Apache Atlas – Building & Installing Apache Atlas

Building & Installing Apache Atlas

Building Apache Atlas

Download Apache Atlas 1.0.0 release sources, apache-atlas-1.0.0-sources.tar.gz, from downloads page. Then follow the instructions below to to build Apache Atlas.

tar xvfz apache-atlas-1.0.0-sources.tar.gz
cd apache-atlas-sources-1.0.0/
export MAVEN_OPTS="-Xms2g -Xmx2g"
mvn clean -DskipTests install

Packaging Apache Atlas

To create Apache Atlas package for deployment in an environment having functional Apache HBase and Apache Solr instances, build with the following command:

mvn clean -DskipTests package -Pdist

NOTES:
- Remove option '-DskipTests' to run unit and integration tests
- To build a distribution without minified js,css file, build with skipMinify profile. By default js and css files are minified.

Above will build Apache Atlas for an environment having functional HBase and Solr instances. Apache Atlas needs to be setup with the following to run in this environment:

Configure atlas.graph.storage.hostname (see "Graph persistence engine - HBase" in the Configuration section).
Configure atlas.graph.index.search.solr.zookeeper-url (see "Graph Search Index - Solr" in the Configuration section).
Set HBASE_CONF_DIR to point to a valid Apache HBase config directory (see "Graph persistence engine - HBase" in the Configuration section).
Create indices in Apache Solr (see "Graph Search Index - Solr" in the Configuration section).

Packaging Apache Atlas with embedded Apache HBase & Apache Solr

To create Apache Atlas package that includes Apache HBase and Apache Solr, build with the embedded-hbase-solr profile as shown below:

mvn clean -DskipTests package -Pdist,embedded-hbase-solr

Using the embedded-hbase-solr profile will configure Apache Atlas so that an Apache HBase instance and an Apache Solr instance will be started and stopped along with the Apache Atlas server.

NOTE: This distribution profile is only intended to be used for single node development not in production.

Packaging Apache Atlas with embedded Apache Cassandra & Apache Solr

To create Apache Atlas package that includes Apache Cassandra and Apache Solr, build with the embedded-cassandra-solr profile as shown below:

mvn clean package -Pdist,embedded-cassandra-solr

Using the embedded-cassandra-solr profile will configure Apache Atlas so that an Apache Cassandra instance and an Apache Solr instance will be started and stopped along with the Atlas server.

NOTE: This distribution profile is only intended to be used for single node development not in production.

Apache Atlas Package

Build will create following files, which are used to install Apache Atlas.

distro/target/apache-atlas-${project.version}-bin.tar.gz
distro/target/apache-atlas-${project.version}-hbase-hook.tar.gz
distro/target/apache-atlas-${project.version}-hive-hook.gz
distro/target/apache-atlas-${project.version}-kafka-hook.gz
distro/target/apache-atlas-${project.version}-sources.tar.gz
distro/target/apache-atlas-${project.version}-sqoop-hook.tar.gz
distro/target/apache-atlas-${project.version}-storm-hook.tar.gz

Installing & Running Apache Atlas

Installing Apache Atlas

From the directory you would like Apache Atlas to be installed, run the following commands:

tar -xzvf apache-atlas-${project.version}-bin.tar.gz
cd atlas-${project.version}

Running Apache Atlas with Local Apache HBase & Apache Solr

To run Apache Atlas with local Apache HBase & Apache Solr instances that are started/stopped along with Atlas start/stop, run following commands:

export MANAGE_LOCAL_HBASE=true
export MANAGE_LOCAL_SOLR=true

bin/atlas_start.py

Using Apache Atlas

To verify if Apache Atlas server is up and running, run curl command as shown below:

  curl -u username:password http://localhost:21000/api/atlas/admin/version

  {"Description":"Metadata Management and Data Governance Platform over Hadoop","Version":"1.0.0","Name":"apache-atlas"}

Run quick start to load sample model and data

  bin/quick_start.py
  Enter username for atlas :-
  Enter password for atlas :-

Access Apache Atlas UI using a browser: http://localhost:21000

Stopping Apache Atlas Server

To stop Apache Atlas, run following command:

bin/atlas_stop.py

Configuring Apache Atlas

By default config directory used by Apache Atlas is {package dir}/conf. To override this set environment variable ATLAS_CONF to the path of the conf dir.

