diff --git a/doc/arch-design/source/design-storage/design-storage-arch.rst b/doc/arch-design/source/design-storage/design-storage-arch.rst index b3bc40ca55..9b67619bd0 100644 --- a/doc/arch-design/source/design-storage/design-storage-arch.rst +++ b/doc/arch-design/source/design-storage/design-storage-arch.rst @@ -24,9 +24,6 @@ be answered: Choosing storage back ends ~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. TODO how to decide (encryption, SLA requirements, live migration - availability) - Users will indicate different needs for their cloud architecture. Some may need fast access to many objects that do not change often, or want to set a time-to-live (TTL) value on a file. Others may access only storage @@ -163,9 +160,6 @@ compute cloud are to provide: Selecting storage hardware ~~~~~~~~~~~~~~~~~~~~~~~~~~ -.. TODO how to design (IOPS requirements [spinner vs SSD]/Read+Write/ - Availability/Migration) - Storage hardware architecture is determined by selecting specific storage architecture. Determine the selection of storage architecture by evaluating possible solutions against the critical factors, the user @@ -260,12 +254,17 @@ What about SSD? DRAM SSD? (14x) Scalability - Scalability, along with expandability, is a major consideration in a - general purpose OpenStack cloud. It might be difficult to predict - the final intended size of the implementation as there are no - established usage patterns for a general purpose cloud. It might - become necessary to expand the initial deployment in order to - accommodate growth and user demand. + Scalability, along with expandability, is a major consideration in + a general purpose OpenStack cloud. It might be difficult to predict the final + intended size of the implementation as there are no established usage patterns + for a general purpose cloud. It might become necessary to expand the initial + deployment in order to accommodate growth and user demand. Many vendors have + implemented their own solutions to this problem. Some use clustered file + systems that span multiple appliances, while others have similar technologies + to allow block storage to scale past a fixed capacity. Ceph, a distributed + storage solution that offers block storage, was designed to solve this scale + issue and does not have the same limitations on domains, clusters, or scale + issues of other appliance driven models. Expandability Expandability is a major architecture factor for storage solutions @@ -492,7 +491,12 @@ nodes and proxy servers should make use of a design which is scalable. Redundancy ---------- - +When making swift more redundant, one approach is to add additonal proxy +servers and load balancing. HAProxy is one method of providing load +balancing and high availability and is often combined with keepalived +or pacemaker to ensure the HAProxy service maintains a stable VIP. +Sample HAProxy configurations can be found in the `OpenStack HA Guide. +`_. Replication -----------