CachingCalciteSchema thread safe ?

[Enrico Olivelli <eo...@gmail.com>]

Hi,
I am getting strange NPEs using Calcite 1.15 (snapshot)
like this:

java.lang.NullPointerException

        at
org.apache.calcite.prepare.PlannerImpl.rootSchema(PlannerImpl.java:312)

        at
org.apache.calcite.prepare.PlannerImpl.createCatalogReader(PlannerImpl.java:291)

        at
org.apache.calcite.prepare.PlannerImpl.validate(PlannerImpl.java:187)

        at herddb.sql.CalcitePlanner.runPlanner(CalcitePlanner.java:346)


I am creating a rootSchema like this:

final SchemaPlus _rootSchema = Frameworks.createRootSchema(true);


then popuplate with subschematas:

for  (String mySchema : mySchematas) {

     SchemaPlus schema = _rootSchema.add(mySchema, new AbstractSchema());

     ....popuplate schema

}


then this  rootSchema is considered immutable, no changes from the
application


There are concurrent calls to  code like this:

SchemaPlus subSchema = schema.getSubSchema(defaultTableSpace);

final FrameworkConfig config = Frameworks.newConfigBuilder()
                .....
                .defaultSchema(subSchema)
                .......
                .build();


Planner planner = Frameworks.getPlanner(config);
SqlNode n = planner.parse(query);
 n = planner.validate(n);


I am not able to reproduce the issue systematically, it happens on system
tests

But after the first error every other call fails with that NPE, so it
sounds like a broken cache o inconsistent status


Does any ring bell ?


Have you have seen concurrency issues in  AbstractCached ?


I will be back with a reproducer as soon as possible.

I see that the 1.15 is still open so maybe I am able to demostrate a real
issue maybe we are in time for a last minute fix


Thanks

Enrico