RESOURCES Policy Item – Model 1
The panel shown in Figure 1 is for an application group of type SYSPLEX, nature SERVER, and Model 1.
If you want to add resource members to an application group of nature MOVE or SERVER, you can attach preference values to those resources (using the Preference column).
COMMANDS ACTIONS HELP
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AOFGARS2 Select Resources Row 1 to 4 of 4
Command ===> SCROLL===> PAGE
Entry Type : ApplicationGroup Entry Name : SYSPLEX_APPLGROUP
Sysplex : SYSPLEX_GROUP_01
Number of selected Resources : 4
Availability Target. . . . . . . *ALL (-3 to 4 , *ALL)
Satisfactory Target. . . . . . . *ALL (Level at which group is available)
Show all Resources . . . . . . . NO YES NO
Show only Resources with String.
Action Preference Resource Name Entry Name
700 SYSPLEX_JOB/APL/FOCB SYSPLEX_JOB
700 SYSPLEX_JOB/APL/FOC1 SYSPLEX_JOB
700 SYSPLEX_JOB/APL/TGT1 SYSPLEX_JOB
700 SYSPLEX_JOB/APL/TGT2 SYSPLEX_JOB
- Number of selected Resources
- This shows the current number of selected resources. It must not exceed a number of 999. You must remove resources if you have more than 999 resources selected.
- Availability Target
- This Availability Target is different depending on the type of application group:
- Server
- Valid values for server application groups are:
- *ALL
- It means that all selected resources must be available before the current ApplicationGroup resource is considered as available.
- number
- This (positive) number is the number of selected resources that must be available before
the current ApplicationGroup resource is considered as available. This number must be less than or
equal to the value in the Number of selected Resources field.
If you enter a number that is greater, it will be changed to the maximum allowed when you leave the panel.
- -number
- This (negative) -number means that all but the number of
selected resources that must be available before the current ApplicationGroup resource is considered
as available. This number must be less than the value in the Number of selected
Resources field.
If -number is lower or equal to the minimum allowed, it will be changed to the minimum when you leave the panel.
- Move
- The Availability Target is always 1. This field cannot be modified for move application groups.
- Basic
- The Availability Target is not applicable and is not displayed for basic application groups.
- Satisfactory Target
- This field
specifies the number of members in the group that must be active before the automation manager treats the group as being in a satisfactory
status.
- Valid values for server application groups are the same as for the Availability Target.
- The Satisfactory Target can be less than, or equal to the Availability Target, but cannot be higher.
- If the Satisfactory Target is of type -number, then it is treated relative to the adjusted Availability Target.
After each selection or deselection of a resource, it is checked whether the Availability Target and Satisfactory Target still match the number of selected resources.- If the number of selected resources becomes less than the original values of the targets, the targets will decrease to the maximum value. Then, if the number of selected resources increases by selecting new resources, the values of the targets will also increase until the original values are reached again.
- Target changes performed by the user are immediately used as new threshold values, if they are valid depending on the current number of selected resources.
- If the number of selected resources is 0, both targets are set to *ALL.
- Show all Resources
- This can be:
- YES
- Shows all selectable resources of type APL, APG, and REF.
- NO
- Only shows selected resources.
- Show only Resources with String
- If you enter a string in this field, only matching resources are listed. Wildcards are not supported.
- Action
- The following actions are valid from the ACTIONS menu and Action prompt:
Action Result (P)RIMARY Sets the preference value to 700. SECON(D)ARY Sets the preference value to 400. (A)DD Sets the preference value to 700. RE(M)OVE Removes the preference value. (S)ELECT Sets the preference value to 700. - Preference
- A resource becomes SELECTED when a positive number is entered to this field. The preference
value says what "role" the selected resource has. The maximum valid value is 3200. Any
value greater than 3200 will be changed to that valid maximum. The following roles are related to the preference values given:
- >2600
- The resource always selected regardless of its state. Use this value if the APL or APG resource must run.
- ≥2000
- The resource always selected unless the observed status of the resource is SYSGONE or HARDDOWN. It is only selected when no other viable member exists. A viable member is a resource that can be started and that is allowed to be started. In principle, the observed status is one of the following: SoftDown, Starting, Degraded, Available or WasAvailable.
