I am getting the error OperationalError: FATAL: sorry, too many clients already when using psycopg2. I am calling the close method on my connection instance after I am done with it. I am not sure what could be causing this, it is my first experience with python and postgresql, but I have a few years experience with php, asp.net, mysql, and sql server.
EDIT: I am running this locally, if the connections are closing like they should be then I only have 1 connection open at a time. I did have a GUI open to the database but even closed I am getting this error. It is happening very shortly after I run my program. I have a function I call that returns a connection that is opened like:
psycopg2.connect(connectionString)
Thanks
Final Edit:
It was my mistake, I was recursively calling the same method on mistake that was opening the same method over and over. It has been a long day..
This error means what it says, there are too many clients connected to postgreSQL.
Questions you should ask yourself:
Are you the only one connected to this database?
Are you running a graphical IDE?
What method are you using to connect?
Are you testing queries at the same time that you running the code?
Any of these things could be the problem. If you are the admin, you can up the number of clients, but if a program is hanging it open, then that won't help for long.
There are many reasons why you could be having too many clients running at the same time.
Make sure your db connection command isn't in any kind of loop. I was getting the same error from my script until I moved my db.database() out of my programs repeating execution loop.
It simple means many clients are making transaction to PostgreSQL at same time.
I was running Postgis container and Django in different docker container. Hence for my case restarting both db and system container solved the problem.
Related
I have set up a telegram bot to fetch data from my mysql db.
Its running well until like after 1 day..And It just cannot connect:
File "/usr/local/lib/python3.8/site-packages/mysql/connector/connection.py", line 809, in cursor
raise errors.OperationalError("MySQL Connection not available.")
I have checked that the script is perfect and I can even run it perfectly on the server, while at the same time if it run through the bot , it throws the above errors.
Even so ,it will resume to normal after I reboot the apache server. Can anyone help??? Thanks first.
It turns out that its not related to my bot. But sql connection called by my django server (not orm, but mysql.connector.)
I didn't close the connection properly (I closed cursor). After I closed the connection conn.close()immediately after the fetch, the problem vanished.
Yet I still dun understand why it doesn't cause any problem when i run the script manually. I feel its something about connection time. I am no expert of mysql, in fact I am just a amateur of programming. see anyone can give further solution. (I have changed the title in order to make my problem more relevant.)
I am consistently getting this error under normal conditions. I am using the Python Cassandra driver (v3.11) to connect locally with RPC enabled. The issue presents itself after a period of time. y assumption was that it was related to max number of connections or queries. Any pointers on where to begin troubleshooting would be greatly appreciated.
Please check if your nodes are really listening by opening up a separate connection from say cqlsh terminal, as you say it is running locally so probably a single node. If that connects, you might want to see how many file handles are open, maybe it is running out of those. We had a similar problem couple of years back, that was attributed to available file handles.
I'm having trouble with MySQL timing out and going away after 8 hours. I am using google app engine as a host. My Python script uses the Tornado framework.
Right now I instantiate my MySQL db connection before any functions right at the top of the main server script. Once I deploy that, the clock starts ticking and 8 hours or so later, MySQL will go away and I will have to deploy my script again.
I haven't been using db.close() at all because I hear that restarting the database connection takes a long time. Is this true? Or is there a proper way to use db.close()?
One of my friends suggested I try getting the database instance and then closing it after each function.. is that recommended and where might I find some tutorials on that?
I'm mostly looking for resources here, but if someone wants to lay it out for me that would be awesome.
Thank you all in advance.
The connection is going away because of the wait_timeout session variable which
is the number of seconds the server waits for activity on a noninteractive connection
before closing it.
http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html#sysvar_wait_timeout
Good way is to close the connection each time and create a new one if you are not reusing the same connection so frequently, otherwise you can increase the value of wait_timeout
Establishing a connection to a MySQL database should be quite fast and it is certainly good practice to keep the connection open only for as long as you need it.
I am not certain why your connection should be non-responsive for 8 hours - have you tried checking your settings?
The correct command in Python is connection.close().
I am running client that is connecting to a redis db. The client is on a WiFi connection and will drop the connection at times. Unfortunately, when this happens, the program just keeps running without throwing any type of warning.
r = redis.StrictRedis(host=XX, password=YY...)
ps = r.pubsub()
ps.subscribe("12345")
for items in ps.listen():
if items['type'] == 'message':
data = items['data']
Ideally, what I am looking for is a catch an event when the connection is lost, try and reestablish the connection, do some error correcting, then get things back up and running. Should this be done in the python program? Should I have an external watchdog?
Unfortunately, one have to 'ping' Redis to check if it is available. If You try to put a value to Redis storage, it will raise an ConnectionError exception if connection is lost. But the listen() generator will not close automatically when connection is lost.
I think that hacking Redis' connection pool could help, give it a try.
P.S. In is very insecure to connect to redis in an untrusted network environment.
This is an old, old question but I linked one of my own questions to it and happened to run across it again. It turned out there was a bug in the redis library that caused the client to enter an infinite loop attempting to reconnect if it lost connection to the redis server. I debugged the issue and PR'd the change. it was merged a long time ago now. Once surfaced the maintainer also knew of a second location that had the same issue.
This problem shouldn't occur anymore.
To fully answer the question, I can't remember which error it is given the time since I fixed this but there is now a specific error returned you can catch and reconnect on.
I'm using SQLAlchemy 0.6.6 against a Postgres 8.3 DB on Windows 7 an PY 2.6. I am leaving the defaults for configuring pooling when I create my engine, which is pool_size=5, max_overflow=10.
For some reason, the connections keep piling up and I intermittently get "Too many clients" from PG. I am positive that connections are being closed in a finally block as this application is only accessed via WSGI (CherryPy) and uses a connection/request pattern. I am also logging when connections are being closed just to make sure.
I've tried to see what's going on by adding echo_pool=true during my engine creation, but nothing is being logged. I can see SQL statement rolling through the console when I set echo=True, but nothing for pooling.
Anyway, this is driving me crazy because my co-worker who is on a Mac doesn't have any of these issues (I know, get a Mac), so I'm trying to see if this is the result of a bug or something. Google has yielded nothing so I'm hoping to get some help here.
Thanks,
cc
Turns out there was ScopedSession being used outside the normal application usage and the close wasn't in a finally.