I am trying to connect to Teradata using teradatasql module in Python. The code is running fine on localhost, but once deployed on the server as part of the server code, it is throwing the error.
the code:
import teradatasql
try:
host, username, password = 'hostname', 'username', '****'
session = teradatasql.connect(host=host, user=username, password=password, logmech="LDAP")
except Exception as e:
print(e)
Error I am getting on server:
[Version 16.20.0.60] [Session 0] [Teradata SQL Driver] Failure receiving Config Response message header↵ at gosqldriver/teradatasql.
(*teradataConnection).makeDriverError TeradataConnection.go:1101↵ at gosqldriver/teradatasql.
(*teradataConnection).sendAndReceive TeradataConnection.go:1397↵ at gosqldriver/teradatasql.newTeradataConnection TeradataConnection.go:180↵ at gosqldriver/teradatasql.(*teradataDriver).
Open TeradataDriver.go:32↵ at database/sql.dsnConnector.Connect sql.go:600↵ at database/sql.(*DB).conn sql.go:1103↵ at database/sql.
(*DB).Conn sql.go:1619↵ at main.goCreateConnection goside.go:275↵ at main.
_cgoexpwrap_212fad278f55_goCreateConnection _cgo_gotypes.go:240↵ at runtime.call64 asm_amd64.s:574↵ at runtime.cgocallbackg1 cgocall.go:316↵ at runtime.cgocallbackg cgocall.go:194↵ at runtime.cgocallback_gofunc asm_amd64.s:826↵ at runtime.goexit asm_amd64.s:2361↵Caused by read tcp IP:PORT->IP:PORT: wsarecv: An existing connection was forcibly closed by the remote host
The root cause of this error is outlined here by tomnolan:
The stack trace indicates that a TCP socket connection was made to the database, then the driver transmitted a Config Request message to the database, then the driver timed out waiting for a Config Response message from the database.
In other words, the driver thought that it had established a TCP socket connection, but the TCP socket connection was probably not fully successful, because a failure occurred on the initial message handshake between the driver and the database.
The most likely cause is that some kind of networking problem prevented the driver from properly connecting to the database.
I had this issue today and resolved it by altering my host. I am also on a VPN and found that the actual host name in DNS didn't work, but the ALIAS available did. For example on Windows:
C:\WINDOWS\system32>nslookup MYDB-TEST # <-- works
Server: abcd.domain.com
Address: <OMITTED>
Name: MYDB.domain.com # <-- doesn't work
Address: <OMITTED>
Aliases: mydb-test.domain.com # <-- works
I recognize this may be a specific solution option that may not work for everyone, but the root of the problem is confirmed to be a TCP connection issue from my experience.
I had been working with pyodbcfor database connection in windows envirnment and it is working fine but now I want to switch to pymssql so that it is easier to be deployed to Linux machine as well. But I am getting this error:
(20009, b'DB-Lib error message 20009, severity 9:\nUnable to connect: Adaptive Server is unavailable or does not exist (localhost:1433)\nNet-Lib error during Unknown error (10060)\n')
My connection code for using both pyodbc and pymssql is:
import pyodbc
import pymssql
def connectODSDB_1():
conn_str = (
r"Driver={SQL Server};"
r"Server=(local);"
r"Database=populatedSandbox;"
r"Trusted_Connection=yes;"
)
return pyodbc.connect(conn_str)
def connectODSDB_2():
server = '(local)'
database = 'populatedSandbox'
conn = pymssql.connect(server=server, database=database)
return conn
What could be the problem? And solution?
Well after browsing internet for a while, it seems pymssql needs TCP/IP be enabled for communication.
Open Sql Server Configuration Manager
Expand SQL Server Network Configuration
Click on Protocols for instance_name
Enable TCP/IP
I have faced the same issue while using RDS(AWS database instance). We should configured the inbound outbound rules.
Do following steps to configure.
Services->RDS->DB Instances -> Select DB-> Connectivity&Security
Under Security Section
VPC security groups -> click on security group
Change the inbound rules.
Check the source IP and change into anywhere or specific IP
I'm already using P4V client and everything is fine, no connection error.
Error:
I've got some SSL errors when I try to execute p4 command from Python.
And it's random, If i re run the script, error isnt thrown everytime
From the client, the output is :
SSL receive failed.\nread: Operation succeed : WSAECONNRESET
From the server side logs, i've got :
Connection from 90.XX.XX.93:53929 broken. SSL receive failed. read:
Connection reset by peer: Connection reset by peer
After le P4 Connection with p4.connect(), I run a p4.run_trust() command and the result seems ok
Trust already established
This error is trown doing a p4 fetch, of p4 edit myfile
Configuration
I'm starting my python script from the same computer running the P4V client. I'm using the same configuration ( user, workspace, url+port > ssl:p4.our-url.domain:1666 ). The SSL error happened with or without the P4V client started.