- 1000
- The resource always started, other resources stopped. (Use if you really want the APL or APG resource to run).
- 700
- The resource is selected for startup after an IPL and after recovery situations. Members with preference 300 will be stopped in favour of this group. It is not stopped unless a very high preference alternative becomes available. This value is the default. Use it in a MOVE group for a resource that normally runs.
- <600
- Used as a threshold. A resource with a preference of 599 and lower will not be selected at group startup.
- 500
- This resource is not selected for startup after IPL but it is started as a backup after failure and continues running even though normal preference (700) alternatives become available. It is stopped at the next (scheduled) outage. Use this value in a MOVE group for the backup resource.
- 400
- This resource is not selected for startup after IPL but it is started as a backup after failure. The difference to preference 500 is that the resource is stopped when normal preference (700) alternatives become available again.
- 300
- Like 200, but a move to an alternate backup (Preference 500) would only occur at a (scheduled) outage.
- 200
- Resource started as backup, stopped as soon as better alternative (Preference 450 and greater) becomes available. (Use where you can have a backup, but you don't really want one).
- 1
- This means that the member will always be deselected and will always have a MakeUnavailable vote propagated to it. This can be useful if you want complete manual control of the move process.
- 0
- This means that the member is a passive member and will never get a vote propagated to it by the group. If a member has its preference changed so it becomes passive, any votes that have been propagated to it from the group will be withdrawn.
Preferences other than those listed are accepted. You can find more information on the meaning of preferences in Controlling Application Move with Preference Values in IBM Z® System Automation User's Guide.
The effective preference of each group member is calculated to determine which group members get picked to be activated by the group. The primary inputs into this are the base preference (as specified through the customization dialogs) and the preference adjustment (specified indirectly through the INGGROUP interface). These are added together to produce the resource's adjusted preference (this is the same as the preference value you actually enter the INGGROUP panels).
The following modifiers are then applied to the resource's adjusted preference if it is >1.
Bonus Reason 25 The member is currently selected and has an adjusted preference ≤1000. 175 The member is currently selected and has an adjusted preference >1000. 220 The member has an observed status of Starting, Stopping or Degraded and the system is not being stopped. 225 The member has an observed status of Available and the system is not being stopped. –400 The member has an adjusted preference >1500 and either the system is being stopped or the system has already been stopped and the member thus has observed status of SysGone. The working value for the preference may then be set to an absolute value if any of the following conditions are satisfied:
Value Condition 3600 - The member has an adjusted preference of 0 (indicating a passive member) and it has an observed status of Starting, Degraded, Available, or WasAvailable.
- The member at startup is of a Move group. This preference is assigned temporarily and makes sure that no other member is selected.
100 The member has a working preference between 2–2599 and requires a resource on an Avoided system. 1 The member has: - An adjusted preference of 0 (indicating a passive member) and its observed status is none of Starting, Degraded, Available or WasAvailable.
- A working preference of 2000–2599, there is a viable alternative resource and the member either has an observed status of HardDown or SysGone or the system that it is on is being stopped.
- A working preference <2000 and has observed status of HardDown or SysGone.
- A working preference <2600 and has observed status of StandBy, Unknown or Problem.
- A working preference <2600, has observed status of Stopping or SoftDown and its automation flag is turned off.
- A working preference <2600 and requires a member on an excluded system.
After all of these adjustments have been made, this produces the member's effective preference. Normally a Move or Server group will pick the members with the highest effective preferences to be available, however there are three special rules to take into consideration:
- A member with an effective preference of 1 may never be picked. SA z/OS sends a MakeUnavailable vote.
- A member with an effective preference <600 may only be picked if the group is in recovery mode (that is, it is recovering from a failure).
- A member requiring a resource on an excluded system must be sent a MakeUnavailable vote, even if it has been picked. This can occur with resources that have adjusted preferences >2600.
Table 1. Preference Value Scenarios Scenario Description Absolute manual control Member to be activated gets preference 3200, all others get preference 1. The member with the 3200 preference will be selected. All others will always have a MakeUnavailable vote propagated to them.
