openstack/swift
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Add read and write affinity options to deployment guide

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Add entries for these options in the deployment guide and
make the text in proxy-server.conf-sample and man page
consistent.

Change-Id: I5854ddb3e5864ddbeaf9ac2c930bfafdb47517c3
This commit is contained in:
Alistair Coles 2017-05-04 16:47:38 +01:00
parent 582af7cd9d
commit f02ec4de81
3 changed files with 78 additions and 27 deletions
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46
doc/manpages/proxy-server.conf.5
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@ -1026,26 +1026,42 @@ Set to the number of nodes to contact for a normal request. You can use '* repli
at the end to have it use the number given times the number of
replicas for the ring being used for the request. The default is '2 * replicas'.
.IP \fBread_affinity\fR
Which backend servers to prefer on reads. Format is r<N> for region
N or r<N>z<M> for region N, zone M. The value after the equals is
the priority; lower numbers are higher priority.
Default is empty, meaning no preference.
Example: first read from region 1 zone 1, then region 1 zone 2, then anything in region 2, then everything else:
read_affinity = r1z1=100, r1z2=200, r2=300
Specifies which backend servers to prefer on reads. Format is a comma
separated list of affinity descriptors of the form <selection>=<priority>.
The <selection> may be r<N> for selecting nodes in region N or r<N>z<M> for
selecting nodes in region N, zone M. The <priority> value should be a whole
number that represents the priority to be given to the selection; lower numbers
are higher priority. Default is empty, meaning no preference.
Example: first read from region 1 zone 1, then region 1 zone 2, then anything
in region 2, then everything else:
.PD 0
.RS 10
.IP "read_affinity = r1z1=100, r1z2=200, r2=300"
.RE
.PD
.IP \fBwrite_affinity\fR
Which backend servers to prefer on writes. Format is r<N> for region
N or r<N>z<M> for region N, zone M. If this is set, then when
handling an object PUT request, some number (see setting
write_affinity_node_count) of local backend servers will be tried
before any nonlocal ones. Default is empty, meaning no preference.
Specifies which backend servers to prefer on writes. Format is a comma
separated list of affinity descriptors of the form r<N> for region N or
r<N>z<M> for region N, zone M. If this is set, then when handling an object
PUT request, some number (see setting write_affinity_node_count) of local
backend servers will be tried before any nonlocal ones. Default is empty,
meaning no preference.
Example: try to write to regions 1 and 2 before writing to any other
nodes:
.PD 0
.RS 10
write_affinity = r1, r2
.RE
.PD
.IP \fBwrite_affinity_node_count\fR
The number of local (as governed by the write_affinity setting)
nodes to attempt to contact first, before any non-local ones. You
can use '* replicas' at the end to have it use the number given
times the number of replicas for the ring being used for the
The number of local (as governed by the write_affinity setting) nodes to
attempt to contact first on writes, before any non-local ones. The value
should be an integer number, or use '* replicas' at the end to have it use
the number given times the number of replicas for the ring being used for the
request. The default is '2 * replicas'.
.IP \fBswift_owner_headers\fR
These are the headers whose values will only be shown to swift_owners. The

32
doc/source/deployment_guide.rst
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@ -1794,6 +1794,38 @@ ionice_priority None I/O scheduling priority of server
I/O priority of the process. Work
only with ionice_class.
Ignored if IOPRIO_CLASS_IDLE is set.
read_affinity None Specifies which backend servers to
prefer on reads; used in conjunction
with the sorting_method option being
set to 'affinity'. Format is a comma
separated list of affinity descriptors
of the form <selection>=<priority>.
The <selection> may be r<N> for
selecting nodes in region N or
r<N>z<M> for selecting nodes in
region N, zone M. The <priority>
value should be a whole number
that represents the priority to
be given to the selection; lower
numbers are higher priority.
Default is empty, meaning no
preference.
write_affinity None Specifies which backend servers to
prefer on writes. Format is a comma
separated list of affinity
descriptors of the form r<N> for
region N or r<N>z<M> for region N,
zone M. Default is empty, meaning no
preference.
write_affinity_node_count 2 * replicas The number of local (as governed by
the write_affinity setting) nodes to
attempt to contact first on writes,
before any non-local ones. The value
should be an integer number, or use
'* replicas' at the end to have it
use the number given times the number
of replicas for the ring being used
for the request.
============================ =============== =====================================
[tempauth]

27
etc/proxy-server.conf-sample
View File

@ -200,9 +200,12 @@ use = egg:swift#proxy
# replicas for the ring being used for the request.
# request_node_count = 2 * replicas
#
# Which backend servers to prefer on reads. Format is r<N> for region
# N or r<N>z<M> for region N, zone M. The value after the equals is
# the priority; lower numbers are higher priority.
# Specifies which backend servers to prefer on reads. Format is a comma
# separated list of affinity descriptors of the form <selection>=<priority>.
# The <selection> may be r<N> for selecting nodes in region N or r<N>z<M> for
# selecting nodes in region N, zone M. The <priority> value should be a whole
# number that represents the priority to be given to the selection; lower
# numbers are higher priority.
#
# Example: first read from region 1 zone 1, then region 1 zone 2, then
# anything in region 2, then everything else:
@ -210,11 +213,11 @@ use = egg:swift#proxy
# Default is empty, meaning no preference.
# read_affinity =
#
# Which backend servers to prefer on writes. Format is r<N> for region
# N or r<N>z<M> for region N, zone M. If this is set, then when
# handling an object PUT request, some number (see setting
# write_affinity_node_count) of local backend servers will be tried
# before any nonlocal ones.
# Specifies which backend servers to prefer on writes. Format is a comma
# separated list of affinity descriptors of the form r<N> for region N or
# r<N>z<M> for region N, zone M. If this is set, then when handling an object
# PUT request, some number (see setting write_affinity_node_count) of local
# backend servers will be tried before any nonlocal ones.
#
# Example: try to write to regions 1 and 2 before writing to any other
# nodes:
@ -222,10 +225,10 @@ use = egg:swift#proxy
# Default is empty, meaning no preference.
# write_affinity =
#
# The number of local (as governed by the write_affinity setting)
# nodes to attempt to contact first, before any non-local ones. You
# can use '* replicas' at the end to have it use the number given
# times the number of replicas for the ring being used for the
# The number of local (as governed by the write_affinity setting) nodes to
# attempt to contact first on writes, before any non-local ones. The value
# should be an integer number, or use '* replicas' at the end to have it use
# the number given times the number of replicas for the ring being used for the
# request.
# write_affinity_node_count = 2 * replicas
#