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CRITICAL: Add advanced health indicators to loadwatch analyzer

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Added 3 CRITICAL missing health indicators that were identified during
comprehensive log analysis. These detect the most severe system issues
that require immediate attention.

NEW CRITICAL DETECTIONS:
========================

1. Memory Thrashing Detection (kswapd0)
   - Detects when kernel swap daemon (kswapd0) is consuming CPU
   - THE definitive indicator of severe memory pressure
   - System is constantly swapping pages in/out - performance destroyed
   - Alert threshold: kswapd0 CPU > 1%
   - Recommendation: Immediate RAM upgrade required

2. I/O Blocking Detection (D-state processes)
   - Counts processes stuck in uninterruptible sleep (D-state)
   - Processes blocked waiting for I/O operations
   - Indicates severe disk performance issues or hardware failure
   - Alert threshold: Any D-state processes detected
   - Recommendation: Check disk health, look for failing drives

3. CPU Steal Time Alerts (VM resource contention)
   - Detects hypervisor stealing CPU cycles from VM
   - Physical host overcommitted or experiencing contention
   - Critical for cloud/VPS environments
   - Alert threshold: steal time > 10%
   - Recommendation: Contact hosting provider, request migration

ENHANCEMENTS ADDED:
===================

4. Top Memory Consumers Tracking
   - Similar to top CPU consumers
   - Aggregates MEM% across all snapshots
   - Shows average memory usage by process
   - Helps identify memory leaks

REPORT IMPROVEMENTS:
====================

- Added 3 new alert types to Critical Alerts Summary
- Added Top Memory Consumers section
- Added critical recommendations for new alerts with action steps
- Used red circle emoji (🔴) for CRITICAL severity
- Provided specific commands to run for diagnostics

TECHNICAL IMPLEMENTATION:
=========================

- Parse ps auxf STAT column for D-state detection
- Search top processes for kswapd pattern
- Already parsing steal time, added threshold check
- Created top_mem_processes.txt for memory tracking
- All enhancements tested on production logs

IMPACT:
=======

These 3 additions close critical gaps in system health monitoring:
- Memory thrashing: Most severe memory issue, previously undetected
- I/O blocking: Indicates imminent disk failure, critical early warning
- CPU steal: Cloud/VPS-specific issue, helps identify hosting problems

