Blob Storage Configuration

The blobs attached to a document in Nuxeo are usually stored separately from the main document database. The way in which they are stored is configurable using the concepts of a Binary Manager, Blob Provider and Blob Dispatcher.

Configuring the Default BlobProvider

The default blobProvider for Nuxeo Platform stores binaries on the local filesystem at a configurable location and with filenames based on their hash (digest).

<extension target="org.nuxeo.ecm.core.blob.BlobManager" point="configuration">
  <blobprovider name="default">
    <class>org.nuxeo.ecm.core.blob.binary.DefaultBinaryManager</class>
    <property name="path">binaries</property>
  </blobprovider>
</extension>

The path property is used to specify the filesystem path at which the binaries will be stored. A relative path will be resolved under $NUXEO/nxserver/data, but an absolute path can be used as well if needed.

The format of the binaries (or other configured path) directory is:

• config.xml a file containing the configuration used.
• data/ the hierarchy with the actual binaries dispatched in subdirectories.
• tmp/ a temporary storage location during creation (this must be on the same filesystem as data/).

The config.xml file looks like this:

<?xml version="1.0"?>
<binary-store>
  <digest>MD5</digest>
  <depth>2</depth>
</binary-store>

It is automatically generated by Nuxeo when initializing an empty binary storage, but you can put it manually and change the configuration:

• digest is a Java MessageDigest name, for example MD5 or SHA-256.
• depth is the depth with which the files are nested in subdirectories to avoid having too many in a single directory.

Registering Another BlobProvider

To register a new blob provider, use the blobprovider extension point and with the class for your binary manager:

<extension target="org.nuxeo.ecm.core.blob.BlobManager" point="configuration">
  <blobprovider name="default">
    <class>org.nuxeo.ecm.core.blob.binary.DefaultBinaryManager</class>
    <property name="path">binaries</property>
  </blobprovider>
</extension>

You will find existing implementations in the binary store main documentation page, with links to specific configuration instructions:

• the one that can be configured without additional addon
• the one that require installation of an addon.

Usually, if you don't use the advanced Blob Dispatcher capabilities, you will need one binary manager per Nuxeo repository. By default Nuxeo uses a binary manager with the same name for each repository, for instance the "default" repository will use the "default" binary manager. For a standard Nuxeo instance with a single repository, this is all taken care of for you in the default template

Blob Dispatcher

Without specific configuration, the DefaultBlobDispatcher stores a document's blob's binary in a blob provider with the same name as the document's repository name.

Advanced dispatching configuration are possible using properties. Each property name is a list of comma-separated clauses, with each clause consisting of a property, an operator and a value. The property can be a document XPath,  ecm:repositoryName , or, to match the current blob being dispatched,  blob:name ,  blob:mime-type ,  blob:encoding ,  blob:digest  or  blob:length . Comma-separated clauses are ANDed together. The special name default defines the default provider, and must be present. Available operators between property and value are =, !=, <, and >.

For example, all the videos could be stored somewhere, the documents from a secret source in an encrypted area, and the rest in a third location. To do this, you would need to specify the following:

<extension target="org.nuxeo.ecm.core.blob.BlobManager" point="configuration">
  <blobdispatcher>
    <class>org.nuxeo.ecm.core.blob.DefaultBlobDispatcher</class>
    <property name="dc:format=video">videos</property>
    <property name="blob:mime-type=video/mp4">videos</property>
    <property name="dc:source=secret">encrypted</property>
    <property name="default">default</property>
  </blobdispatcher>
</extension>

This assumes that you have three blob providers configured, the default one and two additional ones, videos and encrypted. For example you could have:

<extension target="org.nuxeo.ecm.core.blob.BlobManager" point="configuration">
  <blobprovider name="videos">
    <class>org.nuxeo.ecm.core.blob.binary.DefaultBinaryManager</class>
    <property name="path">binaries-videos</property>
  </blobprovider>
  <blobprovider name="encrypted">
    <class>org.nuxeo.ecm.core.blob.binary.AESBinaryManager</class>
    <property name="key">password=secret</property>
  </blobprovider>
</extension>

The default DefaultBlobDispatcher class can be replaced by your own implementation.