List of all parameters included in the Linux environment Monitoring service

Parameter Description OK WARNING CRITICAL Threshold Warning Threshold Critical
Check run_tools script Checks the successful execution or status of a specific system maintenance or utility script. Last execution completed successfully within expected time Execution completed with warnings or exceeded expected runtime Script failed, did not run, timed out, or returned an error    
CPU Idle Checks the percentage of CPU time that is not being used by any process. CPU idle is within normal range CPU idle is low for a sustained period CPU idle is critically low; CPU is saturated <20% idle <10% idle
CPU Temperature Monitors the temperature of the CPU cores and the server case for overheating. All CPU cores < 60°C Any CPU core >= 60°C Any CPU core >= 70°C >=60°C >=70°C
Current Load Monitors the average system load (number of processes waiting for CPU time) over 1, 5, and 15 minutes. Load average below warning thresholds (1/5/15) Load average >= 125,120,115 (1/5/15) Load average >= 150,145,140 (1/5/15) 125,120,115 150,145,140
Current Users Checks the number of users currently logged into the system. Logged-in users <= 5 Logged-in users > 5 Logged-in users > 10 5 10
Memory Usage Monitors the total system RAM usage (used vs. free memory). Free/available memory is >= 10% Free/available memory is < 10% Free/available memory is < 5% <10% free <5% free
Swap Usage Monitors the utilization of the swap space (virtual memory on disk). Swap free is >= 80% (or no active swapping) Swap free is < 80% (or moderate active swapping) Swap free is < 50% (or heavy active swapping) <80% free <50% free
Total Processes Checks the total number of processes currently running on the system. Total processes < 2000 Total processes >= 2000 Total processes >= 2500 2000 2500
Zombie Processes Monitors the number of processes that have terminated but have not yet been reaped by their parent process. Zombie processes < 5 Zombie processes >= 5 Zombie processes >= 10 5 10
APACHE Status Monitors the status and performance metrics of the Apache web server (e.g., number of workers, idle threads). Apache is running and responding normally Apache is running but under high load / degraded performance Apache is down or not responding    
Check FTP Checks the availability and response time of the File Transfer Protocol (FTP) service. FTP service reachable and responding FTP responding slowly or intermittently FTP service unreachable or down    
Check Mailq Monitors the size or status of the mail queue for pending emails. Mail queue size within normal limits Mail queue is growing / above warning threshold Mail queue extremely large or stuck (not decreasing)    
Check MySQL Monitors the size or status of the mail queue for pending emails. MySQL reachable and basic health checks pass MySQL reachable but performance/replication indicators degraded MySQL down, refusing connections, or health check failed    
Check RBL Checks if the server's IP address is listed on any common Real-time Blackhole Lists (RBLs) for spam. IP address is not listed on common RBLs - IP address is listed on one or more RBLs    
Check SSL cert Monitors the expiration date and validity of the SSL certificate for a specified domain. Certificate valid and not close to expiry Certificate expiring soon Certificate expired, invalid, or hostname mismatch  
Memcached Status Checks the availability and performance metrics of the Memcached key-value store. Memcached reachable and responding Memcached responding slowly or intermittently Memcached unreachable or down > 200 ms No response / connection failed
IPTABLES Status Checks the running status of the IPTABLES firewall service. Firewall service is running and rules are loaded - Firewall service stopped and/or rules missing    
PING Checks if the server is reachable on the network, measures packet loss, and Round Trip Time (RTA). Host reachable with acceptable latency and no/low loss Packet loss and/or latency above warning threshold Host unreachable or loss/latency at critical level    
Portscan Checks whether specific (expected) ports are open or closed on the server. All required ports are in the expected state Non-critical port mismatch detected Critical port mismatch (required closed/open) detected    
Check Raid Checks the health and status of the server's hardware or software RAID array. RAID array is healthy/optimal RAID is degraded but still operational RAID failed or data is at risk    
Check Smart sda Checks the Self-Monitoring, Analysis and Reporting Technology (SMART) status for the disk drive sda. SMART status OK SMART indicates degrading attributes SMART reports failure or imminent failure    
Free Space Storage Checks the available free disk space on a primary storage mount point. Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
Free Space home Checks the available free disk space on the /home directory partition. Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
Free Space mysql Checks the available free disk space on the partition hosting MySQL data. Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
Free Space root Checks the available free disk space on the / (root) partition. Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
Free Space usr Checks the available free disk space on the /usr partition. Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
Free Space var Checks the available free disk space on the /var partition (often used for logs). Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
Free Space www Checks the available free disk space on the partition hosting web content (e.g., /var/www). Free space is >= 20% Free space is < 20% Free space is < 10% <20% free <10% free
I/O sda Monitors the input/output operations and performance for disk drive sda. Disk I/O latency and utilization within normal limits High disk I/O latency/utilization detected Disk I/O saturated/timeouts; severe performance impact Latency >400ms <=800ms Latency>800ms