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  1. Calcite
  2. CALCITE-2613

NPE when Avatica used as JDBC transport for Calcite and dynamic param ? used

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 1.17.0, avatica-1.12.0, 1.18.0
    • Fix Version/s: 1.18.0
    • Component/s: avatica, core
    • Labels:
      None

      Description

      This is a follow from dev@apache forum discussion. When avatica is wrapping through JdbcMeta a calcite connection and prepared statement contains dynamic parameters, then AvaticaParameters.toProto throws NPE (underlying Builder of Common.AvaticaParameter to be exact).

      FYI Josh Elser

      I will attach a test case to this issue in a sec.

      An AvaticaParameter with a null classname sounds wrong to me. We should
      know the type (per the schema) for some variable, regardless of whether
      or not it is nullable.

      If you can put together a unit test showing what you're seeing in
      Avatica, that would go an extremely long way. It may also just be
      something Calcite is doing which should be corrected (so, a unit test
      there would be a starting point, too).

      Feel free to ping me on Jira. Thanks Piotr!

      On 10/4/18 9:08 AM, ptr.bojko@gmail.com wrote:
      > I've logged a JIRA for the first bug, with a fix proposal -
      > https://issues.apache.org/jira/browse/CALCITE-2609.
      >
      > But the case with AvaticaParameter NPE still remains unclear for me - in
      > terms of design. Help needed
      >
      > On Wed, Oct 3, 2018 at 4:14 PM ptr.bojko@gmail.com <ptr.bojko@gmail.com>
      > wrote:
      >
      >> As for the nulls in AvaticaParameter class - I believe this is how calcite
      >> works. For example for the following query *"select * from filters where
      >> name = ?"* - despite the definition of filters table - Calcite will
      >> create org.apache.calcite.avatica.AvaticaParameter with nullable className.
      >>
      >> My case with more details is following: based on calcite-avatica/sever
      >> I've created a mini jdbc server (servlet) exposing Calcite connection with
      >> my custom schemas. I would like to expose my domain as an SQL database so
      >> with Calcite as an engine and domain translation and Avatica as a JDBC
      >> implementor the resulting implementation is very elegant and works great.
      >>
      >> However the same query *"select * from filters where name = ?" *run

      >> through avatica jdbc implementation is resulting NPE
      >> in Common.AvaticaParameter AvaticaParameter.toProto().
      >>
      >> On Wed, Oct 3, 2018 at 12:46 AM Josh Elser <elserj@apache.org> wrote:
      >>
      >>> re: nulls on className, that's how Protobuf itself works. You can't set
      >>> null for an attribute.
      >>>
      >>> What is the circumstance where you would have a null className on an
      >>> AvaticaParameter?
      >>>
      >>> We could proactively check in the constructor to AvaticaParameter that
      >>> you don't provide null arguments, but that could be argued in either
      >>> direction (e.g. you should not provide null arguments in the first place).
      >>>
      >>> On 10/2/18 5:11 PM, ptr.bojko@gmail.com wrote:
      >>>> Hello,
      >>>>
      >>>> It seems that my case consists of two bugs:
      >>>>
      >>>> First one is similar to what I've already patched twice - Calcite pushes
      >>>> too much to underlying jdbc schema, in this case "?" operator. Resulting
      >>>> subquery onto jdbc schema ends with error about it (? not resolved).
      >>> This
      >>>> one belongs to Calcite.
      >>>>
      >>>> The second one is located
      >>>> at org.apache.calcite.avatica.AvaticaParameter.toProto method.
      >>>> AvaticaParameter can be a live nullable className but
      >>>> Common.AvaticaParameter does not allow to set nulls on className.
      >>> toProto
      >>>> method - please verify me - should be more carefull about it and not set
      >>>> className on a builder when it is null. This one belongs to Avatica.
      >>>>
      >>>> If anyone has time to check me it would be great. I will log then each
      >>> bug
      >>>> to appropriate apache project in Jira. I should patch first one fairly
      >>> easy.
      >>>>
      >>>> Regards,
      >>>> Piotr
      >>>>
      >>>> On Mon, Oct 1, 2018 at 1:50 PM Francis Chuang <francischuang@apache.org
      >>>>
      >>>> wrote:
      >>>>
      >>>>> Hey Piotr,
      >>>>>
      >>>>> Thanks for reporting this! I am not familiar with Avatica's internals,
      >>>>> so can't recommend how this can be fixed. However, I would suggest
      >>>>> writing a test case to reproduce the problem in the meantime.
      >>>>>
      >>>>> Francis
      >>>>>
      >>>>> On 1/10/2018 8:59 PM, ptr.bojko@gmail.com wrote:
      >>>>>> Hello fellow calcite dev team
      >>>>>>
      >>>>>> I have discovered the case with NPE when trying to use parameters on
      >>>>>> prepared statement:
      >>>>>> java.lang.NullPointerException
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.proto.Common$AvaticaParameter$Builder.setClassName(Common.java:9040)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.AvaticaParameter.toProto(AvaticaParameter.java:64)
      >>>>>> at org.apache.calcite.avatica.Meta$Signature.toProto(Meta.java:835)
      >>>>>> at
      >>>>> org.apache.calcite.avatica.Meta$StatementHandle.toProto(Meta.java:1236)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.Service$PrepareResponse.serialize(Service.java:1310)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.Service$PrepareResponse.serialize(Service.java:1275)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.ProtobufTranslationImpl.serializeResponse(ProtobufTranslationImpl.java:348)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.ProtobufHandler.encode(ProtobufHandler.java:57)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.ProtobufHandler.encode(ProtobufHandler.java:31)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.AbstractHandler.apply(AbstractHandler.java:95)
      >>>>>> at
      >>>>>>
      >>>>>
      >>> org.apache.calcite.avatica.remote.ProtobufHandler.apply(ProtobufHandler.java:46)
      >>>>>>
      >>>>>>
      >>>>>> It looks like CalcitePrepareImpl class does have one method
      >>> implemented:
      >>>>>> private static String getClassName(RelDataType type)

      Unknown macro: { >>>>>> return null; >>>>>> }

      >>>>>> Or Common$AvaticaParameter$Builder.setClassName is too restrictive? Or
      >>>>>> maybe AvaticaParameter.toProto() should not feed the builder with
      >>>>> nullable
      >>>>>> className?
      >>>>>>
      >>>>>> Please advice, so I could help patch this.
      >>>>>>
      >>>>>
      >>>>>
      >>>>
      >>>
      >>
      >>
      >> –
      >> Piotr Bojko
      >> http://about.me/ptr.bojko
      >>
      >

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              • Assignee:
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                Reporter:
                ptrbojko Piotr Bojko
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                  Updated:
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