diff --git a/doc/Pacemaker_Explained/en-US/Ch-Resources.txt b/doc/Pacemaker_Explained/en-US/Ch-Resources.txt index 2d4566b117..f5c873ad9d 100644 --- a/doc/Pacemaker_Explained/en-US/Ch-Resources.txt +++ b/doc/Pacemaker_Explained/en-US/Ch-Resources.txt @@ -1,903 +1,910 @@ :compat-mode: legacy = Cluster Resources = [[s-resource-primitive]] == What is a Cluster Resource? == indexterm:[Resource] A resource is a service made highly available by a cluster. The simplest type of resource, a 'primitive' resource, is described in this chapter. More complex forms, such as groups and clones, are described in later chapters. Every primitive resource has a 'resource agent'. A resource agent is an external program that abstracts the service it provides and present a consistent view to the cluster. This allows the cluster to be agnostic about the resources it manages. The cluster doesn't need to understand how the resource works because it relies on the resource agent to do the right thing when given a `start`, `stop` or `monitor` command. For this reason, it is crucial that resource agents are well-tested. Typically, resource agents come in the form of shell scripts. However, they can be written using any technology (such as C, Python or Perl) that the author is comfortable with. [[s-resource-supported]] == Resource Classes == indexterm:[Resource,class] Pacemaker supports several classes of agents: * OCF * LSB * Upstart * Systemd * Service * Fencing * Nagios Plugins === Open Cluster Framework === indexterm:[Resource,OCF] indexterm:[OCF,Resources] indexterm:[Open Cluster Framework,Resources] The OCF standard footnote:[See https://github.com/ClusterLabs/OCF-spec/tree/master/ra . The Pacemaker implementation has been somewhat extended from the OCF specs.] is basically an extension of the Linux Standard Base conventions for init scripts to: * support parameters, * make them self-describing, and * make them extensible OCF specs have strict definitions of the exit codes that actions must return. footnote:[ The resource-agents source code includes the `ocf-tester` script, which can be useful in this regard. ] The cluster follows these specifications exactly, and giving the wrong exit code will cause the cluster to behave in ways you will likely find puzzling and annoying. In particular, the cluster needs to distinguish a completely stopped resource from one which is in some erroneous and indeterminate state. Parameters are passed to the resource agent as environment variables, with the special prefix +OCF_RESKEY_+. So, a parameter which the user thinks of as +ip+ will be passed to the resource agent as +OCF_RESKEY_ip+. The number and purpose of the parameters is left to the resource agent; however, the resource agent should use the `meta-data` command to advertise any that it supports. The OCF class is the most preferred as it is an industry standard, highly flexible (allowing parameters to be passed to agents in a non-positional manner) and self-describing. For more information, see the http://www.linux-ha.org/wiki/OCF_Resource_Agents[reference] and the 'Resource Agents' chapter of 'Pacemaker Administration'. === Linux Standard Base === indexterm:[Resource,LSB] indexterm:[LSB,Resources] indexterm:[Linux Standard Base,Resources] 'LSB' resource agents are more commonly known as 'init scripts'. If a full path is not given, they are assumed to be located in +/etc/init.d+. Commonly, they are provided by the OS distribution. In order to be used with a Pacemaker cluster, they must conform to the LSB specification. footnote:[ See http://refspecs.linux-foundation.org/LSB_3.0.0/LSB-Core-generic/LSB-Core-generic/iniscrptact.html for the LSB Spec as it relates to init scripts. ] [WARNING] ==== Many distributions or particular software packages claim LSB compliance but ship with broken init scripts. For details on how to check whether your init script is LSB-compatible, see the 'Resource Agents' chapter of 'Pacemaker Administration'. Common problematic violations of the LSB standard include: * Not implementing the +status+ operation at all * Not observing the correct exit status codes for +start+/+stop+/+status+ actions * Starting a started resource returns an error * Stopping a stopped resource returns an error ==== [IMPORTANT] ==== Remember to make sure the computer is _not_ configured to start any services at boot time -- that should be controlled by the cluster. ==== [[s-resource-supported-systemd]] === Systemd === indexterm:[Resource,Systemd] indexterm:[Systemd,Resources] Some newer distributions have replaced the old http://en.wikipedia.org/wiki/Init#SysV-style["SysV"] style of initialization daemons and scripts with an alternative called http://www.freedesktop.org/wiki/Software/systemd[Systemd]. Pacemaker is able to manage these services _if they are present_. Instead of init scripts, systemd has 'unit files'. Generally, the services (unit files) are provided by the OS distribution, but there are online guides for converting from init scripts. footnote:[For example, http://0pointer.de/blog/projects/systemd-for-admins-3.html] [IMPORTANT] ==== Remember to make sure the computer is _not_ configured to start any services at boot time -- that should be controlled by the cluster. ==== === Upstart === indexterm:[Resource,Upstart] indexterm:[Upstart,Resources] Some newer distributions have replaced the old http://en.wikipedia.org/wiki/Init#SysV-style["SysV"] style of initialization daemons (and scripts) with an alternative called http://upstart.ubuntu.com/[Upstart]. Pacemaker is able to manage these services _if they are present_. Instead of init scripts, upstart has 'jobs'. Generally, the services (jobs) are provided by the OS distribution. [IMPORTANT] ==== Remember to make sure the computer is _not_ configured to start any services at boot time -- that should be controlled by the cluster. ==== === System Services === indexterm:[Resource,System Services] indexterm:[System Service,Resources] Since there are various types of system services (+systemd+, +upstart+, and +lsb+), Pacemaker supports a special +service+ alias which intelligently figures out which one applies to a given cluster node. This is particularly useful when the cluster contains a mix of +systemd+, +upstart+, and +lsb+. In order, Pacemaker will try to find the named service as: . an LSB init script . a Systemd unit file . an Upstart job === STONITH === indexterm:[Resource,STONITH] indexterm:[STONITH,Resources] The STONITH class is used exclusively for fencing-related resources. This is discussed later in <>. === Nagios Plugins === indexterm:[Resource,Nagios Plugins] indexterm:[Nagios Plugins,Resources] Nagios Plugins footnote:[The project has two independent forks, hosted at https://www.nagios-plugins.org/ and https://www.monitoring-plugins.org/. Output from both projects' plugins is similar, so plugins from either project can be used with pacemaker.] allow us to monitor services on remote hosts. Pacemaker is able to do remote monitoring with the plugins _if they are present_. A common use case is to configure them as resources belonging to a resource container (usually a virtual machine), and the container will be restarted if any of them has failed. Another use is to configure them as ordinary resources to be used for monitoring hosts or services via the network. The supported parameters are same as the long options