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| -rw-r--r-- | doc/sphinx/Pacemaker_Explained/constraints.rst | 241 |
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diff --git a/doc/sphinx/Pacemaker_Explained/constraints.rst b/doc/sphinx/Pacemaker_Explained/constraints.rst index a78d6c2..cff65c5 100644 --- a/doc/sphinx/Pacemaker_Explained/constraints.rst +++ b/doc/sphinx/Pacemaker_Explained/constraints.rst @@ -38,109 +38,146 @@ configuration might be simpler. Location Properties ___________________ -.. table:: **Attributes of a rsc_location Element** +.. list-table:: **Attributes of a rsc_location Element** :class: longtable - :widths: 1 1 4 - - +--------------------+---------+----------------------------------------------------------------------------------------------+ - | Attribute | Default | Description | - +====================+=========+==============================================================================================+ - | id | | .. index:: | - | | | single: rsc_location; attribute, id | - | | | single: attribute; id (rsc_location) | - | | | single: id; rsc_location attribute | - | | | | - | | | A unique name for the constraint (required) | - +--------------------+---------+----------------------------------------------------------------------------------------------+ - | rsc | | .. index:: | - | | | single: rsc_location; attribute, rsc | - | | | single: attribute; rsc (rsc_location) | - | | | single: rsc; rsc_location attribute | - | | | | - | | | The name of the resource to which this constraint | - | | | applies. A location constraint must either have a | - | | | ``rsc``, have a ``rsc-pattern``, or contain at | - | | | least one resource set. | - +--------------------+---------+----------------------------------------------------------------------------------------------+ - | rsc-pattern | | .. index:: | - | | | single: rsc_location; attribute, rsc-pattern | - | | | single: attribute; rsc-pattern (rsc_location) | - | | | single: rsc-pattern; rsc_location attribute | - | | | | - | | | A pattern matching the names of resources to which | - | | | this constraint applies. The syntax is the same as | - | | | `POSIX <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04>`_ | - | | | extended regular expressions, with the addition of an | - | | | initial ``!`` indicating that resources *not* matching | - | | | the pattern are selected. If the regular expression | - | | | contains submatches, and the constraint is governed by | - | | | a :ref:`rule <rules>`, the submatches can be | - | | | referenced as ``%1`` through ``%9`` in the rule's | - | | | ``score-attribute`` or a rule expression's ``attribute`` | - | | | (see :ref:`s-rsc-pattern-rules`). A location constraint | - | | | must either have a ``rsc``, have a ``rsc-pattern``, or | - | | | contain at least one resource set. | - +--------------------+---------+----------------------------------------------------------------------------------------------+ - | node | | .. index:: | - | | | single: rsc_location; attribute, node | - | | | single: attribute; node (rsc_location) | - | | | single: node; rsc_location attribute | - | | | | - | | | The name of the node to which this constraint applies. | - | | | A location constraint must either have a ``node`` and | - | | | ``score``, or contain at least one rule. | - +--------------------+---------+----------------------------------------------------------------------------------------------+ - | score | | .. index:: | - | | | single: rsc_location; attribute, score | - | | | single: attribute; score (rsc_location) | - | | | single: score; rsc_location attribute | - | | | | - | | | Positive values indicate a preference for running the | - | | | affected resource(s) on ``node`` -- the higher the value, | - | | | the stronger the preference. Negative values indicate | - | | | the resource(s) should avoid this node (a value of | - | | | **-INFINITY** changes "should" to "must"). A location | - | | | constraint must either have a ``node`` and ``score``, | - | | | or contain at least one rule. | - +--------------------+---------+----------------------------------------------------------------------------------------------+ - | resource-discovery | always | .. index:: | - | | | single: rsc_location; attribute, resource-discovery | - | | | single: attribute; resource-discovery (rsc_location) | - | | | single: resource-discovery; rsc_location attribute | - | | | | - | | | Whether Pacemaker should perform resource discovery | - | | | (that is, check whether the resource is already running) | - | | | for this resource on this node. This should normally be | - | | | left as the default, so that rogue instances of a | - | | | service can be stopped when they are running where they | - | | | are not supposed to be. However, there are two | - | | | situations where disabling resource discovery is a good | - | | | idea: when a service is not installed on a node, | - | | | discovery might return an error (properly written OCF | - | | | agents will not, so this is usually only seen with other | - | | | agent types); and when Pacemaker Remote is used to scale | - | | | a cluster to hundreds of nodes, limiting resource | - | | | discovery to allowed nodes can significantly boost | - | | | performance. | - | | | | - | | | * ``always:`` Always perform resource discovery for | - | | | the specified resource on this node. | - | | | | - | | | * ``never:`` Never perform resource discovery for the | - | | | specified resource on this node. This option should | - | | | generally be used with a -INFINITY score, although | - | | | that is not strictly required. | - | | | | - | | | * ``exclusive:`` Perform resource discovery for the | - | | | specified resource only on this