openstack/swift
Code Issues Proposed changes

Add absolute values for shard shrinking config options

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Add two new sharder config options for configuring shrinking
behaviour:

  - shrink_threshold: the size below which a shard may shrink
  - expansion_limit: the maximum size to which an acceptor shard
    may grow

The new options match the 'swift-manage-shard-ranges' command line
options and take absolute values.

The new options provide alternatives to the current equivalent options
'shard_shrink_point' and 'shard_shrink_merge_point', which are
expressed as percentages of 'shard_container_threshold'.
'shard_shrink_point' and 'shard_shrink_merge_point' are deprecated and
will be overridden by the new options if the new options are
explicitly set in a config file.

The default values of the new options are the same as the values that
would result from the default 'shard_container_threshold',
'shard_shrink_point' and 'shard_shrink_merge_point' i.e.:

  - shrink_threshold: 100000
  - expansion_limit: 750000

Change-Id: I087eac961c1eab53540fe56be4881e01ded1f60e
This commit is contained in:
Alistair Coles
2021-03-05 15:59:22 +00:00
parent f7fd99a880
commit 18f20daf38
5 changed files with 323 additions and 75 deletions
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43
doc/source/config/container_server_config.rst
View File

@@ -287,6 +287,8 @@ the following configuration options defined for the `[container-replicator]`_:
* rsync_module
* recon_cache_path
Some config options in this section may also be used by the
:ref:`swift-manage-shard-ranges CLI tool <swift-manage-shard-ranges>`.
================================= ================= =======================================
Option Default Description
@@ -310,8 +312,7 @@ auto_shard false If the auto_shard option
this option to true in a
production cluster.
shard_container_threshold 1000000 When auto-sharding is
enabled this defines the
shard_container_threshold 1000000 This defines the
object count at which a
container with
container-sharding
@@ -326,8 +327,24 @@ shard_container_threshold 1000000 When auto-sharding is
shrinking and merging
shard containers.
shard_shrink_point 10 When auto-sharding is
enabled this defines the
shrink_threshold This defines the
object count below which
a 'donor' shard container
will be considered for
shrinking into another
'acceptor' shard
container. The default is
determined by
shard_shrink_point. If
set, shrink_threshold
will take precedence over
shard_shrink_point.
shard_shrink_point 10 Deprecated: shrink_threshold
is recommended and if set
will take precedence over
shard_shrink_point.
This defines the
object count below which
a 'donor' shard container
will be considered for
@@ -341,8 +358,22 @@ shard_shrink_point 10 When auto-sharding is
10 means 10% of the
shard_container_threshold.
shard_shrink_merge_point 75 When auto-sharding is
enabled this defines the
expansion_limit This defines the
maximum allowed size of
an acceptor shard
container after having a
donor merged into it. The
default is determined by
shard_shrink_merge_point.
If set, expansion_limit
will take precedence over
shard_shrink_merge_point.
shard_shrink_merge_point 75 Deprecated: expansion_limit
is recommended and if set
will take precedence over
shard_shrink_merge_point.
This defines the
maximum allowed size of
an acceptor shard
container after having a