#
# AUTHOR <EMAIL@ADDRESS>, YEAR.
#
msgid ""
msgstr ""
"Project-Id-Version: 0\n"
"POT-Creation-Date: 2018-05-14 18:03-0500\n"
"PO-Revision-Date: 2018-05-14 18:03-0500\n"
"Last-Translator: Automatically generated\n"
"Language-Team: None\n"
"MIME-Version: 1.0\n"
"Content-Type: application/x-publican; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
#. Tag: title
#, no-c-format
msgid "Advanced Configuration"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Specifying When Recurring Actions are Performed"
msgstr ""
#. Tag: para
#, no-c-format
msgid "By default, recurring actions are scheduled relative to when the resource started. So if your resource was last started at 14:32 and you have a backup set to be performed every 24 hours, then the backup will always run in the middle of the business day — hardly desirable."
msgstr ""
#. Tag: para
#, no-c-format
msgid "To specify a date and time that the operation should be relative to, set the operation’s <literal>interval-origin</literal>. The cluster uses this point to calculate the correct <literal>start-delay</literal> such that the operation will occur at <emphasis>origin + (interval * N)</emphasis>."
msgstr ""
#. Tag: para
#, no-c-format
msgid "So, if the operation’s interval is 24h, its interval-origin is set to 02:00 and it is currently 14:32, then the cluster would initiate the operation with a start delay of 11 hours and 28 minutes. If the resource is moved to another node before 2am, then the operation is cancelled."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The value specified for <literal>interval</literal> and <literal>interval-origin</literal> can be any date/time conforming to the <ulink url=\"http://en.wikipedia.org/wiki/ISO_8601\">ISO8601 standard</ulink>. By way of example, to specify an operation that would run on the first Monday of 2009 and every Monday after that, you would add:"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Specifying a Base for Recurring Action Intervals"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<op id=\"my-weekly-action\" name=\"custom-action\" interval=\"P7D\" interval-origin=\"2009-W01-1\"/>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Handling Resource Failure"
msgstr ""
#. Tag: para
#, no-c-format
msgid "By default, Pacemaker will attempt to recover failed resources by restarting them. However, failure recovery is highly configurable."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Failure Counts"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Pacemaker tracks resource failures for each combination of node, resource, and operation (start, stop, monitor, etc.)."
msgstr ""
#. Tag: para
#, no-c-format
msgid "You can query the fail count for a particular node, resource, and/or operation using the <literal>crm_failcount</literal> command. For example, to see how many times the 10-second monitor for <literal>myrsc</literal> has failed on <literal>node1</literal>, run:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_failcount --query -r myrsc -N node1 -n monitor -I 10s"
msgstr ""
#. Tag: para
#, no-c-format
msgid "If you omit the node, <literal>crm_failcount</literal> will use the local node. If you omit the operation and interval, <literal>crm_failcount</literal> will display the sum of the fail counts for all operations on the resource."
msgstr ""
#. Tag: para
#, no-c-format
msgid "You can use <literal>crm_resource --cleanup</literal> or <literal>crm_failcount --delete</literal> to clear fail counts. For example, to clear the above monitor failures, run:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_resource --cleanup -r myrsc -N node1 -n monitor -I 10s"
msgstr ""
#. Tag: para
#, no-c-format
msgid "If you omit the resource, <literal>crm_resource --cleanup</literal> will clear failures for all resources. If you omit the node, it will clear failures on all nodes. If you omit the operation and interval, it will clear the failures for all operations on the resource."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Even when cleaning up only a single operation, all failed operations will disappear from the status display. This allows us to trigger a re-check of the resource’s current status."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Higher-level tools may provide other commands for querying and clearing fail counts."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The <literal>crm_mon</literal> tool shows the current cluster status, including any failed operations. To see the current fail counts for any failed resources, call <literal>crm_mon</literal> with the <literal>--failcounts</literal> option. This shows the fail counts per resource (that is, the sum of any operation fail counts for the resource)."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Failure Response"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Normally, if a running resource fails, pacemaker will try to stop it and start it again. Pacemaker will choose the best location to start it each time, which may be the same node that it failed on."
