With Derby you're specifically suppose to call:
DriverManager.getConnection("jdbc:derby:myDatabase;shutdown=true");
When you want to shutdown the database. However with BoneCP you do:
BoneCPConfig config = new BoneCPConfig();
config.setJdbcUrl("jdbc:derby:myDatabase");
config.setXXX(...);
...
BoneCP connectionPool = new BoneCP(config);
// shutdown connection pool
connectionPool.shutdown();
However with derby you need to call the shutdown command otherwise you can get some errors
So the question is how do I call that shutdown connection string within the BoneCP framework?
In another related newer question, the following appears to be the same cause: "Unless you are running v0.8.1-beta2 or greater, set "disableConnectionTracking" to true in your config."
In other words you need both the derby connection URL as well as the proper config for BoneCP, at least for now...
Please note that you should expect an exception when SUCCESSFULLY shutting down derby: "A successful shutdown always results in an SQLException to indicate that Derby has shut down and that there is no other exception."
Related
I've got the following code to start an H2 daemon and connect to it with Hikari:
// Start H2 daemon
server = Server.createTcpServer("-tcpDaemon").start();
// Connect Hikari to H2 server
HikariConfig hkConfig = new HikariConfig();
hkConfig.setDriverClassName("org.h2.Driver");
hkConfig.setJdbcUrl("jdbc:h2:" + server.getURL() + "/./ghost;MODE=MySQL;IFEXISTS=false");
...
However, even though IFEXISTS is set to false in the JDBC URL, I still get the following exception during pool initialization:
org.h2.jdbc.JdbcSQLNonTransientConnectionException: Database "C:/Users/Cole/IdeaProjects/ghost2/ghost" not found, and IFEXISTS=true, so we cant auto-create it
I tried connecting the 'normal' way with DriverManager to no avail. The same exception was thrown. Is there a different, working way to configure H2 features that I don't know about, or am I doing something wrong?
This appears to be a badly-written error message. See issue #1894 for details.
Strangely enough, this issue doesn't occur in <=1.4.197. The same exact code posted above works. As far as I can tell from #1766, this is a security issue that has been patched.
I have a simple JDBC app (not using Spring or Hibernate) that connects to MySQL. In production, the MySQL connection uses SSL, but it doesn't use SSL in development mode. In development mode, I added "&useSSL=false" to the database URL in order to prevent the MySQL warning "Establishing SSL connection without server's identity verification is not recommended" from filling up my log files.
Now, I am adding a database connection pool using C3P0. Instead of getting a connection from DriverManager.getConnection, I get the connection from C3P0 by calling POOL.getConnection().
The code that sets up C3P0 is pretty simple:
POOL = new ComboPooledDataSource();
POOL.setDriverClass("com.mysql.cj.jdbc.Driver");
POOL.setJdbcUrl(DB_URL);
POOL.setUser(USER);
POOL.setPassword(PASSWORD);
The problem is that this doesn't work. If the DB_URL string contains "&useSSL=false", then POOL.getConnection() hangs. I've removed "&useSSL=false" from the DB_URL, and everything works ok, except that now I'm getting the MySQL SSL warnings.
Can anyone advise me on how to correctly configure C3P0 so that I no longer get the MySQL SSL warnings?
JDBC Connections silently collect warnings that must be actively checked to be seen. Most applications never check them. c3p0 does. Whenever a Connection is checked back in, c3p0 checks, logs, and clears Connection warnings before making the Connection available again within the pool.
If the logging of warnings is annoying to you, just configure your logging library to filter them. All warnings are logged at INFO to a logger called com.mchange.v2.c3p0.SQLWarnings. Just configure whatever logging library you are using not to log `com.mchange.v2.c3p0.SQLWarnings, or to filter it to a higher level of severity than INFO.
See SQLWarnings.
I added setMaxActive(8) on org.apache.tomcat.jdbc.pool.PoolProperties. Every time the DB restarts, the application is unusable because the established connections remain. I get the following error:
org.postgresql.util.PSQLException: This connection has been closed
I've tried using some other settings on the pool to no avail...
Thank you for help!
Use the validationQuery property which will check if the connection is valid before returning the connection.
Ref: Tomcat 6 JDBC Connection Pool
This property is available on latest tomcat versions.
Look at this link:
Postgres connection has been closed error in Spring Boot
Very valid question and this problem is usually faced by many. The
exception generally occurs, when network connection is lost between
pool and database (most of the time due to restart). Looking at the
stack trace you have specified, it is quite clear that you are using
jdbc pool to get the connection. JDBC pool has options to fine-tune
various connection pool settings and log details about whats going on
inside pool.
You can refer to to detailed Apache documentation on pool
configuration to specify abandon timeout
Check for removeAbandoned, removeAbandonedTimeout, logAbandoned parameters
Additionally you can make use of additional properties to further
tighten the validation
Use testXXX and validationQuery for connection validity.
