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This article shows how to setup and secure a SolrCloud cluster with Kerberos and Ranger. Furthermore it outlines some important configurations that are necessary in order to use the combination Solr + HDFS + Kerberos.

Tested on HDP 2.3.4, Ambari 2.1.2, Ranger 0.5, Solr 5.2.1; MIT Kerberos

Pre-Requisites & Service Allocation

You should have a running HDP cluster, including Kerberos, Ranger and HDFS.

For this article I am going to use a 6 node (3 master + 3 worker) cluster with the following service allocation.


Depending on the size and use case of your Solr environment, you can either install Solr on separate nodes (larger workloads and collections) or install them on the same nodes as the Datanodes. For this installation I have decided to install Solr on the 3 Datanodes.

Note: The picture above is only showing the main services and components, there are additional clients and services installed (Yarn, MR, Hive, ...).

Installing the SolrCloud

Solr aka HDPSearch is part of the HDP-Utils repository (see

Install Solr on all Datanodes

yum install lucidworks-hdpsearch
service solr start
ln -s /opt/lucidworks-hdpsearch/solr/server/logs /var/log/solr

Note: Make sure /opt/lucidworks-hdpsearch is owned by user solr and solr is available as a service ("service solr status" should return the Solr status)

Keytabs and Principals

In order for Solr to authenticate itself with the kerberized cluster, it is necessary to create a Solr and Spnego Keytab. The latter is used for authenticating HTTP requests. Its recommended to create a keytab per host, instead of a keytab that is distributed to all hosts, e.g. solr/myhostname@EXAMPLE.COM instead of solr@EXAMPLE.COM

The Solr service keytab will also be used to enable Solr Collections to write to the HDFS.

Create a Solr Service Keytab for each Solr host

addprinc -randkey solr/
xst -k solr.service.keytab.horton04 solr/
addprinc -randkey solr/
xst -k solr.service.keytab.horton05 solr/
addprinc -randkey solr/
xst -k solr.service.keytab.horton06 solr/

Move the Keytabs to the individual hosts (in my case => horton04,horton05,horton06) and save them under /etc/security/keytabs/solr.service.keytab

Create Spnego Service Keytab

To authenticate HTTP requests, it is necessary to create a Spnego Service Keytab, either by making a copy of the existing spnego-Keytab or by creating a separate solr/spnego principal + keytab. On each Solr host do the following:

cp /etc/security/keytabs/spnego.service.keytab /etc/security/keytabs/solr-spnego.service.keytab

Owner & Permissions

Make sure the Keytabs are owned by solr:hadoop and the permissions are set to 400.

chown solr:hadoop /etc/security/keytabs/solr*.keytab
chmod 400 /etc/security/keytabs/solr*.keytab

Configure Solr Cloud

Since all Solr data will be stored in the Hadoop Filesystem, it is important to adjust the time Solr will take to shutdown or "kill" the Solr process (whenever you execute "service solr stop/restart"). If this setting is not adjusted, Solr will try to shutdown the Solr process and because it takes a bit more time when using HDFS, Solr will simply kill the process and most of the time lock the Solr Indexes of your collections. If the index of a collection is locked the following exception is shown after the startup routine "org.apache.solr.common.SolrException: Index locked for write"

Increase the sleep time from 5 to 30 seconds in /opt/lucidworks-hdpsearch/solr/bin/solr

sed -i 's/(sleep 5)/(sleep 30)/g' /opt/lucidworks-hdpsearch/solr/bin/solr

Adjust Solr configuration: /opt/lucidworks-hdpsearch/solr/bin/

SOLR_HOST=`hostname -f`
SOLR_AUTHENTICATION_OPTS="${SOLR_JAAS_FILE} -Dsolr.kerberos.principal=${SOLR_KERB_PRINCIPAL} -Dsolr.kerberos.keytab=${SOLR_KERB_KEYTAB} -Dsolr.kerberos.cookie.domain=${SOLR_HOST} -Dhost=${SOLR_HOST}"

Create Jaas-Configuration

Create a Jaas-Configuration file: /opt/lucidworks-hdpsearch/solr/bin/jaas.conf

Client { required

Make sure the file is owned by solr

chown solr:solr /opt/lucidworks-hdpsearch/solr/bin/jaas.conf


Create a HDFS directory for Solr. This directory will be used for all the Solr data (indexes, etc.).

hdfs dfs -mkdir /apps/solr
hdfs dfs -chown solr /apps/solr
hdfs dfs -chmod 750 /apps/solr


SolrCloud is using Zookeeper to store configurations and cluster states. Its recommended to create a separate ZNode for Solr. The following commands can be executed on one of the Solr nodes.

