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admission control



I get the follwoing error frequently. Do I need to change Admission control configuration?

Please adive. 


Sender timed out waiting for receiver fragment instance: 1a479d6dc1b2bcc9:6a91ac21000003b8, dest node: 250


Below are my present configurations.




Re: admission control

Cloudera Employee

Unlikely to be related to admission control. The error you included is referred to as a DATASTREAM_SENDER_TIMEOUT error in Impala and is thrown by Impala's RPC layer.


What version of Impala are you running? This could be related to IMPALA-6818 which reports a similar error. You could try increasing the value of datastream_sender_timeout_ms to a higher value such as 3600000.

Re: admission control


Thanks for your advice


How can I increase the  datastream_sender_timeout_ms?


Also, can I have your advice on the following error?


RPC client failed to connect: Couldn't open transport for (connect() failed: Connection refused)



Re: admission control

Cloudera Employee

datastream_sender_timeout_ms is an Impala startup flag. See for information on setting startup flag options.


The "RPC client failed to connect" means that a client failed to connect to an impalad process running on It is hard to say which client failed to make the connection without more information, are there additional client and impalad logs available? What version of Impala is running? Is KRPC enabled on your cluster?