diff --git a/doc/Pacemaker_Explained/en-US/Ch-Options.txt b/doc/Pacemaker_Explained/en-US/Ch-Options.txt index a2fbfe2473..df6b71aae4 100644 --- a/doc/Pacemaker_Explained/en-US/Ch-Options.txt +++ b/doc/Pacemaker_Explained/en-US/Ch-Options.txt @@ -1,409 +1,410 @@ = Cluster-Wide Configuration = == CIB Properties == Certain settings are defined by CIB properties (that is, attributes of the +cib+ tag) rather than with the rest of the cluster configuration in the +configuration+ section. The reason is simply a matter of parsing. These options are used by the configuration database which is, by design, mostly ignorant of the content it holds. So the decision was made to place them in an easy-to-find location. .CIB Properties [width="95%",cols="2m,5<",options="header",align="center"] |========================================================= |Field |Description | admin_epoch | indexterm:[Configuration Version,Cluster] indexterm:[Cluster,Option,Configuration Version] indexterm:[admin_epoch,Cluster Option] indexterm:[Cluster,Option,admin_epoch] When a node joins the cluster, the cluster performs a check to see which node has the best configuration. It asks the node with the highest (+admin_epoch+, +epoch+, +num_updates+) tuple to replace the configuration on all the nodes -- which makes setting them, and setting them correctly, very important. +admin_epoch+ is never modified by the cluster; you can use this to make the configurations on any inactive nodes obsolete. _Never set this value to zero_. In such cases, the cluster cannot tell the difference between your configuration and the "empty" one used when nothing is found on disk. | epoch | indexterm:[epoch,Cluster Option] indexterm:[Cluster,Option,epoch] The cluster increments this every time the configuration is updated (usually by the administrator). | num_updates | indexterm:[num_updates,Cluster Option] indexterm:[Cluster,Option,num_updates] The cluster increments this every time the configuration or status is updated (usually by the cluster) and resets it to 0 when epoch changes. | validate-with | indexterm:[validate-with,Cluster Option] indexterm:[Cluster,Option,validate-with] Determines the type of XML validation that will be done on the configuration. If set to +none+, the cluster will not verify that updates conform to the DTD (nor reject ones that don't). This option can be useful when operating a mixed-version cluster during an upgrade. |cib-last-written | indexterm:[cib-last-written,Cluster Property] indexterm:[Cluster,Property,cib-last-written] Indicates when the configuration was last written to disk. Maintained by the cluster; for informational purposes only. |have-quorum | indexterm:[have-quorum,Cluster Property] indexterm:[Cluster,Property,have-quorum] Indicates if the cluster has quorum. If false, this may mean that the cluster cannot start resources or fence other nodes (see +no-quorum-policy+ below). Maintained by the cluster. |dc-uuid | indexterm:[dc-uuid,Cluster Property] indexterm:[Cluster,Property,dc-uuid] Indicates which cluster node is the current leader. Used by the cluster when placing resources and determining the order of some events. Maintained by the cluster. |========================================================= === Working with CIB Properties === Although these fields can be written to by the user, in most cases the cluster will overwrite any values specified by the user with the "correct" ones. To change the ones that can be specified by the user, for example +admin_epoch+, one should use: ---- # cibadmin --modify --crm_xml '' ---- A complete set of CIB properties will look something like this: .Attributes set for a cib object ====== [source,XML] ------- ------- ====== +[[s-cluster-options]] == Cluster Options == Cluster options, as you might expect, control how the cluster behaves when confronted with certain situations. They are grouped into sets within the +crm_config+ section, and, in advanced configurations, there may be more than one set. (This will be described later in the section on <> where we will show how to have the cluster use different sets of options during working hours than during weekends.) For now, we will describe the simple case where each option is present at most once. You can obtain an up-to-date list of cluster options, including their default values, by running the `man pengine` and `man crmd` commands. .Cluster Options [width="95%",cols="5m,2,11>). | enable-startup-probes | TRUE | indexterm:[enable-startup-probes,Cluster Option] indexterm:[Cluster,Option,enable-startup-probes] Should the cluster check for active resources during startup? | maintenance-mode | FALSE | indexterm:[maintenance-mode,Cluster Option] indexterm:[Cluster,Option,maintenance-mode] Should the cluster refrain from monitoring, starting and stopping resources? | stonith-enabled | TRUE | indexterm:[stonith-enabled,Cluster Option] indexterm:[Cluster,Option,stonith-enabled] Should failed nodes and nodes with resources that can't be stopped be shot? If you