Issue in connecting Python with MySQL on Google Cloud Platform - python

I have used the following code in Python:
import mysql.connector as mysql
import sys
HOST = "34.87.95.90"
DATABASE = "CAO_db"
USER = "root"
PASSWORD = "*********"
db_connection = mysql.connect(user=USER, password=PASSWORD, host=HOST, database=DATABASE)
cur = db_connection.cursor()
When I run the above code, I get the following error messages:
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
InterfaceError: 2003: Can't connect to MySQL server on '34.87.95.90:3306' (10060 A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond)
I am not sure of how to fix my code and/or resolve the given errors. Please ask me if you would like more details of the error messages to help with the issue. I would greatly appreciate all the help I can get towards resolving the issues.

One thing I'm not seeing here is whether or not you have configured your Cloud SQL instance to accept connections.
You can configure it to accept connections from within the GCP stratosphere using their "Private IP" internal networking magic, AND you can configure it to accept connections from other machines using a combination of Public IP and either an authorized external network (like if you were accessing your GCP Cloud SQL instance from, say, an Amazon EC2 instance), or their Cloud SQL Proxy tool (which is what I use to connect to my Cloud SQL instance from my laptop).
In the GCP Console, go to your project
From the hamburger menu, select SQL
Click on your Cloud SQL instance
In the left nav, click on Connections
If you have Private IP checked and you're running this code on a GCP Compute/GKE resource, confirm that the "Network" field is set to the network used by that resource.
If you're just trying to get a connection from your local machine and you don't have a static IP to whitelist, your best option is to use Public IP in combination with Cloud SQL Proxy.
Cloud SQL Proxy essentially creates a TCP tunnel that allows your laptop to connect to 'localhost' on a port you specify, and it then redirects your connection to the remote Cloud SQL instance.
Once you've established that your networking situation isn't the problem, you could use the same Python connection code that you wrote above, but change HOST to 127.0.0.1 and add an attribute for PORT=3308.
EDITED to add: I suggest using PORT=3308 for your cloud_sql_proxy connection so that it doesn't interfere with any existing port 3306 (MySQL default) connections that you may already be actually running on your local machine. If this isn't the case, you can either omit the PORT attribute or keep it explicit, but change it to 3306.

Related

Redshift new cluster used to be accessible but not anymore

Last week, I was able to successfully connect to Redshift clusters. This week I am unable to connect even though I gave same configs for the following:
Virtual Private Cloud VPC
Security Groups
Cluster subnet group
Publicly accessible Cluster permissions
But this week I get the error
Traceback (most recent call last):
File "create_staging_tables.py", line 93, in <module>
conn = psycopg2.connect(
File "/Users/bsubramanian/.pyenv/versions/3.8.2/lib/python3.8/site-packages/psycopg2/__init__.py", line 122, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not connect to server: Operation timed out
Is the server running on host "clustername.region.redshift.amazonaws.com" (54.243.82.201) and accepting
TCP/IP connections on port 5439?
when running from a Python script which is used to connect to redshift cluster and create some tables.
How do I debug what is wrong?
Typically these issues are network related. Checking connectivity from your client system to the database is a good start.
First off check the connection information - go to the Redshift console and confirm the IP address given in the error message is the IP address of the leader node. If these don't match your code has some wrong configuration. (Note that Redshift can also have a public IP if you configured the cluster as such. Most users don't do this for security reasons. If you do you likely should be using that IP address.)
Next a simple test of network connectivity is a good step. The Linux command telnet can do this - telnet 5439. Now telnet cannot talk to Redshift but if you get any response other than a time out telnet is able to make the initial connection to Redshift. If this doesn't work then a lot more information about your network configuration will be needed to debug.
Now all of this assumes you don't have a connection pool server in between your client and the DB. It looks to be the case but ...
If you can connect via IP address but not with the cluster DNS name then a DNS issue is likely. We'll need more info on your DNS setup (and some on the network). This doesn't look to be the issue but ...
If telnet can connect but your client cannot (with the same info) then it could be a security group configuration issue.
There are lots of possibilities. Start by checking the connection info and update the issue as you learn more.
I was able to resolve this by creating new instances of the following
Virtual Private Cloud(VPC)
VPC Security Group
Cluster Subnet group

Remote access to mySQL using Python

I have trouble connecting to my mySQL database remotely through Python.
I use the following to connect to mySQL:
import mysql.connector
cnx = mysql.connector.connect(host='XXX.XXX.XXX.X',user='XXXX',password='XXXXXX',database='testdb')
But I get the following error:
2003: Can't connect to MySQL server on '%HOST%:3306' (10060 A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond)
The server is running and when I run the same code on the computer I run the server from using 'localhost'
import mysql.connector
cnx =
mysql.connector.connect(host='localhost',user='XXXX',password='XXXXXX',database='testdb')
it works and I can modify the data in the database. I'm trying to connect it remotely from another computer though.
I've tried using GRANT ALL ON *.* TO User#Host IDENTIFIED BY 'password'; but no result. I checked my firewall and allowed all incoming and outgoing connections through port 3306 which is used by default.
I'm new to mySQL and really have no clue what to do. I don't even know if I use the correct hostname :') I use the IP address of the computer I run the server from,I think that's right.
You dont need to GRANT ALL privilage to the user. You need to tell MYSQL that this user is allowed to login from a remote location.
In fact as you are allowing remote access through this user account now, you should make sure that it can access only the database(s) it needs to, and definitely cannot use GRANT
For example
CREATE USER 'myuser'#'%' IDENTIFIED BY 'mypass';
Will allow this user to connect from any ip address. To be more secure you should try to be more specific and specify a individual ip address if you can
CREATE USER 'myuser'#'11.22.33.44' IDENTIFIED BY 'mypass';
Remember, you are creating a new user account here because you already have a
myuser#localhost
Either way you need to make sure that the password is a strong one, specially is you use the % any ip option

pyodbc: How to test whether it's possible to establish connection with SQL server without freezing up

