Unable to install mpack for DLM Engine - OSError: [Errno 17] File exists

[#1]

This has been tested on Ambari 2.6.2.0 and DLM 1.1.2.0

If there is broken symlink or unwanted directory under /var/lib/ambari-server/resources on Ambari Server, you get below error while installing mpack(management pack) for Beacon service.

[root@XXXXXX ~]# ambari-server install-mpack --mpack /root/beacon-ambari-mpack-1.1.2.0-37.tar.gz --verbose
Using python /usr/bin/python 
Installing management pack 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
INFO: Installing management pack /root/beacon-ambari-mpack-1.1.2.0-37.tar.gz 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
INFO: Download management pack to temp location /var/lib/ambari-server/data/tmp/beacon-ambari-mpack-1.1.2.0-37.tar.gz 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
INFO: Expand management pack at temp location /var/lib/ambari-server/data/tmp/beacon-ambari-mpack-1.1.2.0-37/ 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
INFO: Stage management pack beacon-engine.mpack-1.1.0.0 to staging location /var/lib/ambari-server/resources/mpacks/beacon-engine.mpack-1.1.0.0 
INFO: Processing artifact BEACON-common-services of type service-definitions in /var/lib/ambari-server/resources/mpacks/beacon-engine.mpack-1.1.0.0/common-services 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
INFO: Symlink: /var/lib/ambari-server/resources/common-services/BEACON/1.1.0 
INFO: Processing artifact BEACON-addon-services of type stack-addon-service-definitions in /var/lib/ambari-server/resources/mpacks/beacon-engine.mpack-1.1.0.0/addon-services 
INFO: Loading properties from /etc/ambari-server/conf/ambari.properties 
Traceback (most recent call last): 
File "/usr/sbin/ambari-server.py", line 952, in <module> 
mainBody() 
File "/usr/sbin/ambari-server.py", line 922, in mainBody 
main(options, args, parser) 
File "/usr/sbin/ambari-server.py", line 874, in main 
action_obj.execute() 
File "/usr/sbin/ambari-server.py", line 78, in execute 
self.fn(*self.args, **self.kwargs) 
File "/usr/lib/ambari-server/lib/ambari_server/setupMpacks.py", line 896, in install_mpack 
(mpack_metadata, mpack_name, mpack_version, mpack_staging_dir, mpack_archive_path) = _install_mpack(options, replay_mode) 
File "/usr/lib/ambari-server/lib/ambari_server/setupMpacks.py", line 794, in _install_mpack 
process_stack_addon_service_definitions_artifact(artifact, artifact_source_dir, options) 
File "/usr/lib/ambari-server/lib/ambari_server/setupMpacks.py", line 554, in process_stack_addon_service_definitions_artifact 
sudo.symlink(source_service_version_path, dest_link) 
File "/usr/lib/ambari-server/lib/resource_management/core/sudo.py", line 124, in symlink 
os.symlink(source, link_name) 
OSError: [Errno 17] File exists

Please follow below steps to fix this:

1. Make sure that there is no backup directory under /var/lib/ambari-server/resources like common-services.backup or stacks.old etc. If exists, please move it some other location.

.

2. Delete or move below directories to other location

/var/lib/ambari-server/resources/common-services/BEACON 
/var/lib/ambari-server/resources/mpacks 

.

3. Check if there is any broken symlink for BEACON under stacks directory. If exists, unlink it.

unlink /var/lib/ambari-server/resources/stacks/HDP/2.6/services/BEACON

.

4 Reinstall mpack using command mentioned in the Hortonworks docs.

e.g.

ambari-server install-mpack --mpack /root/beacon-ambari-mpack-1.1.2.0-37.tar.gz --verbose

.

Please comment if you have any feedback/questions/suggestions. Happy Hadooping!!