msgstr ""
#. Tag: para
#, no-c-format
msgid "However, if a resource fails repeatedly, it is possible that there is an underlying problem on that node, and you might desire trying a different node in such a case. Pacemaker allows you to set your preference via the <literal>migration-threshold</literal> resource meta-attribute. <footnote><para> The naming of this option was perhaps unfortunate as it is easily confused with live migration, the process of moving a resource from one node to another without stopping it. Xen virtual guests are the most common example of resources that can be migrated in this manner. </para></footnote>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "If you define <literal>migration-threshold=<replaceable>N</replaceable></literal> for a resource, it will be banned from the original node after <emphasis>N</emphasis> failures."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The <literal>migration-threshold</literal> is per <emphasis>resource</emphasis>, even though fail counts are tracked per <emphasis>operation</emphasis>. The operation fail counts are added together to compare against the <literal>migration-threshold</literal>."
msgstr ""
#. Tag: para
#, no-c-format
msgid "By default, fail counts remain until manually cleared by an administrator using <literal>crm_resource --cleanup</literal> or <literal>crm_failcount --delete</literal> (hopefully after first fixing the failure’s cause). It is possible to have fail counts expire automatically by setting the <literal>failure-timeout</literal> resource meta-attribute."
msgstr ""
#. Tag: para
#, no-c-format
msgid "A successful operation does not clear past failures. If a recurring monitor operation fails once, succeeds many times, then fails again days later, its fail count is 2. Fail counts are cleared only by manual intervention or falure timeout."
msgstr ""
#. Tag: para
#, no-c-format
msgid "For example, a setting of <literal>migration-threshold=2</literal> and <literal>failure-timeout=60s</literal> would cause the resource to move to a new node after 2 failures, and allow it to move back (depending on stickiness and constraint scores) after one minute."
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>failure-timeout</literal> is measured since the most recent failure. That is, older failures do not individually time out and lower the fail count. Instead, all failures are timed out simultaneously (and the fail count is reset to 0) if there is no new failure for the timeout period."
msgstr ""
#. Tag: para
#, no-c-format
msgid "There are two exceptions to the migration threshold concept: when a resource either fails to start or fails to stop."
msgstr ""
#. Tag: para
#, no-c-format
msgid "If the cluster property <literal>start-failure-is-fatal</literal> is set to <literal>true</literal> (which is the default), start failures cause the fail count to be set to <literal>INFINITY</literal> and thus always cause the resource to move immediately."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Stop failures are slightly different and crucial. If a resource fails to stop and STONITH is enabled, then the cluster will fence the node in order to be able to start the resource elsewhere. If STONITH is not enabled, then the cluster has no way to continue and will not try to start the resource elsewhere, but will try to stop it again after the failure timeout."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Please read <xref linkend=\"s-rules-recheck\" /> to understand how timeouts work before configuring a <literal>failure-timeout</literal>."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Moving Resources"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<indexterm> <primary>Moving</primary><secondary>Resources</secondary> </indexterm> <indexterm> <primary>Resources</primary> </indexterm> <indexterm> <primary>Resource</primary><secondary>Moving</secondary> </indexterm> <indexterm> <primary>Moving</primary> </indexterm>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Moving Resources Manually"
msgstr ""
#. Tag: para
#, no-c-format
msgid "There are primarily two occasions when you would want to move a resource from its current location: when the whole node is under maintenance, and when a single resource needs to be moved."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Standby Mode"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Since everything eventually comes down to a score, you could create constraints for every resource to prevent them from running on one node. While pacemaker configuration can seem convoluted at times, not even we would require this of administrators."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Instead, one can set a special node attribute which tells the cluster \"don’t let anything run here\". There is even a helpful tool to help query and set it, called <literal>crm_standby</literal>. To check the standby status of the current machine, run:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_standby -G"
msgstr ""
#. Tag: para
#, no-c-format
msgid "A value of <literal>on</literal> indicates that the node is <emphasis>not</emphasis> able to host any resources, while a value of <literal>off</literal> says that it <emphasis>can</emphasis>."
