I have no problem connecting to a Clickhouse database using DBeaver. My understanding is that DBeaver uses the JDBC driver to interact with databases. The connection details that I am using are similar to what's shown in the image below.
However, I need to use the HTTP interface to query this database so that I can query it programmatically. According to Clickhouse documentation the click-house server should be listening for HTTP on port 8123. When I try to connect to the Clickhouse database with the same connection parameters (with the exception of the connection url) using the curl request
curl --location --request GET 'http://host:8123/?user=username&password=password'
I receive the error
Code: 516, e.displayText() = DB::Exception: username: Authentication failed: password is incorrect or there is no user with such name (version 20.6.4.44 (official build))
I think my question ultimately boils down to what is JDBC doing under the hood? I assume it is using HTTP in some fashion since the JDBC URL uses port 8123. But how can I replicate the JDBC connection using a basic CURL request?
Relevant Clickhouse Documentation
I wanted to make a ODBC connection from Windows PC to AS/400 DB2 server and I wrote a VBA program. But I got the following error.
Remote port could not be resolved
Then, I checked the status of server with CWSPING and got the result below:
I - Verifying connection to system 192.168.1.2...
I - Successfully connected to server application: Central Client
I - Successfully connected to server application: Network File
I - Successfully connected to server application: Network Print
I - Successfully connected to server application: Data Access
I - Successfully connected to server application: Data Queues
I - Successfully connected to server application: Remote Command
I - Successfully connected to server application: Security
E - CWBCO1011 - Remote port could not be resolved
E - CWBCO1008 - Unable to connect to server application DDM, returned 8407
I - Successfully connected to server application: Telnet
W - CWBCO1015 - Connection verified to system 192.168.1.2, but there were warnings
This means DDM service is not working on the server. ODBC connection requires DRDA, which runs upon DDM service, so I think running DDM service is the key to make ODBC connection. So I tried STRTCPSVR *DDM command but got the result below
*DDM not valid for parameter SERVER
And also tried CHGDDMTCPA AUTOSTART(*YES) PWDRQD(*YES) command, but got an error and I got stuck.
Command CHGDDMTCPA in library *LIBL not found
Does anyone have an idea of enabling DDM server on AS400?
Server: IBM AS400
OS version: V4R1
Try STRHOSTSVR *DATABASE.
STRHOSTSVR is used to start servers associated with IBM i Access and i Access Client Solutions.
STRTCPSVR is used, in general, to start servers associated with TCP/IP like FTP, Telnet, etc. Except the HTTP Server which is started via the Web Administration site at http://<server>:2001.
Additionally to the answer from #jmarkmurphy:
You can easily check netstat *cnn for open ports.
There is actually a tcpsvr named *ddm but that isn't used with ODBC.
ODBC-Access only needs host server *database. There aren't any further requirements for host servers.
For checking which services are started at tcp startup time, use strfdu, option 5 with the file qusrsys/qatocstart. From there you can easily view and change what should be started and what not.
Finally, I got connected by using JDBC. The summary of what I found is as follows:
ODBC seems using DRDA(port 446) but the server does not have DRDA/DDM service
OLEDB seems connecting Data Access(port 8471) but issued unknown error
JDBC also connection Data Access(port 8471) and it worked!
The first error I encountered when using ODBC is "Remote port could not be resolved". What happened behind this seems as follows:
ODBC asked Server Mapper(port 449) to find DRDA port(it may change on a server)
Server Mapper could not find DRDA port because the server has no DRDA service
ODBC showed "port not resolved" error
Then, I tried OLEDB this time. It checked user/password correctly but issued unknown error. When I put incorrect password, it showed "password is incorrect", which means OLEDB successfully log on to the server but got some error after sign on.
The last, I used JDBC and successfully connected! Generally, the connection url is like "jdbc:as400://" but it showed error. Using trace of JDBC, it seems to have problem on sign on to the server. So I changed the url to "jdbc:as400://:8471", then I finally connected. Looking into trace, it directly access to port 8741 and send user/password and get connected. I don't know the detail, but it worked!
Appreciated for your help!
I am configuring a SQL Server Express database as mentioned in the link
The master-datasources.xml file has been appropriately changed. However, when I try to start the WSO2 API-M 2.2 server (<*PRODUCT_HOME>/bin/wso2server.bat -Dsetup), I am getting the following exception -
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: The connection to the host xxx.xx.xxx.xxx, named instance \new_instance_exp failed.
Error: "java.net.SocketTimeoutException: Receive timed out". Verify the server and instance names and check that no firewall is blocking UDP traffic to port 1434. For SQL Server 2005 or later, verify that the SQL Server Browser Service is running on the host.
at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:191)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.getInstancePort(SQLServerConnection.java:5247)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.primaryPermissionCheck(SQLServerConnection.java:1871)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:1608)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectInternal(SQLServerConnection.java:1459)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:773)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:1168)
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:278)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:182)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:730)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:664)
at org.apache.tomcat.jdbc.pool.ConnectionPool.getConnection(ConnectionPool.java:200)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:128)
at org.wso2.carbon.utils.dbcreator.DatabaseCreator.createRegistryDatabase(DatabaseCreator.java:58)
... 20 more
I have verified that the SQL Server Browser Service is running on the host.
Note: The APIM databases I am creating are not on the default instance (which use the the default port 1433). I have created a new instance in the same SQL Server with a custom port and I have configured the settings for TCP and Named Pipes (disabled) in the SQL Configuration Manager.
I am using the recommended SQL driver (sqljdbc4) as mentioned in this link - https://docs.wso2.com/display/ADMIN44x/Setting+up+Microsoft+SQL
Recently, I am being instructed to add a machine to the cluster which has openldap server 2.3.43 running on it. However, the client version on the machine is 2.4. After changing the configuration, it has failed to connect with the following error message.
localhost nslcd[26280]: [899b93] failed to bind to LDAP server ldap://*********/: Can't contact LDAP server: Connection timed out
the client is running on CentOS6 while the server is running on CentOS5.
This is a network connectivity problem, not a compatibility problem. Both versions implement the same LDAP protocol.
I am trying to use ldaps to verify connections to an Impala database with the following configuration in the Impala Command Line Argument Advanced Configuration Snippet configuration item in Cloudera Manager:
--enable_ldap=true
--ldap_uri=ldaps://testServ.domain.com
--ldap_ca_certificate="/home/impala/testServ.domain.pem"
Where testServ.domain.pem is the ldap server certificate.
Using wireshark I can see that after receiving the certificate during SSL negotiation Impala always responds with an Unknown CA alert.
I can successfully connect with Impala using unencrypted ldap and I can connect with a different ldaps enabled program using the provided certificate, so I doubt the issue is on the ldap server.
Is there another configuration parameter I need or a way to determine why Impala always rejects the ldap servers certificate?