Environment variables needed to run Apache Atlas can be set in atlas-env.sh file in the conf directory. This file will be sourced by Apache Atlas scripts before any commands are executed. The following environment variables are available to set.

# The java implementation to use. If JAVA_HOME is not found we expect java and jar to be in path
#export JAVA_HOME=

# any additional java opts you want to set. This will apply to both client and server operations
#export ATLAS_OPTS=

# any additional java opts that you want to set for client only
#export ATLAS_CLIENT_OPTS=

# java heap size we want to set for the client. Default is 1024MB
#export ATLAS_CLIENT_HEAP=

# any additional opts you want to set for atlas service.
#export ATLAS_SERVER_OPTS=

# java heap size we want to set for the atlas server. Default is 1024MB
#export ATLAS_SERVER_HEAP=

# What is is considered as atlas home dir. Default is the base location of the installed software
#export ATLAS_HOME_DIR=

# Where log files are stored. Defatult is logs directory under the base install location
#export ATLAS_LOG_DIR=

# Where pid files are stored. Defatult is logs directory under the base install location
#export ATLAS_PID_DIR=

# Where do you want to expand the war file. By Default it is in /server/webapp dir under the base install dir.
#export ATLAS_EXPANDED_WEBAPP_DIR=

Settings to support large number of metadata objects

If you plan to store large number of metadata objects, it is recommended that you use values tuned for better GC performance of the JVM.

The following values are common server side options:

export ATLAS_SERVER_OPTS="-server -XX:SoftRefLRUPolicyMSPerMB=0 -XX:+CMSClassUnloadingEnabled -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:+PrintTenuringDistribution -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=dumps/atlas_server.hprof -Xloggc:logs/gc-worker.log -verbose:gc -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=1m -XX:+PrintGCDetails -XX:+PrintHeapAtGC -XX:+PrintGCTimeStamps"

The -XX:SoftRefLRUPolicyMSPerMB option was found to be particularly helpful to regulate GC performance for query heavy workloads with many concurrent users.

The following values are recommended for JDK 8:

export ATLAS_SERVER_HEAP="-Xms15360m -Xmx15360m -XX:MaxNewSize=5120m -XX:MetaspaceSize=100M -XX:MaxMetaspaceSize=512m"

NOTE for Mac OS users If you are using a Mac OS, you will need to configure the ATLAS_SERVER_OPTS (explained above).

In {package dir}/conf/atlas-env.sh uncomment the following line

#export ATLAS_SERVER_OPTS=

and change it to look as below

export ATLAS_SERVER_OPTS="-Djava.awt.headless=true -Djava.security.krb5.realm= -Djava.security.krb5.kdc="

Configuring Apache HBase as the storage backend for the Graph Repository

By default, Apache Atlas uses JanusGraph as the graph repository and is the only graph repository implementation available currently. Apache HBase versions currently supported are 1.1.x. For configuring Apache Atlas graph persistence on Apache HBase, please see "Graph persistence engine - HBase" in the Configuration section for more details.

Apache HBase tables used by Apache Atlas can be set using the following configurations:

atlas.graph.storage.hbase.table=atlas
atlas.audit.hbase.tablename=apache_atlas_entity_audit

Configuring Apache Solr as the indexing backend for the Graph Repository

By default, Apache Atlas uses JanusGraph as the graph repository and is the only graph repository implementation available currently. For configuring JanusGraph to work with Apache Solr, please follow the instructions below

Install Apache Solr if not already running. The version of Apache Solr supported is 5.5.1. Could be installed from http://archive.apache.org/dist/lucene/solr/5.5.1/solr-5.5.1.tgz

Start Apache Solr in cloud mode.

SolrCloud mode uses a ZooKeeper Service as a highly available, central location for cluster management. For a small cluster, running with an existing ZooKeeper quorum should be fine. For larger clusters, you would want to run separate multiple ZooKeeper quorum with at least 3 servers. Note: Apache Atlas currently supports Apache Solr in "cloud" mode only. "http" mode is not supported. For more information, refer Apache Solr documentation - https://cwiki.apache.org/confluence/display/solr/SolrCloud

For e.g., to bring up an Apache Solr node listening on port 8983 on a machine, you can use the command:

