dCache

The goal of dCache project is to provide a system for storing and retrieving huge amounts of data, distributed among a large number of heterogenous server nodes, under a single virtual filesystem tree with a variety of standard access methods. Depending on the Persistency Model, dCache provides methods for exchanging data with backend (tertiary) Storage Systems as well as space management, pool attraction, dataset replication, hot spot determination and recovery from disk or node failures. Connected to a tertiary storage system, the cache simulates unlimited direct access storage space. Data exchanges to and from the underlying HSM are performed automatically and invisibly to the user. Beside HEP specific protocols, data in dCache can be accessed via NFSv4.1 (pNFS) as well as through WebDav.

Summary:

• Release Notes

  • What's new

  • List of RfCs

  • Deployment Notes

  • Known Issues

  • List of Artifacts

• Documentation

• Support

Release Notes

What's new

Highlights of changes for INDIGO - DataCloud project:

• dCache 3.0.9

  • REST-api: support querying QoS through namespace

    • Several improvments has been done for the error handling for RESTful interface.

      Currently the error JSON object contains potentially useful information in the message and the bugs are logged.

  • dCache has the concept of a home directory: each user may have a directory that is somehow “theirs”. This information was not available to clients accessing dCache via the REST interface. The current release fixed this and querying /api/v1/user provides the user’s home directory in addition to other user-centric information.

    • The RESTful interface exposed some namespace-targeted information through /api/v1/namespace, and QoS information through /api/v1/qos-management/namespace. This was undesirable as dCache exposes namespace-targeted operations in two places. This is now fixed and the client may obtain information by querying /api/v1/namespace.

• dCache 3.0.8

  • FRONTEND

    • Synchronization with REST-api changes.

• dCache 3.0.0

  • REST-api:

    • New functionalities to create, move and rename resources have been added.

    • The pinmanager was adjusted to perform QoS transition from “disk+tape” to “tape”.

  • WEBDAV:

    • Spnego based Kerberos authentication mechanism for SSO has been added.

    • Webdav service is now able to upload files with a PUT using the browser.

    • Faster webdav directory creation is now possible.

    • The generated HTML pages work correctly when proxied by some other web server

    • Fixed an unreleased bug in WebDAV door that caused it to fail to load the errorpage template.

    • Several improvements have been performed to allow clients to handle objects that they don't have permission to access.

       It may be that some users were using that dCache returns the wrong  status-code as a mechanism to clear the browser's BASIC credential  cache (e.g., to "log out").  With this patch, that is not possible and users  must use the facilities the web-browser provides.

Supported platforms:

• CentOS 7 and higher, Scientific Linux 7 and higher, Ubuntu 14.04 and higher

List of RfCs

• N/A

Deployment Notes

• Classical package-based installation, see Installing dCache book

Known Issues

• N/A

List of Artifacts

Packages:

• dcache_3.0.12_all.deb
• dcache-3.0.12.noarch.rpm

Documentation

• dCache Gitbook

Support

• E-mail support is available via [e-mail], and a mailing list for discussions amongst users (with the developers participating) is at [e-mail].
• GGUS unit: dCache Support
• You can also use the INDIGO - DataCloud CatchAll GGUS Support Unit