of the plugin. [[primitive-resource]] == Resource Properties == These values tell the cluster which resource agent to use for the resource, where to find that resource agent and what standards it conforms to. .Properties of a Primitive Resource [width="95%",cols="1m,<6",options="header",align="center"] |========================================================= |Field |Description |id |Your name for the resource indexterm:[id,Resource] indexterm:[Resource,Property,id] |class |The standard the resource agent conforms to. Allowed values: +lsb+, +nagios+, +ocf+, +service+, +stonith+, +systemd+, +upstart+ indexterm:[class,Resource] indexterm:[Resource,Property,class] |type |The name of the Resource Agent you wish to use. E.g. +IPaddr+ or +Filesystem+ indexterm:[type,Resource] indexterm:[Resource,Property,type] |provider |The OCF spec allows multiple vendors to supply the same resource agent. To use the OCF resource agents supplied by the Heartbeat project, you would specify +heartbeat+ here. indexterm:[provider,Resource] indexterm:[Resource,Property,provider] |========================================================= The XML definition of a resource can be queried with the `crm_resource` tool. For example: ---- # crm_resource --resource Email --query-xml ---- might produce: .A system resource definition ===== [source,XML] ===== [NOTE] ===== One of the main drawbacks to system services (LSB, systemd or Upstart) resources is that they do not allow any parameters! ===== //// See https://tools.ietf.org/html/rfc5737 for choice of example IP address //// .An OCF resource definition ===== [source,XML] ------- ------- ===== [[s-resource-options]] == Resource Options == Resources have two types of options: 'meta-attributes' and 'instance attributes'. Meta-attributes apply to any type of resource, while instance attributes are specific to each resource agent. === Resource Meta-Attributes === Meta-attributes are used by the cluster to decide how a resource should behave and can be easily set using the `--meta` option of the `crm_resource` command. .Meta-attributes of a Primitive Resource [width="95%",cols="2m,2,<5",options="header",align="center"] |========================================================= |Field |Default |Description |priority |0 |If not all resources can be active, the cluster will stop lower priority resources in order to keep higher priority ones active. indexterm:[priority,Resource Option] indexterm:[Resource,Option,priority] |target-role |Started a|What state should the cluster attempt to keep this resource in? Allowed values: * +Stopped:+ Force the resource to be stopped * +Started:+ Allow the resource to be started (and in the case of <>, promoted to master if appropriate) * +Slave:+ Allow the resource to be started, but only in Slave mode if the resource is <> * +Master:+ Equivalent to +Started+ indexterm:[target-role,Resource Option] indexterm:[Resource,Option,target-role] |is-managed |TRUE |Is the cluster allowed to start and stop the resource? Allowed values: +true+, +false+ indexterm:[is-managed,Resource Option] indexterm:[Resource,Option,is-managed] |maintenance |FALSE |Similar to the +maintenance-mode+ <>, but for a single resource. If true, the resource will not be started, stopped, or monitored on any node. This differs from +is-managed+ in that monitors will not be run. Allowed values: +true+, +false+ indexterm:[maintenance,Resource Option] indexterm:[Resource,Option,maintenance] |resource-stickiness |1 for individual clone instances, 0 for all other resources |A score that will be added to the current node when a resource is already active. This allows running resources to stay where they are, even if they would be placed elsewhere if they were being started from a stopped state. indexterm:[resource-stickiness,Resource Option] indexterm:[Resource,Option,resource-stickiness] |requires |+quorum+ for resources with a +class+ of +stonith+, otherwise +unfencing+ if unfencing is active in the cluster, otherwise +fencing+ if +stonith-enabled+ is true, otherwise +quorum+ a|Conditions under which the resource can be started Allowed values: * +nothing:+ can always be started * +quorum:+ The cluster can only start this resource if a majority of the configured nodes are active * +fencing:+ The cluster can only start this resource if a majority of the configured nodes are active _and_ any failed or unknown nodes have been <> * +unfencing:+ The cluster can only start this resource if a majority of the configured nodes are active _and_ any failed or unknown nodes have been fenced _and_ only on nodes that have been <> indexterm:[requires,Resource Option] indexterm:[Resource,Option,requires] |migration-threshold |INFINITY |How many failures may occur for this resource on a node, before this node is marked ineligible to host this resource. A value of 0 indicates that this feature is disabled (the node will never be marked ineligible); by constrast, the cluster treats INFINITY (the default) as a very large but finite number. This option has an effect only if the failed operation specifies +on-fail+ as +restart+ (the default), and additionally for failed +start+ operations, if the cluster property +start-failure-is-fatal+ is +false+. indexterm:[migration-threshold,Resource Option] indexterm:[Resource,Option,migration-threshold] |failure-timeout |0 |How many seconds to wait before acting as if the failure had not occurred, and potentially allowing the resource back to the node on which it failed. A value of 0 indicates that this feature is disabled. As with any time-based actions, this is not guaranteed to be checked more frequently than the value of +cluster-recheck-interval+ (see <>). indexterm:[failure-timeout,Resource Option] indexterm:[Resource,Option,failure-timeout] |multiple-active |stop_start a|What should the cluster do if it ever finds the resource active on more than one node? Allowed values: * +block:+ mark the resource as unmanaged * +stop_only:+ stop all active instances and leave them that way * +stop_start:+ stop all active instances and start the resource in one location only indexterm:[multiple-active,Resource Option] indexterm:[Resource,Option,multiple-active] |allow-migrate |TRUE for ocf:pacemaker:remote resources, FALSE otherwise |Whether the cluster should try to "live migrate" this resource when it needs to be moved (see <>) |container-attribute-target | |Specific to bundle resources; see <> |remote-node | |The name of the Pacemaker Remote guest node this resource is associated with, if any. If specified, this both enables the resource as a guest node and defines the unique name used to identify the guest node. The guest must be configured to run the Pacemaker Remote daemon when it is started. +WARNING:+ This value cannot overlap with any resource or node IDs. |remote-port |3121 |If +remote-node+ is specified, the port on the guest used for its Pacemaker Remote connection. The Pacemaker Remote daemon on the guest must be configured to listen on this port. |remote-addr |value of +remote-node+ |If +remote-node+ is specified, the IP address or hostname used to connect to the guest via Pacemaker Remote. The Pacemaker Remote daemon on the guest must be configured to accept connections on this address. |remote-connect-timeout |60s |If +remote-node+ is specified, how long before a pending guest connection will time