Objectives
This tutorial will walk you the process of starting Atlas on the Hortonworks Sandbox for HDP 2.5. By default the service is disabled. However manually starting the service will fail unless you start the dependencies. Atlas depends on Ambari Infra (which provides Solr), Kafka and HBase. Atlas will start with just the Ambari Infra service running, you won't have proper functionality without Kafka and KBase
Scope
This has been testing on the following:
- VirtualBox 5.1.6
- Hortonworks Sandbox for HDP 2.5
Steps
Start Atlas Service
Get your sandbox up and running and log into Ambari. Click on the Atlas service link. You should see something similar to this:
Because Atlas is in maintenance mode, it will not automatically start. When you try to start it by going to Service Actions -> Start like this:
You will see the following error:
If you look at the error message provide you will see the problem is related to Solr:
Client is connected to ZooKeeper Using default ZkACLProvider Updating cluster state from ZooKeeper... No live SolrServers available to handle this request org.apache.solr.client.solrj.SolrServerException: No live SolrServers available to handle this request at org.apache.solr.client.solrj.impl.LBHttpSolrClient.request(LBHttpSolrClient.java:350) at org.apache.solr.client.solrj.impl.CloudSolrClient.sendRequest(CloudSolrClient.java:1100) at org.apache.solr.client.solrj.impl.CloudSolrClient.requestWithRetryOnStaleState(CloudSolrClient.java:870) at org.apache.solr.client.solrj.impl.CloudSolrClient.request(CloudSolrClient.java:806) at org.apache.solr.client.solrj.SolrRequest.process(SolrRequest.java:149) at org.apache.solr.client.solrj.SolrRequest.process(SolrRequest.java:166)
This is because Atlas is using the Solr instance in the Ambari Infra service, which is in maintenance mode and does not auto start. Let's start the service.
Start Ambari Infra Service
If you click on the Ambari Infra Service you should see something like this:
Click the Service Actions -> Start button. This should start Ambari Infra.
Start Atlas Service
Now that Ambari Infra is running, you should be able to start the Atlas service.
Start Kafka and HBase Service
While Atlas did start with only the Ambari Infra service running. It also depends on Kafka and HBase for full functionality. You should start both of those services similar to how we started the Ambari Infra service.
Review
The Ambari Infra service provides a Solr instance for core HDP component access. By default this service is in maintenance mode and does not start which causes the Atlas service to fail. By starting the Amabari Infra service before Atlas, you will be able to start Atlas.
If you turn off maintanence mode for Ambari Infra, then it will auto start.