The SSL certificate was generated during the Perforce Server installation and configuration.
There is no apache server behind our subdomain p4.our-domain, so I can't test the SSL certificate using online SSL checker ( my network knowledge reach its limit there )
When i do a p4 info there is a "peer address", basically my IP with a random generated port (53929). What is this port ? Do i need to set a fixed port and redirect to my computer runing the script ?
Do you have any ideas where that error come from ? Is that a bad server configuration ( weird cause every p4v client in the office works).
Do i need to establish and distribute a new certificate to all users of the P4Python script ?
Python 3.5.4
PyOpenssl 18.0.0
P4Python 2017.2.1615960
Thanks a lot for any advice.
ANSWER suggested by Sam Stafford
Sam was right, It seems I got a timeout. I was opening the P4 connection and connecting to the server on the script launch, then processing was launched to generate files before using p4 fetch/add/submit. Here is a workaround to reconnect in case on disconnection from the server
# self.myp4 = P4() was created on init, files are added
submited = False
maxTry = 5
while not submited and maxTry > 0:
try:
reslist = self.p4.run_submit(ch)
except P4Exception as p4e:
print(str(self.p4.errors))
self.myp4.disconnect()
maxTry -= 1
self.myp4.connect()
submited = reslist is not None and len(reslist) > 0
That works if you want to keep the connection open. I guess the best way to avoid timeout is to call P4.connect() method just before any P4.run_*method*() and close it after. Instead of wating for timeout to restart the connection.
"Connection reset by peer" is a TCP error.
What does "connection reset by peer" mean?
Maybe your script is holding its connection open longer than P4V does, and a transient network failure during that period causes the connection to be reset? The best fix is probably to have the script catch the error, open a new connection, and pick up where it left off.
While trying to connect to MSSQL Server 2012 using pymssql, I get the following error.
My server name in Windows Authentication is SARATH,User Name is Sarath\SarathShanker and I did not set a password.
Code:
mssql_conn=pymssql.connect(host='SARATH',user='Sarath\SarathShanker',password='',database='matrix')
Error:
Traceback (most recent call last):
File "", line 1, in
File "pymssql.pyx", line 556, in pymssql.connect (pymssql.c:7990)
pymssql.OperationalError: (18452, 'Login failed. The login is from an untrusted
domain and cannot be used with Windows authentication.DB-Lib error message 18452
, severity 14:\nGeneral SQL Server error: Check messages from the SQL Server\nDB
-Lib error message 20002, severity 9:\nAdaptive Server connection failed\nDB-Lib
error message 18452, severity 14:\nGeneral SQL Server error: Check messages fro
m the SQL Server\nDB-Lib error message 20002, severity 9:\nAdaptive Server conne
ction failed\n')
How should I modify my script in order to connect to MSSQL Server using pymssql.
P.S I have already imported pymssql as well. (Not Shown in Code above)
Try this:
conn = pymssql.connect(host='myhost', database='mydb')
This is with Python Version 3.4 and for Windows Authentication.
If on RHEL, try
os.environ["FREETDSCONF"] = "/etc/freetds.conf"
If you are using the latest version of pymssql (I use 2.1.3),
pymssql.connect(server='<TEST_SERVER>', database='<TEST_DB>')
Simply replace the '' and '' with your server and DB name.
I'm having an issue connecting to my local MySQL database using Python's MySQLdb library. The script has been working well previously, but I will occasionally get the MySQL error in the title. There seems to be no explanation for when the error occurs, and the script is always run from the same machine with the same arguments.
The MySQL server is running as a service on Windows XP SP3 using port 3306 (locally hosted phpMyAdmin works), and the script is run from an Ubuntu 10.04 guest operating system in Oracle VM VirtualBox.
I am currently working around this issue by opening a command prompt and executing 'net stop MySQL' then 'net start MySQL'. This allows me to run the script a few times again before resulting in the error, which I've been fixing by restarting the MySQL service.
As I am still making changes to the script, there are occasions when the script raises an exception and doesn't exit gracefully, though I do catch the exception and close the cursor and connection.
