Usage

The Solr Catalog Embedded Provider is an embedded, local Solr Server instance used in conjunction with an Apache Solr Server data store. It is a local instance that is a lightweight solution that works out of the box without any configuration. It however does not provide a Solr Admin GUI or a "REST-like HTTP/XML and JSON API." If that is necessary, see Standalone Solr Server.

Embedded Solr Catalog Provider Pros/Cons Chart

Feature	Pro	Con
Scalability		Does not scale. Only runs one single server instance. Does not allow the middle tier to be scaled.
Flexibility	Can be embedded in Java easily. Requires no HTTP Connection. Uses the same interface as the Standalone Solr Server uses under the covers Allows for full control over the Solr Server. No synchronous issues on startup, i.e. the Solr Server will synchronously start up with the Solr Catalog Provider Runs within the same JVM Setup and Installation is simple. "Unzip and run"	Only can be interfaced using Java
(Administrative) Tools	External open source tools like Luke will work to allow admins to check index contents JMX metrics reporting is enabled	No Admin Console. No easy way to natively access (out of the box) what is in the index files or health of server at the data store level.
Security	Does not open any ports which means no ports have to be secured.
Performance	Requires no HTTP or Network overhead Near Real-time indexing Can understand complex queries
Backup/Recovery	Can manually or through custom scripts back up the indexes	Must copy files when server is shutdown

When to Use

Use the local, embedded Solr Catalog Provider when only one

DDF

instance is necessary and scalability is not an issue. The local, embedded Solr Catalog Provider requires no installation and little to no configuration since it is ready out of the box. It is great for demonstrations, training exercises, or for sparse querying and ingesting.

Installation/Uninstall

Prerequisites

Before the DDF Solr Catalog Application can be installed:

the DDF Kernel must be running
the DDF Platform Application must be installed
the DDF Catalog Application must be installed

Installation

By default, the correct features should be installed for the Embedded Solr Server configuration.

Verification

To verify if the DDF Solr Catalog Application was successfully installed for the Embedded Solr Server configuration, verify the appropriate features have been successfully installed. The features catalog-solr-external-provider and catalog-solr-server should be uninstalled by default.

DDF Solr Catalog Application installed features for Embedded Solr Provider configuration

ddf@local>features:list | grep catalog-solr-app
[installed  ] [2.3.0] catalog-solr-embedded-provider       catalog-solr-app-2.3.0    Catalog Provider with locally Embedded Solr Server, implemented using Solr 4.1.0.
[uninstalled] [2.3.0] catalog-solr-external-provider       catalog-solr-app-2.3.0    Catalog Provider to interface with an external Solr 4.1.0 Server
[uninstalled] [2.3.0] catalog-solr-server                  catalog-solr-app-2.3.0    Deploys and starts a preconfigured Solr War into this container

Verify the DDF Solr Catalog Application bundles are Active for the embedded provider:

DDF Solr Catalog Application's active bundles for Embedded Solr Provider configuration

ddf@local>list | grep -i solr
[ 268] [Active     ] [            ] [       ] [   80] Apache ServiceMix :: Bundles :: SolrJ (0.3.0.2)
[ 270] [Active     ] [Created     ] [       ] [   80] DDF :: Catalog :: Solr :: Embedded :: Provider (2.3.0)

Uninstall

Reverting the Uninstall

Upgrade

Configuration

Embedded Solr Server and Solr Catalog Provider

No configuration is necessary in order for the embedded Solr Server and the Solr Catalog Provider to work out of the box. The standard installation described above is sufficient. When the catalog-solr-embedded-provider feature is installed, it by default stores the Solr index files to <DISTRIBUTION_INSTALLATION_DIRECTORY>/data/solr. A user does not have to specify any parameters. In addition, the catalog-solr-embedded-provider feature contains all files necessary for Solr to start the server.

However, this component can be configured to specify the directory to use for data storage using the normal processes described in the Configuration section.

The configurable properties for the SCP are accessed from the Catalog Embedded Solr Catalog Provider Configurations in the Admin Console.

Handy Tip

The Embedded (Local) Solr Catalog Provider works on startup without any configuration because a local embedded Solr Server is automatically started and pre-configured.