msgstr ""
#. Tag: para
#, no-c-format
msgid "You can also check the status of other nodes in the cluster by specifying the <literal>--node</literal> option:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_standby -G --node sles-2"
msgstr ""
#. Tag: para
#, no-c-format
msgid "To change the current node’s standby status, use <literal>-v</literal> instead of <literal>-G</literal>:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_standby -v on"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Again, you can change another host’s value by supplying a hostname with <literal>--node</literal>."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Moving One Resource"
msgstr ""
#. Tag: para
#, no-c-format
msgid "When only one resource is required to move, we could do this by creating location constraints. However, once again we provide a user-friendly shortcut as part of the <literal>crm_resource</literal> command, which creates and modifies the extra constraints for you. If <literal>Email</literal> were running on <literal>sles-1</literal> and you wanted it moved to a specific location, the command would look something like:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_resource -M -r Email -H sles-2"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Behind the scenes, the tool will create the following location constraint:"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<rsc_location rsc=\"Email\" node=\"sles-2\" score=\"INFINITY\"/>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "It is important to note that subsequent invocations of <literal>crm_resource -M</literal> are not cumulative. So, if you ran these commands"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_resource -M -r Email -H sles-2\n"
"# crm_resource -M -r Email -H sles-3"
msgstr ""
#. Tag: para
#, no-c-format
msgid "then it is as if you had never performed the first command."
msgstr ""
#. Tag: para
#, no-c-format
msgid "To allow the resource to move back again, use:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_resource -U -r Email"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Note the use of the word <emphasis>allow</emphasis>. The resource can move back to its original location but, depending on <literal>resource-stickiness</literal>, it might stay where it is. To be absolutely certain that it moves back to <literal>sles-1</literal>, move it there before issuing the call to <literal>crm_resource -U</literal>:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_resource -M -r Email -H sles-1\n"
"# crm_resource -U -r Email"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Alternatively, if you only care that the resource should be moved from its current location, try:"
msgstr ""
#. Tag: screen
#, no-c-format
msgid "# crm_resource -B -r Email"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Which will instead create a negative constraint, like"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<rsc_location rsc=\"Email\" node=\"sles-1\" score=\"-INFINITY\"/>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "This will achieve the desired effect, but will also have long-term consequences. As the tool will warn you, the creation of a <literal>-INFINITY</literal> constraint will prevent the resource from running on that node until <literal>crm_resource -U</literal> is used. This includes the situation where every other cluster node is no longer available!"
msgstr ""
#. Tag: para
#, no-c-format
msgid "In some cases, such as when <literal>resource-stickiness</literal> is set to <literal>INFINITY</literal>, it is possible that you will end up with the problem described in <xref linkend=\"node-score-equal\" />. The tool can detect some of these cases and deals with them by creating both positive and negative constraints. E.g."