value your data, set up a STONITH device and enable this. If true, or unset, the cluster will refuse to start resources unless one or more STONITH resources have been configured. If false, unresponsive nodes are immediately assumed to be running no resources, and resource takeover to online nodes starts without any further protection (which means _data loss_ if the unresponsive node still accesses shared storage, for example). See also the +requires+ meta-attribute in <>. | stonith-action | reboot | indexterm:[stonith-action,Cluster Option] indexterm:[Cluster,Option,stonith-action] Action to send to STONITH device. Allowed values are +reboot+ and +off+. The value +poweroff+ is also allowed, but is only used for legacy devices. | stonith-timeout | 60s | indexterm:[stonith-timeout,Cluster Option] indexterm:[Cluster,Option,stonith-timeout] How long to wait for STONITH actions (reboot, on, off) to complete | concurrent-fencing | FALSE | indexterm:[concurrent-fencing,Cluster Option] indexterm:[Cluster,Option,concurrent-fencing] Is the cluster allowed to initiate multiple fence actions concurrently? | cluster-delay | 60s | indexterm:[cluster-delay,Cluster Option] indexterm:[Cluster,Option,cluster-delay] Estimated maximum round-trip delay over the network (excluding action execution). If the TE requires an action to be executed on another node, it will consider the action failed if it does not get a response from the other node in this time (after considering the action's own timeout). The "correct" value will depend on the speed and load of your network and cluster nodes. | dc-deadtime | 20s | indexterm:[dc-deadtime,Cluster Option] indexterm:[Cluster,Option,dc-deadtime] How long to wait for a response from other nodes during startup. The "correct" value will depend on the speed/load of your network and the type of switches used. | cluster-recheck-interval | 15min | indexterm:[cluster-recheck-interval,Cluster Option] indexterm:[Cluster,Option,cluster-recheck-interval] Polling interval for time-based changes to options, resource parameters and constraints. The Cluster is primarily event-driven, but your configuration can have elements that take effect based on the time of day. To ensure these changes take effect, we can optionally poll the cluster's status for changes. A value of 0 disables polling. Positive values are an interval (in seconds unless other SI units are specified, e.g. 5min). | pe-error-series-max | -1 | indexterm:[pe-error-series-max,Cluster Option] indexterm:[Cluster,Option,pe-error-series-max] The number of PE inputs resulting in ERRORs to save. Used when reporting problems. A value of -1 means unlimited (report all). | pe-warn-series-max | -1 | indexterm:[pe-warn-series-max,Cluster Option] indexterm:[Cluster,Option,pe-warn-series-max] The number of PE inputs resulting in WARNINGs to save. Used when reporting problems. A value of -1 means unlimited (report all). | pe-input-series-max | -1 | indexterm:[pe-input-series-max,Cluster Option] indexterm:[Cluster,Option,pe-input-series-max] The number of "normal" PE inputs to save. Used when reporting problems. A value of -1 means unlimited (report all). | remove-after-stop | FALSE | indexterm:[remove-after-stop,Cluster Option] indexterm:[Cluster,Option,remove-after-stop] _Advanced Use Only:_ Should the cluster remove resources from the LRM after they are stopped? Values other than the default are, at best, poorly tested and potentially dangerous. | startup-fencing | TRUE | indexterm:[startup-fencing,Cluster Option] indexterm:[Cluster,Option,startup-fencing] _Advanced Use Only:_ Should the cluster shoot unseen nodes? Not using the default is very unsafe! | election-timeout | 2min | indexterm:[election-timeout,Cluster Option] indexterm:[Cluster,Option,election-timeout] _Advanced Use Only:_ If you need to adjust this value, it probably indicates the presence of a bug. | shutdown-escalation | 20min | indexterm:[shutdown-escalation,Cluster Option] indexterm:[Cluster,Option,shutdown-escalation] _Advanced Use Only:_ If you need to adjust this value, it probably indicates the presence of a bug. | crmd-integration-timeout | 3min | indexterm:[crmd-integration-timeout,Cluster Option] indexterm:[Cluster,Option,crmd-integration-timeout] _Advanced Use Only:_ If you need to adjust this value, it probably indicates the presence of a bug. | crmd-finalization-timeout | 30min | indexterm:[crmd-finalization-timeout,Cluster Option] indexterm:[Cluster,Option,crmd-finalization-timeout] _Advanced Use Only:_ If you need to adjust this value, it probably indicates the presence of a bug. | crmd-transition-delay | 0s | indexterm:[crmd-transition-delay,Cluster Option] indexterm:[Cluster,Option,crmd-transition-delay] _Advanced Use Only:_ Delay cluster recovery for the configured interval to allow for additional/related events to occur. Useful if your configuration is sensitive to the order in which ping updates arrive. Enabling this option will slow down cluster recovery under all conditions. |default-resource-stickiness | 0 | indexterm:[default-resource-stickiness,Cluster Option] indexterm:[Cluster,Option,default-resource-stickiness] _Deprecated:_ See <> instead | is-managed-default | TRUE | indexterm:[is-managed-default,Cluster Option] indexterm:[Cluster,Option,is-managed-default] _Deprecated:_ See <> instead | default-action-timeout | 20s | indexterm:[default-action-timeout,Cluster Option] indexterm:[Cluster,Option,default-action-timeout] _Deprecated:_ See <> instead |========================================================= === Querying and Setting Cluster Options === indexterm:[Querying,Cluster Option] indexterm:[Setting,Cluster Option] indexterm:[Cluster,Querying Options] indexterm:[Cluster,Setting Options] Cluster options can be queried and modified using the `crm_attribute` tool. To get the current value of +cluster-delay+, you can run: ---- # crm_attribute --query --name cluster-delay ---- which is more simply written as ---- # crm_attribute -G -n cluster-delay ---- If a value is found, you'll see a result like this: ---- # crm_attribute -G -n cluster-delay scope=crm_config name=cluster-delay value=60s ---- If no value is found, the tool will display an error: ---- # crm_attribute -G -n clusta-deway scope=crm_config name=clusta-deway value=(null) Error performing operation: No such device or address ---- To use a different value (for example, 30 seconds), simply run: ---- # crm_attribute --name cluster-delay --update 30s ---- To go back to the cluster's default value, you can delete the value, for example: ---- # crm_attribute --name cluster-delay --delete Deleted crm_config option: id=cib-bootstrap-options-cluster-delay name=cluster-delay ---- === When Options are Listed More Than Once === If you ever see something like the following, it means that the option you're modifying is present more than once. .Deleting an option that is listed twice ======= ------ # crm_attribute --name batch-limit --delete Multiple attributes match name=batch-limit in crm_config: Value: 50 (set=cib-bootstrap-options, id=cib-bootstrap-options-batch-limit) Value: 100 (set=custom, id=custom-batch-limit) Please choose from one of the matches above and supply the 'id' with --id ------- ======= In such cases, follow the on-screen instructions to perform the requested action. To determine which value is currently being used by the cluster, refer to <>. diff --git a/doc/Pacemaker_Explained/en-US/Ch-Resources.txt b/doc/Pacemaker_Explained/en-US/Ch-Resources.txt index 9453954d8e..bb4f101013 100644 --- a/doc/Pacemaker_Explained/en-US/Ch-Resources.txt +++ b/doc/Pacemaker_Explained/en-US/Ch-Resources.txt @@ -1,835 +1,838 @@ = Cluster Resources = == 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 http://www.opencf.org/cgi-bin/viewcvs.cgi/specs/ra/resource-agent-api.txt?rev=HEAD -- at least as it relates to resource agents. The Pacemaker implementation has been somewhat extended from the OCF specs, but none of those changes are incompatible with the original OCF specification.] 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 <>. === Linux Standard Base === indexterm:[Resource,LSB] indexterm:[LSB,Resources] indexterm:[Linux Standard Base,Resources] LSB resource agents are those found in +/etc/init.d+. Generally, they are provided by the OS distribution and, in order to be used with the cluster, they must conform to the LSB Spec. 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 claim LSB compliance but ship with broken init scripts. For details on how to check whether your init script is LSB-compatible, see <>. 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. ==== === 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> resources, they will not be promoted to master) * +master:+ Allow the resource to be started and, if appropriate, promoted 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] |resource-stickiness |value of +resource-stickiness+ in the +rsc_defaults+ section |How much does the resource prefer to stay where it is? indexterm:[resource-stickiness,Resource Option] indexterm:[Resource,Option,resource-stickiness] |requires |fencing (unless +stonith-enabled+ is +false+ or +class+ is +stonith+, in which case it defaults to quorum) |Conditions under which the resource can be started ('Since 1.1.8') 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 powered off * +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 powered off _and_ only on nodes that have been 'unfenced' 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 INFINITY indicates that this feature is disabled. 