Kafka connect and HDFS in docker

Question

I am using kafka connect HDFS sink and Hadoop (for HDFS) in a docker-compose.

Hadoop (namenode and datanode) seems working correctly.

But I have an error with kafka connect sink:

ERROR Recovery failed at state RECOVERY_PARTITION_PAUSED 
(io.confluent.connect.hdfs.TopicPartitionWriter:277) 
org.apache.kafka.connect.errors.DataException: 
Error creating writer for log file hdfs://namenode:8020/logs/MyTopic/0/log

For information:

• Hadoop services in my docker-compose.yml:

   namenode: image: uhopper/hadoop-namenode:2.8.1 hostname: namenode container_name: namenode ports: - "50070:50070" networks: default: fides-webapp: aliases: - "hadoop" volumes: - namenode:/hadoop/dfs/name env_file: - ./hadoop.env environment: - CLUSTER_NAME=hadoop-cluster datanode1: image: uhopper/hadoop-datanode:2.8.1 hostname: datanode1 container_name: datanode1 networks: default: fides-webapp: aliases: - "hadoop" volumes: - datanode1:/hadoop/dfs/data env_file: - ./hadoop.env 

And my kafka-connect file:

    name=hdfs-sink
    connector.class=io.confluent.connect.hdfs.HdfsSinkConnector
    tasks.max=1
    topics=MyTopic
    hdfs.url=hdfs://namenode:8020
    flush.size=3

EDIT:

I add an env variable for kafka connect to be aware of the cluster name (env variable: CLUSTER_NAME to add in kafka connect service in docker compose file).

The error is not the same (and it seems to solve a problem):

INFO Starting commit and rotation for topic partition scoring-topic-0 with start offsets {partition=0=0} and end offsets {partition=0=2} 
 (io.confluent.connect.hdfs.TopicPartitionWriter:368)
ERROR Exception on topic partition MyTopic-0: (io.confluent.connect.hdfs.TopicPartitionWriter:403)
org.apache.kafka.connect.errors.DataException: org.apache.hadoop.ipc.RemoteException(java.io.IOException): 
File /topics/+tmp/MyTopic/partition=0/bc4cf075-ccfa-4338-9672-5462cc6c3404_tmp.avro 
could only be replicated to 0 nodes instead of minReplication (=1).  
There are 1 datanode(s) running and 1 node(s) are excluded in this operation.

EDIT2:

The hadoop.env file is:

    CORE_CONF_fs_defaultFS=hdfs://namenode:8020

    # Configure default BlockSize and Replication for local
    # data. Keep it small for experimentation.
    HDFS_CONF_dfs_blocksize=1m

    YARN_CONF_yarn_log___aggregation___enable=true
    YARN_CONF_yarn_resourcemanager_recovery_enabled=true
    YARN_CONF_yarn_resourcemanager_store_class=org.apache.hadoop.yarn.server.resourcemanager.recovery.FileSystemRMStateStore
    YARN_CONF_yarn_resourcemanager_fs_state___store_uri=/rmstate
    YARN_CONF_yarn_nodemanager_remote___app___log___dir=/app-logs

    YARN_CONF_yarn_log_server_url=http://historyserver:8188/applicationhistory/logs/
    YARN_CONF_yarn_timeline___service_enabled=true
    YARN_CONF_yarn_timeline___service_generic___application___history_enabled=true
    YARN_CONF_yarn_resourcemanager_system___metrics___publisher_enabled=true

    YARN_CONF_yarn_resourcemanager_hostname=resourcemanager
    YARN_CONF_yarn_timeline___service_hostname=historyserver

Answer 1

Finaly like noticed by @cricket_007 I need to configure hadoop.conf.dir .

The directory should contain hdfs-site.xml .

When each service is dockerized, I need to create a named volume in order to share configuration files between kafka-connect service and namenode service.

To do this I add in my docker-compose.yml :

volumes:
  hadoopconf:

Then for namenode service I add:

volumes:
  - hadoopconf:/etc/hadoop

And for kafka connect service:

volumes:
    - hadoopconf:/usr/local/hadoop-conf

Finaly I set hadoop.conf.dir in my HDFS sink properties file to /usr/local/hadoop-conf .