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>Email</literal> prefers <literal>sles-1</literal> with a score of <literal>-INFINITY</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>Email</literal> prefers <literal>sles-2</literal> with a score of <literal>INFINITY</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "which has the same long-term consequences as discussed earlier."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Moving Resources Due to Connectivity Changes"
msgstr ""
#. Tag: para
#, no-c-format
msgid "You can configure the cluster to move resources when external connectivity is lost in two steps."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Tell Pacemaker to Monitor Connectivity"
msgstr ""
#. Tag: para
#, no-c-format
msgid "First, add an <emphasis role=\"strong\">ocf:pacemaker:ping</emphasis> resource to the cluster. The <emphasis role=\"strong\">ping</emphasis> resource uses the system utility of the same name to a test whether list of machines (specified by DNS hostname or IPv4/IPv6 address) are reachable and uses the results to maintain a node attribute called <literal>pingd</literal> by default. <footnote><para> The attribute name is customizable, in order to allow multiple ping groups to be defined. </para></footnote>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Older versions of Pacemaker used a different agent <emphasis role=\"strong\">ocf:pacemaker:pingd</emphasis> which is now deprecated in favor of <emphasis role=\"strong\">ping</emphasis>. If your version of Pacemaker does not contain the <emphasis role=\"strong\">ping</emphasis> resource agent, download the latest version from <ulink url=\"https://github.com/ClusterLabs/pacemaker/tree/master/extra/resources/ping\">https://github.com/ClusterLabs/pacemaker/tree/master/extra/resources/ping</ulink>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Normally, the ping resource should run on all cluster nodes, which means that you’ll need to create a clone. A template for this can be found below along with a description of the most interesting parameters."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Common Options for a <emphasis>ping</emphasis> Resource"
msgstr ""
#. Tag: entry
#, no-c-format
msgid "Field"
msgstr ""
#. Tag: entry
#, no-c-format
msgid "Description"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>dampen</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The time to wait (dampening) for further changes to occur. Use this to prevent a resource from bouncing around the cluster when cluster nodes notice the loss of connectivity at slightly different times. <indexterm> <primary>dampen</primary><secondary>Ping Resource Option</secondary> </indexterm> <indexterm> <primary>Ping Resource Option</primary> </indexterm> <indexterm> <primary>Ping Resource</primary><secondary>Option</secondary><tertiary>dampen</tertiary> </indexterm> <indexterm> <primary>Option</primary><secondary>dampen</secondary> </indexterm> <indexterm> <primary>dampen</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>multiplier</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The number of connected ping nodes gets multiplied by this value to get a score. Useful when there are multiple ping nodes configured. <indexterm> <primary>multiplier</primary><secondary>Ping Resource Option</secondary> </indexterm> <indexterm> <primary>Ping Resource Option</primary> </indexterm> <indexterm> <primary>Ping Resource</primary><secondary>Option</secondary><tertiary>multiplier</tertiary> </indexterm> <indexterm> <primary>Option</primary><secondary>multiplier</secondary> </indexterm> <indexterm> <primary>multiplier</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>host_list</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The machines to contact in order to determine the current connectivity status. Allowed values include resolvable DNS host names, IPv4 and IPv6 addresses. <indexterm> <primary>host_list</primary><secondary>Ping Resource Option</secondary> </indexterm> <indexterm> <primary>Ping Resource Option</primary> </indexterm> <indexterm> <primary>Ping Resource</primary><secondary>Option</secondary><tertiary>host_list</tertiary> </indexterm> <indexterm> <primary>Option</primary><secondary>host_list</secondary> </indexterm> <indexterm> <primary>host_list</primary> </indexterm>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "An example ping cluster resource that checks node connectivity once every minute"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<clone id=\"Connected\">\n"
" <primitive id=\"ping\" provider=\"pacemaker\" class=\"ocf\" type=\"ping\">\n"
" <instance_attributes id=\"ping-attrs\">\n"
" <nvpair id=\"pingd-dampen\" name=\"dampen\" value=\"5s\"/>\n"
" <nvpair id=\"pingd-multiplier\" name=\"multiplier\" value=\"1000\"/>\n"
" <nvpair id=\"pingd-hosts\" name=\"host_list\" value=\"my.gateway.com www.bigcorp.com\"/>\n"
" </instance_attributes>\n"
" <operations>\n"
" <op id=\"ping-monitor-60s\" interval=\"60s\" name=\"monitor\"/>\n"
" </operations>\n"
" </primitive>\n"
"</clone>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "You’re only half done. The next section deals with telling Pacemaker how to deal with the connectivity status that <literal>ocf:pacemaker:ping</literal> is recording."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Tell Pacemaker How to Interpret the Connectivity Data"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Before attempting the following, make sure you understand <xref linkend=\"ch-rules\" />."
