Timeout error trying to lock table in h2

h2
user339108 picture user339108 · Nov 12, 2010 · Viewed 43.5k times · Source

I get the following error under a certain scenario

When a different thread is populating a lot of users via the bulk upload operation and I was trying to view the list of all users on a different web page. The list query, throws the following timeout error. Is there a way to set this timeout so that I can avoid this timeout error.

Env: h2 (latest), Hibernate 3.3.x

Caused by: org.h2.jdbc.JdbcSQLException: Timeout trying to lock table "USER"; SQL statement:

[50200-144]

    at org.h2.message.DbException.getJdbcSQLException(DbException.java:327)
    at org.h2.message.DbException.get(DbException.java:167)
    at org.h2.message.DbException.get(DbException.java:144)
    at org.h2.table.RegularTable.doLock(RegularTable.java:482)
    at org.h2.table.RegularTable.lock(RegularTable.java:416)
    at org.h2.table.TableFilter.lock(TableFilter.java:139)
    at org.h2.command.dml.Select.queryWithoutCache(Select.java:571)
    at org.h2.command.dml.Query.query(Query.java:257)
    at org.h2.command.dml.Query.query(Query.java:227)
    at org.h2.command.CommandContainer.query(CommandContainer.java:78)
    at org.h2.command.Command.executeQuery(Command.java:132)
    at org.h2.server.TcpServerThread.process(TcpServerThread.java:278)
    at org.h2.server.TcpServerThread.run(TcpServerThread.java:137)
    at java.lang.Thread.run(Thread.java:619)
    at org.h2.engine.SessionRemote.done(SessionRemote.java:543)
    at org.h2.command.CommandRemote.executeQuery(CommandRemote.java:152)
    at org.h2.jdbc.JdbcPreparedStatement.executeQuery(JdbcPreparedStatement.java:96)
    at org.jboss.resource.adapter.jdbc.WrappedPreparedStatement.executeQuery(WrappedPreparedStatement.java:342)
    at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
    at org.hibernate.loader.Loader.getResultSet(Loader.java:1808)
    at org.hibernate.loader.Loader.doQuery(Loader.java:697)
    at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    at org.hibernate.loader.Loader.doList(Loader.java:2228)
    ... 125 more

Answer

Thomas Mueller picture Thomas Mueller · Nov 12, 2010

Yes, you can change the lock timeout. The default is relatively low: 1 second (1000 ms).

In many cases the problem is that another connection has locked the table, and using multi-version concurrency also solves the problem (append ;MVCC=true to the database URL).

EDIT: MVCC=true param is no longer supported, because since h2 1.4.200 it's always true for a MVStore engine, which is a default engine.