My own $0.02: use these two parameters:
validationQuery=<TEST SQL>
testOnBorrow=true
I have a long-running method which executes a large number of native SQL queries through the EntityManager (TopLink Essentials). Each query takes only milliseconds to run, but there are many thousands of them. This happens within a single EJB transaction. After 15 minutes, the database closes the connection which results in following error:
Exception [TOPLINK-4002] (Oracle TopLink Essentials - 2.1 (Build b02-p04 (04/12/2010))): oracle.toplink.essentials.exceptions.DatabaseException
Internal Exception: java.sql.SQLException: Closed Connection
Error Code: 17008
Call: select ...
Query: DataReadQuery()
at oracle.toplink.essentials.exceptions.DatabaseException.sqlException(DatabaseException.java:319)
.
.
.
RAR5031:System Exception.
javax.resource.ResourceException: This Managed Connection is not valid as the phyiscal connection is not usable
at com.sun.gjc.spi.ManagedConnection.checkIfValid(ManagedConnection.java:612)
In the JDBC connection pool I set is-connection-validation-required="true" and connection-validation-method="table" but this did not help .
I assumed that JDBC connection validation is there to deal with precisely this kind of errors. I also looked at TopLink extensions (http://www.oracle.com/technetwork/middleware/ias/toplink-jpa-extensions-094393.html) for some kind of timeout settings but found nothing. There is also the TopLink session configuration file (http://download.oracle.com/docs/cd/B14099_19/web.1012/b15901/sessions003.htm) but I don't think there is anything useful there either.
I don't have access to the Oracle DBA tables, but I think that Oracle closes connections after 15 minutes according to the setting in CONNECT_TIME profile variable.
Is there any other way to make TopLink or the JDBC pool to reestablish a closed connection?
The database is Oracle 10g, application server is Sun Glassfish 2.1.1.
All JPA implementations (running on a Java EE container) use a datasource with an associated connection pool to manage connectivity with the database.
The persistence context itself is associated with the datasource via an appropriate entry in persistence.xml. If you wish to change the connection timeout settings on the client-side, then the associated connection pool must be re-configured.
In Glassfish, the timeout settings associated with the connection pool can be reconfigured by editing the pool settings, as listed in the following links:
Changing timeout settings in GlassFish 3.1
Changing timeout settings in GlassFish 2.1
On the server-side (whose settings if lower than the client settings, would be more important), the Oracle database can be configured to have database profiles associated with user accounts. The session idle_time and connect_time parameters of a profile would constitute the timeout settings of importance in this aspect of the client-server interaction. If no profile has been set, then by default, the timeout is unlimited.
Unless you've got some sort of RAC failover, when the connection is terminated, it will end the session and transaction.
The admins may have set into some limits to prevent runaway transactions or a single job 'hogging' a connection in a pool. You generally don't want to lock a connection in a pool for an extended period.
If these queries aren't necessarily part of the same transaction, then you could try terminating and restarting a new connection.
Are you able to restructure your code so that it completes in under 15 minutes. A stored procedure in the background may be able to do the job a lot quicker than dragging the results of thousands of operations over the network.
I see you set your connection-validation-method="table" and is-connection-validation-required="true", but you do not mention that you specified the table you were validating on; did you set validation-table-name="any_table_you_know_exists" and provide any existing table-name? validation-table-name="existing_table_name" is required.
See this article for more details on connection validation.
Related StackOverflow article with similar problem - he wants to flush the entire invalid connection pool.
I am using connection pooling of tomcat with oracle database. It is working fine, but when i use my application after a long time it is giving error that "connection reset". I am getting this error because of physical connection at oracle server closed before logical connection closed at tomcat datasource. So before getting the connection from datasource i am checking the connection validity with isValid(0) method of connection object which gives false if the physical connection was closed. But i don't know how to remove that invalid connection object from the pool.
This could be because on the db server, there is a timeout to not allow connections to live beyond a set time, or to die if it does not receive something saying it is still valid. One way to fix this is to turn on keepalives. These basically ping the db server saying that they are still valid connections.
This is a pretty good link on Tomcats DBCP configurations. Take a look at the section titled "Preventing dB connection pool leaks". That looks like it may be a good place to start.
I used validatationquery while configuring the datasource in server.xml file. It is going to check the validity of the connection by executing the query at database before giving to the application.
for Oracle
validationQuery="/* select 1 from dual */"
for MySql
validationQuery="/* ping */"
Try closing it and opening it if it's invalid. I mean u would reinitialize it in this way so u won't need to remove it from the pool and reuse it.
If we want to dispose an ill java.sql.connection from Tomcat jdbc connection pool,
we may do this explicitly in the program.
Unwrap it into an org.apache.tomcat.jdbc.pool.PooledConnection,
setDiscarded(true) and close the JDBC connection finally.
The ConnectionPool will remove the underlying connection once it has been returned.
(ConnectionPool.returnConnection(....))
e.g.
PooledConnection pconn = conn.unwrap(PooledConnection.class); pconn.setDiscarded(true);
conn.close();