I face some problems to launch hortonworks services through Ambari by starting all services, So I decide to start those services manually and I'm not sure if there is a order I should respect when starting those services. I've installed almost all sevices that we could find on hortonworks data platform.
To start hortonworks data platform services manually through Ambari, there is a order to respect, the following link displays the list of the most frequent services we can use on HDP :
Ranger
Knox
ZooKeeper
HDFS
YARN
HBase
Hive Metastore
HiveServer2
WebHCat
Oozie
Hue
Storm
Kafka
Atlas
To be precise, Ambari starts services by following the Role command order definition files. These files may be defined per-service, or once for the entire stack.
So you may take a look at role_command_order.json files in your stack. For example, here is the role_command_order.json file for HDP-2.0.6 stack.
If the role_command_order.json file is missing, then it is inherited from some other stack. For example the <extends> tag here means that HDP-2.6 stack extends HDP-2.5 stack. Basically, all HDP-2.x stacks inherit
the role_command_order.json file for HDP-2.0.6 stack.
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I just installed new version of hadoop2, I wish to know if I config a hadoop cluster and it's brought up, how can I know if data transmission is failed, and there's a need for failover?
Do I have to install other components like zookeeper to track/enable any HA events?
Thanks!
High Availability is not enabled by default. I would highly encourage you to read the Hadoop documentation from Apache. (http://hadoop.apache.org/) It will give an overview of the architecture and services that run on a Hadoop cluster.
Zookeeper is required for many Hadoop services to coordinate their actions across the entire Hadoop cluster, regardless of the cluster being HA or not. More information can be found in the Apache Zookeeper documentation (http://zookeeper.apache.org/).
I have a hadoop cluster with apache hadoop 2.0.7.
I want to know how to integrate Ambari with the apache hadoop without the HDP(HortonWorks).
Actually, If I use HDP the solution is easy. but , I don't want to use the in my situation.
Do you have an any Idea?
Ambari relies on 'Stack' definitions to describe what services the Hadoop cluster consists of. Hortonworks defined a custom Ambari stack, its called HDP.
You could define your own stack and use any services and respective versions that you wanted. See the ambari wiki for more information about defining stacks and services.
That being said, I don't think it's possible to use your pre-existing installation of Hadoop with Ambari. Ambari is used to provision and manage hadoop clusters. It keeps track of the state of each of its stacks services, and the states of each services components. Since your cluster is already provisioned it would be difficult (maybe impossible) to add it to an Ambari instance.
We are currently using Apache Hadoop (Vanilla Version) in our org. We are planning to migrate to AWS EMR. I'm trying to understand how AWS EMR Hadoop works internally (not how to use it), I'm mainly interested in Hadoop administration steps and how master and slave communicates and various configuration configurations. I already checked the AWS EMR documentation but I don't see detailed comparison.
Can someone recommend me a link/tutorial for migrating to AWS EMR from an Apache Hadoop.
During EMR cluster creation, it will ask you to specify Master and Node. a default settings will provision 1 master and two nodes for you. You can also specify what all applications you want to be in the cluster (e.g.: hadoop, hive, spark, zeppelin, hue, etc.).
Once the cluster is created, it will provision all the services. you can click on these services and access them via web, or using ssh into the master. For e.g: to access the ambari interface, go to the service within EMR and click it. a new window will be launched with the ambari monitoring service interface.
Installing these applications is very easy. all you have to do is specify all the services while cluster creation.
Amazon Elastic MapReduce uses a mostly standard implementation of Hadoop and associated tools.
See: AMI Versions Supported in Amazon EMR
The benefits of using EMR are in the automated deployment of instances. For example, launching a cluster with an appropriate AMI means that software is already loaded on each instance and HDFS is configured across the core nodes.
The Master and Slave (Core/Task) nodes communicate in exactly the normal way that they communicate in any Hadoop cluster. However, only one Master is supported (with no backup Master).
When migrating to EMR, check that you are using compatible versions of software (eg Hadoop, Hive, Pig, Impala, etc). Also consider using Amazon S3 for storage of data instead of HDFS, especially for storing source data, since data on S3 persists even after the EMR cluster is terminated.
Technically, Hadoop provided with EMR, can be few releases back. You should check EMR release notes for detailed application provided with each version. EMR takes care application provisioning, setup and configuration. Based on EC2 instance type, Hadoop (and other application configuration) will change. You can override default settings using configure application.
Other than this Hadoop you have on premises and EMR should be the same.
I have a 10 node existing cluster in RHEL 6.6 which was prepared by plain apache Hadoop configuration XMLs. Now I wanted to check the cluster status by Ambari. Would it be possible to install Hortonworks Ambari just to monitor only not to install Hadoop.
No, Ambari must provision the cluster it's monitoring.
Ambari is designed around a Stack concept where each stack consists of several services. A stack definition is what allows Ambari to install, manage and monitor the services in the cluster.
In order for you to use Ambari with the hadoop core that you built you would have to provide your own Ambari stack definition.
Specifically in your case your existing Hadoop installation would not have the necessary alert.json descriptors used by Ambari to provide alerts for any given service.
As I mention in this title, can I skip the step of install hadoop cluster for that cluster already exist and which in service?
Ambari relies on 'Stack' definitions to describe what services the Hadoop cluster consists of. Hortonworks defined a custom Ambari stack, its called HDP.
You could define your own stack and use any services and respective versions that you wanted. See the ambari wiki for more information about defining stacks and services.
That being said, I don't think it's possible to use your pre-existing installation of Hadoop with Ambari. Ambari is used to provision and manage hadoop clusters. It keeps track of the state of each of its stacks services, and the states of each services components. Since your cluster is already provisioned it would be difficult (maybe impossible) to add it to an Ambari instance.
One of the minimum requierments of installing Ambari is removing the pre-existing installations of tools mentioned here.It is not mentioned to remove any pre-existing hadoop installation.