Initialize Zookeeper Znode for Solr:

/opt/lucidworks-hdpsearch/solr/server/scripts/cloud-scripts/ -zkhost,, -cmd makepath /solr

The security.json file needs to in the the root folder of the Solr-Znode. This file contains configurations for the authentication and authorization provider.

/opt/lucidworks-hdpsearch/solr/server/scripts/cloud-scripts/ -zkhost,, -cmd put /solr/security.json '{"authentication":{"class": ""},"authorization":{"class": "org.apache.ranger.authorization.solr.authorizer.RangerSolrAuthorizer"}}'

Install & Enable Ranger Solr-Plugin

Log into the Ranger UI and create a Solr repository and user.

Create Ranger-Solr Repository (Access Manager -> Solr -> Add(+))

Service Name: <clustername>_solr

Username: amb_ranger_admin

Password: <password> (typically this is admin)

Solr Url:

Add Ranger-Solr User

Create a new user called " solr" with an arbitrary password.

This user is necessary to assign policy permissions to the Solr user

Add base policy

Creating a new Solr repository in Ranger usually creates a base policy as well. If you dont see a policy in the Solr repository, create a Solr Base policy with the following settings:

Policy Name: e.g. clustername

Solr Collections: *

Description: Default Policy for Service: bigdata_solr

Audit Logging: Yes

User: solr, amb_ranger_admin

Permissions: all permissions + delegate admin


Install Solr-Plugin

Install and enable the Ranger Solr Plugin on all nodes that have Solr installed.

yum -y install ranger_*-solr-plugin.x86_64

Copy Mysql-Connector-Java (optional, Audit to DB)

This is only necessary if you want to setup Audit to DB

cp /usr/share/java/mysql-connector-java.jar /usr/hdp/

Adjust Plugin Configuration

Plugin properties are located here: /usr/hdp/<hdp-version>/ranger-solr-plugin/

Change the following values:


If you want to enable Audit to DB, also change:

(set this password to whatever you set when running Mysql pre-req steps for Ranger)

Enable the Plugin and (Re)start Solr

export JAVA_HOME=<path_to_jdk>
service solr restart

The enable script will distribute some files and create sym-links in /opt/lucidwords-hdpsearch/solr/server/solr-webapp/webapp/WEB-INF/lib

If you go to the Ranger UI, you should be able to see whether your Solr instances are communicating with Ranger or not.


Smoke Test

Everything has been setup and the policies have been synced with the Solr nodes, its time for some smoke tests :)

To test our installation we are going to setup a test collection with one of the sample datasets from Solr, called "films".

Go to the first node of your Solr Cloud (e.g. horton04)

Create the initial Solr Collection configuration by using the basic_config, which is part of every Solr installation

mkdir /opt/lucidworks-hdpsearch/solr_collections
mkdir /opt/lucidworks-hdpsearch/solr_collections/films
chown -R solr:solr /opt/lucidworks-hdpsearch/solr_collections
cp -R /opt/lucidworks-hdpsearch/solr/server/solr/configsets/basic_configs/conf /opt/lucidworks-hdpsearch/solr_collections/films

Adjust solrconfig.xml (/opt/lucidworks-hdpsearch/solr_collections/films/conf)

1) Remove any existing directoryFactory-element

2) Add new Directory Factory for HDFS (make sure to modify the values for solr.hdfs.home and