I am writing an app with wxPython that incorporates pyodbc to access SQL Server. A user must first establish a VPN connection before they can establish a connection with the SQL server. In cases where a user forgets to establish a VPN connection or is simply not authorized to access a particular server, the app will freeze for up to 60+ seconds before it produces an error message. Often, users will get impatient and force-close the app before the error message pops up.
I wonder if there is a way to test whether it's possible to connect to the server without freezing up. I thought about using timeout, but it seems that timeout can be used only after I establish a connection
A sample connection string I use is below:
connection = pyodbc.connect(r'DRIVER={SQL Server};SERVER=ServerName;database=DatabaseName;Trusted_Connection=True;unicode_results=True')
See https://code.google.com/archive/p/pyodbc/wikis/Connection.wiki under timeout
Note: This attribute only affects queries. To set the timeout for the
actual connection process, use the timeout keyword of the
pyodbc.connect function.
So change your connection string to:
connection = pyodbc.connect(r'DRIVER={SQL Server};SERVER=ServerName;database=DatabaseName;Trusted_Connection=True;unicode_results=True', timeout=3)
should work
took a while before it threw an error message about server not existing or access being denied
Your comment conflates two very different kinds of errors:
server not existing is a network error. Either the name has no address, or the address is unreachable. No connection can be made.
access being denied is a response from the server. For the server to respond, a connection must exist. This is not to be confused with connection refused (ECONNREFUSED), which means the remote is not accepting connections on the port.
SQL Server uses TCP/IP. You can use standard network functions to determine if the network hostname of the machine running SQL Server can be found, and if the IP address is reachable. One advantage to using them to "pre-test" the connection is that any error you'll get will be much more specific than the typical there was a problem connecting to the server.
Note that not all delay-inducing errors can be avoided. For example, if the DNS server is not responding, the resolver will typically wait 30 seconds before giving up. If an IP address is valid, but there's no machine with that address, attempting a connection will take a long time to fail. There's no way for the client to know there's no such machine; it could just be taking a long time to get a response.

Pymongo connection timeout from remote machine

I have a Bitnami MEAN Stack running on AWS EC2. I'm trying to connect from a remote machine using PyMongo.
from pymongo import MongoClient
conn = MongoClient('mongodb://username:password#ec2blah.us-east-1.compute.amazonaws.com:27017/dbname')
but I keep getting an error along the lines of pymongo.errors.ConnectionFailure: timed out
I have edited /opt/bitnami/mongodb/mongodb.conf to supposedly allow external connections by commenting out bind_ip = 127.0.0.1 and uncommented bind_ip = 0.0.0.0 and all permutations of commenting/uncommenting those lines.
I've looked over the web for about 90 minutes now trying different things but without luck!
On the mongoDB server, do the port connection test, and make sure the DB service running well. If not, start the service.
telnet ec2blah.us-east-1.compute.amazonaws.com 27017
On the remote machine, do the port connection test, to make sure there is no firewall issue.
telnet ec2blah.us-east-1.compute.amazonaws.com 27017
If you have issue to connect, you need check security groups on this instance.
Click the ec2 instance name --> Description --> view rules, you should see the ports are opened
If not, create a new security group , such as `mongoDB`, tcp port 27017 should be opened for inbound traffic, then assign to that instance.
You should be fine to connect it now.
At the time of start-up of MongoDB, set the bind_ip argument to ::,0.0.0.0
mongod --bind_ip ::,0.0.0.0
Read more in the docs of MongoDB: IP Binding.

Using Pymongo to connect to MongoDB on AWS instance from Windows

An error is repeatedly being thrown at this line:
client = MongoClient('ec2-12-345-67-89.us-east-2.compute.amazonaws.com', 27017,
ssl=True, ssl_keyfile='C:\\mongo.pem')
(Paths and instance name changed for obvious reasons)
The port (27017) for mongo is allowed inbound connections from my AWS security group. First, I allowed only my IP, now I'm allowing all via that port. I have tried preceding the connection string with "mongodb://" and removing the SSL arguments (I'm fairly certain I don't need it).
The error IntelliJ keeps throwing me is:
pymongo.errors.ConnectionFailure: [WinError 10061] No connection could be made because the target machine actively refused it
It works if I transport the script to the AWS instance and replace the DNS with 'localhost' and remove SSL parameters, but I need this to work remotely.
Three ideas:
Ensure "bind_ip" is set to "0.0.0.0" in your mongod.conf and restart mongod, as #ajduke suggests.
Make sure mongod is running.
Try to connect to the mongod from your client machine using the "mongo" shell to see if it gives you a more informative error.

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