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diff --git a/health/guides/vernemq/vernemq_mqtt_subscribe_error.md b/health/guides/vernemq/vernemq_mqtt_subscribe_error.md deleted file mode 100644 index f14d18d55..000000000 --- a/health/guides/vernemq/vernemq_mqtt_subscribe_error.md +++ /dev/null @@ -1,58 +0,0 @@ -### Understand the alert - -This alert is related to `VerneMQ`, the open-source, distributed MQTT message broker. If you receive this alert, it means that the number of failed v3/v5 `SUBSCRIBE` operations has increased in the last minute. - -### What do v3 and v5 SUBSCRIBE operations mean? - -MQTT v3 and v5 are different versions of the MQTT protocol, used for the Internet of Things (IoT) devices and their communication. The `SUBSCRIBE` operation allows a client (device) to subscribe to a specific topic and receive messages published under that topic. - -### Troubleshoot the alert - -- Check the VerneMQ logs - -1. Identify the location of the VerneMQ logs. The default location is `/var/log/vernemq`. If you have changed the default location, you can find it in the `vernemq.conf` file by looking for `log.console.file` and `log.error.file`. - - ``` - grep log.console.file /etc/vernemq/vernemq.conf - grep log.error.file /etc/vernemq/vernemq.conf - ``` - -2. Analyze the logs for any errors or issues related to the `SUBSCRIBE` operation: - - ``` - tail -f /path/to/vernemq/logs - ``` - -- Check the system resources - -1. Check the available resources (RAM and CPU) on your system: - - ``` - top - ``` - -2. If you find that the system resources are low, consider adding more resources or stopping unnecessary processes/applications. - -- Check the client-side logs - -1. Most MQTT clients (e.g., Mosquitto, Paho, MQTT.js) provide their logs to help you identify any issues related to the `SUBSCRIBE` operation. - -2. Analyze the client logs for errors in connecting, subscribing, or receiving messages from the MQTT broker. - -- Analyze the topics and subscriptions - -1. Verify if there are any invalid, restricted, or forbidden topics in your MQTT broker. - -2. Check the ACLs (Access Control Lists) and client authentication settings in your VerneMQ `vernemq.conf` file. - - ``` - grep -E '^(allow_anonymous|vmq_acl.acl_file|vmq_passwd.password_file)' /etc/vernemq/vernemq.conf - ``` - -3. Ensure the `ACLs` and authentication configuration are correct and allow the clients to subscribe to the required topics. - -### Useful resources - -1. [VerneMQ Administration](https://vernemq.com/docs/administration/) -2. [VerneMQ Configuration](https://vernemq.com/docs/configuration/) -3. [VerneMQ Logging](https://vernemq.com/docs/guide/internals.html#logging)
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