Impala connections to the backend client are subject to failure
in cases when the network is momentarily overloaded.
To avoid failed queries due to transient network problems, you can
configure the number of Thrift connection retries using the following
option:
-
In Cloudera Manager, navigate to .
- In the Impala Daemon Command Line Argument Advanced
Configuration Snippet (Safety Valve) field, specify the
following.
To avoid failed queries due to transient network problems, you can
configure the number of Thrift connection retries using the
following option:
- The
--backend_client_connection_num_retries
option specifies the number of times Impala will try connecting to
the backend client after the first connection attempt fails. By
default, impalad will attempt three
re-connections before it returns a failure.
You can configure timeouts for sending and receiving data from the
backend client. Therefore, if for some reason a query does not respond, instead
of waiting indefinitely for a response, Impala will terminate the
connection after a configurable timeout.
- The
--backend_client_rpc_timeout_ms option can
be used to specify the number of milliseconds Impala should wait
for a response from the backend client before it terminates the
connection and signals a failure. The default value for this
property is 300000 milliseconds, or 5 minutes.
- Click Save Changes and restart
Impala.