      $SOLR_HOME/bin/solr start -c -z <zookeeper_host:port> -p 8983

Run the following commands from SOLR_BIN (e.g. $SOLR_HOME/bin) directory to create collections in Apache Solr corresponding to the indexes that Apache Atlas uses. In the case that the Apache Atlas and Apache Solr instances are on 2 different hosts, first copy the required configuration files from ATLAS_HOME/conf/solr on the Apache Atlas instance host to Apache Solr instance host. SOLR_CONF in the below mentioned commands refer to the directory where Apache Solr configuration files have been copied to on Apache Solr host:

  $SOLR_BIN/solr create -c vertex_index -d SOLR_CONF -shards #numShards -replicationFactor #replicationFactor
  $SOLR_BIN/solr create -c edge_index -d SOLR_CONF -shards #numShards -replicationFactor #replicationFactor
  $SOLR_BIN/solr create -c fulltext_index -d SOLR_CONF -shards #numShards -replicationFactor #replicationFactor

Note: If numShards and replicationFactor are not specified, they default to 1 which suffices if you are trying out solr with ATLAS on a single node instance. Otherwise specify numShards according to the number of hosts that are in the Solr cluster and the maxShardsPerNode configuration. The number of shards cannot exceed the total number of Solr nodes in your !SolrCloud cluster.

The number of replicas (replicationFactor) can be set according to the redundancy required.

Also note that Apache Solr will automatically be called to create the indexes when Apache Atlas server is started if the SOLR_BIN and SOLR_CONF environment variables are set and the search indexing backend is set to 'solr5'.

Change ATLAS configuration to point to Apache Solr instance setup. Please make sure the following configurations are set to the below values in ATLAS_HOME/conf/atlas-application.properties

 atlas.graph.index.search.backend=solr
 atlas.graph.index.search.solr.mode=cloud
 atlas.graph.index.search.solr.zookeeper-url=<the ZK quorum setup for solr as comma separated value> eg: 10.1.6.4:2181,10.1.6.5:2181
 atlas.graph.index.search.solr.zookeeper-connect-timeout=<SolrCloud Zookeeper Connection Timeout>. Default value is 60000 ms
 atlas.graph.index.search.solr.zookeeper-session-timeout=<SolrCloud Zookeeper Session Timeout>. Default value is 60000 ms

For more information on JanusGraph solr configuration , please refer http://docs.janusgraph.org/0.2.0/solr.html

Pre-requisites for running Apache Solr in cloud mode * Memory - Apache Solr is both memory and CPU intensive. Make sure the server running Apache Solr has adequate memory, CPU and disk. Apache Solr works well with 32GB RAM. Plan to provide as much memory as possible to Apache Solr process * Disk - If the number of entities that need to be stored are large, plan to have at least 500 GB free space in the volume where Apache Solr is going to store the index data * SolrCloud has support for replication and sharding. It is highly recommended to use SolrCloud with at least two Apache Solr nodes running on different servers with replication enabled. If using SolrCloud, then you also need ZooKeeper installed and configured with 3 or 5 ZooKeeper nodes

Configuring Elasticsearch as the indexing backend for the Graph Repository (Tech Preview)

By default, Apache Atlas uses JanusGraph as the graph repository and is the only graph repository implementation available currently. For configuring JanusGraph to work with Elasticsearch, please follow the instructions below

Install an Elasticsearch cluster. The version currently supported is 5.6.4, and can be acquired from: https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.4.tar.gz

For simple testing a single Elasticsearch node can be started by using the 'elasticsearch' command in the bin directory of the Elasticsearch distribution.

Change Apache Atlas configuration to point to the Elasticsearch instance setup. Please make sure the following configurations are set to the below values in ATLAS_HOME/conf/atlas-application.properties

 atlas.graph.index.search.backend=elasticsearch
 atlas.graph.index.search.hostname=<the hostname(s) of the Elasticsearch master nodes comma separated>
 atlas.graph.index.search.elasticsearch.client-only=true

For more information on JanusGraph configuration for elasticsearch, please refer http://docs.janusgraph.org/0.2.0/elasticsearch.html

Configuring Kafka Topics

Apache Atlas uses Apache Kafka to ingest metadata from other components at runtime. This is described in the Architecture page in more detail. Depending on the configuration of Apache Kafka, sometimes you might need to setup the topics explicitly before using Apache Atlas. To do so, Apache Atlas provides a script bin/atlas_kafka_setup.py which can be run from Apache Atlas server. In some environments, the hooks might start getting used first before Apache Atlas server itself is setup. In such cases, the topics can be run on the hosts where hooks are installed using a similar script hook-bin/atlas_kafka_setup_hook.py. Both these use configuration in atlas-application.properties for setting up the topics. Please refer to the Configuration page for these details.

