Overview
The Fedora 4 Backup capability allows a user, such as the repository manager, make a REST call to have the repository binaries and metadata exported to the local file system. Inversely, the Restore capability allows a user to make a REST call to have the repository restored from the contents of a previous Backup operation. In addition, with the default configuration, files are stored on disk named according to their SHA1 digest, so a filesystem backup approach can also be used.Usage
Backup
If a POST body specifying a writeable directory (local to Fedora 4 server) is not included in the request, the backup will be written to the system temp directory.
Perform a backup of a running Fedora 4 repository
Request
POST /rest/fcr:backup
> optional POST body
Response
On success
- HTTP/1.1 200 OK
- Path where the backup was written
Response body
- Absolute path of local backup directory
Restore
Note: Restoring a backup replaces the repository content with the contents of the backup, so any data in the repository will be lost.
Perform a restore of a running Fedora 4 repository
Request
POST /rest/fcr:restore
> with POST body
A POST body containing the full path to a previous backup.
Response
On success
- HTTP/1.1 204 No Content
Configurations
The following configurations have been successfully tested with the Backup and Restore functionality
- Non-clustered Fedora, using Infinispan cache backed by LevelDB (config)
Backup Format
Regardless of the repository configuration, the output of the backup process creates resources of the same format. Further details on backup contents and the underlying implementation can be found in ModeShape's documentation.
The backup directory will contain
- 'binaries' directory that contains the repository "content" binaries stored in a pair-tree like structure. The filename of the binary is the SHA-1 of the content with the extension '.bin'. The directory structure in which each binary is found is three levels deep based on the SHA-1.
For example, binary content in the repository with a SHA-1 of "5613537644c4d081c1dc3530fdb1a2fe843e570170d3d054", would look like
├── binaries └── 44 └── c4 └── d0 └── 44c4d081c1dc3530fdb1a2fe843e570170d3d054.bin
- One or more "documents_00000n.bin.gz" files which contains a concatenated listing of the metadata for each of the repository objects in JSON format
For example
{ "metadata" : { "id" : "87a0a8c317f1e7/jcr:system/jcr:nodeTypes/nt:unstructured//undefined/1" , "contentType" : "application/json" } , "content" : { "key" : "87a0a8c317f1e7/jcr:system/jcr:nodeTypes/nt:unstructured//undefined/1" , "parent" : "87a0a8c317f1e7/jcr:system/jcr:nodeTypes/nt:unstructured" , "properties" : { "http://www.jcp.org/jcr/1.0" : { "primaryType" : { "$name" : "nt:propertyDefinition" } , "onParentVersion" : "COPY" , "multiple" : false , "protected" : false , "availableQueryOperators" : [ "jcr.operator.equal.to" , "jcr.operator.greater.than" , "jcr.operator.greater.than.or.equal.to" , "jcr.operator.less.than" , "jcr.operator.less.than.or.equal.to" , "jcr.operator.like" , "jcr.operator.not.equal.to" ] , "requiredType" : "UNDEFINED" , "mandatory" : false , "autoCreated" : false } } } }
Filesystem Backup
By default, files larger than 4KB are stored on disk named after their SHA1 digest, in the directory fcrepo.binary.directory. (4KB is the default, but can be changed by updating the minimumBinarySizeInBytes property in repository.json). That is, a file with the SHA1 "a1b2c369563c0465ab82cdb2789d45ce1c3585b1" would be stored on disk in /path/to/fcrepo4-data/fcrepo.binary.directory/a1/b2/c3/a1b2c369563c0465ab82cdb2789d45ce1c3585b1. So files in the repository can be backed up backing up the directory fcrepo.binary.directory.