msgstr ""
#. Tag: para
#, no-c-format
msgid "There are a number of ways to use the connectivity data."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The most common setup is for people to have a single ping target (e.g. the service network’s default gateway), to prevent the cluster from running a resource on any unconnected node."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Don’t run a resource on unconnected nodes"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<rsc_location id=\"WebServer-no-connectivity\" rsc=\"Webserver\">\n"
" <rule id=\"ping-exclude-rule\" score=\"-INFINITY\" >\n"
" <expression id=\"ping-exclude\" attribute=\"pingd\" operation=\"not_defined\"/>\n"
" </rule>\n"
"</rsc_location>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "A more complex setup is to have a number of ping targets configured. You can require the cluster to only run resources on nodes that can connect to all (or a minimum subset) of them."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Run only on nodes connected to three or more ping targets."
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<primitive id=\"ping\" provider=\"pacemaker\" class=\"ocf\" type=\"ping\">\n"
"... <!-- omitting some configuration to highlight important parts -->\n"
" <nvpair id=\"pingd-multiplier\" name=\"multiplier\" value=\"1000\"/>\n"
"...\n"
"</primitive>\n"
"...\n"
"<rsc_location id=\"WebServer-connectivity\" rsc=\"Webserver\">\n"
" <rule id=\"ping-prefer-rule\" score=\"-INFINITY\" >\n"
" <expression id=\"ping-prefer\" attribute=\"pingd\" operation=\"lt\" value=\"3000\"/>\n"
" </rule>\n"
"</rsc_location>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Alternatively, you can tell the cluster only to <emphasis>prefer</emphasis> nodes with the best connectivity. Just be sure to set <literal>multiplier</literal> to a value higher than that of <literal>resource-stickiness</literal> (and don’t set either of them to <literal>INFINITY</literal>)."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Prefer the node with the most connected ping nodes"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<rsc_location id=\"WebServer-connectivity\" rsc=\"Webserver\">\n"
" <rule id=\"ping-prefer-rule\" score-attribute=\"pingd\" >\n"
" <expression id=\"ping-prefer\" attribute=\"pingd\" operation=\"defined\"/>\n"
" </rule>\n"
"</rsc_location>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "It is perhaps easier to think of this in terms of the simple constraints that the cluster translates it into. For example, if <emphasis role=\"strong\">sles-1</emphasis> is connected to all five ping nodes but <emphasis role=\"strong\">sles-2</emphasis> is only connected to two, then it would be as if you instead had the following constraints in your configuration:"
msgstr ""
#. Tag: title
#, no-c-format
msgid "How the cluster translates the above location constraint"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<rsc_location id=\"ping-1\" rsc=\"Webserver\" node=\"sles-1\" score=\"5000\"/>\n"
"<rsc_location id=\"ping-2\" rsc=\"Webserver\" node=\"sles-2\" score=\"2000\"/>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The advantage is that you don’t have to manually update any constraints whenever your network connectivity changes."
msgstr ""
#. Tag: para
#, no-c-format
msgid "You can also combine the concepts above into something even more complex. The example below shows how you can prefer the node with the most connected ping nodes provided they have connectivity to at least three (again assuming that <literal>multiplier</literal> is set to 1000)."
msgstr ""
#. Tag: title
#, no-c-format
msgid "A more complex example of choosing a location based on connectivity"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<rsc_location id=\"WebServer-connectivity\" rsc=\"Webserver\">\n"
" <rule id=\"ping-exclude-rule\" score=\"-INFINITY\" >\n"
" <expression id=\"ping-exclude\" attribute=\"pingd\" operation=\"lt\" value=\"3000\"/>\n"
" </rule>\n"
" <rule id=\"ping-prefer-rule\" score-attribute=\"pingd\" >\n"
" <expression id=\"ping-prefer\" attribute=\"pingd\" operation=\"defined\"/>\n"
" </rule>\n"
"</rsc_location>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Migrating Resources"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Normally, when the cluster needs to move a resource, it fully restarts the resource (i.e. stops the resource on the current node and starts it on the new node)."
