I have a local network connecting 15 PCs. Every PC has postgres installed (8.3, 8.4, 9.2). Every database has the exact same installation parameters as name, user, password, etc.
I'm using a Java application, which implements JDBC library and I have been able to connect correctly to the databases in EVERY computer but one. I'm pretty sure I have set correctly the necesary parameters for pg_hba.conf and postgresql.conf, because they are set the same in all the 15 PCs.
I also have set the Windows Firewall exception for the port 5432
All this has lead me to conclude that the problem lies in that specific PC that doesn't accepts the connection. It has Windows 7 Ultimate installed, the same as the rest, and postgres 8.3.
This is the error that i get: org.postgresql.util.PSQLException: Connection attempt timed out.
I don't want to format the PC from zero
Can someone help me with this?
Well, now I know how to solve the problem with a not very orthodox solution. When this happens, we just copy the pg_hba.conf from a working PC and this solves the problem. I hope this helps.
Related
I am new to Oracle, and am trying to run a simple example code with Java, but am getting this error when executing the code.. I am able to start up the listener via CMD and am also able to run SQL Plus. Can anyone give me a hand and tell me what I might be doing wrong?
Update:
I am using JDBC.
Database is local, and I actually had it working but it stopped working just today. I'm not really sure why though. Would you mind giving me some procedures to follow by since I don't know much.
Either:
The database isn't running
You got the URL wrong
There is a firewall in the way.
(This strange error message is produced by Oracle's JDBC driver when it can't connect to the database server. 'Network adapter' appears to refer to some component of their code, which isn't very useful. Real network adapters (NICs) don't establish connections at all: TCP protocol stacks do that. It would have been a lot more useful if they had just let the original ConnectException be thrown, or at least used its error message and let it appear in the stack trace.)
I had the same problem, and this is how I fixed it.
I was using the wrong port for my connection.
private final String DB_URL = "jdbc:oracle:thin:#localhost:1521:orcll"; // 1521 my wrong port
go to your localhost
(my localhost address) : https://localhost:1158/em
login
user name
password
connect as --> normal
Below 'General' click on LISTENER_localhost
look at you port number
Net Address (ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1522))
Connect to port 1522
Edit you connection
change port 1521 to 1522.
done
Another thing you might want to check that the listener.ora file matches the way you are trying to connect to the DB. If you were connecting via a localhost reference and your listener.ora file got changed from:
HOST = localhost
to
HOST = 192.168.XX.XX
then this can cause the error that you had unless you update your hosts file to accommodate for this. Someone might have made this change to allow for remote connections to the DB from other machines.
I figured out that in my case, my database was in different subnet than the subnet from where i was trying to access the db.
I had this error when i renamed the pc in the windows-properties. The pc-name must be updated in the listener.ora-file
Most probably you have listener configured wrongly, the hostname you specify in connection string must be the same as in the listener.
First check the Firewall and network related issues.
Check if Oracle Listener service is available and running. If not you may use Oracle Net Configuration Assistant tool to add and register new listener.
If the above steps are ok then you need to configure Oracle Listener appropriately. You may use Oracle Net Manager tool or edit “%ORACLE_HOME%\network\admin\listener.ora” file manually.
There are 2 options that need to be considered carefully:
Listening Locations associated with the Listener – Hostname(IP) and Port in Listening Location must exactly match the ones used in the connection string.
For example, if you use 192.168.74.139 as target hostname, then there must be Listening Location registered with the same IP address.
Also make sure the you use the same SID as indicated in Database Service associated with the Listener.
https://adhoctuts.com/fix-oracle-io-error-the-network-adapter-could-not-establish-the-connection-error/
IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=iKQM6lBbSLiArrYuDqud8A==)
if you are facing this issue
1- make sure you have downloaded oracle databases like oracle 11g,19c, 21c, or any latest databases.
2- search for services in your computer or type win+r then services.mis then search for oracleservice you will find orcl or xe or any other sid like oracleserviceorcl;
after that you can test your connection using sql developer, sql plus or cmd
To resolve the Network Adapter Error I had to remove the - in the name of the computer name.
In my case, I needed to specify a viahost and viauser. Worth trying if you're in a complex system. :)
For me the basic oracle only was not installed. Please ensure you have oracle installed and then try checking host and port.