<directoryFactory name="DirectoryFactory" class="solr.HdfsDirectoryFactory">
     <str name="solr.hdfs.home">hdfs://bigdata/apps/solr</str>
     <str name="solr.hdfs.confdir">/etc/hadoop/conf</str>
     <bool name="">true</bool>
     <str name="">/etc/security/keytabs/solr.service.keytab</str>
     <str name="">solr/${host:}@EXAMPLE.COM</str>
     <bool name="solr.hdfs.blockcache.enabled">true</bool>
     <int name="solr.hdfs.blockcache.slab.count">1</int>
     <bool name="">true</bool>
     <int name="solr.hdfs.blockcache.blocksperbank">16384</int>
     <bool name="">true</bool>
     <bool name="solr.hdfs.blockcache.write.enabled">true</bool>
     <bool name="solr.hdfs.nrtcachingdirectory.enable">true</bool>
     <int name="solr.hdfs.nrtcachingdirectory.maxmergesizemb">16</int>
     <int name="solr.hdfs.nrtcachingdirectory.maxcachedmb">192</int>

3) Adjust Lock-type

Search the lockType-element and change it to "hdfs"


Adjust schema.xml (/opt/lucidworks-hdpsearch/solr_collections/films/conf)

Add the following field definitions in the schema.xml file (There are already some base field definitions, simply copy-and-paste the following 4 lines somewhere nearby).

<field name="directed_by" type="string" indexed="true" stored="true" multiValued="true"/>
<field name="name" type="text_general" indexed="true" stored="true"/>
<field name="initial_release_date" type="string" indexed="true" stored="true"/>
<field name="genre" type="string" indexed="true" stored="true" multiValued="true"/>

Upload Films-configuration to Zookeeper (solr-znode)

Since this is a SolrCloud setup, all configuration files will be stored in Zookeeper.

/opt/lucidworks-hdpsearch/solr/server/scripts/cloud-scripts/ -zkhost,, -cmd upconfig -confname films -confdir /opt/lucidworks-hdpsearch/solr_collections/films/conf

Create the Films-Collection

Note: Make sure you have a valid Kerberos ticket from the Solr user (e.g. "kinit -kt solr.service.keytab solr/`hostname -f`")

curl --negotiate -u : ""

Check available collections:

curl --negotiate -u : ""



Load data into the collection

curl --negotiate -u : '' --data-binary @/opt/lucidworks-hdpsearch/solr/example/films/films.json -H 'Content-type:application/json'

Select data from the Films-Collection

curl --negotiate -u :*

This should return the data from the films-Collection.

Since the Solr-user is part of the base policy in Ranger, above commands should not bring up any errors or authorization issues.

Tests with new user (=> Tom)

To see whether Ranger is working or not, authenticate yourself as a different user (e.g. Tom) and select the data from "films"

kinit tom@EXAMPLE.COM
curl --negotiate -u :*

This should return "Unauthorized Request (403)"


Add Policy

Add a new Ranger-Solr-Policy for the films collection and authorize Tom


Query the collection again

curl --negotiate -u : "*&wt=json"


               "Gary Lennon"
               "Black comedy",
               "Psychological thriller",
               "Indie film",
               "Action Film",
               "Crime Thriller",
               "Crime Fiction",

Common Errors

Unauthorized Request (403)

Ranger denied access to the specified Solr Collection. Check the Ranger audit log and Solr policies.

Authentication Required

Make sure you have a valid kerberos ticket!

Defective Token detected

Caused by: GSSException: Defective token detected (Mechanism level: GSSHeader did not find
the right tag)

Usually this issue surfaces during Spnego authentication, the token supplied by the client is not accepted by the server.

