question CM API enable_nn_ha "Could not find NameNode" in Archives of Support Questions (Read Only)

CM API enable_nn_ha "Could not find NameNode"

TylerHale — Fri, 16 Sep 2022 10:16:37 GMT

I'm using the python CM API to try and enable HDFS HA on my cluster:

hdfs_service.enable_nn_ha(active_name=hdfs_nn_host, nameservice="nameservice1",
   standby_host_id=api.get_host(hdfs_snn_host).hostId, jns=journal_nodes,
   zk_service_name=ZOOKEEPER_SERVICE_NAME, force_init_znode=True,
   clear_existing_standby_name_dirs=True, clear_existing_jn_edits_dir=True).wait()

This command leads to the error:

cm_api.api_client.ApiException: Could not find NameNode with name 'host1'

where host1 is the name of host running the NameNode service as shown by Cloudera Manager. My question around the active_name parameter to this function is what actual value is the CM API looking for? I've tried supplying the hostId value for this node as well, with no luck. My HDFS service is up/running healthy as I am able to do all hdfs dfs * commands.

Re: CM API enable_nn_ha "Could not find NameNode"

michalis — Fri, 06 May 2016 00:01:27 GMT

It's expecting the role/instance name of your NN, you can retrieve that by

example code using python

from cm_api.api_client import ApiResource

api = ApiResource(server_host="nightly57-1.gce.cloudera.com")

#assuming your cluster name is 'Cluster 1' and hdfs service name is 'HDFS-1'

NameNodes = api.get_cluster("Cluster 1").get_service("HDFS-1").get_roles_by_type("NAMENODE")

print [instance.name for instance in NameNodes]

# sample stdout

[u'HDFS-1-NAMENODE-51999a2564364e0f3a6a74def356741b', u'HDFS-1-NAMENODE-46bf2f74734fa565bb829ef019ff4a2d']

Alternatively, open your browser to http://cm_server:port/api/v6/clusters/{clusterName}/services/{HdfsServiceName}/roles

...
"items" : [ {
    "name" : "HDFS-1-NAMENODE-51999a2564364e0f3a6a74def356741b", <=== this
    "type" : "NAMENODE",
...

see:

https://cloudera.github.io/cm_api/apidocs/v11/path__clusters_-clusterName-_services_-serviceName-_roles.html

Re: CM API enable_nn_ha "Could not find NameNode"

TylerHale — Fri, 06 May 2016 12:07:06 GMT

Thanks - that worked!