Client Configuration Files
To allow clients to use the HBase, HDFS, Hive, MapReduce, and YARN services, Cloudera Manager creates zip archives of the configuration files containing the service properties. The zip archive is referred to as a client configuration file. Each archive contains the set of configuration files needed to access the service: for example, the MapReduce client configuration file contains copies of core-site.xml, hadoop-env.sh, hdfs-site.xml, log4j.properties and mapred-site.xml.
Client configuration files are generated automatically by Cloudera Manager based on the services and roles you have installed and Cloudera Manager deploys these configurations automatically when you install your cluster, add a service on a host, or add a gateway role on a host. Specifically, for each host that has a service role instance installed, and for each host that is configured as a gateway role for that service, the deploy function downloads the configuration zip file, unzips it into the appropriate configuration directory, and uses the Linux "alternatives" mechanism to set a given, configurable priority level. If you are installing on a system that happens to have pre-existing alternatives, then it is possible another alternative may have higher priority and will continue to be used. The alternatives priority of the Cloudera Manager client configuration is configurable under the Gateway sections of the Configuration tab for the appropriate service.
You can also manually distribute client configuration files to the clients of a service.
The main circumstance that may require a redeployment of the client configuration files is when you have modified a configuration. In this case you will typically see a message instructing you to redeploy your client configurations. The affected service(s) will also display a icon. Click the indicator to display the Stale Configurations page.
How Client Configurations are Deployed
Client configuration files are deployed on any host that is a client for a service—that is, that has a role for the service on that host. This includes roles such as DataNodes, TaskTrackers, RegionServers and so on as well as gateway roles for the service.
If roles for multiple services are running on the same host (for example, a DataNode role and a TaskTracker role on the same host) then the client configurations for both roles are deployed on that host, with the alternatives priority determining which configuration takes precedence.
For example, suppose we have six hosts running roles as follows: host H1: HDFS-NameNode; host H2: MR-JobTracker; host H3: HBase-Master; host H4: MR-TaskTracker, HDFS-DataNode, HBase-RegionServer; host H5: MR-Gateway; host H6: HBase-Gateway. Client configuration files will be deployed on these hosts as follows: host H1: hdfs-clientconfig (only); host H2: mapreduce-clientconfig, host H3: hbase-clientconfig; host H4: hdfs-clientconfig, mapreduce-clientconfig, hbase-clientconfig; host H5: mapreduce-clientconfig; host H6: hbase-clientconfig
If the HDFS NameNode and MapReduce JobTracker were on the same host, then that host would have both hdfs-clientconfig and mapreduce-clientconfig installed.
Downloading Client Configuration Files
- Do one of the following:
- On the Home page, click to the right of the cluster name and select View Client Configuration URLs. A pop-up window with links to the configuration files for the services you have installed displays.
- Click a link or save the link URL and download the file using wget or curl.
- Go to a service whose client configuration you want to download.
- Select .
Manually Redeploying Client Configuration Files
Although Cloudera Manager will deploy client configuration files automatically in many cases, if you have modified the configurations for a service, you may need to redeploy those configuration files.
If your client configurations were deployed automatically, the command described in this section will attempt to redeploy them as appropriate.
- On the Home page, click to the right of the cluster name and select Deploy Client Configuration.
- Click Deploy Client Configuration.