This error occurs with Java JDK 1.8.0_40 (

Solution: This bug was acknowledged and fixed by Oracle in Java JDK >= 1.8.0_60

White Page / Too many groups

Problem: When the Solr Admin interface ( http://<solr_instance>; :8389/solr) is secured with Kerberos, users with too many AD groups cant access the page. Usually these users only see a white page as a result and the solr log is showing the following message.

badMessage: java.lang.IllegalStateException: too much data after closed for
HttpParser Header is too large >8192

Also see:

Possible solution:

Search for the file: /opt/lucidworks-hdpsearch/solr/server/etc/jetty.xml

Increase the "solr.jetty.request.header.size" from 8192 to about 51200 (should be sufficient for plenty of groups).

sed -i 's/name="solr.jetty.request.header.size" default="8192"/name="solr.jetty.request.header.size" default="51200"/g' /opt/lucidworks-hdpsearch/solr/server/etc/jetty.xml

Useful Links

Looking forward to your feedback


Rising Star

Great article. One feedback while creating collections, instead of #shards=1, it should be &numShards=1

  1. curl --negotiate -u :""
Expert Contributor

@Jonas Straub Hello Jonas , thanks for the article its a well documented steps for having ranger plugin installed for solr. I have tried to follow the steps but have some hiccups wanted to see if you can help me out here .

As mentioned in the document , I have created a policy for solr , but am unable to test the connection , getting the below error.


Also after, I made changed to files, enabling the plugin and restarting solr , i do not see plugin synced to ranger ui.


Jagdish Saripella

@Jagdish Saripella

Is this the connection test included in the Ranger UI when you setup a new Solr Service?

To be honest I have never tried that, but my guess is that this connection test is not working with SolrCloud.


@Jagdish Saripella I looked into this and according to the logs, Kerberos /Spnego is the problem. Although the only feature you are missing if the test connection fails, is the lookup of solr Collections when you create policies. The plugin works even if the connection fails.

New Contributor

Hi Jonas,

Very nice article. When I try to create collection as suggested

curl --negotiate -u :""

I get error saying - numShards is a required parameter.

<?xml version="1.0" encoding="UTF-8"?>
<lst name="responseHeader"><int name="status">400</int><int name="QTime">24</int></lst><str name="Operation create caused exception:">org.apache.solr.common.SolrException:org.apache.solr.common.SolrException: numShards is a required param (when using CompositeId router).</str><lst name="exception"><str name="msg">numShards is a required param (when using CompositeId router).</str><int name="rspCode">400</int></lst><lst name="error"><str name="msg">numShards is a required param (when using CompositeId router).</str><int name="code">400</int></lst>

I also tried to define numShards as 2 and proceed, however it return an error from one of the other datanodes

curl --negotiate -u : ""

<?xml version="1.0" encoding="UTF-8"?>
<lst name="responseHeader"><int name="status">0</int><int name="QTime">1596</int></lst><lst name="failure"><str>org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException:Error from server at Error CREATEing SolrCore 'films_shard1_replica1': Unable to create core [films_shard1_replica1] Caused by: bigdata</str><str>org.apache.solr.client.solrj.impl.HttpSolrClient$RemoteSolrException:Error from server at Error CREATEing SolrCore 'films_shard2_replica1': Unable to create core [films_shard2_replica1] Caused by: bigdata</str></lst>

Any ideas what might be causing this, and how can i disable CompositeId router??


@Anand Pandit what is the name of your cluster?

Expert Contributor

This is a great tutorial for users @Jonas Straub! I've seen a few people use and reference this link already. Question: do you have steps for adding kerberos rules for Solr?

Expert Contributor

Great article,

When testing the connection to Solr from Ranger as @Jonas Straub mentions the /var/log/ranger/admin/xa_portal.log shows the URL. It tries to access ${Solr URL}/admin/collections. So you should enter an URL ending with /solr.

Than the log gives an Authentication Required 401. Now Solr is Kerbors-secured the request from Ranger to fetch collections should also use a kerberos-ticket...

Did someone manage to make the lookup from Ranger to Solr (/w kerberos) work?

Expert Contributor

Hi @Jonas Straub, we configured a secure SolrCloud cluster, with success. There is one MAJOR issue:

The ranger plugins (hive, hdfs, kafka, hbase, solr) generating audit logs, are not able to send the audit-logs to a secure Solr.

The bug was reported 06/Oct/15, but not yet addressed. How do we get it addressed so people can start using a secure Solr for audit logging?




I'm a bit confused by SOLR_KERB_PRINCIPAL


In the instruction, we are creating a service principal "addprinc -randkey solr/".

Can't I use this one for above?

Do I have to use HTTP?