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Guide to Common Errors

This document is a quick guide to identify and fix failures in custom scripts on Monsta Tecnologia. If you encountered a runtime error or an unexpected return in a sensor, consult the categories below.

Structure of each topic:

Error: Description of the symptom or log message.
Probable Cause: What usually triggers this behavior.
Solution: Step-by-step instructions for correction.

Lua script runner timeout

Field	Description
Error	Lua script runner timeout: deadline has elapsed
Cause	This error occurs when Monsta’s execution engine terminates the Lua script because it exceeded the allowed timeout for a sensor’s execution. By default, Monsta kills scripts that take too long to respond to prevent the system from hanging or consuming excessive server resources.
Solution	Go to Configuration > Parameters and use the search field to locate the `lua.timeout` key. The default value is 130 seconds. To change it, click Unlock, enter the new value and save.

Pagefile: Timeout connecting

Field	Description
Error	Pagefile: Timeout connecting to xx.xx.xx.xx:xxxx stack traceback: [C]: in function ‘poll’ [string ”?”]:x: in function ‘connect’ [string “script”]:xxx: in function <[string “script”]:xxx> (tail call): in function <(tail call):-1>
Cause	This error indicates a failure attempting to establish a network connection. The Lua script was able to start the call, but it timed out before the destination device responded to the connection handshake. The “stack traceback” shows that the failure occurred exactly at the moment of attempting the connection (`in function 'connect'`), even before any data was sent or received.
Solution	Edit the device, go to Collection > WMI and increase the WMI Timeout field. Use the “Test” button to validate communication. Then save the changes. If the problem persists, other network-related factors may be blocking this communication. In that case, check the following on your network: • Firewall/Blocking: Is there a firewall rule on the destination or along the path (ACL, IPS) blocking Monsta’s IP on the specified port. • Service Offline: The service you are trying to monitor (e.g., API, web server, database) is stopped or not listening on that specific port. • Unreachable Network: The Monsta server does not have a valid route to the destination IP. • Incorrect Port: The script is attempting to connect to a different port than the service uses. • Excessive Load on Target: The target device’s CPU is so high that it cannot process new connection requests.

Response Time: ping failed

Field	Description
Error	Tempo de Resposta: ping failed: Request timeout for icmp_seq x
Cause	This error occurs when Monsta sends an ICMP echo packet (the familiar “ping”) to a device but does not receive the reply (Echo Reply) within the expected time.
Solution	The monitored device did not respond to Monsta’s ICMP (ping) requests. 💡 Tip: If the equipment is on a network with high latency or packet loss, adjust the detection sensitivity. To do this, edit the device and go to Details > Sensitivity, changing the parameters according to the environment’s needs.

SNMP timeout stack traceback

Field	Description
Error	SNMP timeout stack traceback: [C]: in function ‘poll’ [string robbery/snmp_checker]:xx: in function ‘getex’ [string “script”]:xx: in function ‘get’ [string “script”]:xx: in main chunk
Cause	This error occurs when the script attempts an SNMP read and the connection times out without receiving the requested data.
Solution	The monitored device did not respond to Monsta’s SNMP requests. Edit the device, go to Collection > SNMP and increase the SNMP Timeout. Use the “Test” button to validate communication. Then save the changes. If the problem persists, check the following on your network: • Incorrect SNMP Community: The “Community String” (e.g., `public` or `private`) configured in Monsta does not match the one configured on the device. • SNMP Version Mismatch: The device is using SNMP v2c and the script/configuration is trying v1 (or vice-versa), or there are credential errors for v3. • ACL or Firewall: The device has an access control list (ACL) that only allows specific IPs to perform SNMP queries, and Monsta’s IP is not included. • Port Blocked: UDP port 161 (SNMP default) is blocked along the path. • SNMP Agent Overload: The monitored device’s processor is so busy that the SNMP agent cannot respond to the query in time.

Error converting to type: Float

Field	Description
Error	Error converting to type: Float
Cause	This error occurs when the system expects a decimal number (Float) but received something it cannot convert to a number, such as an invalid text (String) or a null value (`nil`).
Solution	Review the monitor script to ensure the return value does not contain strings (such as commas or measurement units) in the value field. If the monitor shows normal readings but intermittently fails with this error, the device is likely returning a null (nil) value. This happens when there is no response to the query; in such cases, check the device logs for any failures.

Error: wamp.error.no_such_procedure

Field	Description
Error	`wamp.error.no_such_procedure`
Cause	This usually indicates that the `monkerneld` service is not running on the Linux operating system where the software is installed. The `monkerneld` service is important for the software to function correctly, and its inactivity prevents Monsta from executing required procedures.
Solution	The solution involves ensuring the `monkerneld` service is started. The user can choose between two main approaches to work around this situation: A. Reboot the System: The most comprehensive way to resolve most service startup issues is to reboot the Linux system where the software is installed. On reboot, the operating system will attempt to load and start all configured services, including `monkerneld`, automatically. B. Start the Service Manually (Recommended): If rebooting is not feasible or takes too long, the user can try to start the service directly using `systemctl`, which is the standard service management tool on many modern Linux distributions (such as Ubuntu, Debian, CentOS, RHEL, etc.). Steps: 1. Open a Terminal (or use an SSH session) on the Linux server. 2. Run the following command to attempt to start the service: `sudo systemctl start monsta-com.monkerneld` Note: This command must be run with superuser (sudo) privileges. After performing either action above (rebooting the system or starting the service manually), you can check the service status to ensure it is active and running: `systemctl status monsta-com.monkerneld` The ideal status should indicate `active (running)`

Ssh error occured: Key exchange init failed

Field	Description
Error	Ssh error occured: Key exchange init failed stack traceback
Cause	This error occurs during an SSH connection attempt between Monsta and a remote device (usually older models of switches, routers, or radios). It indicates that Monsta and the device could not agree on which key exchange algorithm to use, because the device uses standards now considered legacy or insecure by modern libraries.
Solution	Monsta uses up-to-date cryptographic libraries. A key exchange failure is a warning that your remote device is operating with obsolete security standards. The definitive fix is to upgrade the monitored device so it supports secure cryptographic algorithms.

No route to host (os error 113)

Field	Description
Error	No route to host (os error 113) stack traceback
Cause	The `os error 113` is an operating system network error code indicating that the destination host could not be reached. The operating system does not know which network interface to use to send a packet to that specific IP.
Solution	To resolve the error, ensure the system’s routing table has a valid path to the destination IP and that the default gateway is configured correctly to forward packets outside the local network.