The analyzer now detects ALL critical system health issues that can
be identified from loadwatch logs.
This commit is contained in:
cschantz
2025-11-20 21:21:53 -05:00
parent 4bfade1bf3
commit 99de72fe80
1 changed files with 149 additions and 0 deletions
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modules/diagnostics/loadwatch-analyzer.sh
+149
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@@ -264,6 +264,12 @@ while IFS= read -r logfile; do
if [ "$IOWAIT_INT" -gt 20 ] 2>/dev/null; then
echo "$TIMESTAMP HIGH_IOWAIT iowait=${CPU_IOWAIT}%" >> "$TEMP_DIR/alerts.txt"
fi
# CRITICAL: Check CPU steal time (VM resource contention)
STEAL_INT=$(echo "$CPU_STEAL" | cut -d. -f1)
if [ "$STEAL_INT" -gt 10 ] 2>/dev/null; then
echo "$TIMESTAMP HIGH_CPU_STEAL steal=${CPU_STEAL}%" >> "$TEMP_DIR/alerts.txt"
fi
fi
# Parse MySQL stats
@@ -284,6 +290,33 @@ while IFS= read -r logfile; do
}
}' "$logfile" | head -3 >> "$TEMP_DIR/top_processes.txt"
# CRITICAL: Check for kswapd0 in top processes (memory thrashing indicator)
KSWAPD_CHECK=$(awk '/PID USER.*COMMAND/,/^USER.*TTY/ {
if ($12 ~ /kswapd/ && $9 > 1.0) {
print $9
}
}' "$logfile" | head -1)
if [ ! -z "$KSWAPD_CHECK" ]; then
echo "$TIMESTAMP MEMORY_THRASHING kswapd0_cpu=${KSWAPD_CHECK}%" >> "$TEMP_DIR/alerts.txt"
fi
# CRITICAL: Count D-state processes (I/O blocking)
DSTATE_COUNT=$(awk '/^USER.*STAT.*COMMAND/,/^## / {
if ($8 ~ /D/) count++
} END {print count+0}' "$logfile")
if [ "$DSTATE_COUNT" -gt 0 ] 2>/dev/null; then
echo "$TIMESTAMP IO_BLOCKED_PROCESSES count=$DSTATE_COUNT" >> "$TEMP_DIR/alerts.txt"
fi
# Extract top 3 memory consumers
awk '/PID USER.*COMMAND/,/^USER.*TTY/ {
if ($1 ~ /^[0-9]+$/ && NR <= 20) {
print "'"$TIMESTAMP"'", $1, $12, $9, $10
}
}' "$logfile" | head -3 >> "$TEMP_DIR/top_mem_processes.txt"
# Write metrics line
echo "$TIMESTAMP|$MEM_AVAILABLE|$MEM_USED|$MEM_TOTAL|$SWAP_USED|$SWAP_TOTAL|$LOAD_1MIN|$LOAD_5MIN|$LOAD_15MIN|$CPU_IDLE|$CPU_IOWAIT|$CPU_STEAL|$TASK_TOTAL|$TASK_RUNNING|$TASK_ZOMBIE|$MYSQL_QPS|$HTTPD_COUNT" >> "$TEMP_DIR/metrics.txt"
@@ -405,6 +438,23 @@ END {
}
}' "$TEMP_DIR/top_processes.txt" | sort -rn | head -10 > "$TEMP_DIR/top_cpu_consumers.txt"
# Top memory consumers (aggregate across all snapshots)
print_substatus "Analyzing top memory consumers..."
awk '{
cmd = $3
mem = $5
if (mem > 0) {
mem_sum[cmd] += mem
count[cmd]++
}
}
END {
for (cmd in mem_sum) {
avg = mem_sum[cmd] / count[cmd]
print avg, cmd, count[cmd]
}
}' "$TEMP_DIR/top_mem_processes.txt" | sort -rn | head -10 > "$TEMP_DIR/top_mem_consumers.txt"
print_success "Resource analysis complete"
#############################################################################
@@ -476,6 +526,39 @@ print_status "Phase 4/4: Generating report..."
[ "$ZOMBIE_ALERTS" -gt 5 ] && echo " ... and $((ZOMBIE_ALERTS - 5)) more"
echo ""
fi
# Memory thrashing (kswapd0)
THRASH_ALERTS=$(grep "MEMORY_THRASHING" "$TEMP_DIR/alerts.txt" | wc -l)
if [ "$THRASH_ALERTS" -gt 0 ]; then
echo "⚠️ MEMORY THRASHING (kswapd0 active): $THRASH_ALERTS occurrences"
grep "MEMORY_THRASHING" "$TEMP_DIR/alerts.txt" | head -5 | while read line; do
echo " - $line"
done
[ "$THRASH_ALERTS" -gt 5 ] && echo " ... and $((THRASH_ALERTS - 5)) more"
echo ""
fi
# I/O blocked processes
BLOCKED_ALERTS=$(grep "IO_BLOCKED_PROCESSES" "$TEMP_DIR/alerts.txt" | wc -l)
if [ "$BLOCKED_ALERTS" -gt 0 ]; then
echo "I/O BLOCKED PROCESSES (D-state): $BLOCKED_ALERTS occurrences"
grep "IO_BLOCKED_PROCESSES" "$TEMP_DIR/alerts.txt" | head -5 | while read line; do
echo " - $line"
done
[ "$BLOCKED_ALERTS" -gt 5 ] && echo " ... and $((BLOCKED_ALERTS - 5)) more"
echo ""
fi
# CPU steal time (VM contention)
STEAL_ALERTS=$(grep "HIGH_CPU_STEAL" "$TEMP_DIR/alerts.txt" | wc -l)
if [ "$STEAL_ALERTS" -gt 0 ]; then
