Hue install bootstrap error using AWS EMR with Boto

Question

With the release of AMI 3.3.0, AWS supports Hue as an installable "app" in EMR, like Hive/Pig. Using the EMR web UI, creating a cluster with Hue works fine for me, however when adding a Hue installation bootstrap action via Boto, I am getting a non-deterministic error (it periodically crashes). I have tested 4 times with identical configuration and the crash rate is 50%.

In Boto, I add an additional bootstrap action, as is done automatically when creating a cluster from the web UI when Hue is enabled:

BootstrapAction('Install Hue', 's3://elasticmapreduce/libs/hue/install-hue', [])

The cluster then terminates with a:

Terminated with errors: On the master instance (i-c6b7582a), 
bootstrap action 2 returned a non-zero return code

And in the bootstrap action logs:

Existing lock /var/run/yum.pid: another copy is running as pid 2007. Another app is currently holding the yum lock; waiting for it to exit... The other application is: yum Memory : 22 M RSS (305 MB VSZ) Started: Tue Nov 11 21:00:12 2014 - 00:19 ago State : Sleeping, pid: 2007 Another app is currently holding the yum lock; waiting for it to exit...

Tons of those, and finally a large stacktrace:

Trying other mirror.
http://packages.ap-southeast-2.amazonaws.com/2014.09/main/20140901f63e/x86_64/repodata/repomd.xml?instance_id=i-c6b7582a&region=us-east-1: [Errno 12] Timeout on http://packages.ap-southeast-2.amazonaws.com/2014.09/main/20140901f63e/x86_64/repodata/repomd.xml?instance_id=i-c6b7582a&region=us-east-1: (28, 'Connection timed out after 10000 milliseconds')
Trying other mirror.
Traceback (most recent call last):
  File "/usr/bin/yum", line 29, in <module>
    yummain.user_main(sys.argv[1:], exit_code=True)
  File "/usr/share/yum-cli/yummain.py", line 355, in user_main
    errcode = main(args)
  File "/usr/share/yum-cli/yummain.py", line 174, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 572, in doCommands
    return self.yum_cli_commands[self.basecmd].doCommand(self, self.basecmd, self.extcmds)
  File "/usr/share/yum-cli/yumcommands.py", line 432, in doCommand
    return base.installPkgs(extcmds, basecmd=basecmd)
  File "/usr/share/yum-cli/cli.py", line 968, in installPkgs
    txmbrs = self.install(pattern=arg)
  File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 4721, in install
    mypkgs = self.pkgSack.returnPackages(patterns=pats,
  File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 1069, in <lambda>
    pkgSack = property(fget=lambda self: self._getSacks(),
  File "/usr/lib/python2.6/site-packages/yum/__init__.py", line 774, in _getSacks
    self.repos.populateSack(which=repos)
  File "/usr/lib/python2.6/site-packages/yum/repos.py", line 383, in populateSack
    sack.populate(repo, mdtype, callback, cacheonly)
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 250, in populate
    if self._check_db_version(repo, mydbtype):
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 342, in _check_db_version
    return repo._check_db_version(mdtype)
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1520, in _check_db_version
    repoXML = self.repoXML
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1706, in <lambda>
    repoXML = property(fget=lambda self: self._getRepoXML(),
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1702, in _getRepoXML
    self._loadRepoXML(text=self.ui_id)
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1693, in _loadRepoXML
    return self._groupLoadRepoXML(text, self._mdpolicy2mdtypes())
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1667, in _groupLoadRepoXML
    if self._commonLoadRepoXML(text):
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1495, in _commonLoadRepoXML
    self._revertOldRepoXML()
  File "/usr/lib/python2.6/site-packages/yum/yumRepo.py", line 1345, in _revertOldRepoXML
    os.rename(old_data['old_local'], old_data['local'])
OSError: [Errno 2] No such file or directory

In contrast, the bootstrap log shows a single line on success:

Warning: RPMDB altered outside of yum.

Answer 1

Example to install and run Hue in EMR AMI 3.3

import boto.emr
from boto.emr.emrobject import InstanceGroup
from boto.emr.bootstrap_action import BootstrapAction
from boto.emr.step import ScriptRunnerStep

conn = boto.emr.EmrConnection()

jobid = conn.run_jobflow(name="Hue Example", ami_version = "3.3.0",
                                log_uri="s3n://your-log-path-here",
                                instance_groups= get_instance_groups(),
                                bootstrap_actions=get_bootstrap_actions(),
                                ec2_keyname="your-ec2-key-name",
                                steps = get_startup_steps()
                                )

def get_bootstrap_actions():
    install_hue_action = BootstrapAction("Install Hue ",
                                "s3n://us-east-1.elasticmapreduce/libs/hue/install-hue",
                                bootstrap_action_args=None)
    return [install_hue_action]


def get_startup_steps():
    runHueStep = ScriptRunnerStep(name="Run Hue",
                                        step_args = ["s3n://us-east-1.elasticmapreduce/libs/hue/run-hue"])
    return [runHueStep]


def get_instance_groups():
    #This is just an example. Actual implementation will have core, and task instance groups as well. Please choose your instance type, number, and bid price wisely as might it get too expensive too quickly.
    spotInstanceGroup =  InstanceGroup()
    spotInstanceGroup.name="Spot Instance Group Master"
    spotInstanceGroup.bidprice="0.20"
    spotInstanceGroup.num_instances = 1
    spotInstanceGroup.market="SPOT"
    spotInstanceGroup.type="c3.2xlarge"
    spotInstanceGroup.role="MASTER"