out. |========================================================= As an example of setting resource options, if you performed the following commands on an LSB Email resource: ------- # crm_resource --meta --resource Email --set-parameter priority --parameter-value 100 # crm_resource -m -r Email -p multiple-active -v block ------- the resulting resource definition might be: .An LSB resource with cluster options ===== [source,XML] ------- ------- ===== In addition to the cluster-defined meta-attributes described above, you may also configure arbitrary meta-attributes of your own choosing. Most commonly, this would be done for use in <>. For example, an IT department might define a custom meta-attribute to indicate which company department each resource is intended for. To reduce the chance of name collisions with cluster-defined meta-attributes added in the future, it is recommended to use a unique, organization-specific prefix for such attributes. [[s-resource-defaults]] === Setting Global Defaults for Resource Meta-Attributes === To set a default value for a resource option, add it to the +rsc_defaults+ section with `crm_attribute`. For example, ---- # crm_attribute --type rsc_defaults --name is-managed --update false ---- would prevent the cluster from starting or stopping any of the resources in the configuration (unless of course the individual resources were specifically enabled by having their +is-managed+ set to +true+). === Resource Instance Attributes === The resource agents of some resource classes (lsb, systemd and upstart 'not' among them) can be given parameters which determine how they behave and which instance of a service they control. If your resource agent supports parameters, you can add them with the `crm_resource` command. For example, ---- # crm_resource --resource Public-IP --set-parameter ip --parameter-value 192.0.2.2 ---- would create an entry in the resource like this: .An example OCF resource with instance attributes ===== [source,XML] ------- ------- ===== For an OCF resource, the result would be an environment variable called +OCF_RESKEY_ip+ with a value of +192.0.2.2+. The list of instance attributes supported by an OCF resource agent can be found by calling the resource agent with the `meta-data` command. The output contains an XML description of all the supported attributes, their purpose and default values. .Displaying the metadata for the Dummy resource agent template ===== ---- # export OCF_ROOT=/usr/lib/ocf # $OCF_ROOT/resource.d/pacemaker/Dummy meta-data ---- [source,XML] ------- 1.0 This is a Dummy Resource Agent. It does absolutely nothing except keep track of whether its running or not. Its purpose in life is for testing and to serve as a template for RA writers. NB: Please pay attention to the timeouts specified in the actions section below. They should be meaningful for the kind of resource the agent manages. They should be the minimum advised timeouts, but they shouldn't/cannot cover _all_ possible resource instances. So, try to be neither overly generous nor too stingy, but moderate. The minimum timeouts should never be below 10 seconds. Example stateless resource agent Location to store the resource state in. State file Fake attribute that can be changed to cause a reload Fake attribute that can be changed to cause a reload Number of seconds to sleep during operations. This can be used to test how the cluster reacts to operation timeouts. Operation sleep duration in seconds. ------- ===== == Resource Operations == indexterm:[Resource,Action] 'Operations' are actions the cluster can perform on a resource by calling the resource agent. Resource agents must support certain common operations such as start, stop, and monitor, and may implement any others. Operations may be explicitly configured for two purposes: to override defaults for options (such as timeout) that the cluster will use whenever it initiates the operation, and to run an operation on a recurring basis (for example, to monitor the resource for failure). .An OCF resource with a non-default start timeout ===== [source,XML] ------- ------- ===== Pacemaker identifies operations by a combination of name and interval, so this combination must be unique for each resource. That is, you should not configure two operations for the same resource with the same name and interval. +[[s-operation-properties]] +=== Operation Properties === + +Operation properties may be specified directly in the +op+ element as +XML attributes, or in a separate +meta_attributes+ block as +nvpair+ elements. +XML attributes take precedence over +nvpair+ elements if both are specified. + .Properties of an Operation [width="95%",cols="2m,3,<6",options="header",align="center"] |========================================================= |Field |Default |Description |id | |A unique name for the operation. indexterm:[id,Action Property] indexterm:[Action,Property,id] |name | |The action to perform. This can be any action supported by the agent; common values include +monitor+, +start+, and +stop+. indexterm:[name,Action Property] indexterm:[Action,Property,name] |interval |0 |How frequently (in seconds) to perform the operation. A value of 0 means "when needed". A positive value defines a 'recurring action', which is typically used with <>. indexterm:[interval,Action Property] indexterm:[Action,Property,interval] |timeout | |How long to wait before declaring the action has failed indexterm:[timeout,Action Property] indexterm:[Action,Property,timeout] |on-fail |restart '(except for +stop+ operations, which default to' fence 'when STONITH is enabled and' block 'otherwise)' a|The action to take if this action ever fails. Allowed values: * +ignore:+ Pretend the resource did not fail. * +block:+ Don't perform any further operations on the resource. * +stop:+ Stop the resource and do not start it elsewhere. * +restart:+ Stop the resource and start it again (possibly on a different node). * +fence:+ STONITH the node on which the resource failed. * +standby:+ Move _all_ resources away from the node on which the resource failed. indexterm:[on-fail,Action Property] indexterm:[Action,Property,on-fail] |enabled |TRUE |If +false+, ignore this operation definition. This is typically used to pause a particular recurring +monitor+ operation; for instance, it can complement the respective resource being unmanaged (+is-managed=false+), as this alone will <>. Disabling the operation does not suppress all actions of the given type. Allowed values: +true+, +false+. indexterm:[enabled,Action Property] indexterm:[Action,Property,enabled] |record-pending |TRUE |If +true+, the intention to perform the operation is recorded so that GUIs and CLI tools can indicate that an operation is in progress. This is best set as an _operation default_ (see <>). Allowed values: +true+, +false+. indexterm:[enabled,Action Property] indexterm:[Action,Property,enabled] |role | |Run the operation only on node(s) that the cluster thinks should be in the specified role. This only makes sense for recurring +monitor+ operations. Allowed (case-sensitive) values: +Stopped+, +Started+, and in the case of <>, +Slave+ and +Master+. indexterm:[role,Action Property] indexterm:[Action,Property,role] |========================================================= [[s-resource-monitoring]] === Monitoring Resources for Failure === When Pacemaker first starts a