README.rst 6.4 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. On your host system, you need to have the python "virtualenv" package
  42. installed.
  43. 2. Also, you'll need these library development packages and tools installed on
  44. your system:
  45. Debian:
  46. * gcc
  47. * libmysqlclient-dev
  48. * libsasl2-dev
  49. * libsqlite3-dev
  50. * libxml2-dev
  51. * libxslt-dev
  52. * maven2
  53. * python-dev
  54. * python-setuptools
  55. * python-simplejson
  56. CentOS:
  57. * cyrus-sasl-devel
  58. * gcc
  59. * libxml2-devel
  60. * libxslt-devel
  61. * maven2
  62. * mysql
  63. * mysql-devel
  64. * python-devel
  65. * python-setuptools
  66. * python-simplejson (for the crepo tool)
  67. * sqlite-devel
  68. MacOS (mac port):
  69. * liblxml
  70. * libxml2
  71. * libxslt
  72. * mysql5-devel
  73. * simplejson (easy_install)
  74. * sqlite3
  75. 3. You need to have crepo installed, and preferably on your path. If it is not
  76. on your path, set the environment variable ``CREPO`` to point to ``crepo.py``
  77. from that distribution. You can clone crepo from
  78. http://github.com/cloudera/crepo.git somewhere else on your system.
  79. Getting Started
  80. ===============
  81. To build and get the core server running::
  82. $ export HADOOP_HOME=<path-to-hadoop-home>
  83. $ git clone http://github.com/cloudera/hue.git
  84. $ cd hue
  85. $ make apps
  86. $ build/env/bin/hue runserver_plus
  87. To start the helper daemons::
  88. $ build/env/bin/hue beeswax_server
  89. $ build/env/bin/hue jobsubd
  90. Now Hue should be running on http://localhost:8000.
  91. Setting up Hadoop
  92. =================
  93. In order to start up a pseudo-distributed cluster with the plugins enabled,
  94. run::
  95. $ ./tools/scripts/configure-hadoop.sh all
  96. After doing so, running ``jps`` should show all the daemons running (NN, JT,
  97. TT, DN) and you should be able to see the web UI on http://localhost:50030/ and
  98. http://localhost:50070/.
  99. FAQ
  100. ===
  101. 1: What does "Exception: no app!" mean?
  102. Your template has an error in it. Check for messages from the server that
  103. look like::
  104. INFO:root:Processing exception: Unclosed tag 'if'. Looking for one of: else, endif
  105. 2: What do I do if I get "There was an error launching ..."?
  106. Turn on debugging by issuing ``dbug.cookie()`` in a Firebug console.
  107. Django Conventions
  108. ==================
  109. If you need to name your urls
  110. (http://docs.djangoproject.com/en/dev/topics/http/urls/#naming-url-patterns)
  111. because there's ambiguity in the view, be sure to prefix the name
  112. with the application name. The url name namespace is global. So
  113. ``jobsub.list`` is fine, but ``list`` is not.
  114. Hue is using Django 1.1, which supports the notion of URL namespaces:
  115. http://docs.djangoproject.com/en/dev/topics/http/urls/#url-namespaces.
  116. We have yet to move over our URLs to this construct. Brownie points for the
  117. developer who takes this on.
  118. Using and Installing Thrift
  119. ===========================
  120. Right now, we check in the generated thrift code.
  121. To generate the code, you'll need the thrift binary.
  122. Compile it like so::
  123. $ git clone http://github.com/dreiss/thrift.git
  124. $ cd thrift
  125. $ ./bootstrap.sh
  126. $ ./configure --with-py=no --with-java=no --with-perl=no --prefix=$HOME/pub
  127. We exclude python, java, and perl because they don't like
  128. to install in prefix. If you look around at configure's --help,
  129. there are environment variables that determine where those
  130. runtime bindings are installed.
  131. ::
  132. $ make && make install
  133. When preparing ``.thrift`` files, you can use she-bangs to generate
  134. the python bindings like so::
  135. #!/usr/bin/env thrift -r --gen py:new_style -o ../../../
  136. .. note::
  137. This file is in reStructuredText. You may run
  138. ``rst2html README.rst > README.html`` to produce a HTML.
  139. Profiling Hue Apps
  140. ==================
  141. Hue has a profiling system built in, which can be used to analyze server-side
  142. performance of applications. To enable profiling::
  143. $ build/env/bin/hue runprofileserver
  144. Then, access the page that you want to profile. This will create files like
  145. /tmp/useradmin.users.000072ms.2011-02-21T13:03:39.745851.prof. The format for
  146. the file names is /tmp/<app_module>.<page_url>.<time_taken>.<timestamp>.prof.
  147. Hue uses the hotshot profiling library for instrumentation. The documentation
  148. for this library is located at: http://docs.python.org/library/hotshot.html.
  149. To make use of the profiling data quickly, you can create a script that does
  150. the following::
  151. #!/usr/bin/python
  152. import hotshot.stats
  153. import sys
  154. stats = hotshot.stats.load(sys.argv[1])
  155. stats.sort_stats('cumulative', 'calls')
  156. stats.print_stats(100)
  157. This script takes in a .prof file, and orders function calls by the cumulative
  158. time spent in that function, followed by the number of times the function was
  159. called, and then prints out the top 100 time-wasters. For information on the
  160. other stats available, take a look at this website:
  161. http://docs.python.org/library/profile.html#pstats.Stats