Description:

The Data Aggregator (DA) was found to have its service, the dadaemon, no longer running. How can we check for basic causes?

Solution:

One of the more common causes is that the Data Repository Vertica database is down. When the DB is down after 10 minutes the DA will shut itself down to protect itself from crashing.

This can be determined by examining the $DA_HOME/apache-karaf-2.3.0/shutdown.log file. Default location would have $DA_HOME represented by /opt.

If the case is cause by a down DB, the common error messages observed would appear similar to:

ERROR | nager-thread-854 | 2014-09-29 23:19:46,378 | shutdown | ces.shutdown.ShutdownManagerImpl  150 | ces.shutdown.ShutdownManagerImpl  150 | ommon.core.services.impl |

     | Shutting down the data aggregator. It was detected that no data repository nodes were contactable. The uncontactable hosts are:[<DATA REPOSITORY HOSNTAME>]

This indicates that no Data Repository hosts are available because the DB is down for some reason. Therefore the DA shut itself down.

In this case we would need to verify that the Data Repository us running and accessible from the Data Aggregator server as well as ensuring the DB is started and running.

If the DB is found to be down, and is restarted, restart the DA dadaemon service. This is done as the root or sudo root install owner by running:

service dadaemon start