[couchdb-documentation] branch shard-level-docs updated: Improve placement docs, closes #374 (#376)
This is an automated email from the ASF dual-hosted git repository. wohali pushed a commit to branch shard-level-docs in repository https://gitbox.apache.org/repos/asf/couchdb-documentation.git The following commit(s) were added to refs/heads/shard-level-docs by this push: new 2a7418c Improve placement docs, closes #374 (#376) new 6703ed3 Merge branch 'master' into shard-level-docs 2a7418c is described below commit 2a7418cfe01e43bbfa5e9cb6fa3725096fb9a4be Author: Joan Touzet AuthorDate: Fri Jan 18 23:56:50 2019 -0500 Improve placement docs, closes #374 (#376) Closes #374 . --- src/cluster/databases.rst | 5 + src/cluster/sharding.rst | 8 src/config/cluster.rst| 5 + 3 files changed, 18 insertions(+) diff --git a/src/cluster/databases.rst b/src/cluster/databases.rst index f008eb6..09876d0 100644 --- a/src/cluster/databases.rst +++ b/src/cluster/databases.rst @@ -51,6 +51,11 @@ In BigCouch, the predecessor to CouchDB 2.0's clustering functionality, there was the concept of zones. CouchDB 2.0 carries this forward with cluster placement rules. +.. warning:: + +Use of the ``placement`` argument will **override** the standard +logic for shard replica cardinality (specified by ``[cluster] n``.) + First, each node must be labeled with a zone attribute. This defines which zone each node is in. You do this by editing the node's document in the ``/nodes`` database, which is accessed through the "back-door" (5986) port. diff --git a/src/cluster/sharding.rst b/src/cluster/sharding.rst index aeb8d02..cc7268e 100644 --- a/src/cluster/sharding.rst +++ b/src/cluster/sharding.rst @@ -468,6 +468,11 @@ Specifying database placement You can configure CouchDB to put shard replicas on certain nodes at database creation time using placement rules. +.. warning:: + +Use of the ``placement`` option will **override** the ``n`` option, +both in the ``.ini`` file as well as when specified in a ``URL``. + First, each node must be labeled with a zone attribute. This defines which zone each node is in. You do this by editing the node’s document in the ``/_nodes`` database, which is accessed through the node-local @@ -509,6 +514,9 @@ when the database is created, using the same syntax as the ini file: curl -X PUT $COUCH_URL:5984/?zone= +The ``placement`` argument may also be specified. Note that this *will* +override the logic that determines the number of created replicas! + Note that you can also use this system to ensure certain nodes in the cluster do not host any replicas for newly created databases, by giving them a zone attribute that does not appear in the ``[cluster]`` diff --git a/src/config/cluster.rst b/src/config/cluster.rst index 969f7e2..a7d605f 100644 --- a/src/config/cluster.rst +++ b/src/config/cluster.rst @@ -56,6 +56,11 @@ Cluster Options .. config:option:: placement +.. warning:: + +Use of this option will **override** the ``n`` option for replica +cardinality. Use with care. + Sets the cluster-wide replica placement policy when creating new databases. The value must be a comma-delimited list of strings of the format ``zone_name:#``, where ``zone_name`` is a zone as specified in
[couchdb-documentation] branch shard-level-docs updated: Improve placement docs, closes #374 (#376)
This is an automated email from the ASF dual-hosted git repository. wohali pushed a commit to branch shard-level-docs in repository https://gitbox.apache.org/repos/asf/couchdb-documentation.git The following commit(s) were added to refs/heads/shard-level-docs by this push: new 2a7418c Improve placement docs, closes #374 (#376) new 306d961 Merge branch 'master' into shard-level-docs 2a7418c is described below commit 2a7418cfe01e43bbfa5e9cb6fa3725096fb9a4be Author: Joan Touzet AuthorDate: Fri Jan 18 23:56:50 2019 -0500 Improve placement docs, closes #374 (#376) Closes #374 . --- src/cluster/databases.rst | 5 + src/cluster/sharding.rst | 8 src/config/cluster.rst| 5 + 3 files changed, 18 insertions(+) diff --git a/src/cluster/databases.rst b/src/cluster/databases.rst index f008eb6..09876d0 100644 --- a/src/cluster/databases.rst +++ b/src/cluster/databases.rst @@ -51,6 +51,11 @@ In BigCouch, the predecessor to CouchDB 2.0's clustering functionality, there was the concept of zones. CouchDB 2.0 carries this forward with cluster placement rules. +.. warning:: + +Use of the ``placement`` argument will **override** the standard +logic for shard replica cardinality (specified by ``[cluster] n``.) + First, each node must be labeled with a zone attribute. This defines which zone each node is in. You do this by editing the node's document in the ``/nodes`` database, which is accessed through the "back-door" (5986) port. diff --git a/src/cluster/sharding.rst b/src/cluster/sharding.rst index aeb8d02..cc7268e 100644 --- a/src/cluster/sharding.rst +++ b/src/cluster/sharding.rst @@ -468,6 +468,11 @@ Specifying database placement You can configure CouchDB to put shard replicas on certain nodes at database creation time using placement rules. +.. warning:: + +Use of the ``placement`` option will **override** the ``n`` option, +both in the ``.ini`` file as well as when specified in a ``URL``. + First, each node must be labeled with a zone attribute. This defines which zone each node is in. You do this by editing the node’s document in the ``/_nodes`` database, which is accessed through the node-local @@ -509,6 +514,9 @@ when the database is created, using the same syntax as the ini file: curl -X PUT $COUCH_URL:5984/?zone= +The ``placement`` argument may also be specified. Note that this *will* +override the logic that determines the number of created replicas! + Note that you can also use this system to ensure certain nodes in the cluster do not host any replicas for newly created databases, by giving them a zone attribute that does not appear in the ``[cluster]`` diff --git a/src/config/cluster.rst b/src/config/cluster.rst index 969f7e2..a7d605f 100644 --- a/src/config/cluster.rst +++ b/src/config/cluster.rst @@ -56,6 +56,11 @@ Cluster Options .. config:option:: placement +.. warning:: + +Use of this option will **override** the ``n`` option for replica +cardinality. Use with care. + Sets the cluster-wide replica placement policy when creating new databases. The value must be a comma-delimited list of strings of the format ``zone_name:#``, where ``zone_name`` is a zone as specified in