I was having issues with this as well. I was using the jdbc connection string to connect to the database. The hostname was incorrectly configured in the string. I am using Mac, and the same string was being used on Windows machines without an issue. On my connection string, I had to make sure that I had the full url with the appending "organizationname.com" to the end of the hostname.
Hope this helps.
Just try to re-create connection. In my situation one of jdbc connection stopped working for no reason. From console sqlplus was working ok.
It took me 2 hours to realize that If i create the same connection - it works.
I am new to Oracle, and am trying to run a simple example code with Java, but am getting this error when executing the code.. I am able to start up the listener via CMD and am also able to run SQL Plus. Can anyone give me a hand and tell me what I might be doing wrong?
Update:
I am using JDBC.
Database is local, and I actually had it working but it stopped working just today. I'm not really sure why though. Would you mind giving me some procedures to follow by since I don't know much.
Either:
The database isn't running
You got the URL wrong
There is a firewall in the way.
(This strange error message is produced by Oracle's JDBC driver when it can't connect to the database server. 'Network adapter' appears to refer to some component of their code, which isn't very useful. Real network adapters (NICs) don't establish connections at all: TCP protocol stacks do that. It would have been a lot more useful if they had just let the original ConnectException be thrown, or at least used its error message and let it appear in the stack trace.)
I had the same problem, and this is how I fixed it.
I was using the wrong port for my connection.
private final String DB_URL = "jdbc:oracle:thin:#localhost:1521:orcll"; // 1521 my wrong port
go to your localhost
(my localhost address) : https://localhost:1158/em
login
user name
password
connect as --> normal
Below 'General' click on LISTENER_localhost
look at you port number
Net Address (ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1522))
Connect to port 1522
Edit you connection
change port 1521 to 1522.
done
Another thing you might want to check that the listener.ora file matches the way you are trying to connect to the DB. If you were connecting via a localhost reference and your listener.ora file got changed from:
HOST = localhost
to
HOST = 192.168.XX.XX
then this can cause the error that you had unless you update your hosts file to accommodate for this. Someone might have made this change to allow for remote connections to the DB from other machines.
I figured out that in my case, my database was in different subnet than the subnet from where i was trying to access the db.
I had this error when i renamed the pc in the windows-properties. The pc-name must be updated in the listener.ora-file
Most probably you have listener configured wrongly, the hostname you specify in connection string must be the same as in the listener.
First check the Firewall and network related issues.
Check if Oracle Listener service is available and running. If not you may use Oracle Net Configuration Assistant tool to add and register new listener.
If the above steps are ok then you need to configure Oracle Listener appropriately. You may use Oracle Net Manager tool or edit “%ORACLE_HOME%\network\admin\listener.ora” file manually.
There are 2 options that need to be considered carefully:
Listening Locations associated with the Listener – Hostname(IP) and Port in Listening Location must exactly match the ones used in the connection string.
For example, if you use 192.168.74.139 as target hostname, then there must be Listening Location registered with the same IP address.
Also make sure the you use the same SID as indicated in Database Service associated with the Listener.
https://adhoctuts.com/fix-oracle-io-error-the-network-adapter-could-not-establish-the-connection-error/
IO Error: The Network Adapter could not establish the connection (CONNECTION_ID=iKQM6lBbSLiArrYuDqud8A==)
if you are facing this issue
1- make sure you have downloaded oracle databases like oracle 11g,19c, 21c, or any latest databases.
2- search for services in your computer or type win+r then services.mis then search for oracleservice you will find orcl or xe or any other sid like oracleserviceorcl;
after that you can test your connection using sql developer, sql plus or cmd
To resolve the Network Adapter Error I had to remove the - in the name of the computer name.
In my case, I needed to specify a viahost and viauser. Worth trying if you're in a complex system. :)
For me the basic oracle only was not installed. Please ensure you have oracle installed and then try checking host and port.
I was having issues with this as well. I was using the jdbc connection string to connect to the database. The hostname was incorrectly configured in the string. I am using Mac, and the same string was being used on Windows machines without an issue. On my connection string, I had to make sure that I had the full url with the appending "organizationname.com" to the end of the hostname.
Hope this helps.