Setting up Apache Atlas

There are a few steps that setup dependencies of Apache Atlas. One such example is setting up the JanusGraph schema in the storage backend of choice. In a simple single server setup, these are automatically setup with default configuration when the server first accesses these dependencies.

However, there are scenarios when we may want to run setup steps explicitly as one time operations. For example, in a multiple server scenario using High Availability, it is preferable to run setup steps from one of the server instances the first time, and then start the services.

To run these steps one time, execute the command bin/atlas_start.py -setup from a single Apache Atlas server instance.

However, Apache Atlas server does take care of parallel executions of the setup steps. Also, running the setup steps multiple times is idempotent. Therefore, if one chooses to run the setup steps as part of server startup, for convenience, then they should enable the configuration option atlas.server.run.setup.on.start by defining it with the value true in the atlas-application.properties file.

Examples: calling Apache Atlas REST APIs

Here are few examples of calling Apache Atlas REST APIs via curl command.

List the types in the repository

  curl -u username:password http://localhost:21000/api/atlas/v2/types/typedefs/headers
  [ {"guid":"fa421be8-c21b-4cf8-a226-fdde559ad598","name":"Referenceable","category":"ENTITY"},
    {"guid":"7f3f5712-521d-450d-9bb2-ba996b6f2a4e","name":"Asset","category":"ENTITY"},
    {"guid":"84b02fa0-e2f4-4cc4-8b24-d2371cd00375","name":"DataSet","category":"ENTITY"},
    {"guid":"f93975d5-5a5c-41da-ad9d-eb7c4f91a093","name":"Process","category":"ENTITY"},
    {"guid":"79dcd1f9-f350-4f7b-b706-5bab416f8206","name":"Infrastructure","category":"ENTITY"}
  ]

List the instances for a given type

  curl -u username:password http://localhost:21000/api/atlas/v2/search/basic?typeName=hive_db
  {
    "queryType":"BASIC",
    "searchParameters":{
      "typeName":"hive_db",
      "excludeDeletedEntities":false,
      "includeClassificationAttributes":false,
      "includeSubTypes":true,
      "includeSubClassifications":true,
      "limit":100,
      "offset":0
    },
    "entities":[
      {
        "typeName":"hive_db",
        "guid":"5d900c19-094d-4681-8a86-4eb1d6ffbe89",
        "status":"ACTIVE",
        "displayText":"default",
        "classificationNames":[],
        "attributes":{
          "owner":"public",
          "createTime":null,
          "qualifiedName":"default@cl1",
          "name":"default",
          "description":"Default Hive database"
        }
      },
      {
        "typeName":"hive_db",
        "guid":"3a0b14b0-ab85-4b65-89f2-e418f3f7f77c",
        "status":"ACTIVE",
        "displayText":"finance",
        "classificationNames":[],
        "attributes":{
          "owner":"hive",
          "createTime":null,
          "qualifiedName":"finance@cl1",
          "name":"finance",
          "description":null
        }
      }
    ]
  }

Search for entities

  curl -u username:password http://localhost:21000/api/atlas/v2/search/dsl?query=hive_db%20where%20name='default'
    {
      "queryType":"DSL",
      "queryText":"hive_db where name='default'",
      "entities":[
        {
          "typeName":"hive_db",
          "guid":"5d900c19-094d-4681-8a86-4eb1d6ffbe89",
          "status":"ACTIVE",
          "displayText":"default",
          "classificationNames":[],
          "attributes":{
            "owner":"public",
            "createTime":null,
            "qualifiedName":"default@cl1",
            "name":"default",
            "description":
            "Default Hive database"
          }
        }
      ]
    }

Troubleshooting

Setup issues

If the setup of Apache Atlas service fails due to any reason, the next run of setup (either by an explicit invocation of atlas_start.py -setup or by enabling the configuration option atlas.server.run.setup.on.start) will fail with a message such as A previous setup run may not have completed cleanly.. In such cases, you would need to manually ensure the setup can run and delete the Zookeeper node at /apache_atlas/setup_in_progress before attempting to run setup again.

If the setup failed due to Apache HBase schema setup errors, it may be necessary to repair Apache HBase schema. If no data has been stored, one can also disable and drop the Apache HBase tables used by Apache Atlas and run setup again.