Tag Archives: TDengine

[Solved] failed to connect to server, reason: Unable to establish connection

Prerequisites: Precautions for installing in Windows:

Note:

    1. You need to install the server side, start taosd.exe, and wait for the
10/12 10:45:10.026000 00022304 DND TDengine initialized successfully
10/12 10:46:10.463000 00022216 MND succeed to send telemetry report

Then keep taosd.exe opened. Use the taos command of the taos shell to check whether it is started. If it succeeds, a prompt appears:

Server is Community Edition.

2. Check whether the configuration is modified successfully

taos.cfg

hosts

    Add a line of ipv4 address computer name at the end of the file, eg:
192.168.1.32 nodes1

[Solved] Cause: java.sql.SQLException: TDengine ERROR (8000000b): Unable to establish connection

FQDN is not configured during installation and configuration. There is no error when starting spingboot. The following error is reported when inserting data

Tdengine error (800000b): unable to establish connection

### Cause: java.sql.SQLException: TDengine ERROR (8000000b): Unable to establish connection

Solution:

vi /etc/taos/taos.cfg

/var/lib/taos/dnode/dnodeEps.json

The local windows system must install the client tdengine-client

Hosts to be set, as shown in the following figure

[Solved] TDengine Error: Unable to resolve FQDN

TDengine Error: Unable to resolve FQDN

Project scenario:

Win10 using Python link tdengine to read the database

Problem description

Problems encountered in the Project:

Unable to resolve FQDN is reported when the code reads the contents of the database

# connect the database of taos
conn = taos.connect(host=ip, user=user, password=pwd, database=db_database)
cursor = conn.cursor()
cursor.execute('select * from sensor_data')

Solution:

In the server, find the contents under the/etc/hosts file, copy them to the local file C:\Windows\System32\drivers\etc\hosts, and rerun the code

JNI ERROR (2354): JNI connection is NULL [How to Solve]

JNI error (2354) encountered by tdengine during springboot integration: JNI connection is null
possible problems are as follows
1. The client version of tdengine is inconsistent with the server version
2. The server version and jdbc driver version are not matched. The following figure shows the version correspondence figure

Tdengine failed to start, start request repeated too quickly for taosd.service

When you disable TDEngine, you will be presented with Start Request (as evidenced by Too Quickly for Taosd.service)

The solution
Edit taosd.service and look at the prompts. Line 3 of the image above. Loaded: Loaded follows

vim /etc/systemd/system/taosd.service

Modify StartLimitBurst = 0

[Unit]
Description=TDengine server service
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
ExecStart=/usr/bin/taosd
ExecStartPre=/usr/local/taos/bin/startPre.sh
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
StandardOutput=null
Restart=always
StartLimitBurst=0
StartLimitInterval=60s

[Install]
WantedBy=multi-user.target

Launch OK again