.git
  83. $ cd hue
  84. $ make apps
  85. $ build/env/bin/hue runserver_plus
  86. To start the helper daemons::
  87. $ build/env/bin/hue beeswax_server
  88. $ build/env/bin/hue jobsubd
  89. Now Hue should be running on http://localhost:8000.
  90. Setting up Hadoop
  91. =================
  92. In order to start up a pseudo-distributed cluster with the plugins enabled,
  93. run::
  94. $ ./tools/scripts/configure-hadoop.sh all
  95. After doing so, running ``jps`` should show all the daemons running (NN, JT,
  96. TT, DN) and you should be able to see the web UI on http://localhost:50030/ and
  97. http://localhost:50070/.
  98. FAQ
  99. ===
  100. 1: What does "Exception: no app!" mean?
  101. Your template has an error in it. Check for messages from the server that
  102. look like::
  103. INFO:root:Processing exception: Unclosed tag 'if'. Looking for one of: else, endif
  104. 2: What do I do if I get "There was an error launching ..."?
  105. Turn on debugging by issuing ``dbug.cookie()`` in a Firebug console.
  106. Django Conventions
  107. ==================
  108. If you need to name your urls
  109. (http://docs.djangoproject.com/en/dev/topics/http/urls/#naming-url-patterns)
  110. because there's ambiguity in the view, be sure to prefix the name
  111. with the application name. The url name namespace is global. So
  112. ``jobsub.list`` is fine, but ``list`` is not.
  113. Hue is using Django 1.1, which supports the notion of URL namespaces:
  114. http://docs.djangoproject.com/en/dev/topics/http/urls/#url-namespaces.
  115. We have yet to move over our URLs to this construct. Brownie points for the
  116. developer who takes this on.
  117. Using and Installing Thrift
  118. ===========================
  119. Right now, we check in the generated thrift code.
  120. To generate the code, you'll need the thrift binary.
  121. Compile it like so::
  122. $ git clone http://github.com/dreiss/thrift.git
  123. $ cd thrift
  124. $ ./bootstrap.sh
  125. $ ./configure --with-py=no --with-java=no --with-perl=no --prefix=$HOME/pub
  126. We exclude python, java, and perl because they don't like
  127. to install in prefix. If you look around at configure's --help,
  128. there are environment variables that determine where those
  129. runtime bindings are installed.
  130. ::
  131. $ make && make install
  132. When preparing ``.thrift`` files, you can use she-bangs to generate
  133. the python bindings like so::
  134. #!/usr/bin/env thrift -r --gen py:new_style -o ../../../
  135. .. note::
  136. This file is in reStructuredText. You may run
  137. ``rst2html README.rst > README.html`` to produce a HTML.
  138. Profiling Hue Apps
  139. ==================
  140. Hue has a profiling system built in, which can be used to analyze server-side
  141. performance of applications. To enable profiling::
  142. $ build/env/bin/hue runprofileserver
  143. Then, access the page that you want to profile. This will create files like
  144. /tmp/useradmin.users.000072ms.2011-02-21T13:03:39.745851.prof. The format for
  145. the file names is /tmp/<app_module>.<page_url>.<time_taken>.<timestamp>.prof.
  146. Hue uses the hotshot profiling library for instrumentation. The documentation
  147. for this library is located at: http://docs.python.org/library/hotshot.html.
  148. To make use of the profiling data quickly, you can create a script that does
  149. the following::
  150. #!/usr/bin/python
  151. import hotshot.stats
  152. import sys
  153. stats = hotshot.stats.load(sys.argv[1])
  154. stats.sort_stats('cumulative', 'calls')
  155. stats.print_stats(100)
  156. This script takes in a .prof file, and orders function calls by the cumulative
  157. time spent in that function, followed by the number of times the function was
  158. called, and then prints out the top 100 time-wasters. For information on the
  159. other stats available, take a look at this website:
  160. http://docs.python.org/library/profile.html#pstats.Stats