resource, it runs one-time +monitor+ operations (referred to as 'probes') to ensure the resource is running where it's supposed to be, and not running where it's not supposed to be. (This behavior can be affected by the +resource-discovery+ location constraint property.) Other than those initial probes, Pacemaker will 'not' (by default) check that the resource continues to stay healthy. footnote:[Currently, anyway. Automatic monitoring operations may be added in a future version of Pacemaker.] You must configure +monitor+ operations explicitly to perform these checks. .An OCF resource with a recurring health check ===== [source,XML] ------- ------- ===== By default, a +monitor+ operation will ensure that the resource is running where it is supposed to. The +target-role+ property can be used for further checking. For example, if a resource has one +monitor+ operation with +interval=10 role=Started+ and a second +monitor+ operation with +interval=11 role=Stopped+, the cluster will run the first monitor on any nodes it thinks 'should' be running the resource, and the second monitor on any nodes that it thinks 'should not' be running the resource (for the truly paranoid, who want to know when an administrator manually starts a service by mistake). [NOTE] ==== Currently, monitors with +role=Stopped+ are not implemented for <> resources. ==== [[s-monitoring-unmanaged]] === Monitoring Resources When Administration is Disabled === Recurring +monitor+ operations behave differently under various administrative settings: * When a resource is unmanaged (by setting +is-managed=false+): No monitors will be stopped. + If the unmanaged resource is stopped on a node where the cluster thinks it should be running, the cluster will detect and report that it is not, but it will not consider the monitor failed, and will not try to start the resource until it is managed again. + Starting the unmanaged resource on a different node is strongly discouraged and will at least cause the cluster to consider the resource failed, and may require the resource's +target-role+ to be set to +Stopped+ then +Started+ to be recovered. * When a node is put into standby: All resources will be moved away from the node, and all +monitor+ operations will be stopped on the node, except those specifying +role+ as +Stopped+ (which will be newly initiated if appropriate). * When the cluster is put into maintenance mode: All resources will be marked as unmanaged. All monitor operations will be stopped, except those specifying +role+ as +Stopped+ (which will be newly initiated if appropriate). As with single unmanaged resources, starting a resource on a node other than where the cluster expects it to be will cause problems. [[s-operation-defaults]] === Setting Global Defaults for Operations === You can change the global default values for operation properties in a given cluster. These are defined in an +op_defaults+ section of the CIB's +configuration+ section, and can be set with `crm_attribute`. For example, ---- # crm_attribute --type op_defaults --name timeout --update 20s ---- would default each operation's +timeout+ to 20 seconds. If an operation's definition also includes a value for +timeout+, then that value would be used for that operation instead. === When Implicit Operations Take a Long Time === The cluster will always perform a number of implicit operations: +start+, +stop+ and a non-recurring +monitor+ operation used at startup to check whether the resource is already active. If one of these is taking too long, then you can create an entry for them and specify a longer timeout. .An OCF resource with custom timeouts for its implicit actions ===== [source,XML] ------- ------- ===== === Multiple Monitor Operations === Provided no two operations (for a single resource) have the same name and interval, you can have as many +monitor+ operations as you like. In this way, you can do a superficial health check every minute and progressively more intense ones at higher intervals. To tell the resource agent what kind of check to perform, you need to provide each monitor with a different value for a common parameter. The OCF standard creates a special parameter called +OCF_CHECK_LEVEL+ for this purpose and dictates that it is "made available to the resource agent without the normal +OCF_RESKEY+ prefix". Whatever name you choose, you can specify it by adding an +instance_attributes+ block to the +op+ tag. It is up to each resource agent to look for the parameter and decide how to use it. .An OCF resource with two recurring health checks, performing different levels of checks specified via +OCF_CHECK_LEVEL+. ===== [source,XML] ------- ------- ===== === Disabling a Monitor Operation === The easiest way to stop a recurring monitor is to just delete it. However, there can be times when you only want to disable it temporarily. In such cases, simply add +enabled=false+ to the operation's definition. .Example of an OCF resource with a disabled health check ===== [source,XML] ------- ------- ===== This can be achieved from the command line by executing: ---- # cibadmin --modify --xml-text '' ---- Once you've done whatever you needed to do, you can then re-enable it with ---- # cibadmin --modify --xml-text '' ---- diff --git a/doc/Pacemaker_Explained/en-US/Ch-Rules.txt b/doc/Pacemaker_Explained/en-US/Ch-Rules.txt index 8cdf52b82e..a2f8b87cef 100644 --- a/doc/Pacemaker_Explained/en-US/Ch-Rules.txt +++ b/doc/Pacemaker_Explained/en-US/Ch-Rules.txt @@ -1,646 +1,757 @@ :compat-mode: legacy = Rules = //// We prefer [[ch-rules]], but older versions of asciidoc don't deal well with that construct for chapter headings //// anchor:ch-rules[Chapter 8, Rules] -indexterm:[Resource,Constraint,Rule] - -Rules can be used to make your configuration more dynamic. One common -example is to set one value for +resource-stickiness+ during working -hours, to prevent resources from being moved back to their most -preferred location, and another on weekends when no-one is around to -notice an outage. - -Another use of rules might be to assign machines to different -processing groups (using a node attribute) based on time and to then -use that attribute when creating location constraints. - -Each rule can contain a number of expressions, date-expressions and -even other rules. The results of the expressions are combined based -on the rule's +boolean-op+ field to determine if the rule ultimately -evaluates to +true+ or +false+. What happens next depends on the -context in which the rule is being used. - +indexterm:[Constraint,Rule] + +Rules can be used to make your configuration more dynamic, allowing values to +change depending on the time or the value of a node attribute. Examples of +things rules are useful for: + +* Set a higher value for <> during + working hours, to minimize downtime, and a lower value on weekends, to allow + resources to move to their most preferred locations when people aren't around + to notice. + +* Automatically place the cluster into maintenance mode during a scheduled + maintenance window. + +* Assign certain nodes and resources to a particular department via custom + node attributes and meta-attributes, and add a single location constraint + that restricts the department's resources to run only on those nodes. + +Each constraint type or property set that supports rules may contain one or more ++rule+ elements specifying conditions under which the constraint or properties +take effect. Examples later in this chapter will make this clearer. + == Rule Properties == -.Properties of a Rule +indexterm:[XML element,rule element] + +.Attributes of a rule Element [width="95%",cols="2m,1,<5",options="header",align="center"] |========================================================= -|Field +|Attribute |Default |Description |id | |A unique name for the rule (required) - indexterm:[id,Constraint Rule] - indexterm:[Constraint,Rule,id] + indexterm:[XML attribute,id attribute,rule element] + indexterm:[XML element,rule element,id attribute] |role |+Started+ -|Limits the rule to apply only when the resource is in the specified +|The rule is in effect only when the resource is in the specified role. Allowed values are +Started+, +Slave+, and +Master+. A rule with +role="Master"+ cannot determine the initial location of a clone instance and will only affect which of the active instances will be promoted. - indexterm:[role,Constraint Rule] - indexterm:[Constraint,Rule,role] + indexterm:[XML attribute,role attribute,rule element] + indexterm:[XML element,rule element,role attribute] |score | -|The score to apply if the rule evaluates to +true+. Limited to use in - rules that are part of location constraints. - indexterm:[score,Constraint Rule] - indexterm:[Constraint,Rule,score] +|If this rule is used in a location constraint and evaluates to true, apply + this score to the constraint. Only one of +score+ and +score-attribute+ may be + used. + indexterm:[XML attribute,score attribute,rule element] + indexterm:[XML element,rule element,score attribute] |score-attribute | -|The node attribute to look up and use as a score if the rule - evaluates to +true+. Limited to use in rules that are part of - location constraints. - indexterm:[score-attribute,Constraint Rule] - indexterm:[Constraint,Rule,score-attribute] +|If this rule is used in a location constraint and evaluates to true, use the + value of this node attribute as the score to apply to the constraint. Only one + of +score+ and +score-attribute+ may be used. + indexterm:[XML attribute,score-attribute attribute,rule element] + indexterm:[XML element,rule element,score-attribute attribute] |boolean-op |+and+ -|How to combine the result of multiple expression objects. Allowed - values are +and+ and +or+. - indexterm:[boolean-op,Constraint Rule] - indexterm:[Constraint,Rule,boolean-op] +|If this rule contains more than one condition, a value of +and+ specifies that + the rule evaluates to true only if all conditions are true, and a value of + +or+ specifies that the rule evaluates to true if any condition is true. + indexterm:[XML attribute,boolean-op attribute,rule element] + indexterm:[XML element,rule element,boolean-op attribute] |========================================================= +A +rule+ element must contain one or more conditions. A condition may be an ++expression+ element, a +date_expression+ element, or another +rule+ element. + == Node Attribute Expressions == [[node-attribute-expressions]] -indexterm:[Resource,Constraint,Attribute Expression] +indexterm:[Rule,Node Attribute Expression] +indexterm:[XML element,expression element] -Expression objects are used to control a resource based on the -attributes defined by a node or nodes. +Expressions are rule conditions based on the values of node attributes. -.Properties of an Expression +.Attributes of an expression Element [width="95%",cols="2m,1,<5",options="header",align="center"] |========================================================= |Field |Default |Description |id | |A unique name for the expression (required) - indexterm:[id,Constraint Expression] - indexterm:[Constraint,Attribute Expression,id] + indexterm:[XML attribute,id attribute,expression element] + indexterm:[XML element,expression element,id attribute] |attribute | |The node attribute to test (required) - indexterm:[attribute,Constraint Expression] - indexterm:[Constraint,Attribute Expression,attribute] + indexterm:[XML attribute,attribute attribute,expression element] + indexterm:[XML element,expression element,attribute attribute] |type |+string+ -|Determines how the value(s) should be tested. Allowed values are +|How the node attributes should be compared. Allowed values are +string+, +integer+, and +version+. - indexterm:[type,Constraint Expression] - indexterm:[Constraint,Attribute Expression,type] + indexterm:[XML attribute,type attribute,expression element] + indexterm:[XML element,expression element,type attribute] |operation | a|The comparison to perform (required). Allowed values: -* +lt:+ True if the value of the node's +attribute+ is less than +value+ -* +gt:+ True if the value of the node's +attribute+ is greater than +value+ -* +lte:+ True if the value of the node's +attribute+ is less than or equal to +value+ -* +gte:+ True if the value of the node's +attribute+ is greater than or equal to +value+ -* +eq:+ True if the value of the node's +attribute+ is equal to +value+ -* +ne:+ True if the value of the node's +attribute+ is not equal to +value+ +* +lt:+ True if the node attribute value is less than the comparison value +* +gt:+ True if the node attribute value is greater than the comparison value +* +lte:+ True if the node attribute value is less than or equal to the comparison value +* +gte:+ True if the node attribute value is greater than or equal to the comparison value +* +eq:+ True if the node attribute value is equal to the comparison value +* +ne:+ True if the node attribute value is not equal to the comparison value * +defined:+ True if the node has the named attribute * +not_defined:+ True if the node does not have the named attribute - indexterm:[operation,Constraint Expression] - indexterm:[Constraint,Attribute Expression,operation] + indexterm:[XML attribute,operation attribute,expression element] + indexterm:[XML element,expression element,operation attribute] |value | |User-supplied value for comparison (required for operations other than +defined+ and +not_defined+) - indexterm:[value,Constraint Expression] - indexterm:[Constraint,Attribute Expression,value] + indexterm:[XML attribute,value attribute,expression element] + indexterm:[XML element,expression element,value attribute] |value-source |+literal+ a|How the +value+ is derived. Allowed values: * +literal+: +value+ is a literal string to compare against * +param+: +value+ is the name of a resource parameter to compare against (only valid in location constraints) * +meta+: +value+ is the name of a resource meta-attribute to compare against (only valid in location constraints) - indexterm:[value,Constraint Expression] - indexterm:[Constraint,Attribute Expression,value] + indexterm:[XML attribute,value-source attribute,expression element] + indexterm:[XML element,expression element,value-source attribute] |========================================================= [[node-attribute-expressions-special]] -In addition to any attributes added by the administrator, the cluster defines -special, built-in node attributes for each node that can also be used. +In addition to custom node attributes defined by the administrator, the cluster +defines special, built-in node attributes for each node that can also be used +in rule expressions. -.Built-in node attributes +.Built-in Node Attributes [width="95%",cols="1m,<5",options="header",align="center"] |========================================================= |Name |Value |#uname |Node <> |#id |Node ID |#kind |Node type. Possible values are +cluster+, +remote+, and +container+. Kind is +remote+ for Pacemaker Remote nodes created with the +ocf:pacemaker:remote+ resource, and +container+ for Pacemaker Remote guest nodes and bundle nodes |#is_dc |"true" if this node is a Designated Controller (DC), "false" otherwise |#cluster-name |The value of the +cluster-name+ cluster property, if set |#site-name |The value of the +site-name+ node attribute, if set, otherwise identical to +#cluster-name+ |#role a|The role the relevant promotable clone resource has on this node. Valid only within a rule for a location constraint for a promotable clone resource. //// // if uncommenting, put a pipe in front of first two lines #ra-version The installed version of the resource agent on the node, as defined by the +version+ attribute of the +resource-agent+ tag in the agent's metadata. Valid only within rules controlling resource options. This can be useful during rolling upgrades of a backward-incompatible resource agent. '(coming in x.x.x)' //// |========================================================= -== Time- and Date-Based Expressions == +== Date/Time Expressions == -indexterm:[Time Based Expressions] -indexterm:[Resource,Constraint,Date/Time Expression] +indexterm:[Rule,Date/Time Expression] +indexterm:[XML element,date_expression element] -As the name suggests, +date_expressions+ are used to control a -resource or cluster option based on the current date/time. They may -contain an optional +date_spec+ and/or +duration+ object depending on -the context. +Date/time expressions are rule conditions based (as the name suggests) on the +current date and time. + +A +date_expression+ element may optionally contain a +date_spec+ or +duration+ +element depending on the context. -.Properties of a Date Expression +.Attributes of a date_expression Element [width="95%",cols="2m,<5",options="header",align="center"] |========================================================= |Field |Description +|id +|A unique name for the expression (required) + indexterm:[XML attribute,id attribute,date_expression element] + indexterm:[XML element,date_expression element,id attribute] + |start |A date/time conforming to the http://en.wikipedia.org/wiki/ISO_8601[ISO8601] - specification. - indexterm:[start,Constraint Expression] - indexterm:[Constraint,Date/Time Expression,start] + specification. May be used when +operation+ is +in_range+ (in which case at + least one of +start+ or +end+ must be specified) or +gt+ (in which case + +start+ is required). + indexterm:[XML attribute,start attribute,date_expression element] + indexterm:[XML element,date_expression element,start attribute] |end |A date/time conforming to the http://en.wikipedia.org/wiki/ISO_8601[ISO8601] - specification. Can be inferred by supplying a value for +start+ and a - +duration+. - indexterm:[end,Constraint Expression] - indexterm:[Constraint,Date/Time Expression,end] + specification. May be used when +operation+ is +in_range+ (in which case at + least one of +start+ or +end+ must be specified) or +lt+ (in which case + +end+ is required). + indexterm:[XML attribute,end attribute,date_expression element] + indexterm:[XML element,date_expression element,end attribute] |operation a|Compares the current date/time with the start and/or end date, depending on the context. Allowed values: * +gt:+ True if the current date/time is after +start+ * +lt:+ True if the current date/time is before +end+ -* +in_range:+ True if the current date/time is after +start+ and before +end+ -* +date_spec:+ True if the current date/time matches a +date_spec+ object - (described below) - indexterm:[operation,Constraint Expression] - indexterm:[Constraint,Date/Time Expression,operation] +* +in_range:+ True if the current date/time is after +start+ (if specified) + and before either +end+ (if specified) or +start+ plus the value of the + +duration+ element (if one is contained in the +date_expression+) +* +date_spec:+ True if the current date/time matches the specification + given in the contained +date_spec+ element (described below) + indexterm:[XML attribute,operation attribute,date_expression element] + indexterm:[XML element,date_expression element,operation attribute] |========================================================= [NOTE] ====== -As these comparisons (except for +date_spec+) include the time, the -+eq+, +neq+, +gte+ and +lte+ operators have not been implemented since -they would only be valid for a single second. +There is no +eq+, +neq+, +gte+, or +lte+ operation, since they would be valid +only for a single second. ====== === Date Specifications === -indexterm:[Date Specification] -indexterm:[Resource,Constraint,Date Specification] - -+date_spec+ objects are used to create cron-like expressions relating -to time. Each field can contain a single number or a single range. -Instead of defaulting to zero, any field not supplied is ignored. - -For example, +monthdays="1"+ matches the first day of every month and -+hours="09-17"+ matches the hours between 9am and 5pm (inclusive). -At this time, multiple ranges (e.g. +weekdays="1,2"+ or -+weekdays="1-2,5-6"+) are not supported; depending on -demand, this might be implemented in a future release. - -.Properties of a Date Specification +indexterm:[Rule,Date/Time Expression,Date Specification] +indexterm:[XML element,date_spec element] + +A +date_spec+ element is used to create a cron-like expression relating +to time. Each field can contain a single number or range. Any field not +supplied is ignored. + +.Attributes of a date_spec Element [width="95%",cols="2m,<5",options="header",align="center"] |========================================================= |Field |Description |id -|A unique name for the object - indexterm:[id,Date Specification] - indexterm:[Constraint,Date Specification,id] +|A unique name for the object (required) + indexterm:[XML attribute,id attribute,date_spec element] + indexterm:[XML element,date_spec element,id attribute] |hours -|Allowed values: 0-23 - indexterm:[hours,Date Specification] - indexterm:[Constraint,Date Specification,hours] +|Allowed values: 0-23 (where 0 is midnight and 23 is 11 p.m.) + indexterm:[XML attribute,hours attribute,date_spec element] + indexterm:[XML element,date_spec element,hours attribute] |monthdays |Allowed values: 1-31 (depending on month and year) - indexterm:[monthdays,Date Specification] - indexterm:[Constraint,Date Specification,monthdays] + indexterm:[XML attribute,monthdays attribute,date_spec element] + indexterm:[XML element,date_spec element,monthdays attribute] |weekdays -|Allowed values: 1-7 (1=Monday, 7=Sunday) - indexterm:[weekdays,Date Specification] - indexterm:[Constraint,Date Specification,weekdays] +|Allowed values: 1-7 (where 1 is Monday and 7 is Sunday) + indexterm:[XML attribute,weekdays attribute,date_spec element] + indexterm:[XML element,date_spec element,weekdays attribute] |yeardays |Allowed values: 1-366 (depending on the year) - indexterm:[yeardays,Date Specification] - indexterm:[Constraint,Date Specification,yeardays] + indexterm:[XML attribute,yeardays attribute,date_spec element] + indexterm:[XML element,date_spec element,yeardays attribute] |months |Allowed values: 1-12 - indexterm:[months,Date Specification] - indexterm:[Constraint,Date Specification,months] + indexterm:[XML attribute,months attribute,date_spec element] + indexterm:[XML element,date_spec element,months attribute] |weeks |Allowed values: 1-53 (depending on weekyear) - indexterm:[weeks,Date Specification] - indexterm:[Constraint,Date Specification,weeks] + indexterm:[XML attribute,weeks attribute,date_spec element] + indexterm:[XML element,date_spec element,weeks attribute] |years |Year according to the Gregorian calendar - indexterm:[years,Date Specification] - indexterm:[Constraint,Date Specification,years] + indexterm:[XML attribute,years attribute,date_spec element] + indexterm:[XML element,date_spec element,years attribute] |weekyears -|Year in which the week started; e.g. 1 January 2005 - can be specified as '2005-001 Ordinal', '2005-01-01 Gregorian' or '2004-W53-6 - Weekly' and thus would match +years="2005"+ or +weekyears="2004"+ - indexterm:[weekyears,Date Specification] - indexterm:[Constraint,Date Specification,weekyears] +|Year in which the week started; for example, 1 January 2005 can be specified + in ISO 8601 as '2005-001 Ordinal', '2005-01-01 Gregorian' or + '2004-W53-6 Weekly' and thus would match +years="2005"+ or +weekyears="2004"+ + indexterm:[XML attribute,weekyears attribute,date_spec element] + indexterm:[XML element,date_spec element,weekyears attribute] |moon -|Allowed values are 0-7 (0 is new, 4 is full moon). Seriously, you can - use this. This was implemented to demonstrate the ease with which new - comparisons could be added. - indexterm:[moon,Date Specification] - indexterm:[Constraint,Date Specification,moon] +|Allowed values are 0-7 (where 0 is the new moon and 4 is full moon). + Seriously, you can use this. This was implemented to demonstrate the ease with + which new comparisons could be added. + indexterm:[XML attribute,moon attribute,date_spec element] + indexterm:[XML element,date_spec element,moon attribute] |========================================================= +For example, +monthdays="1"+ matches the first day of every month, and ++hours="09-17"+ matches the hours between 9 a.m. and 5 p.m. (inclusive). + +At this time, multiple ranges (e.g. +weekdays="1,2"+ or +weekdays="1-2,5-6"+) +are not supported. + === Durations === -indexterm:[Duration] -indexterm:[Resource,Constraint,Duration] +indexterm:[Rule,Date/Time Expression,Duration] +indexterm:[XML element,duration element] -Durations are used to calculate a value for +end+ when one is not -supplied to +in_range+ operations. They contain the same fields as -+date_spec+ objects but without the limitations (e.g. you can have a -duration of 19 months). As with +date_specs+, any field not supplied is -ignored. +A +duration+ is used to calculate a value for +end+ when one is not supplied to ++in_range+ operations. It contains one or more attributes each containing a +single number. Any attribute not supplied is ignored. -=== Sample Time-Based Expressions === +.Attributes of a duration Element +[width="95%",cols="2m,<5",options="header",align="center"] +|========================================================= -A small sample of how time-based expressions can be used: +|Field +|Description -//// -On older versions of asciidoc, the [source] directive makes the title disappear -//// +|id +|A unique name for this duration element (required) + indexterm:[XML attribute,id attribute,duration element] + indexterm:[XML element,duration element,id attribute] + +|seconds +|This many seconds will be added to the total duration + indexterm:[XML attribute,seconds attribute,duration element] + indexterm:[XML element,duration element,seconds attribute] + +|minutes +|This many minutes will be added to the total duration + indexterm:[XML attribute,minutes attribute,duration element] + indexterm:[XML element,duration element,minutes attribute] + +|hours +|This many hours will be added to the total duration + indexterm:[XML attribute,hours attribute,duration element] + indexterm:[XML element,duration element,hours attribute] + +|weeks +|This many weeks will be added to the total duration + indexterm:[XML attribute,weeks attribute,duration element] + indexterm:[XML element,duration element,weeks attribute] + +|months +|This many months will be added to the total duration + indexterm:[XML attribute,months attribute,duration element] + indexterm:[XML element,duration element,months attribute] + +|years +|This many years will be added to the total duration + indexterm:[XML attribute,years attribute,duration element] + indexterm:[XML element,duration element,years attribute] + +|========================================================= + +=== Example Time-Based Expressions === + +A small sample of how time-based expressions can be used: .True if now is any time in the year 2005 ==== [source,XML] ---- - + - + ---- ==== .Equivalent expression ==== [source,XML] ---- - + - + ---- ==== .9am-5pm Monday-Friday ==== [source,XML] ------- - + - + ------- ==== Please note that the +16+ matches up to +16:59:59+, as the numeric value (hour) still matches! .9am-6pm Monday through Friday or anytime Saturday ==== [source,XML] ------- - + - + - + ------- ==== .9am-5pm or 9pm-12am Monday through Friday ==== [source,XML] ------- - - + + - + - + - + - + ------- ==== .Mondays in March 2005 ==== [source,XML] ------- - + - + - + ------- ==== [NOTE] ====== Because no time is specified with the above dates, 00:00:00 is implied. This means that the range includes all of 2005-03-01 but none of 2005-04-01. You may wish to write +end="2005-03-31T23:59:59"+ to avoid confusion. ====== .A full moon on Friday the 13th ===== [source,XML] ------- - + - + ------- ===== +[[s-rules-recheck]] +=== Ensuring Time-Based Rules Take Effect === + +A Pacemaker cluster is an event-driven system. As such, it won't +recalculate the best place for resources to run unless something +(like a resource failure or configuration change) happens. This can +mean that a location constraint that only allows resource X to run +between 9am and 5pm is not enforced. + +If you rely on time-based rules, the +cluster-recheck-interval+ cluster option +(which defaults to 15 minutes) is essential. This tells the cluster to +periodically recalculate the ideal state of the cluster. + +For example, if you set +cluster-recheck-interval="5m"+, then sometime between +09:00 and 09:05 the cluster would notice that it needs to start resource X, +and between 17:00 and 17:05 it would realize that X needed to be stopped. +The timing of the actual start and stop actions depends on what other actions +the cluster may need to perform first. + == Using Rules to Determine Resource Location == indexterm:[Rule,Determine Resource Location] indexterm:[Resource,Location,Determine by Rules] -A location constraint may contain rules. When the constraint's outermost -rule evaluates to +false+, the cluster treats the constraint as if it were not -there. When the rule evaluates to +true+, the node's preference for running -the resource is updated with the score associated with the rule. +A location constraint may contain one or more top-level rules. The cluster +will act as if there is a separate location constraint for each rule that +evaluates as true. -If this sounds familiar, it is because you have been using a simplified -syntax for location constraint rules