openstack/swift
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Made spacing after period consistent throughout, removed a couple of spurious commas

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Brian K. Jones 2010-07-23 12:05:14 -04:00
parent f5a2c5374c
commit 4a855fa21e
1 changed files with 24 additions and 24 deletions
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18
doc/source/overview_architecture.rst
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@ -15,7 +15,7 @@ The public API is also exposed through the Proxy Server.
A large number of failures are also handled in the Proxy Server. For A large number of failures are also handled in the Proxy Server. For
example, if a server is unavailable for an object PUT, it will ask the example, if a server is unavailable for an object PUT, it will ask the
ring for a handoff server, and route there instead. ring for a handoff server and route there instead.
When objects are streamed to or from an object server, they are streamed When objects are streamed to or from an object server, they are streamed
directly through the proxy server to of from the user -- the proxy server directly through the proxy server to of from the user -- the proxy server
@ -25,7 +25,7 @@ does not spool them.
The Ring The Ring
-------- --------
A ring represents a mapping between the names of entities stored on disk, and A ring represents a mapping between the names of entities stored on disk and
their physical location. There are separate rings for accounts, containers, and their physical location. There are separate rings for accounts, containers, and
objects. When other components need to perform any operation on an object, objects. When other components need to perform any operation on an object,
container, or account, they need to interact with the appropriate ring to container, or account, they need to interact with the appropriate ring to
@ -42,13 +42,13 @@ of a partition is guaranteed to reside in a different zone. A zone could
represent a drive, a server, a cabinet, a switch, or even a datacenter. represent a drive, a server, a cabinet, a switch, or even a datacenter.
The partitions of the ring are equally divided among all the devices in the The partitions of the ring are equally divided among all the devices in the
Swift installation. When an event occurs that requires partitions to be Swift installation. When partitions need to be moved around (for example if a
moved around (for example if a device is added to the cluster), the ring device is added to the cluster), the ring ensures that a minimum number of
ensures that a minimum number of partitions are moved at a time, and only partitions are moved at a time, and only one replica of a partition is moved at
one replica of a partition is moved at a time. a time.
Weights can be used to balance the distribution of partitions on drives Weights can be used to balance the distribution of partitions on drives
across the cluster. This can be useful, for example, if different sized across the cluster. This can be useful, for example, when different sized
drives are used in a cluster. drives are used in a cluster.
The ring is used by the Proxy server and several background processes The ring is used by the Proxy server and several background processes
@ -62,7 +62,7 @@ The Object Server is a very simple blob storage server that can store,
retrieve and delete objects stored on local devices. Objects are stored retrieve and delete objects stored on local devices. Objects are stored
as binary files on the filesystem with metadata stored in the file's as binary files on the filesystem with metadata stored in the file's
extended attributes (xattrs). This requires that the underlying filesystem extended attributes (xattrs). This requires that the underlying filesystem
choice for object servers must support xattrs on files. Some filesystems, choice for object servers support xattrs on files. Some filesystems,
like ext3, have xattrs turned off by default. like ext3, have xattrs turned off by default.
Each object is stored using a path derived from the object name's hash and Each object is stored using a path derived from the object name's hash and
@ -95,7 +95,7 @@ Replication
----------- -----------
Replication is designed to keep the system in a consistent state in the face Replication is designed to keep the system in a consistent state in the face
of temporary error conditions like network partitions or drive failures. of temporary error conditions like network outages or drive failures.
The replication processes compare local data with each remote copy to ensure The replication processes compare local data with each remote copy to ensure
they all contain the latest version. Object replication uses a hash list to they all contain the latest version. Object replication uses a hash list to