Configurable Properties

Title Property Type Description Default
Value Required

Data Directory File Path

dataDirectoryPath

String

Title	Property	Type	Description	Default Value	Required
Data Directory File Path	dataDirectoryPath	String	Specifies the directory to use for data storage. A shutdown of the server is necessary for this property to take effect. If a filepath is provided with directories that don't exist, SCP will attempt to create those directories. Out of the box (without configuration), the SCP writes to <DISTRIBUTION_INSTALLATION_DIRECTORY>/data/solr If dataDirectoryPath is left blank (empty string), it will default to <DISTRIBUTION_INSTALLATION_DIRECTORY>/data/solr. If `Data Directory File Path` is a relative string, the SCP will write the data files starting at the installation directory. For instance if the string scp/solr_data is provided, then the data directory would be at <DISTRIBUTION_INSTALLATION_DIRECTORY>/scp/solr_data If `Data Directory File Path` is /solr_data in Windows, the Solr Catalog Provider will write the data files starting at the beginning of the drive such as C:/solr_data. It is recommended to use an absolute filepath to minimize confusion such as /opt/solr_data in Linux or C:/solr_data in Windows. Permissions are necessary to write to the directory.		No
Force Auto Commit	forceAutoCommit	Boolean / Checkbox	WARNING: Performance Impact. Only in special cases should auto-commit be forced. Forcing auto-commit makes the search results visible immediately.		No

Specifies the directory to use for data storage. A shutdown of the server is necessary for this property to take effect. If a filepath is provided with directories that don't exist, SCP will attempt to create those directories. Out of the box (without configuration), the SCP writes to <DISTRIBUTION_INSTALLATION_DIRECTORY>/data/solr

If dataDirectoryPath is left blank (empty string), it will default to <DISTRIBUTION_INSTALLATION_DIRECTORY>/data/solr.

If Data Directory File Path is a relative string, the SCP will write the data files starting at the installation directory. For instance if the string scp/solr_data is provided, then the data directory would be at <DISTRIBUTION_INSTALLATION_DIRECTORY>/scp/solr_data

If Data Directory File Path is /solr_data in Windows, the Solr Catalog Provider will write the data files starting at the beginning of the drive such as C:/solr_data.

It is recommended to use an absolute filepath to minimize confusion such as /opt/solr_data in Linux or C:/solr_data in Windows. Permissions are necessary to write to the directory.

Force Auto Commit forceAutoCommit Boolean / Checkbox WARNING: Performance Impact. Only in special cases should auto-commit be forced. Forcing auto-commit makes the search results visible immediately. No

Solr Configuration Files

The Apache Solr product has Configuration files to customize behavior for the Solr Server. These files can be found at <DISTRIBUTION_INSTALLATION_DIRECTORY>/etc/solr. Care must be taken in editing these files because they will directly affect functionality and performance of the Solr Catalog Provider. A restart of the distribution is necessary for changes to take effect.

Note on Solr Configuration File Changes

Solr Configuration files should not be changed in most cases. Changes to the schema.xml will most likely need code changes within the Solr Catalog Provider.

Moving Solr Data to a New Location

If SCP has been installed for the first time, then changing the (1) Data Directory File Path property and (2) restarting the distribution is all that is necessary because no data had been written into Solr previously. Nonetheless, if a user needs to change the location after the user has already ingested data in a previous location, these are the steps that are required:

Change the Data Directory File Path property within the Catalog Embedded Solr Catalog Provider Configuration in the Admin Console to the desired future location of the Solr data files.
Shutdown the distribution.
Find the future location on the drive. If the current location does not exist, create the directories.
Find the location of where the current Solr data files exist and copy all the directories in that location to the future the location. For instance if the previous Solr data files existed at C:/solr_data and it is necessary to move it to C:/solr_data_new, then copy all directories within C:/solr_data into C:/solr_data_new. Usually this consists of copying the index and tlog directories into the new data directory.
Start the distribution. SCP should recognize the index files and be able to query them as it could before.

Note: Changes Require a Distribution Restart

If the Data Directory File Path property is changed, no changes will occur to the SCP until the distribution has been restarted.

Handy Tip

If Data Directory File Path property is changed to a new directory and the previous data is not moved into that directory, then no data will be in Solr. Solr will create an empty index. Therefore it is possible to have multiple places where Solr files are stored and a user can toggle between those locations for different sets of data.

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