Understanding Serviceguard Package Dependencies, April 2009

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5. You have 3 packages. Both pkgA and pkgB require pkgC to be UP on the
same node. If pkgB fails, it should not affect pkgA. If pkgA fails, it should be
able to drag pkgC to a node where both can run. If pkgA is not up, pkgB
should be able to drag pkgC.
• Assign the highest priority to pkgA.
• Assign the 2nd highest priority to pkgB.
• Set pkgA’s priority to 10, pkgB’s to 20 and pkgC’s to 30.
6. You have three packages. PkgA depends on pkgC on the same node. PkgB
depends on pkgC on any node. If pkgA fails, it should be able to drag pkgC
to a node where both can run.
• Assign the highest priority to pkgA
• Since pkgB has an "any node" dependency on pkgC, its priority must be the same or lower
than pkgC.
• Assign 10, 30, and 20 to pkgA, pkgB and pkgC respectively. Another solution would be to
assign say priority of 10 to pkgA and “no_priority” to pkgB and pkgC.
7. You have three packages. PkgA and pkgB depend on pkgC to be UP on the
same node. If either pkgA or pkgB fails, they should not affect each other.
Note: this is the default behavior if you do not assign priority to packages with the same node up
dependencies.
• Solution 1:
– Set priority of all three packages to “no_priority”
• Solution 2:
– Assign the highest priority to pkgC. Since pkgC is the highest priority, the priorities of pkgA
and pkgB do not matter.
– Assign priority 10 to pkgC. Assign 20 and 30 to pkgA and pkgB respectively.
8. You have three packages. PkgA requires both pkgB and pkgC to be UP on
the same node. If A fails, it should drag the others to a node where all can
run.
• Make pkgA the highest priority package. The relative priorities of pkgB and pkgC do not
matter.
• Assign 10, 20, and 30 to pkgA, pkgB, and pkgC respectively.