msgstr ""
#. Tag: para
#, no-c-format
msgid "However, some types of resources, such as Xen virtual guests, are able to move to another location without loss of state (often referred to as live migration or hot migration). In pacemaker, this is called resource migration. Pacemaker can be configured to migrate a resource when moving it, rather than restarting it."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Not all resources are able to migrate; see the Migration Checklist below, and those that can, won’t do so in all situations. Conceptually, there are two requirements from which the other prerequisites follow:"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The resource must be active and healthy at the old location; and"
msgstr ""
#. Tag: para
#, no-c-format
msgid "everything required for the resource to run must be available on both the old and new locations."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The cluster is able to accommodate both <emphasis>push</emphasis> and <emphasis>pull</emphasis> migration models by requiring the resource agent to support two special actions: <literal>migrate_to</literal> (performed on the current location) and <literal>migrate_from</literal> (performed on the destination)."
msgstr ""
#. Tag: para
#, no-c-format
msgid "In push migration, the process on the current location transfers the resource to the new location where is it later activated. In this scenario, most of the work would be done in the <literal>migrate_to</literal> action and, if anything, the activation would occur during <literal>migrate_from</literal>."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Conversely for pull, the <literal>migrate_to</literal> action is practically empty and <literal>migrate_from</literal> does most of the work, extracting the relevant resource state from the old location and activating it."
msgstr ""
#. Tag: para
#, no-c-format
msgid "There is no wrong or right way for a resource agent to implement migration, as long as it works."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Migration Checklist"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The resource may not be a clone."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The resource must use an OCF style agent."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The resource must not be in a failed or degraded state."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The resource agent must support <literal>migrate_to</literal> and <literal>migrate_from</literal> actions, and advertise them in its metadata."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The resource must have the <literal>allow-migrate</literal> meta-attribute set to <literal>true</literal> (which is not the default)."
msgstr ""
#. Tag: para
#, no-c-format
msgid "If an otherwise migratable resource depends on another resource via an ordering constraint, there are special situations in which it will be restarted rather than migrated."
msgstr ""
#. Tag: para
#, no-c-format
msgid "For example, if the resource depends on a clone, and at the time the resource needs to be moved, the clone has instances that are stopping and instances that are starting, then the resource will be restarted. The scheduler is not yet able to model this situation correctly and so takes the safer (if less optimal) path."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Also, if a migratable resource depends on a non-migratable resource, and both need to be moved, the migratable resource will be restarted."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Tracking Node Health"
msgstr ""
#. Tag: para
#, no-c-format
msgid "A node may be functioning adequately as far as cluster membership is concerned, and yet be \"unhealthy\" in some respect that makes it an undesirable location for resources. For example, a disk drive may be reporting SMART errors, or the CPU may be highly loaded."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Pacemaker offers a way to automatically move resources off unhealthy nodes."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Node Health Attributes"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Pacemaker will treat any node attribute whose name starts with <literal>#health</literal> as an indicator of node health. Node health attributes may have one of the following values:"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Allowed Values for Node Health Attributes"
msgstr ""
#. Tag: entry
#, no-c-format
msgid "Value"
msgstr ""
#. Tag: entry
#, no-c-format
msgid "Intended significance"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>red</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "This indicator is unhealthy <indexterm> <primary>Node health</primary><secondary>red</secondary> </indexterm> <indexterm> <primary>red</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>yellow</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "This indicator is becoming unhealthy <indexterm> <primary>Node health</primary><secondary>yellow</secondary> </indexterm> <indexterm> <primary>yellow</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>green</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "This indicator is healthy <indexterm> <primary>Node health</primary><secondary>green</secondary> </indexterm> <indexterm> <primary>green</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<emphasis>integer</emphasis>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "A numeric score to apply to all resources on this node (0 or positive is healthy, negative is unhealthy) <indexterm> <primary>Node health</primary><secondary>score</secondary> </indexterm> <indexterm> <primary>score</primary> </indexterm>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Node Health Strategy"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Pacemaker assigns a node health score to each node, as the sum of the values of all its node health attributes. This score will be used as a location constraint applied to this node for all resources."