Just try to re-create connection. In my situation one of jdbc connection stopped working for no reason. From console sqlplus was working ok.
It took me 2 hours to realize that If i create the same connection - it works.
I'm working on a project and I have a java program that parses a bunch of files and breaks them into records which are to be stored within a database. I've tested the program on my own server using the following (intellij generated) string:
And the above string works fine in the code and all the data is stored
But when I try to connect to the (external) project database located at 104.131.96.199 using the following
(There are two open ports: 22 and 80)
On port 80 it hangs on "connecting to database" forever (over 10 mins),
and on port 22 I get the packet size error above.
I've gone into phpmyadmin and changed the max_allowed_packet variable to 4739923, but still get the same issue (the change still isn't reflected in the error).
I'm not in charge of this db, although I have the admin user and pass.
Any help in the matter would be greatly appreciated
I guess I have 2 questions:
Is my connection string syntactically correct (and if not what should it be)
If the string is correct, what to do about the packet size issue / hanging forever
1.) Yes, the URL is syntactically correct. If you want to specify a user and password, you can add ?user=<username>&password=<password> to the end of the String.
2.) It most likely doesnt work because you are apparently using the SSH port (22) and the HTTP port (80) instead of the MySQL port (3306). If these are the only two open ports you will have to ask the server admin to manually allow remote connections to his MySQL server
Syntax is correct.
packet size issue - The changes to max_allowed_packet have possibly not taken effect. Run the below to check the value:
SHOW VARIABLES LIKE 'max_allowed_packet';
hanging forever - Check that the port used is correct.
I am trying to connect to open shift with mysql workbench on an iMac. A colleague has shown me his setup on Windows which looks exactly as follows (other than the usernames / passwords changing)
However I keep running in to the following error and I have no idea how to fix it - I am 100% sure my password is ok, so don't really understand why it would say password yes.
Is there any special configuration differences needed between a Mac and PC setup?
Thanks for your time.
It looks like adminM4B1nHl is connecting from 10.34.23.71 which might not work. Check your MySQL security settings. Sometimes admins can only connect from localhost (127.0.0.1). You may have to grant the user access from any IP address. Refer to MySQL docs on how to do that.
I have developed an application in java that access remote mysql database. While I am running it by netbeans IDE of system which have running that wamp server. But while i try I make connection in another system to remote system database by netbeans it shows following error.
Unable to add connection, Cannot establish a connection to jdbc:mysql://192.168.1.14:3306/test using(CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
Please, kindly help me.
Thanks in Advance
From mysql forums
You could be getting this because (1) the URL of the DB is wrong, because (2) the DB isn't set up to accept connections from the web host, or because (3) some intermediate networking component is misconfigured. (1) is your problem; (2) and (3) might be your problem or the web hosting's problem, depending on where the DB is located, what administrative privileges on the DB that you have, and how the networking is set up.
You need to have the right privileges to be able to connect to MySQL remotely. There are several tools available to set it up.
Here is an article outlining several steps of which the grant step is most commonly needed.
mysql> GRANT ALL ON foo.* TO bar#'202.54.10.20' IDENTIFIED BY 'PASSWORD';
There has also been problems reported when connecting to MySQL databases in Windows Vista, but i'm not sure wether this is relevant to this case or not.
Do you have ssh access to the server? I would have run a tunnel with ssh, plink or putty (ssh -L 3305:127.0.0.1:3306 192.168.1.14) and then use this connection url
jdbc:mysql://127.0.0.1:3305/test
It would be easier to assist if we'd known your operating system.
If this is a deployment situation, opening the firewall for port 3306 from your IP address is probably the right thing. In linux you might find the settings in /etc/sysconfig/iptables, but your sysadmin may have other safe guards in place. You must also verify that mysql is actually listening on the IP-address, and not only localhost.
MySQL is standard protected so you can't access it remotely. You'll have to grant MySQL as well as the user connecting to MySQL access from outside the MySQL-machine.
Perhaps a low-level network issue.
Can you ping that IP ?
Can you telnet to that IP/port ?
e.g. telnet 192.168.1.14 3306
Establishing whether you can talk to the machine and whether you can create a basic TCP connection to the MySQL process on that machine will tell you a lot - is your network sound, is a process listening on that port etc.