H2数据库（嵌入式）连接超时

Question

I get the following exception when connecting to the database:

org.h2.jdbc.JdbcSQLException: Connection is broken: "connect timed out" [90067-142]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:327)
    at org.h2.message.DbException.get(DbException.java:156)
    at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:326)
    at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:248)
    at org.h2.engine.SessionRemote.createSession(SessionRemote.java:214)
    at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:111)
    at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:95)
    at org.h2.Driver.connect(Driver.java:73)
    at java.sql.DriverManager.getConnection(DriverManager.java:582)
    at java.sql.DriverManager.getConnection(DriverManager.java:185)
................
Caused by: java.net.SocketTimeoutException: connect timed out
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
    at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
    at java.net.Socket.connect(Socket.java:525)
    at org.h2.util.NetUtils.createSocket(NetUtils.java:109)
    at org.h2.util.NetUtils.createSocket(NetUtils.java:91)
    at org.h2.engine.SessionRemote.initTransfer(SessionRemote.java:92)
    at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:322)
    ... 38 more

The connection string looks as follows:

jdbc:h2:C:\Users\Michael\.myadd\db;AUTO_SERVER=TRUE;CIPHER=AES

What can be the reason for such exception?

Thanks!

Answer 1

For h2 default connection pool size is 10 and login timeout is 30 sec, if we acquire 10 simultaneous connection for longer period then new request to acquire connection will be timed out. for my case found that connection was not getting closed due to bug in code. we can increase max connection count.

connectionPool.setMaxConnections(20);

but by default db manager is single threaded so more connection will not gain any performance.

Answer 2

I guess you read the docs about the automatic mixed mode ? It's hard to say what the problem is, because for me it works. Could you post the content of the file C:\\Users\\Michael.myadd\\db.lock.db ? For me it is (after connecting):

#FileLock
#Tue Dec 14 22:29:22 CET 2010
id=12ce6c9a16a912077e514cc6fff231e91b09d2dbe43
method=file
server=192.168.0.126\:52068

That means the database is open, and the client that opened it started a server on this IP address and port.