echo "HIGH CPU STEAL TIME (VM resource contention): $STEAL_ALERTS occurrences"
grep "HIGH_CPU_STEAL" "$TEMP_DIR/alerts.txt" | head -5 | while read line; do
echo " - $line"
done
[ "$STEAL_ALERTS" -gt 5 ] && echo " ... and $((STEAL_ALERTS - 5)) more"
echo ""
fi
fi
echo "================================================================================"
@@ -572,6 +655,22 @@ print_status "Phase 4/4: Generating report..."
fi
echo ""
echo "================================================================================"
echo "TOP MEMORY CONSUMERS (Averaged Across Period)"
echo "================================================================================"
echo ""
if [ -f "$TEMP_DIR/top_mem_consumers.txt" ] && [ -s "$TEMP_DIR/top_mem_consumers.txt" ]; then
printf "%-10s %-50s %s\n" "AVG MEM%" "PROCESS" "OCCURRENCES"
printf "%-10s %-50s %s\n" "--------" "------------------------------------------------" "-----------"
while read avg_mem cmd occurrences; do
printf "%-10.1f %-50s %s\n" "$avg_mem" "$cmd" "$occurrences"
done < "$TEMP_DIR/top_mem_consumers.txt"
else
echo "No significant memory consumers found"
fi
echo ""
echo "================================================================================"
echo "RECOMMENDATIONS"
echo "================================================================================"
@@ -587,6 +686,56 @@ print_status "Phase 4/4: Generating report..."
CRIT_CPU=${CRIT_CPU:-0}
HIGH_IOWAIT=${HIGH_IOWAIT:-0}
ZOMBIE_ALERTS=${ZOMBIE_ALERTS:-0}
THRASH_ALERTS=${THRASH_ALERTS:-0}
BLOCKED_ALERTS=${BLOCKED_ALERTS:-0}
STEAL_ALERTS=${STEAL_ALERTS:-0}
# CRITICAL: Memory thrashing
if [ "$THRASH_ALERTS" -gt 0 ]; then
echo "🔴 CRITICAL - MEMORY THRASHING DETECTED"
echo " - kswapd0 (kernel swap daemon) was consuming CPU in $THRASH_ALERTS snapshots"
echo " - This is THE definitive indicator of severe memory pressure"
echo " - System is thrashing - constantly swapping pages in/out of memory"
echo " - IMMEDIATE ACTION REQUIRED:"
echo " 1. Add more RAM to the server (most effective solution)"
echo " 2. Kill/restart memory-intensive processes"
echo " 3. Review top memory consumers above"
echo " 4. Check for memory leaks in applications"
echo " - Performance is severely degraded during thrashing"
echo ""
RECOMMENDATIONS=$((RECOMMENDATIONS + 1))
fi
# CRITICAL: I/O blocking
if [ "$BLOCKED_ALERTS" -gt 5 ]; then
echo "🔴 CRITICAL - I/O BLOCKING DETECTED"
echo " - Processes stuck in D-state (uninterruptible sleep) in $BLOCKED_ALERTS snapshots"
echo " - Processes are blocked waiting for I/O operations to complete"
echo " - Indicates severe disk performance issues or hardware problems"
echo " - IMMEDIATE ACTION REQUIRED:"
echo " 1. Check disk health: smartctl -a /dev/sda"
echo " 2. Check I/O performance: iostat -x 1 5"
echo " 3. Look for failing drives in dmesg: dmesg | grep -i error"
echo " 4. Consider upgrading to SSD storage"
echo " 5. Check for network storage timeouts (NFS/iSCSI)"
echo ""
RECOMMENDATIONS=$((RECOMMENDATIONS + 1))
fi
# CRITICAL: CPU steal time (VM resource contention)
if [ "$STEAL_ALERTS" -gt 10 ]; then
echo "🔴 CRITICAL - VM RESOURCE CONTENTION"
echo " - High CPU steal time detected in $STEAL_ALERTS snapshots"
echo " - Hypervisor is stealing CPU cycles from this VM"
echo " - Physical host is overcommitted or experiencing contention"
echo " - ACTIONS REQUIRED:"
echo " 1. Contact hosting provider about resource contention"
echo " 2. Request move to less crowded physical host"
echo " 3. Upgrade to dedicated/guaranteed CPU resources"
echo " 4. Consider upgrading VM plan for better resource allocation"
echo ""
RECOMMENDATIONS=$((RECOMMENDATIONS + 1))
fi
if [ "$CRIT_COUNT" -gt 0 ] || [ "$AVG_MEM" -lt 300 ]; then
echo "⚠ MEMORY: Critical memory pressure detected"