This does not change even if the system with the selected member leaves the sysplex.
A shutdown of the primary system will not initiate a move of the application, as the 400 point penalty is not sufficient to drop its preference below 2600.
Move only after system failure Primary member defined preference 2800, backups preference 500. As long as the primary is not SYSGONE it will be selected. If the primary is SYSGONE, its preference drops to 2575 (2800 – 400 + 175), allowing an alternative viable member to be selected.
The backups will only be viable if the resource was previously active because of the groups recovery mode.
A shutdown of the primary system will not initiate a move of the application. Although the primary systems preference will be below 2600, there will be no viable alternatives as the backups may only be used if the group is in recovery mode.
Move only if system down or stopping Primary member defined preference 2800, backups preference 700. As long as the primary member is not SYSGONE and its system is not being stopped it will be selected. If the primary member is SYSGONE or its system is being stopped, its preference drops to 2575 (2800 – 400 + 175), allowing an alternative viable resource to be selected.
The backups are always viable.
A shutdown of the primary system will initiate a move of the application during the shutdown.
Sticky move only after system down or stopping Primary member defined preference 2801, backups preference 2800. As long as the primary member is not SYSGONE and its system is not being stopped, it will be selected. If the primary becomes SYSGONE or its system is being stopped, its preference drops to 2576 (2801 – 400 + 175), allowing one of the backups to be selected. The sticky bonus raises its preference to 2975 (2800 + 175), meaning that even when the primary returns the selected backup system will remain selected.
It will only be deselected if it goes to SYSGONE or its system is being stopped, in which case the primary will be re-selected if it is available otherwise another backup would be picked.
A shutdown of the primary system will initiate a move of the application during the shutdown.
Move only after system or application failure Primary member defined with preference 2400, backups preference 500. As long as the primary member does not fail to SYSGONE or HARDDOWN it remains selected. If it gets to HARDDOWN or SYSGONE without failing, there are no viable alternatives, so it will not be moved. If it does fail, its preference is between 2600 and 2000 and the backups are viable, so one of them can be picked.
The backups are only viable if the group is in recovery mode (that is, the member was active when the failure occurred).
Move only if system down, being stopped or application failure Primary member defined with preference 2400, backups preference 700. As long as the primary member is not SYSGONE or HARDDOWN and its system is not being stopped it remains selected. If it is HARDDOWN or SYSGONE or its system is being stopped its preference is between 2600 and 2000, so a viable alternative can be selected.
A shutdown of the primary system will initiate a move of the application, as it will have lost its 225 point bonus for being available and have incurred a 400 point penalty, bringing its preference down to well below 2600, allowing the selection of an alternative resource if there is a viable one.
Sticky move if system down or being stopped, move after application failure Primary member defined with preference 2401, backups preference 2400. As long as the primary is not SYSGONE or HARDDOWN and its system is not being stopped it remains selected. If it is SYSGONE or HARDDOWN or its system is being stopped its preference is between 2000–2600, so a viable alternative may be chosen.
The sticky bonus raises the preference of the selected member to 2575 (2400 + 175), so it will remain selected until it gets to a state of SYSGONE or HARDDOWN or its system is being stopped, at which point another viable alternative will be selected, with the primary member having preference.
The individual shutdown of the active member will not trigger a move.
A shutdown of the primary system will result in a move of the application. It will have a 400 point penalty, dropping its preference to between 2600 and 2000, permitting the selection of a viable alternative.
Sticky move group, unless member stopped Primary member defined with preference 701, backups preference 700. As long as the primary member is startable, it remains selected. If it becomes non-startable, another member is selected and that remains selected as long as it is startable.
Individually stopping the active member will trigger a move. If the members were defined with preferences >1500, the bonus would be 175 points rather than 25 points.
Sticky move group, until told otherwise Primary member defined with preference 3200, backups with preference 1600. With base preferences of 3200, you get it picking a member when the sysplex is IPLd and retaining that one until an operator uses INGGROUP to make it pick another one.
Beware of timing problems as the first system with a member to register will probably get it.