CODEWITHSUNDEEP
akkaapache-spark
user2728024
user2728024

Reputation: 1556

Apache Spark - Connection refused for worker

Hi I was new to apache spark and i was trying to learn it

While creating a new standalone cluster I met with this error.

I started my master and it is active in port 7077, i can see that in the ui (port 8080)

While startting the server using the command 

 ./bin/spark-class org.apache.spark.deploy.worker.Worker spark://192.168.0.56:7077

I am meeting with a connection refused error

14/07/22 13:18:30 ERROR EndpointWriter: AssociationError [akka.tcp://sparkWorker@node-        physical:55124] -> [akka.tcp://[email protected]:7077]: Error [Association failed     with [akka.tcp://[email protected]:7077]] [
akka.remote.EndpointAssociationException: Association failed with [akka.tcp://[email protected]:7077]
Caused by: akka.remote.transport.netty.NettyTransport$$anonfun$associate$1$$anon$2:     Connection refused: /192.168.0.56:7077

Please help me with the error i am sruck here for a long time.

I hope the information is enough. Please help

Upvotes: 9

Views: 25596

Answers (11)

Mohammad Reza Rezaei
Mohammad Reza Rezaei

Reputation: 1

Don't overthink it. Just go to a separate page and manually specify the local host:

I had two workers:

http://localhost:8081/

http://localhost:8082/

Upvotes: 0

Alfonso_MA
Alfonso_MA

Reputation: 555

Use ifconfig command to know your private IP. Then, use that IP on your start-master.sh script like this:

./start-master.sh --host 192.168.1.15 --port 7077

At this point, use telnet command like this:

telnet 192.168.1.15 7077

and the ouput should confirm that you were able to connect without any issue:

Trying 192.168.1.15...
Connected to 192.168.1.15.

Finally, use start-worker.sh script like this:

start-worker.sh spark://192.168.1.15:7077

Upvotes: 0

Joseph Hui
Joseph Hui

Reputation: 587

I do not have a DNS and I added entries in /etc/hosts in the master node to refer to the IPs and hostnames of all master and worker nodes. In worker nodes, I added the IP and hostname of the master node in /etc/hosts.

Upvotes: 0

devm2024
devm2024

Reputation: 11

I had the similar problem in a docker container, I solved it by setting the IP for master and driver as localhost, specifically:

    set('spark.master.hostname' ,'localhost')
    set('spark.driver.hostname', 'localhost')

Upvotes: 1

Ironluca
Ironluca

Reputation: 3762

For Windows: spark-class org.apache.spark.deploy.master.Master -h [Interface IP to bind to]

Upvotes: 0

Hohenheimsenberg
Hohenheimsenberg

Reputation: 980

Change the SPARK_MASTER_HOST=< ip> in the spark-env.sh of the master node.

Then restart the master, if you grep the process you will see it changes from

java -cp /spark/conf/:/spark/jars/* -Xmx1g org.apache.spark.deploy.master.Master --host < HOST NAME> --port 7077 --webui-port 8080

to

java -cp /spark/conf/:/spark/jars/* -Xmx1g org.apache.spark.deploy.master.Master --host < HOST IP> --port 7077 --webui-port 8080

Upvotes: 4

user2395069
user2395069

Reputation: 71

Try "./sbin/start-master -h ". It works, when I specify the host name as IP address.

Upvotes: 6

dsncode
dsncode

Reputation: 2441

it seems like spark is very picky about IP and machine names. so, when starting your master, it will use your machine name to register spark master. if that name is not reachable from your workers, it will be almost impossible to reach.

a way to solve it, is to start your master like this:

SPARK_MASTER_IP=YOUR_SPARK_MASTER_IP ${SPARK_HOME}/sbin/start-master.sh

then, you will be able to connect your slaves like this

${SPARK_HOME}/sbin/start-slave.sh spark://YOUR_SPARK_MASTER_IP:PORT

i hope it helps!

Upvotes: 1

tdebroc
tdebroc

Reputation: 1526

In my case, I went to /etc/hosts and :

  • removed the line with 127.0.1.1 and it worked.
  • wrote "MASTER_IP MACHINE_NAME"

Upvotes: 8

napster
napster

Reputation: 193

did you add the entries of master and worker nodes in etc/hosts, if not add every machines ip and host name mappings in all the machines.

Upvotes: 0

Jorge Luis
Jorge Luis

Reputation: 731

Check if your firewall is turned off as it might be blocking the worker connection by either turning off the firewall temporarily: 

$ sudo service iptables stop

or permanently:

$ sudo chkconfig iptables off

Upvotes: 1

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