Refs #533: add total-minus-used memory fallback

This commit is contained in:
rcourtman 2025-10-15 18:19:54 +00:00
parent 5ce47a72ec
commit 32421b36b8
5 changed files with 148 additions and 39 deletions

View file

@ -3,6 +3,7 @@ package monitoring
import (
"context"
"fmt"
"math"
"os"
"sort"
"strings"
@ -173,6 +174,34 @@ func (m *Monitor) pollVMsWithNodesOptimized(ctx context.Context, instanceName st
guestRaw.MemInfoBuffers = status.MemInfo.Buffers
guestRaw.MemInfoCached = status.MemInfo.Cached
guestRaw.MemInfoShared = status.MemInfo.Shared
componentAvailable := status.MemInfo.Free
if status.MemInfo.Buffers > 0 {
if math.MaxUint64-componentAvailable < status.MemInfo.Buffers {
componentAvailable = math.MaxUint64
} else {
componentAvailable += status.MemInfo.Buffers
}
}
if status.MemInfo.Cached > 0 {
if math.MaxUint64-componentAvailable < status.MemInfo.Cached {
componentAvailable = math.MaxUint64
} else {
componentAvailable += status.MemInfo.Cached
}
}
if status.MemInfo.Total > 0 && componentAvailable > status.MemInfo.Total {
componentAvailable = status.MemInfo.Total
}
availableFromUsed := uint64(0)
if status.MemInfo.Total > 0 && status.MemInfo.Used > 0 && status.MemInfo.Total >= status.MemInfo.Used {
availableFromUsed = status.MemInfo.Total - status.MemInfo.Used
guestRaw.MemInfoTotalMinusUsed = availableFromUsed
}
missingCacheMetrics := status.MemInfo.Available == 0 &&
status.MemInfo.Buffers == 0 &&
status.MemInfo.Cached == 0
switch {
case status.MemInfo.Available > 0:
@ -186,6 +215,17 @@ func (m *Monitor) pollVMsWithNodesOptimized(ctx context.Context, instanceName st
status.MemInfo.Cached
memorySource = "meminfo-derived"
}
if memAvailable == 0 && availableFromUsed > 0 && missingCacheMetrics {
const vmTotalMinusUsedGapTolerance uint64 = 4 * 1024 * 1024
if availableFromUsed > componentAvailable {
gap := availableFromUsed - componentAvailable
if componentAvailable == 0 || gap >= vmTotalMinusUsedGapTolerance {
memAvailable = availableFromUsed
memorySource = "meminfo-total-minus-used"
}
}
}
}
if vmStatus.Balloon > 0 && vmStatus.Balloon < vmStatus.MaxMem {
memTotal = vmStatus.Balloon