[Cloudera][ThriftExtension] (3) Error occurred while contacting server: ETIMEDOUT

[#1]

We use the Cloudera ODBC Driver for Impala from c# .Net using an OdbcConnection.  We are using MIT Kerberos on Windows and keytab authentication.  Occasionally, the process begins throwing the bellow Exception.  Over time, the exception seems to correct itself, however the only known fix to us is to restart the process (which is a problem..)

Exception:

[Cloudera][ThriftExtension] (3) Error occurred while contacting server: ETIMEDOUT. The connection has been configured to use a SASL mechanism for authentication. This error might be due to the server is not using SASL for authentication.

Connection String:

Driver={Cloudera ODBC Driver for Impala};Host=[ImpalaHostName];Port=21050;AuthMech=1;KrbRealm=[KerberosRealm];KrbServiceName=impala;UseKeytab=1;KrbFQDN=_HOST;UID=[UserName];UPNKeytabMappingFile=[jsonKeyTabMappingFile];UseNativeQuery=1;CurrentSchemaRestrictedMetadata=1;Schema=[Database];SocketTimeout=120

We have also occasionally seen the bellow exception, but these seem to be intermittent.

[Cloudera][ImpalaODBC] (450) Error when calling the Impala Thrift API ExecuteStatement: ETIMEDOUT

[#2]

Hello,

Below exception is due to the Front_Service_Threads exhaustion.

It will authenticate the user but does not start the session because there's no availability for another threads.

[Cloudera][ThriftExtension] (3) Error occurred while contacting server: ETIMEDOUT. The connection has been configured to use a SASL mechanism for authentication. This error might be due to the server is not using SASL for authentication.

I recommend to increase "--fe_service_threads" by default, it is set to 64.

Cloudera Manager > Impala > Configuration > search "Impala Command Line Argument Advanced Configuration Snippet (Safety Valve)" > --fe_service_threads=256 > Save and Restart Impala.

Thanks,

Pradheep

[#3]

Thanks @Pradheep, That's very useful.  I'm just a client of the cluster, so I have no permissions to view or alter such server side settings.  However, at least I know that questions to ask the administrators of the cluster now.

Next I just need to find out more about the (450) error. It's a shame the Cloudera ODBC for Impala Driver error messages are so vague and unclear.