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Fix host metrics on overprovisioning change #12403

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Fix host metrics on overprovisioning change #12403

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32 changes: 10 additions & 22 deletions server/src/main/java/com/cloud/capacity/CapacityManagerImpl.java
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Original file line number Diff line number Diff line change
Expand Up @@ -704,22 +704,16 @@ public void updateCapacityForHost(final Host host) {
so = _offeringsDao.findByIdIncludingRemoved(vm.getServiceOfferingId());
}
if (so.isDynamic()) {
usedMemory +=
((Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.memory.name())) * 1024L * 1024L) / ramOvercommitRatio) *
clusterRamOvercommitRatio;
usedMemory += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.memory.name())) * 1024L * 1024L;
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@abh1sar abh1sar Jan 19, 2026

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There seems to be some intentional logic behind the old code:

ramOvercommitRatio is saved in VM settings (which is set equal to the clusterOvercommitRatio whenever the VM is started)
clusterRamOvercommitRatio is the current ratio set on the cluster.

The idea behind the old code seems to be that for running VMs the used stats are kept at the same ratio to the total capacity.

For example, let's say total capacity is 64G and a VM is using 32G (Half of the total capacity)
Now, the clusterOvercommitRatio is changed from 1 to 2.
The VM's used will change to 64G (32/1 * 2). This means the running VM is still using half of the total capacity of the host.

The logic seems to be a safeguard against a running VM not getting affected by sudden capacity jumps using the overCommit ratio of the cluster.

Think of a little extreme case when clusterOvercommitRatio is changed from 1 to 5. Without this change, it is bound to affect the running VM which might not be intended.

When the VM restarts, its ramOvercommitRatio will change to 2. The VM used will then become 32G (32/2 * 2).

Basically the logic seems to be that running VMs should not be affected by sudden jumps in the clusterOvercommitRatio.

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@abh1sar abh1sar Jan 19, 2026

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cc @vishesh92 @DaanHoogland @NuxRo

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@DaanHoogland DaanHoogland Jan 19, 2026

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you are asking if this change is functionaly sane @abh1sar?

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@abh1sar abh1sar Jan 19, 2026

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yes @DaanHoogland , I think the behaviour is by design and this change will affect functionality

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@vishesh92 vishesh92 Jan 27, 2026

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The value of cpuOvercommitRatio for a VM can only be changed when the VM is stopped. When the VM is started, the value is reset to the cluster's cpu.overprovisioning.factor.

This basically means that ramOvercommitRatio is always equal to clusterRamOvercommitRatio & cpuOvercommitRatio is equal to clusterCpuOvercommitRatio. Before this change, we were just multiplying and then divided the value with the same number.

if(vmDetails.containsKey(UsageEventVO.DynamicParameters.cpuSpeed.name())) {
usedCpu +=
((Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuSpeed.name()))) / cpuOvercommitRatio) *
clusterCpuOvercommitRatio;
usedCpu += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuSpeed.name()));
} else {
usedCpu +=
((Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * so.getSpeed()) / cpuOvercommitRatio) *
clusterCpuOvercommitRatio;
usedCpu += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * so.getSpeed();
}
usedCpuCore += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name()));
} else {
usedMemory += ((so.getRamSize() * 1024L * 1024L) / ramOvercommitRatio) * clusterRamOvercommitRatio;
usedCpu += ((so.getCpu() * so.getSpeed()) / cpuOvercommitRatio) * clusterCpuOvercommitRatio;
usedMemory += so.getRamSize() * 1024L * 1024L;
usedCpu += so.getCpu() * so.getSpeed();
usedCpuCore += so.getCpu();
}
}
Expand Down Expand Up @@ -748,22 +742,16 @@ public void updateCapacityForHost(final Host host) {
so = _offeringsDao.findByIdIncludingRemoved(vm.getServiceOfferingId());
}
if (so.isDynamic()) {
reservedMemory +=
((Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.memory.name())) * 1024L * 1024L) / ramOvercommitRatio) *
clusterRamOvercommitRatio;
reservedMemory += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.memory.name())) * 1024L * 1024L;
if(vmDetails.containsKey(UsageEventVO.DynamicParameters.cpuSpeed.name())) {
reservedCpu +=
((Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuSpeed.name()))) / cpuOvercommitRatio) *
clusterCpuOvercommitRatio;
reservedCpu += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuSpeed.name()));
} else {
reservedCpu +=
((Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * so.getSpeed()) / cpuOvercommitRatio) *
clusterCpuOvercommitRatio;
reservedCpu += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name())) * so.getSpeed();
}
reservedCpuCore += Integer.parseInt(vmDetails.get(UsageEventVO.DynamicParameters.cpuNumber.name()));
} else {
reservedMemory += ((so.getRamSize() * 1024L * 1024L) / ramOvercommitRatio) * clusterRamOvercommitRatio;
reservedCpu += (so.getCpu() * so.getSpeed() / cpuOvercommitRatio) * clusterCpuOvercommitRatio;
reservedMemory += so.getRamSize() * 1024L * 1024L;
reservedCpu += so.getCpu() * so.getSpeed();
reservedCpuCore += so.getCpu();
}
} else {
Expand Down
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