On 25-11-2010 22:28:17 +0100, Wouter Alink wrote:

Dear users,

I'm currently struggling with concurrent access to MonetDB/SQL via JDBC.

Version: MonetDB server v5.20.4 (64-bit), based on kernel v1.38.4 (64-bit oids).

I might still have some concurrency issues with my own code, but somehow I frequently end up with the following error message: (while stress-testing by querying with 10 threads at the same time)

class java.sql.SQLException: TypeException:user.s3_1[448]:'user.contains' undefined in: _1933:any := user.contains(_1929:str, _1931:str, _474:bit) TypeException:user.s3_1[449]:'bat.insert' undefined in: _1934:any := bat.insert(_1923:bat[:oid,:bit], _1928:oid, _1933:any) TypeException:user.s3_1[645]:'user.contains' undefined in: _1946:any := user.contains(_1942:str, _1944:str, _474:bit) TypeException:user.s3_1[646]:'bat.insert' undefined in: _1947:any := bat.insert(_1938:bat[:oid,:bit], _1941:oid, _1946:any) TypeException:user.s3_1[1042]:'user.contains' undefined in: _1959:any := user.contains(_1955:str, _1957:str, _474:bit) TypeException:user.s3_1[1043]:'bat.insert' undefined in: _1960:any := bat.insert(_1951:bat[:oid,:bit], _1954:oid, _1959:any) TypeException:user.s3_1[1226]:'user.contains' undefined in: _1974:any := user.contains(_1970:str, _1972:str, _474:bit) TypeException:user.s3_1[1227]:'bat.insert' undefined in: _1975:any := bat.insert(_1964:bat[:oid,:bit], _1969:oid, _1974:any) SQLException:SQLengine:Program contains errors nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.executeQuery(MonetConnection.java:2209) nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.processQuery(MonetConnection.java:1968) nl.cwi.monetdb.jdbc.MonetStatement.internalExecute(MonetStatement.java:506) nl.cwi.monetdb.jdbc.MonetStatement.execute(MonetStatement.java:347) nl.cwi.monetdb.jdbc.MonetStatement.executeUpdate(MonetStatement.java:542)

Does anyone else have experienced such error messages before, or does anyone have a clue to where to look?

I think I've seen this before too, as well as some bug reports about it.

(like too many open connections, concurrent access of the same connection, querying a closed connection, or perhaps a bug inside monetdb)?

It is a MAL response, so it means the connection is fine, but somehow the plan generation is faulty, or the MAL interpreter gets lost.

The problem is that it is hard to reproduce.