msgstr ""
#. Tag: para
#, no-c-format
msgid "The <literal>node-health-strategy</literal> cluster option controls how Pacemaker responds to changes in node health attributes, and how it translates <literal>red</literal>, <literal>yellow</literal>, and <literal>green</literal> to scores."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Allowed values are:"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Node Health Strategies"
msgstr ""
#. Tag: entry
#, no-c-format
msgid "Effect"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>none</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Do not track node health attributes at all. <indexterm> <primary>Node health</primary><secondary>none</secondary> </indexterm> <indexterm> <primary>none</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>migrate-on-red</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Assign the value of <literal>-INFINITY</literal> to <literal>red</literal>, and 0 to <literal>yellow</literal> and <literal>green</literal>. This will cause all resources to move off the node if any attribute is <literal>red</literal>. <indexterm> <primary>Node health</primary><secondary>migrate-on-red</secondary> </indexterm> <indexterm> <primary>migrate-on-red</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>only-green</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Assign the value of <literal>-INFINITY</literal> to <literal>red</literal> and <literal>yellow</literal>, and 0 to <literal>green</literal>. This will cause all resources to move off the node if any attribute is <literal>red</literal> or <literal>yellow</literal>. <indexterm> <primary>Node health</primary><secondary>only-green</secondary> </indexterm> <indexterm> <primary>only-green</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>progressive</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Assign the value of the <literal>node-health-red</literal> cluster option to <literal>red</literal>, the value of <literal>node-health-yellow</literal> to <literal>yellow</literal>, and the value of <literal>node-health-green</literal> to <literal>green</literal>. Each node is additionally assigned a score of <literal>node-health-base</literal> (this allows resources to start even if some attributes are <literal>yellow</literal>). This strategy gives the administrator finer control over how important each value is. <indexterm> <primary>Node health</primary><secondary>progressive</secondary> </indexterm> <indexterm> <primary>progressive</primary> </indexterm>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "<literal>custom</literal>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Track node health attributes using the same values as <literal>progressive</literal> for <literal>red</literal>, <literal>yellow</literal>, and <literal>green</literal>, but do not take them into account. The administrator is expected to implement a policy by defining rules (see <xref linkend=\"ch-rules\" />) referencing node health attributes. <indexterm> <primary>Node health</primary><secondary>custom</secondary> </indexterm> <indexterm> <primary>custom</primary> </indexterm>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Measuring Node Health"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Since Pacemaker calculates node health based on node attributes, any method that sets node attributes may be used to measure node health. The most common ways are resource agents or separate daemons."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Pacemaker provides examples that can be used directly or as a basis for custom code. The <literal>ocf:pacemaker:HealthCPU</literal> and <literal>ocf:pacemaker:HealthSMART</literal> resource agents set node health attributes based on CPU and disk parameters. The <literal>ipmiservicelogd</literal> daemon sets node health attributes based on IPMI values (the <literal>ocf:pacemaker:SystemHealth</literal> resource agent can be used to manage the daemon as a cluster resource). In order to take advantage of this feature - firstly add the resource to your cluster, preferably as a cloned resource to constatnly measure health on all nodes:"
msgstr ""
#. Tag: para
#, no-c-format
msgid "This way <literal>attrd_updater</literal> will set proper status for each node running this resource. Any attribute matching <literal>#health-[a-zA-z]+</literal> will force cluster to migrate all resources from unhealthy node and place it on other nodes according to all constraints defined in your cluster. When the node is no longer faulty you can force the cluster to restart the cloned resource on faulty node and make it available to take resources, in this case since we are using HealthIOWait provider:"
msgstr ""
#. Tag: title
#, no-c-format
msgid "Reloading Services After a Definition Change"
msgstr ""
#. Tag: para
#, no-c-format
msgid "The cluster automatically detects changes to the definition of services it manages. The normal response is to stop the service (using the old definition) and start it again (with the new definition). This works well, but some services are smarter and can be told to use a new set of options without restarting."
