Database Reference
In-Depth Information
Connectivity Failures
There are a few ways you can connect to your cluster. You can use remote desktop login to connect to the head node,
you can use the ODBC endpoint on port
443
to connect to the Hive service, and you can navigate through the
REST-based protocols to different URLs from Internet Explorer.
Always, make sure to test these different types of connections when you encounter a specific problem. For example,
if you are unable to remotely log in to one of your data nodes, try to open the Hadoop Name Node Status portal and
check if the number of live nodes is reported correctly.
■
azure VMs periodically go through a process called
re-imaging
, where an existing VM is released and a new
VM gets provisioned. the node is expected to be down for up to 15 minutes when this happens. this is an unattended,
automated process, and the end user has absolutely no control over this.
Note
ODBC failures deserve some additional attention. You typically use a client like Microsoft Excel to create your
data models from HDInsight data. Any such front-end tool leverages the Hive ODBC driver to connect to Hive running
on HDInsight. A typical failure can be like this:
Errors:
From Excel:
"Unable to establish connection with hive server"
From PowerPivot:
Failed connect to the server. Reason: ERROR [HY000] Invalid Attribute Persist Security Info
ERROR [01004] Out connection string buffer not allocated
ERROR [08001] Unable to establish connection with hive server
To start with, always make sure that the basic DSN configuration parameters such as port number,
authentication, and so on are properly set. For Azure HDInsight Service, make sure that:
•
You are connecting to port
443
.
•
Hive Server Type is set to
Hive Server 2
.
•
Authentication Mechanism is set to
Windows Azure HDInsight Service
.
•
The correct cluster user name and password are provided.
For the Azure HDInsight Emulator, confirm that
•
You are connecting to port
10001
.
•
Hive Server Type is set to
Hive Server 2
.
•
Authentication Mechanism is set to
Windows Azure HDInsight Emulator
.
If the problem persists even when all the preceding items are set correctly, try to test basic connectivity from
Internet Explorer. Navigate to the following URLs, which target the same endpoints that ODBC uses:
Localhost:
http://localhost:10001/servlets/thrifths