The code to connect to the database:
def __init__(self):
try:
print "Connecting to the MySQL database..."
self.conn = MySQLdb.connect( host = "192.168.56.1",
user = "guestos",
passwd = "guestpw",
db = "testdb")
self.cursor = self.conn.cursor(MySQLdb.cursors.DictCursor)
print "MySQL Connection OK"
except MySQLdb.Error, e:
print "MySQLdb error %d: %s" % (e.args[0],e.args[1])
raise
The full error generated when this happens is as follows:
MySQLdb error 2013: Lost connection to MySQL server at 'reading initial communication packet', system error: 0
Traceback (most recent call last):
File "search.py", line 45, in <module>
dataHandler = DataHandler()
File "/home/guestos_user/workspace/Search/src/data_handler.py", line 25, in __init__
db = "testdb")
File "/usr/lib/pymodules/python2.6/MySQLdb/__init__.py", line 81, in Connect
return Connection(*args, **kwargs)
File "/usr/lib/pymodules/python2.6/MySQLdb/connections.py", line 170, in __init__
super(Connection, self).__init__(*args, **kwargs2)
_mysql_exceptions.OperationalError: (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 0")
sudo vi /etc/mysql/my.cnf
delete
bind-address = 127.0.0.1
then
sudo reboot now
That's it. Be aware that this will make your mysql server less secure as you are exposing it.
I have seen this happen when child processes try to share the same mysql connection id (solution = create new connections for each child process). I'm not sure if this is also possible when sharing connection objects with multiple threads.
However, that's only one of the many possible causes. See VVS's answer in MySQL Error 2013 for a list of troubleshooting resources.
Do you have in your MySQL server an acount called guestos#YOURIPADDRESS?
You must have an account to access to your MySQL server from YOURIPADDRESS!
For example:
Your IP address is 192.168.56.2; then you must create and account if not exist to access.
mysql> create user guestos#192.168.56.2 identified by 'guestpw';
The problem fixed for me just by restarting my mac. Though there might be a more specific fix for it.
I received a similar error when attempting to connect to my MySQL server remotely through a user with the sufficient permissions.
After editing the /etc/mysql/my.cnf file to include
[mysqld]
bind-address=xx.xx.xxx.xxx
where xx.xx.xxx.xxx is my local IP address, I began experiencing the exact same error as you. From there, I found an answer regarding this issue (answered by Coffee Converter) which worked for me, and can be found here: Lost connection to MySQL server at 'reading initial communication packet', system error: 0 on a windows machine
All I did to fix the issue for myself was edit the /etc/hosts.allow to include
mysqld: ALL: allow
Works great now! I hope this helped :)
Could you change the bind-address=localhost and restart MySQL server? Seems like this issue is related to yours: http://forums.mysql.com/read.php?152,355740,355742#msg-355742
Also this-
If MySQL port is wrong result is MySQL client error 2013 "Lost
connection ...". Note that this error also occurs if port forwarding
is disabled in SSH configuration (the configuration parameter
'AllowTcpForwarding' is set to 'no' in the 'sshd_config' file). It
(here) simply tells that there is no connection from SSH to MySQL for
some reason. But the mySQL client API 'thinks' there was one
connection and that is why is says 'Lost connection ...' and not
'Can’t connect...'. There was one successful connection - but not to
the MySQL server - to the SSH daemon only! But the MySQL client API is
not designed to 'see' the difference!
Refer this.
I run a windows server and from time to time the php-win.exe will load and stay in the processes list on the windows task manager.
If you know the host file is correct, then kill the php-win.exe process and restart iis iisreset
If you are running windows then your problem should be solved.
I've had the exact same mysql error (ERROR 2013 (HY000): Lost connection to MySQL server at 'reading initial communication packet', system error: 0=) and have resolved it by adding a newline to /etc/hosts.deny.
Possibility: your database is corrupted.
I encountered this situation when I was running an UPDATE statement on a specific row of a specific table. (Specifically, I was editing an item in a Django Admin site.) Most of the time the database worked just fine.
I finally resolved the problem by running:
OPTIMIZE TABLE `your_table`
After that everything was OK, no connection lost.
Conclusion:
The problem "Lost connection to MySQL server at 'reading initial communication packet'", sometimes "Can't connect to MySQL server on '127.0.0.1'", could possibly be resolved by running a full database optimization if the database is corrupted. For more info, read this.
Just to further extend the list of possible causes: it could also be as banal as wrong connection data/credentials. I encountered this error in conjunction with sqlalchemy:
sqlalchemy.exc.OperationalError: (mysql.connector.errors.OperationalError) 2013 (HY000): Lost connection to MySQL server at 'reading initial communication packet', system error: 0
In my code I connect to several different databases and once in a while it happens that I don't get the mapping between the db connections and their credentials (e.g. ip address of server, db-name, password etc.) right, which then also results in the 2013-error (in this case wrapped into an sqlalchemy operational error).
setting.py file set like:
'ENGINE': 'django.db.backends.mysql',
'NAME': 'test2',
'USER': 'root',
'PASSWORD': '',
'HOST': 'localhost',
'PORT': '3308',
This bug report might be of interest to you. Don't know if this will help you, but some were able to solve it by using the name of the server rather than the ip address in the connection properties.