Description
dCache is a distributed multi-tiered data storage system widely used
by High Energy Physics and other scientific communities. It natively
supports a variety of storage media including spinning disk, SSD and
tape devices. Data migration between different media tiers is handled
manually or automatically based on policies. In order to provide
different levels of quality of service concerning performance, data
availability and data durability, dCache manages multiple copies of
data on different storage devices. In dCache, this feature is called
data resilience.
In this paper we discuss the design and implementation of the
Resilience Service in dCache. The service was conceived to meet the
requirements of flexibility, fine-grained definition of resilience
constraints, ease of configuration and integration with existing
dCache services. We will also detail several optimizations that were
applied to improve concurrency, consistency and fairness, along with
the rich set of diagnostic and control commands available through the
dCache admin interface. A test procedure and results will be covered
as well.
| Primary Keyword (Mandatory) | Storage systems |
|---|---|
| Secondary Keyword (Optional) | Storage systems |