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 |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] |remote-node | |The name of the remote-node this resource defines. This both enables the resource as a remote-node and defines the unique name used to identify the remote-node. If no other parameters are set, this value will also be assumed as the hostname to connect to at the port specified by +remote-port+. +WARNING:+ This value cannot overlap with any resource or node IDs. If not specified, this feature is disabled. |remote-port |3121 |Port to use for the guest connection to pacemaker_remote |remote-addr |value of +remote-node+ |The IP address or hostname to connect to if remote-node's name is not the hostname of the guest. |+remote-connect-timeout+ |60s |How long before a pending guest connection will time out. |========================================================= [NOTE] ==== Support for remote nodes was added in pacemaker 1.1.10. If you are using an earlier version, options related to remote nodes will not be available. ==== 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] ------- ------- ===== [[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. Some operations are generated by the cluster itself, for example, stopping and starting resources as needed. You can configure operations in the cluster configuration. As an example, by default the cluster will 'not' ensure your resources stay healthy once they are started. footnote:[Currently, anyway. Automatic monitoring operations may be added in a future version of Pacemaker.] To instruct the cluster to do this, you need to add a +monitor+ operation to the resource's definition. .An OCF resource with a recurring health check ===== [source,XML] ------- ------- ===== .Properties of an Operation [width="95%",cols="2m,3,6>. 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)' |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 | |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 next section). 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 <> resources, +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. As in the example above, you must configure monitor operations explicitly to perform these checks. 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). [[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 with +role=Stopped+. Monitor operations with +role=Stopped+ will be started on the node 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 with +role=Stopped+. 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_Remote/en-US/Ch-Options.txt b/doc/Pacemaker_Remote/en-US/Ch-Options.txt index f04b8b6e94..5faaaf2713 100644 --- a/doc/Pacemaker_Remote/en-US/Ch-Options.txt +++ b/doc/Pacemaker_Remote/en-US/Ch-Options.txt @@ -1,121 +1,121 @@ = Configuration Explained = The walk-through examples use some of these options, but don't explain exactly what they mean or do. This section is meant to be the go-to resource for all the options available for configuring pacemaker_remote-based nodes. (((configuration))) == Resource Meta-Attributes for Guest Nodes == When configuring a virtual machine to use as a guest node, these are the metadata options available to enable the resource as a guest node and define its connection parameters. .Meta-attributes for configuring VM resources as guest nodes [width="95%",cols="2m,1,4<",options="header",align="center"] |========================================================= |Option |Default |Description |remote-node |'none' |The node name of the guest node this resource defines. This both enables the resource as a guest node and defines the unique name used to identify the guest node. If no other parameters are set, this value will also be assumed as the hostname to use when connecting to pacemaker_remote on the VM. This value *must not* overlap with any resource or node IDs. |remote-port |3121 |The port on the virtual machine that the cluster will use to connect to pacemaker_remote. |remote-addr |'value of' +remote-node+ |The IP address or hostname to use when connecting to pacemaker_remote on the VM. |remote-connect-timeout |60s |How long before a pending guest connection will time out. |========================================================= == Connection Resources for Remote Nodes == A remote node is defined by a connection resource. That connection resource has instance attributes that define where the remote node is located on the network and how to communicate with it. Descriptions of these instance attributes can be retrieved using the following `pcs` command: ---- # pcs resource describe remote ocf:pacemaker:remote - remote resource agent Resource options: server: Server location to connect to. This can be an ip address or hostname. port: tcp port to connect to. - reconnect_interval: Time in seconds to wait before attempting to reconnect to - a remote node after an active connection to the remote - node has been severed. This wait is recurring. If - reconnect fails after the wait period, a new reconnect - attempt will be made after observing the wait time. When - this option is in use, pacemaker will keep attempting to - reach out and connect to the remote node indefinitely - after each wait interval. + reconnect_interval: Interval in seconds at which Pacemaker will attempt to + reconnect to a remote node after an active connection to + the remote node has been severed. When this value is + nonzero, Pacemaker will retry the connection + indefinitely, at the specified interval. As with any + time-based actions, this is not guaranteed to be checked + more frequently than the value of the + cluster-recheck-interval cluster option. ---- When defining a remote node's connection resource, it is common and recommended to name the connection resource the same as the remote node's hostname. By default, if no *server* option is provided, the cluster will attempt to contact the remote node using the resource name as the hostname. Example defining a remote node with the hostname *remote1*: ---- # pcs resource create remote1 remote ---- Example defining a remote node to connect to a specific IP address and port: ---- # pcs resource create remote1 remote server=192.168.122.200 port=8938 ---- == Environment Variables for Daemon Start-up == Authentication and encryption of the connection between cluster nodes and nodes running pacemaker_remote is achieved using with https://en.wikipedia.org/wiki/TLS-PSK[TLS-PSK] encryption/authentication over TCP (port 3121 by default). This means that both the cluster node and remote node must share the same private key. By default, this key is placed at +/etc/pacemaker/authkey+ on each node. You can change the default port and/or key location for Pacemaker and pacemaker_remote via environment variables. These environment variables can be enabled by placing them in the +/etc/sysconfig/pacemaker+ file. ---- #==#==# Pacemaker Remote # Use a custom directory for finding the authkey. PCMK_authkey_location=/etc/pacemaker/authkey # # Specify a custom port for Pacemaker Remote connections PCMK_remote_port=3121 ---- == Removing Remote Nodes and Guest Nodes == If the resource creating a guest node, or the *ocf:pacemaker:remote* resource creating a connection to a remote node, is removed from the configuration, the affected node will continue to show up in output as an offline node. If you want to get rid of that output, run (replacing $NODE_NAME appropriately): ---- # crm_node --force --remove $NODE_NAME ---- [WARNING] ========= Be absolutely sure that the node's resource has been deleted from the configuration first. ========= diff --git a/extra/resources/remote b/extra/resources/remote index 447267e778..bf6a91c0d1 100644 --- a/extra/resources/remote +++ b/extra/resources/remote @@ -1,125 +1,125 @@ #!/bin/sh # # # remote OCF RA. This script provides metadata for the internal # pacemaker remote lrmd connection agent. Outside of acting # as a place holder so the remote ra script can be indexed and # providing metadata, this script should never be invoked. The # actual functionality behind the remote lrmd connection lives # within pacemaker's crmd component. # # Copyright (c) 2013 David Vossel # # This program is free software; you can redistribute it and/or modify # it under the terms of version 2 of the GNU General Public License as # published by the Free Software Foundation. # # This program is distributed in the hope that it would be useful, but # WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. # # Further, this software is distributed without any warranty that it is # free of the rightful claim of any third person regarding infringement # or the like. Any license provided herein, whether implied or # otherwise, applies only to this software file. Patent licenses, if # any, provided herein do not apply to combinations of this program with # other software, or any other product whatsoever. # # You should have received a copy of the GNU General Public License # along with this program; if not, write the Free Software Foundation, # Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. # ####################################################################### # Initialization: : ${OCF_FUNCTIONS=${OCF_ROOT}/resource.d/heartbeat/.ocf-shellfuncs} . ${OCF_FUNCTIONS} : ${__OCF_ACTION=$1} ####################################################################### meta_data() { cat < 0.1 remote resource agent Server location to connect to. This can be an ip address or hostname. Server location tcp port to connect to. tcp port - Time in seconds to wait before attempting to reconnect to a remote node - after an active connection to the remote node has been severed. This wait - is recurring. If reconnect fails after the wait period, a new reconnect - attempt will be made after observing the wait time. When this option is - in use, pacemaker will keep attempting to reach out and connect to the - remote node indefinitely after each wait interval. + Interval in seconds at which Pacemaker will attempt to reconnect to a + remote node after an active connection to the remote node has been + severed. When this value is nonzero, Pacemaker will retry the connection + indefinitely, at the specified interval. As with any time-based actions, + this is not guaranteed to be checked more frequently than the value of + the cluster-recheck-interval cluster option. reconnect interval END } ####################################################################### remote_usage() { cat <