node (and other nodes | - | | | similarly marked as ``exclusive``). Multiple location | - | | | constraints using ``exclusive`` discovery for the | - | | | same resource across different nodes creates a subset | - | | | of nodes resource-discovery is exclusive to. If a | - | | | resource is marked for ``exclusive`` discovery on one | - | | | or more nodes, that resource is only allowed to be | - | | | placed within that subset of nodes. | - +--------------------+---------+----------------------------------------------------------------------------------------------+ + :widths: 1 1 1 4 + :header-rows: 1 + + * - Name + - Type + - Default + - Description + * - .. rsc_location_id: + + .. index:: + single: rsc_location; attribute, id + single: attribute; id (rsc_location) + single: id; rsc_location attribute + + id + - :ref:`id <id>` + - + - A unique name for the constraint (required) + * - .. rsc_location_rsc: + + .. index:: + single: rsc_location; attribute, rsc + single: attribute; rsc (rsc_location) + single: rsc; rsc_location attribute + + rsc + - :ref:`id <id>` + - + - The name of the resource to which this constraint applies. A location + constraint must either have a ``rsc``, have a ``rsc-pattern``, or + contain at least one resource set. + * - .. rsc_pattern: + + .. index:: + single: rsc_location; attribute, rsc-pattern + single: attribute; rsc-pattern (rsc_location) + single: rsc-pattern; rsc_location attribute + + rsc-pattern + - :ref:`text <text>` + - + - A pattern matching the names of resources to which this constraint + applies. The syntax is the same as `POSIX + <http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04>`_ + extended regular expressions, with the addition of an initial ``!`` + indicating that resources *not* matching the pattern are selected. If + the regular expression contains submatches, and the constraint contains + a :ref:`rule <rules>`, the submatches can be referenced as ``%1`` + through ``%9`` in the rule's ``score-attribute`` or a rule expression's + ``attribute`` (see :ref:`s-rsc-pattern-rules`). A location constraint + must either have a ``rsc``, have a ``rsc-pattern``, or contain at least + one resource set. + * - .. rsc_location_node: + + .. index:: + single: rsc_location; attribute, node + single: attribute; node (rsc_location) + single: node; rsc_location attribute + + node + - :ref:`text <text>` + - + - The name of the node to which this constraint applies. A location + constraint must either have a ``node`` and ``score``, or contain at + least one rule. + * - .. rsc_location_score: + + .. index:: + single: rsc_location; attribute, score + single: attribute; score (rsc_location) + single: score; rsc_location attribute + + score + - :ref:`score <score>` + - + - Positive values indicate a preference for running the affected + resource(s) on ``node`` -- the higher the value, the stronger the + preference. Negative values indicate the resource(s) should avoid this + node (a value of **-INFINITY** changes "should" to "must"). A location + constraint must either have a ``node`` and ``score``, or contain at + least one rule. + * - .. rsc_location_role: + + .. index:: + single: rsc_location; attribute, role + single: attribute; role (rsc_location) + single: role; rsc_location attribute + + role + - :ref:`enumeration <enumeration>` + - ``Started`` + - This is significant only for + :ref:`promotable clones <s-resource-promotable>`, is allowed only if + ``rsc`` or ``rsc-pattern`` is set, and is ignored if the constraint + contains a rule. Allowed values: + + * ``Started`` or ``Unpromoted``: The constraint affects the location of + all instances of the resource. (A promoted instance must start in the + unpromoted role before being promoted, so any location requirement for + unpromoted instances also affects promoted instances.) + * ``Promoted``: The constraint does not affect the location of + instances, but instead affects which of the instances will be + promoted. + + * - .. resource_discovery: + + .. index:: + single: rsc_location; attribute, resource-discovery + single: attribute; resource-discovery (rsc_location) + single: resource-discovery; rsc_location attribute + + resource-discovery + - :ref:`enumeration <enumeration>` + - always + - Whether Pacemaker should perform resource discovery (that is, check + whether the resource is already running) for this resource on this node. + This should normally be left as the default, so that rogue instances of + a service can be stopped when they are running where they are not + supposed to be. However, there are two situations where disabling + resource discovery is a good idea: when a service is not installed on a + node, discovery might return an error (properly written OCF agents will + not, so this is usually only seen with other agent types); and when + Pacemaker Remote is used to scale a cluster to hundreds of nodes, + limiting resource discovery to allowed nodes can significantly boost + performance. Allowed values: + + * ``always:`` Always perform resource discovery for the specified + resource on this node. + * ``never:`` Never perform resource discovery for the specified resource + on this node. This option should generally be used with a -INFINITY + score, although that is not strictly required. + * ``exclusive:`` Perform resource discovery for the specified resource + only on this node (and other nodes similarly marked as ``exclusive``). + Multiple location constraints using ``exclusive`` discovery for the + same resource across different nodes creates a subset of nodes + resource-discovery is exclusive to. If a resource is marked for + ``exclusive`` discovery on one or more nodes, that resource is only + allowed to be placed within that subset of nodes. .. warning:: |