Moving measurement data between InfluxDB databases

I want to move my energy measurement data to another InfluxDB database on the same server to create a new downsampling policy.

select * into Verhaeg_Energy..[measurement_name_destination] from Verhaeg_IoT..[measurement_name_source] group by *

Be aware of the .. in between the database name and the measurement name.

InfluxDB api unavailable after x attempts

The InfluxDB start-up script checks if the HTTP service is running by trying to connect to it. However, I have disabled HTTP in my configuration and use HTTPS. This behavior is also described on Github.

You can workaround this issue by adjusting the InfluxDB service configuration file (/etc/systemd/system/influxd.service). The commented out lines are old configuration and replaced by the used lines.

[Unit]
Description=InfluxDB is an open-source, distributed, time series database
Documentation=https://docs.influxdata.com/influxdb/
After=network-online.target

[Service]
User=influxdb
Group=influxdb
LimitNOFILE=65536
EnvironmentFile=-/etc/default/influxdb
ExecStart=/usr/bin/influxd -config /etc/influxdb/influxdb.conf $INFLUXD_OPTS
#ExecStart=/usr/lib/influxdb/scripts/influxd-systemd-start.sh
KillMode=control-group
Restart=on-failure
Type=simple
#Type=forking
PIDFile=
#PIDFile=/var/lib/influxdb/influxd.pid

[Install]
WantedBy=multi-user.target
Alias=influxd.service

Configure TLS for Mosquitto using a self-signed certificate

This article describes how to configure TLS for Mosquitto using a self-signed certificate. I assume that Mosquitto is installed and running.

Browse to the right directory:

cd /etc/mosquitto/certs 

Generate a 3DES private key using OpenSSL and put it in the moquitto directory for certificates:

openssl genrsa -des3 -out ca.key 2048

Generate the 3DES certificates using the private key:

openssl req -new -x509 -days 3650 -key ca.key -out ca.crt

Copy the certificate to the right directory:

sudo cp ca.crt /etc/mosquitto/ca_certificates/

Generate an RSA private key :

openssl genrsa -out server.key 2048

Generate the RSA public key:

openssl req -new -out server.csr -key server.key

Generate the RSA certificates using the private key:

openssl x509 -req -in server.csr -CA ca.crt -CAkey ca.key -CAcreateserial -out server.crt -days 3650

Configure Mosquitto to listen for TLS connections:

cd /etc/mosquitto/conf.d
nano listener.conf

listener xxxx 192.168.x.x
cafile /etc/mosquitto/ca_certificates/ca.crt
certfile /etc/mosquitto/certs/server.crt
keyfile /etc/mosquitto/certs/server.key
require_certificate false

I don’t enforce the usage of a certificate.

Go to the certificates folder and give the right permissions to the generated certificates.

cd /etc/mosquitto/certs
chmod 400 server.key
chmod 444 server.crt
chown mosquitto server*

Restart the Mosquitto service:

systemctl restart mosquitto.service

This is working for me now. However, while I was documenting this process I figured out I might have mixed up the 3DES and RSA certificates in the Mosquitto configuration. Something to look into at a later moment in time.