msgstr ""
#. Tag: para
#, no-c-format
msgid "To take advantage of this capability, the resource agent must:"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Accept the <literal>reload</literal> operation and perform any required actions. <emphasis>The actions here depend completely on your application!</emphasis>"
msgstr ""
#. Tag: title
#, no-c-format
msgid "The DRBD agent’s logic for supporting <literal>reload</literal>"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "case $1 in\n"
" start)\n"
" drbd_start\n"
" ;;\n"
" stop)\n"
" drbd_stop\n"
" ;;\n"
" reload)\n"
" drbd_reload\n"
" ;;\n"
" monitor)\n"
" drbd_monitor\n"
" ;;\n"
" *)\n"
" drbd_usage\n"
" exit $OCF_ERR_UNIMPLEMENTED\n"
" ;;\n"
"esac\n"
"exit $?"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Advertise the <literal>reload</literal> operation in the <literal>actions</literal> section of its metadata"
msgstr ""
#. Tag: title
#, no-c-format
msgid "The DRBD Agent Advertising Support for the <literal>reload</literal> Operation"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<?xml version=\"1.0\"?>\n"
" <!DOCTYPE resource-agent SYSTEM \"ra-api-1.dtd\">\n"
" <resource-agent name=\"drbd\">\n"
" <version>1.1</version>\n"
"\n"
" <longdesc>\n"
" Master/Slave OCF Resource Agent for DRBD\n"
" </longdesc>\n"
"\n"
" ...\n"
"\n"
" <actions>\n"
" <action name=\"start\" timeout=\"240\" />\n"
" <action name=\"reload\" timeout=\"240\" />\n"
" <action name=\"promote\" timeout=\"90\" />\n"
" <action name=\"demote\" timeout=\"90\" />\n"
" <action name=\"notify\" timeout=\"90\" />\n"
" <action name=\"stop\" timeout=\"100\" />\n"
" <action name=\"meta-data\" timeout=\"5\" />\n"
" <action name=\"validate-all\" timeout=\"30\" />\n"
" </actions>\n"
" </resource-agent>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Advertise one or more parameters that can take effect using <literal>reload</literal>."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Any parameter with the <literal>unique</literal> set to 0 is eligible to be used in this way."
msgstr ""
#. Tag: title
#, no-c-format
msgid "Parameter that can be changed using reload"
msgstr ""
#. Tag: programlisting
#, no-c-format
msgid "<parameter name=\"drbdconf\" unique=\"0\">\n"
" <longdesc>Full path to the drbd.conf file.</longdesc>\n"
" <shortdesc>Path to drbd.conf</shortdesc>\n"
" <content type=\"string\" default=\"${OCF_RESKEY_drbdconf_default}\"/>\n"
"</parameter>"
msgstr ""
#. Tag: para
#, no-c-format
msgid "Once these requirements are satisfied, the cluster will automatically know to reload the resource (instead of restarting) when a non-unique field changes."
msgstr ""
#. Tag: para
#, no-c-format
msgid "Metadata will not be re-read unless the resource needs to be started. This may mean that the resource will be restarted the first time, even though you changed a parameter with <literal>unique=0</literal>."
msgstr ""
#. Tag: para
#, no-c-format
msgid "If both a unique and non-unique field are changed simultaneously, the resource will still be restarted."
msgstr ""