Note
This is the development-oriented readme. If you want to write notes for
end users, please put them in dist/README
.
Hue is both a web UI for Hadoop and a framework to create interactive web applications. It features a FileBrowser for accessing HDFS, JobSub and JobBrowser applications for submitting and viewing MapReduce jobs, a Beeswax application for interacting with Hive. On top of that, the web frontend is mostly built from declarative widgets that require no JavaScript and are easy to learn.
The "core" stuff is in desktop/core/
, whereas installable apps live in
apps/
. Please place third-party dependencies in the app's ext-py/
directory.
The typical directory structure for inside an application includes:
- src/
- for Python code
- conf/
- for configuration (
.ini
) files to be installed- static/
- for static HTML and js resources
- templates/
- for data to be put through a template engine
- docs/
- for helpful notes
The python code is structured simply as
module/package.py
,
where module may be "filebrowser" or "jobsub". Because it is unlikely that
there are going to be huge conflicts, we're going without a deep nested
hierarchy.
core/src/desktop/urls.py
contains the current layout for top-level URLs.
For the URLs within your application, you should make your own urls.py
which will be automatically rooted at /yourappname/
in the global
namespace. See apps/hello/src/hello/urls.py
for an example.
You'll need these library development packages and tools installed on your system:
- Ubuntu:
- ant
- gcc
- g++
- libkrb5-dev
- libmysqlclient-dev
- libssl-dev
- libsasl2-dev
- libsasl2-modules-gssapi-mit
- libsqlite3-dev
- libtidy-0.99-0 (for unit tests only)
- libxml2-dev
- libxslt-dev
- mvn (from
maven2
package or tarball)- openldap-dev / libldap2-dev
- python-dev
- python-simplejson
- python-setuptools
- CentOS:
- ant
- asciidoc
- cyrus-sasl-devel
- cyrus-sasl-gssapi
- gcc
- gcc-c++
- krb5-devel
- libtidy (for unit tests only)
- libxml2-devel
- libxslt-devel
- mvn (from
maven2
package or tarball)- mysql
- mysql-devel
- openldap-devel
- python-devel
- python-simplejson
- sqlite-devel
- MacOS (mac port):
- liblxml
- libxml2
- libxslt
- mysql5-devel
- simplejson (easy_install)
- sqlite3
To build and get the core server running:
$ export HADOOP_HOME=<path-to-hadoop-home> $ git clone http://github.com/cloudera/hue.git $ cd hue $ make apps $ build/env/bin/hue runserver_plus
To start the helper daemons:
$ build/env/bin/hue beeswax_server $ build/env/bin/hue jobsubd
Now Hue should be running on http://localhost:8000.
- 1: What does "Exception: no app!" mean?
Your template has an error in it. Check for messages from the server that look like:
INFO:root:Processing exception: Unclosed tag 'if'. Looking for one of: else, endif
- 2: What do I do if I get "There was an error launching ..."?
- Turn on debugging by issuing
dbug.cookie()
in a Firebug console.
If you need to name your urls
(http://docs.djangoproject.com/en/dev/topics/http/urls/#naming-url-patterns)
because there's ambiguity in the view, be sure to prefix the name
with the application name. The url name namespace is global. So
jobsub.list
is fine, but list
is not.
Hue is using Django 1.2, which supports the notion of URL namespaces: http://docs.djangoproject.com/en/dev/topics/http/urls/#url-namespaces. We have yet to move over our URLs to this construct. Brownie points for the developer who takes this on.
Right now, we check in the generated thrift code. To generate the code, you'll need the thrift binary version 0.7.0. Please download from http://thrift.apache.org/.
When preparing .thrift
files, you can use she-bangs to generate
the python bindings like so:
#!/usr/bin/env thrift -r --gen py:new_style -o ../../../
Hue has a profiling system built in, which can be used to analyze server-side performance of applications. To enable profiling:
$ build/env/bin/hue runprofileserver
Then, access the page that you want to profile. This will create files like /tmp/useradmin.users.000072ms.2011-02-21T13:03:39.745851.prof. The format for the file names is /tmp/<app_module>.<page_url>.<time_taken>.<timestamp>.prof.
Hue uses the hotshot profiling library for instrumentation. The documentation for this library is located at: http://docs.python.org/library/hotshot.html.
You can use kcachegrind to view the profiled data graphically:
$ hotshot2calltree /tmp/xyz.prof > /tmp/xyz.trace $ kcachegrind /tmp/xyz.trace
More generally, you can programmatically inspect a trace:
#!/usr/bin/python import hotshot.stats import sys stats = hotshot.stats.load(sys.argv[1]) stats.sort_stats('cumulative', 'calls') stats.print_stats(100)
This script takes in a .prof file, and orders function calls by the cumulative time spent in that function, followed by the number of times the function was called, and then prints out the top 100 time-wasters. For information on the other stats available, take a look at this website: http://docs.python.org/library/profile.html#pstats.Stats
How to update the messages: compile-locale rule in Makefile.sdk
How to create a new locale for an app: LOCALE_ROOT = $APP_ROOT/src/$APP_NAME/locale ./build/env/bin/pybabel init -D django -i $LOCALE_ROOT/en_US.pot -d $LOCALE_ROOT -l fr