already. Consider the following -location constraint: +Consider the following simple location constraint: -.Prevent myApacheRsc from running on c001n03 +.Prevent resource "webserver" from running on node3 ===== [source,XML] ------- - + ------- ===== -This constraint can be more verbosely written as: +The constraint can be more verbosely written using a rule: -.Prevent myApacheRsc from running on c001n03 - expanded version +.Prevent resource "webserver" from running on node3 using rule ===== [source,XML] ------- - - - + + + ------- ===== -The advantage of using the expanded form is that one can then add -extra clauses to the rule, such as limiting the rule such that it only -applies during certain times of the day or days of the week. +The advantage of using the expanded form is that one could add more expressions +(for example, limiting the constraint to certain days of the week), or activate +the constraint by some node attribute other than node name. === Location Rules Based on Other Node Properties === The expanded form allows us to match on node properties other than its name. If we rated each machine's CPU power such that the cluster had the following nodes section: .A sample nodes section for use with score-attribute ===== [source,XML] ------- ------- ===== then we could prevent resources from running on underpowered machines with this rule: [source,XML] ------- ------- === Using +score-attribute+ Instead of +score+ === When using +score-attribute+ instead of +score+, each node matched by the rule has its score adjusted differently, according to its value for the named node attribute. Thus, in the previous example, if a rule used +score-attribute="cpu_mips"+, +c001n01+ would have its preference to run the resource increased by +1234+ whereas +c001n02+ would have its preference increased by +5678+. -== Using Rules to Control Resource Options == +== Using Rules to Define Options == + +Rules may be used to control a variety of options: + +* <> (+cluster_property_set+ elements) +* <> (as +instance_attributes+ or + +utilization+ elements inside a +node+ element) +* <> (as +utilization+, +meta_attributes+, + or +instance_attributes+ elements inside a resource definition element or + +op+ , +rsc_defaults+, +op_defaults+, or +template+ element) +* <> (+meta_attributes+ + inside an +op+ or +op_defaults+ element) + +=== Using Rules to Control Resource Options === Often some cluster nodes will be different from their peers. Sometimes, these differences -- e.g. the location of a binary or the names of network interfaces -- require resources to be configured differently depending on the machine they're hosted on. By defining multiple +instance_attributes+ objects for the resource and adding a rule to each, we can easily handle these special cases. In the example below, +mySpecialRsc+ will use eth1 and port 9999 when run on +node1+, eth2 and port 8888 on +node2+ and default to eth0 and port 9999 for all other nodes. .Defining different resource options based on the node name ===== [source,XML] ------- ------- ===== The order in which +instance_attributes+ objects are evaluated is determined by their score (highest to lowest). If not supplied, score defaults to zero, and objects with an equal score are processed in listed order. If the +instance_attributes+ object has no rule or a +rule+ that evaluates to +true+, then for any parameter the resource does not yet have a value for, the resource will use the parameter values defined by the +instance_attributes+. For example, given the configuration above, if the resource is placed on node1: . +special-node1+ has the highest score (3) and so is evaluated first; its rule evaluates to +true+, so +interface+ is set to +eth1+. . +special-node2+ is evaluated next with score 2, but its rule evaluates to +false+, so it is ignored. . +defaults+ is evaluated last with score 1, and has no rule, so its values are examined; +interface+ is already defined, so the value here is not used, but +port+ is not yet defined, so +port+ is set to +9999+. -== Using Rules to Control Cluster Options == -indexterm:[Rule,Controlling Cluster Options] -indexterm:[Cluster,Setting Options with Rules] - -Controlling cluster options is achieved in much the same manner as -specifying different resource options on different nodes. +=== Using Rules to Control Resource Defaults === -The difference is that because they are cluster options, one cannot -(or should not, because they won't work) use attribute-based -expressions. The following example illustrates how to set a different -+resource-stickiness+ value during and outside work hours. This -allows resources to automatically move back to their most preferred -hosts, but at a time that (in theory) does not interfere with business -activities. +Rules can be used for resource and operation defaults. The following example +illustrates how to set a different +resource-stickiness+ value during and +outside work hours. This allows resources to automatically move back to their +most preferred hosts, but at a time that (in theory) does not interfere with +business activities. .Change +resource-stickiness+ during working hours ===== [source,XML] ------- ------- ===== -[[s-rules-recheck]] -== Ensuring Time-Based Rules Take Effect == +Rules may be used similarly in +instance_attributes+ or +utilization+ blocks. -A Pacemaker cluster is an event-driven system. As such, it won't -recalculate the best place for resources to run unless something -(like a resource failure or configuration change) happens. This can -mean that a location constraint that only allows resource X to run -between 9am and 5pm is not enforced. +Any single block may directly contain only a single rule, but that rule may +itself contain any number of rules. -If you rely on time-based rules, the +cluster-recheck-interval+ cluster option -(which defaults to 15 minutes) is essential. This tells the cluster to -periodically recalculate the ideal state of the cluster. +=== Using Rules to Control Cluster Options === +indexterm:[Rule,Controlling Cluster Options] +indexterm:[Cluster,Setting Options with Rules] -For example, if you set +cluster-recheck-interval="5m"+, then sometime between -09:00 and 09:05 the cluster would notice that it needs to start resource X, -and between 17:00 and 17:05 it would realize that X needed to be stopped. -The timing of the actual start and stop actions depends on what other actions -the cluster may need to perform first. +Controlling cluster options is achieved in much the same manner as +specifying different resource options on different nodes. + +The difference is that because they are cluster options, one cannot (or should +not, because they won't work) use attribute-based expressions. The following +example illustrates how to set +maintenance_mode+ during a scheduled +maintenance window. This will keep the cluster running but not monitor, start, +or stop resources during this time. + +.Schedule a maintenance window for 9 to 11 p.m. CDT Sept. 20, 2019 +===== +[source,XML] +------- + + + + + + + + + + + + + + +------- +===== + +[IMPORTANT] +==== +The +cluster_property_set+ with an +id+ set to "cib-bootstrap-options" will +'always' have the highest priority, regardless of any scores. Therefore, +rules in another +cluster_property_set+ can never take effect for any +properties listed in the bootstrap set. +====