Unable to GlobalAlloc memory for LAN message buffer.
Hi There,
I'm not sure if this is the right place to be posting this topic, but I'm not sure where else to put it. I think it's more of a Microsoft issue than a Java one, but maybe someone can point me in the right direction of where to look.
I have written a front-end Java application that acts as an interface for a Teradata back-end. It has a JTree that displays data warehouses, tables and columns. Once you click on a node, some queries are executed to fetch the data for that node and cache it in a Java object for easy access. That all works well.
Now I have written a class that queries the database, creates the objects and caches all of them at once so that the user does not have to wait for the database to be queried every time an un-cached node is clicked. This is where the problem comes in...
The design of the Java classes is that each table or column are stored as custom-made Entity classes. Depending on the type of Entity it is (i.e. a table or column), it can contain LinkedLists of type Mapping, Index, or IndexColumn. Of course, to create each object requires a new query to be executed.
There are in excess of 19,000 tables and columns that are created. For each of these, anything between 2 to 5 queries may be executed. I realise this may well be a design issue, but for now I want to try complete as much as possible of what I already have, with code revisions and possible re-designs being done afterwards.
When I run the class to cache all of the relevant tables and columns at once, it gets to about 18,000 Entity objects (i.e. tables or columns containing their own LinkedLists of the above-mentioned types) and then throws the following error:
java.sql.SQLException: [NCR][ODBC Teradata Driver] Unable to GlobalAlloc memory for LAN message buffer.
It then continues creating Entity objects representing tables, but does not create Entity objects representing columns anymore. It then creates the very last Entity object representing a table, after which it throws the following error:
Exception java.lang.OutOfMemoryError: requested 655360 bytes for GrET* in C:/BUILD_AREA/jdk1.5.0_06/hotspot\src\share\vm\utilities\growableArray.cpp. Out of swap space?
I have been running the class to create the objects with -Xmx256m as the virtual memory allocation in the command line. I have also tried changing this number, but I still seem to get the same error.
I have added memory handling to detect when the virtual memory is starting to run out of space. When this is detected, the objects that have been created thus far are written to file. I have tested this by only caching 20 Entity objects and changing the virtual memory to a very small amount. Under these circumstances, my memory handling works. However, it does not work when I run the full method because of the initial GlobalAlloc error that is thrown.
I think the GlobalAlloc() error is a Microsoft problem, but I have tried that avenue and haven't really received much support.
Can anyone help?
